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• 21. [Article] A comparison of progeny testing methods and estimates of combining ability for seed yield and associated variables in tall fescue (Festuca arundinacea, Schreb.)

  Eight genotypes of tall fescue were selected from a plant population consisting of 9000 individuals. Selection was based on early maturity, self-sterility, seed and forage potential, and nutritive value. Parental ...

  Citation × Citation Citation Abstract Copy Title: A comparison of progeny testing methods and estimates of combining ability for seed yield and associated variables in tall fescue (Festuca arundinacea, Schreb.) Author: Echeverri, Silvio Eight genotypes of tall fescue were selected from a plant population consisting of 9000 individuals. Selection was based on early maturity, self-sterility, seed and forage potential, and nutritive value. Parental clones, single cross, open pollinated, self pollinated and polycross seeds were organized into a randomized block experiment with five replications each of which contained 63 entries with ten plants to the entry. The distance between entry rows was three feet; plants within the entry were planted one foot apart. The experimental nursery was planted on October 11, 1961, at the Hyslop Agronomy Farm, Corvallis, Oregon. Alta and Kentucky 31 varieties were used as checks. Parchment bags were used to secure information on self sterility and seed production. Height, maturity, disease incidence, number of culms per plant, panicles not harvested and forage yield were also evaluated. Griffing's model 1, experimental method 4, was used to test both general and specific combining ability. Simple correlation coefficients were calculated to measure the association between characters and between progeny testing methods within characters. The height of F₁ progenies was positively correlated with the height of both the mean of the parents and the largest parent. Height was also correlated with the number of culms per plant and the stage of maturity before harvesting. The stage of maturity of the single crosses was positively correlated with the stage of maturity of both the mean of the parents and the largest parent. Either polycross or open pollination may be used for evaluating maturity with comparable results. Although there was an incidence of Helminthisporium dyctioides, it was not serious enough to affect markedly the general performance of the plants in the nursery. The number of culms per plant for single crosses was negatively correlated with the number of culms for both the mean of the parents and the smallest parent. The number of culms per plant was also correlated with seed yield. From parents to S₁ there was a reduction in the number per plant. Title: A comparison of progeny testing methods and estimates of combining ability for seed yield and associated variables in tall fescue (Festuca arundinacea, Schreb.) Author: Echeverri, Silvio Eight genotypes of tall fescue were selected from a plant population consisting of 9000 individuals. Selection was based on early maturity, self-sterility, seed and forage potential, and nutritive value. Parental clones, single cross, open pollinated, self pollinated and polycross seeds were organized into a randomized block experiment with five replications each of which contained 63 entries with ten plants to the entry. The distance between entry rows was three feet; plants within the entry were planted one foot apart. The experimental nursery was planted on October 11, 1961, at the Hyslop Agronomy Farm, Corvallis, Oregon. Alta and Kentucky 31 varieties were used as checks. Parchment bags were used to secure information on self sterility and seed production. Height, maturity, disease incidence, number of culms per plant, panicles not harvested and forage yield were also evaluated. Griffing's model 1, experimental method 4, was used to test both general and specific combining ability. Simple correlation coefficients were calculated to measure the association between characters and between progeny testing methods within characters. The height of F₁ progenies was positively correlated with the height of both the mean of the parents and the largest parent. Height was also correlated with the number of culms per plant and the stage of maturity before harvesting. The stage of maturity of the single crosses was positively correlated with the stage of maturity of both the mean of the parents and the largest parent. Either polycross or open pollination may be used for evaluating maturity with comparable results. Although there was an incidence of Helminthisporium dyctioides, it was not serious enough to affect markedly the general performance of the plants in the nursery. The number of culms per plant for single crosses was negatively correlated with the number of culms for both the mean of the parents and the smallest parent. The number of culms per plant was also correlated with seed yield. From parents to S₁ there was a reduction in the number per plant. Close

• 22. [Article] Heritabilities and associations of seed yield components and seed yield in tall fescue (Festuca arundinacea, Schreb.)

  Estimates of heritability and associations of tiller number, seed number, seed weight, and seed yield were determined in two groups of tall fescue. Group E was early maturing and had eight parental clones, ...

  Citation × Citation Citation Abstract Copy Title: Heritabilities and associations of seed yield components and seed yield in tall fescue (Festuca arundinacea, Schreb.) Author: Thomas, Johnny Ray Estimates of heritability and associations of tiller number, seed number, seed weight, and seed yield were determined in two groups of tall fescue. Group E was early maturing and had eight parental clones, while group I was intermediate in maturity and had nine parental clones. The parents and five progeny groups were included in the study: first generation selfed progeny (S₁), open-pollinated progeny, polycross progeny, single-cross progeny, and selfed progeny from the single-crosses (F₂). Each entry consisted of ten plants in a nine foot row, with three feet between rows. The plants were established in the field in October 1962, in a randomized block design with four replications. Data were collected during the summers of 1963, 1964, and 1965. Group E plants had slightly higher seed yields than group I plants. This yield advantage was mainly the result of heavier seeds in group E. The parents and the open-pollinated, polycross, and single-cross progeny were generally highest in performance for all four characteristics, while the S₁ progeny were intermediate and the F₂ progeny were lowest in performance. The open-pollinated and polycross progeny were limited in their usefulness for evaluating breeding material since there were no significant differences among the open-pollinated progenies in 13 of 24 analyses of variance and there were no significant differences among the polycross progenies in 12 of 24 analyses of variance. Six methods (regression of the S₁ progeny on the parents, two times the regression of the open-pollinated progeny on the parents, two times the regression of the polycross progeny on the parents, regression of the single-cross progeny on the mid-parents, regression of the F₂ progeny on the mid-parents, and mean squares from the diallel analysis) of estimating heritability were compared for both populations. There were large differences in the heritability estimates among years and among methods. Two methods, 2([superscript b][subscript OP.P]) and [superscript b][subscript SX.MP'] generally resulted in higher heritability estimates than the other four methods. The "average heritability" (averaged across six methods and three years) for tiller number, seed number, seed weight, and seed yield were .187, .371, .506, and .193 respectively for group E and .567, .417, .622, and .374 for group I. The correlation and path-coefficient analysis for groups E and I indicated that tiller number had the largest direct effect in 1963, while seed number was most important in 1964 and both were equally important in 1965. Seed weight had relatively small effects all three years. All indirect effects were minor in both populations. The correlations and the direct and indirect effects for the parent, single-cross and F₂ generations were more variable and they were not always in agreement with the direct and indirect effects for the combined data of the parents and five progeny groups. There were large negative indirect effects in the individual generations which were not evident for the combined data of the parents and five progeny groups. Group E could be improved most by breeding for increased seed number while selection for yield would be most worthwhile in group I. However, maximum improvement could be made by combining the attributes of the two populations. The high seed weight of group E could be incorporated into group I and seed number of group E could be increased by crossing plants of group E with plants of group I. Title: Heritabilities and associations of seed yield components and seed yield in tall fescue (Festuca arundinacea, Schreb.) Author: Thomas, Johnny Ray Estimates of heritability and associations of tiller number, seed number, seed weight, and seed yield were determined in two groups of tall fescue. Group E was early maturing and had eight parental clones, while group I was intermediate in maturity and had nine parental clones. The parents and five progeny groups were included in the study: first generation selfed progeny (S₁), open-pollinated progeny, polycross progeny, single-cross progeny, and selfed progeny from the single-crosses (F₂). Each entry consisted of ten plants in a nine foot row, with three feet between rows. The plants were established in the field in October 1962, in a randomized block design with four replications. Data were collected during the summers of 1963, 1964, and 1965. Group E plants had slightly higher seed yields than group I plants. This yield advantage was mainly the result of heavier seeds in group E. The parents and the open-pollinated, polycross, and single-cross progeny were generally highest in performance for all four characteristics, while the S₁ progeny were intermediate and the F₂ progeny were lowest in performance. The open-pollinated and polycross progeny were limited in their usefulness for evaluating breeding material since there were no significant differences among the open-pollinated progenies in 13 of 24 analyses of variance and there were no significant differences among the polycross progenies in 12 of 24 analyses of variance. Six methods (regression of the S₁ progeny on the parents, two times the regression of the open-pollinated progeny on the parents, two times the regression of the polycross progeny on the parents, regression of the single-cross progeny on the mid-parents, regression of the F₂ progeny on the mid-parents, and mean squares from the diallel analysis) of estimating heritability were compared for both populations. There were large differences in the heritability estimates among years and among methods. Two methods, 2([superscript b][subscript OP.P]) and [superscript b][subscript SX.MP'] generally resulted in higher heritability estimates than the other four methods. The "average heritability" (averaged across six methods and three years) for tiller number, seed number, seed weight, and seed yield were .187, .371, .506, and .193 respectively for group E and .567, .417, .622, and .374 for group I. The correlation and path-coefficient analysis for groups E and I indicated that tiller number had the largest direct effect in 1963, while seed number was most important in 1964 and both were equally important in 1965. Seed weight had relatively small effects all three years. All indirect effects were minor in both populations. The correlations and the direct and indirect effects for the parent, single-cross and F₂ generations were more variable and they were not always in agreement with the direct and indirect effects for the combined data of the parents and five progeny groups. There were large negative indirect effects in the individual generations which were not evident for the combined data of the parents and five progeny groups. Group E could be improved most by breeding for increased seed number while selection for yield would be most worthwhile in group I. However, maximum improvement could be made by combining the attributes of the two populations. The high seed weight of group E could be incorporated into group I and seed number of group E could be increased by crossing plants of group E with plants of group I. Close

• 23. [Article] Heterosis and inbreeding in the progeney of genetically diverse parental clones of Festuca arundinacea Schreb

  The response of maturity, vigor, plant spread, plant height, three forage harvest yields, and total forage yield to heterosis and inbreeding was studied in tall fescue. Parent clones selected for diverse ...

  Citation × Citation Citation Abstract Copy Title: Heterosis and inbreeding in the progeney of genetically diverse parental clones of Festuca arundinacea Schreb Author: Johnson, Blaine Earl The response of maturity, vigor, plant spread, plant height, three forage harvest yields, and total forage yield to heterosis and inbreeding was studied in tall fescue. Parent clones selected for diverse anthesis date, origin, and morphology were separated into two groups based on anthesis date, those having early maturity and those having late maturity. Parents, single-cross (SX), and first generation selfed (S₁) progeny were field evaluated. Parents, S₁, and SX progeny were space planted on a . 914 x 1.219 meter basis at the Hyslop Agronomy Field Laboratory, Corvallis, Oregon, in September, 1969. A randomized block design having four blocks and 14 plant rows as entries was used. Data were collected during the spring, summer, and fall of 1972. Single-cross progeny had a mean performance better than their midparents ' mean performance for all characteristics, with all differences significant except for plant height and third harvest forage yield. Single-cross progeny averaged 7. 03, 13. 18, 13. 50, 3. 89, 42. 93, 51. 72, 15. 14, and 37. 12 percent better than their midparents for maturity rating, vigor rating, plant spread, plant height, first, second, and third harvest forage yield, and forage yield, respectively. There was a greater frequency of individual single-crosses that exhibited significant heterosis in the early x late group than in either the early x early or late x late groups. In addition the average heterotic response of the early x late group was consistently greater than that of either of the other two groups. Thus it appears significant heterosis is more likely to occur, and is likely to be of a greater magnitude, in the progeny of parents having maturity differences, and presumably, greater genetic differences. Significant variation occurred among the single-cross maturity group means for all characteristics with the early x early single crosses most often being the better performers. Consequently the additional heterosis observed in the early x late group was usually insufficient to bring performance of this group up to that of the higher performing but less heterotic early x early single-crosses. This suggests heterosis may be of little practical importance. Inbreeding depression of S₁ progeny was significant for all characteristics. The inbreeding depression was of the greatest magnitude in the progeny of the early parents. Performance of early parents and early S₁ progeny was generally better than that of their late counterparts. Heritability estimates were high, particularly those obtained by regressing single-cross progeny on midparents, although two did not differ significantly from zero. The coefficients of determination for the same associations were likewise high, with over 70 percent of progeny variation being explained by linear association with parents for most characteristics. As superior progeny came from superior parents, this high degree of association suggests clonal evaluation may be an effective screening method in tall fescue. There was strong association among the characteristics of maturity rating, plant spread, plant height, first and third forage yield, and total forage yield, with the lowest of these coefficients of determination, R² = .6031, occurring between maturity rating and plant spread. Vigor rating, second harvest yield, seedling vigor index, and panicle number showed little association among themselves or among the other characteristics, with the highest association, R² = . 3599, occurring between panicle number and third harvest yield. Seed yield was moderately associated with forage characteristics, with R² values of about .5000, but showed no association with panicle number. Title: Heterosis and inbreeding in the progeney of genetically diverse parental clones of Festuca arundinacea Schreb Author: Johnson, Blaine Earl The response of maturity, vigor, plant spread, plant height, three forage harvest yields, and total forage yield to heterosis and inbreeding was studied in tall fescue. Parent clones selected for diverse anthesis date, origin, and morphology were separated into two groups based on anthesis date, those having early maturity and those having late maturity. Parents, single-cross (SX), and first generation selfed (S₁) progeny were field evaluated. Parents, S₁, and SX progeny were space planted on a . 914 x 1.219 meter basis at the Hyslop Agronomy Field Laboratory, Corvallis, Oregon, in September, 1969. A randomized block design having four blocks and 14 plant rows as entries was used. Data were collected during the spring, summer, and fall of 1972. Single-cross progeny had a mean performance better than their midparents ' mean performance for all characteristics, with all differences significant except for plant height and third harvest forage yield. Single-cross progeny averaged 7. 03, 13. 18, 13. 50, 3. 89, 42. 93, 51. 72, 15. 14, and 37. 12 percent better than their midparents for maturity rating, vigor rating, plant spread, plant height, first, second, and third harvest forage yield, and forage yield, respectively. There was a greater frequency of individual single-crosses that exhibited significant heterosis in the early x late group than in either the early x early or late x late groups. In addition the average heterotic response of the early x late group was consistently greater than that of either of the other two groups. Thus it appears significant heterosis is more likely to occur, and is likely to be of a greater magnitude, in the progeny of parents having maturity differences, and presumably, greater genetic differences. Significant variation occurred among the single-cross maturity group means for all characteristics with the early x early single crosses most often being the better performers. Consequently the additional heterosis observed in the early x late group was usually insufficient to bring performance of this group up to that of the higher performing but less heterotic early x early single-crosses. This suggests heterosis may be of little practical importance. Inbreeding depression of S₁ progeny was significant for all characteristics. The inbreeding depression was of the greatest magnitude in the progeny of the early parents. Performance of early parents and early S₁ progeny was generally better than that of their late counterparts. Heritability estimates were high, particularly those obtained by regressing single-cross progeny on midparents, although two did not differ significantly from zero. The coefficients of determination for the same associations were likewise high, with over 70 percent of progeny variation being explained by linear association with parents for most characteristics. As superior progeny came from superior parents, this high degree of association suggests clonal evaluation may be an effective screening method in tall fescue. There was strong association among the characteristics of maturity rating, plant spread, plant height, first and third forage yield, and total forage yield, with the lowest of these coefficients of determination, R² = .6031, occurring between maturity rating and plant spread. Vigor rating, second harvest yield, seedling vigor index, and panicle number showed little association among themselves or among the other characteristics, with the highest association, R² = . 3599, occurring between panicle number and third harvest yield. Seed yield was moderately associated with forage characteristics, with R² values of about .5000, but showed no association with panicle number. Close

• 24. [Article] An examination of seedling vigor and the effects of genetic diversity on response to heterosis in tall fescue (Festuca arundinacea Schreb.)

  Response to heterosis for plant height, anthesis date, panicle number, seed yield, and fall vigor rating was determined in a tall. fescue group selected for diverse morphology, origin, and anthesis date. ...

  Citation × Citation Citation Abstract Copy Title: An examination of seedling vigor and the effects of genetic diversity on response to heterosis in tall fescue (Festuca arundinacea Schreb.) Author: Moutray, Jim B., 1939- Response to heterosis for plant height, anthesis date, panicle number, seed yield, and fall vigor rating was determined in a tall. fescue group selected for diverse morphology, origin, and anthesis date. Parents, single-cross progeny (SX), and first generation selfed progeny (S₁) were included in the study. Each experimental plot consisted of 14 plants spaced three feet apart in a row with four feet between rows. Plants were established in the field in September, 1969, in a randomized block design with four replications. Data were collected during the summer and fall of 1970. Single-cross progeny were superior to parents with the exception of seed yield, with parents above S₁ progeny except in plant height. Single-crosses averaged 15. 36, 2. 60, 28.21, 24. 79, and 23. 04 percent above the mid-parent for plant height, early anthesis date, panicle number, seed yield, and fall vigor rating respectively. Single-crosses averaged 5.85 and 10.27 percent above the high-parent for panicle number and fall vigor rating respectively. Crosses between maturity groups resulted in the greatest heterosis above the mid-parent for all characteristics and above the high-parent for panicle number (117.50 percent of the high-parent). Early x early single-crosses were tallest (106. 49 percent of the high-parent) and had the most vegetative vigor (115. 36 percent of the high-parent). Indications are that crosses between parents of diverse morphology and origin result in a greater expression of heterosis than crosses among similar parents. Diverse anthesis date appears to increase response to heterosis. Vigor and associations among vigor characteristics were determined from single-cross and S₁ seed and seedlings. Respiration, germination, root and shoot growth, rate of growth, and unit growth characteristics were measured using a Gilson differential respirometer and a seed germinator. For most seed and seedling vigor characteristics S₁ 's and SX's were very similar. Early S₁ and early x early SX groups were consistently more vigorous than late S₁ and late x late SX groups with the early x late SX group intermediate between early x early and late x late SX groups for all seedling vigor characteristics. Root length and vigor index were two of the better indicators of early seedling vigor, with vigor index favored because it takes less time to measure and requires less space. Selection on the basis of vigor index should be an effective laboratory method of screening for higher seedling vigor in tall fescue. There was a significant association between most seed and seedling vigor characteristics in SX's and S₁'s, and most seed and seedling vigor characteristics were associated with from one to three mature plant characteristics, most often fall vigor rating. Three methods of selection for high and low seedling vigor (seed weight, head selection on shoot length, and emergence from deep seeding) resulted in small changes in seed weight and vigor index of progeny. Clones from a population with low seed weight and seedling vigor were self-pollinated and topcrossed to a source with high seed weight and seedling vigor. Positive associations between topcrosses and S₁'s for seed weight and vigor index suggests a lack of appreciable heterosis for these characteristics. The association of forage and seed yield was studied in duplicate populations of parents and five progeny groups. These were: first generation selfed (S₁), open-pollinated OP), polycross (PX), single-cross (SX), and selfed single-cross (F ). Nurseries were planted in a randomized block design with four replications, with harvests made during the spring and summer of 1969. There were significant associations of forage and seed yield in four progeny groups with no association in parents and polycross progeny. The highest correlation occurred in the S₁ progeny (r .794). High forage and seed yields in certain OP, PX, and SX progenies indicate the possibility of breeding for both characteristics simultaneously. Title: An examination of seedling vigor and the effects of genetic diversity on response to heterosis in tall fescue (Festuca arundinacea Schreb.) Author: Moutray, Jim B., 1939- Response to heterosis for plant height, anthesis date, panicle number, seed yield, and fall vigor rating was determined in a tall. fescue group selected for diverse morphology, origin, and anthesis date. Parents, single-cross progeny (SX), and first generation selfed progeny (S₁) were included in the study. Each experimental plot consisted of 14 plants spaced three feet apart in a row with four feet between rows. Plants were established in the field in September, 1969, in a randomized block design with four replications. Data were collected during the summer and fall of 1970. Single-cross progeny were superior to parents with the exception of seed yield, with parents above S₁ progeny except in plant height. Single-crosses averaged 15. 36, 2. 60, 28.21, 24. 79, and 23. 04 percent above the mid-parent for plant height, early anthesis date, panicle number, seed yield, and fall vigor rating respectively. Single-crosses averaged 5.85 and 10.27 percent above the high-parent for panicle number and fall vigor rating respectively. Crosses between maturity groups resulted in the greatest heterosis above the mid-parent for all characteristics and above the high-parent for panicle number (117.50 percent of the high-parent). Early x early single-crosses were tallest (106. 49 percent of the high-parent) and had the most vegetative vigor (115. 36 percent of the high-parent). Indications are that crosses between parents of diverse morphology and origin result in a greater expression of heterosis than crosses among similar parents. Diverse anthesis date appears to increase response to heterosis. Vigor and associations among vigor characteristics were determined from single-cross and S₁ seed and seedlings. Respiration, germination, root and shoot growth, rate of growth, and unit growth characteristics were measured using a Gilson differential respirometer and a seed germinator. For most seed and seedling vigor characteristics S₁ 's and SX's were very similar. Early S₁ and early x early SX groups were consistently more vigorous than late S₁ and late x late SX groups with the early x late SX group intermediate between early x early and late x late SX groups for all seedling vigor characteristics. Root length and vigor index were two of the better indicators of early seedling vigor, with vigor index favored because it takes less time to measure and requires less space. Selection on the basis of vigor index should be an effective laboratory method of screening for higher seedling vigor in tall fescue. There was a significant association between most seed and seedling vigor characteristics in SX's and S₁'s, and most seed and seedling vigor characteristics were associated with from one to three mature plant characteristics, most often fall vigor rating. Three methods of selection for high and low seedling vigor (seed weight, head selection on shoot length, and emergence from deep seeding) resulted in small changes in seed weight and vigor index of progeny. Clones from a population with low seed weight and seedling vigor were self-pollinated and topcrossed to a source with high seed weight and seedling vigor. Positive associations between topcrosses and S₁'s for seed weight and vigor index suggests a lack of appreciable heterosis for these characteristics. The association of forage and seed yield was studied in duplicate populations of parents and five progeny groups. These were: first generation selfed (S₁), open-pollinated OP), polycross (PX), single-cross (SX), and selfed single-cross (F ). Nurseries were planted in a randomized block design with four replications, with harvests made during the spring and summer of 1969. There were significant associations of forage and seed yield in four progeny groups with no association in parents and polycross progeny. The highest correlation occurred in the S₁ progeny (r .794). High forage and seed yields in certain OP, PX, and SX progenies indicate the possibility of breeding for both characteristics simultaneously. Close

• 25. [Article] Heritability estimates for seed and plant characteristics in white clover (Trifolium repens L.)

  Genetic differences, extent of hybrid vigor, nature of gene action, heritability estimates, and associations among characteristics, and between progenies and their respective mid-parents were determined for ...

  Citation × Citation Citation Abstract Copy Title: Heritability estimates for seed and plant characteristics in white clover (Trifolium repens L.) Author: Kim, Dal Ung Genetic differences, extent of hybrid vigor, nature of gene action, heritability estimates, and associations among characteristics, and between progenies and their respective mid-parents were determined for seed and plant characteristics in white clover (Trifolium repens L.). Ten seed and seedling vigor characteristics, including seed weight, ATP content in seed, seed respiration, and seedling vigor index were studied for a diallel cross consisting of 28 single crosses, five test-crosses, four checks, and eight open-pollinated seed and seedlings. Twenty-three plant characteristics on stolon, petiole, leaf, and forage were examined on the eight clones diallel cross, five test-crosses, three checks, the eight parental clones of single crosses, and six parent clones of the test-crosses. These 14 parent clones for this study were assembled on the basis of diverse morphology and origin. Most seed and seedling vigor characteristics, except RQ values, and most plant characteristics, except internode length, LAR and diurnal ratio in SLW, expressed significant differences among and within most groups of progenies and parental clones. All seed and seedling vigor characteristics, except RQ values, responded primarily to the nonadditive type of gene action. This suggests that the plant breeder should design his breeding program to develop varieties where hybrid vigor can be used to advantage. Among the criteria used in this study to measure seed and seedling vigor, ATP content per seed was closely associated with seedling vigor index and with certain plant characteristics, including forage yield per plant. The associations of seed weight with other seed and seedling vigor characteristics were negative or poor. Most plant characteristics showed apparent hybrid vigor when progenies were compared with their respective mid-parents. With few exceptions, most plant characteristics, stolon, petiole, leaf and forage yield per plant, responded primarily to the nonadditive gene system. This indicated that the plant breeder may use the hybrid approach to white clover variety development. The exceptions were leaf ratio and SLW which responded primarily to additive gene action, and area and dry weight per leaf appeared to respond equally to additive and nonadditive gene action. Genetic differences were more readily identified for stolon number and length when measurements were taken after 70 days of growth. Yield components, such as number, length, and diameter of stolon, petiole length, number of leaves per plant, and dry weight per leaf were closely related to each other. The leaf components of yield, dry weight per leaf and number of leaves per plant, had the highest direct and indirect effects on forage yields per plant among the yield components. This study showed nonadditive gene action primarily responsible for most seed and plant characteristics. Considering the ease of vegetative propagation in this species along with the self-incompatibility, mechanisms, it is suggested that parent geneotypes may be developed by some recurrent selection procedure, then crossed on a two clone synthetic basis to form experimental lines for testing purposes. Title: Heritability estimates for seed and plant characteristics in white clover (Trifolium repens L.) Author: Kim, Dal Ung Genetic differences, extent of hybrid vigor, nature of gene action, heritability estimates, and associations among characteristics, and between progenies and their respective mid-parents were determined for seed and plant characteristics in white clover (Trifolium repens L.). Ten seed and seedling vigor characteristics, including seed weight, ATP content in seed, seed respiration, and seedling vigor index were studied for a diallel cross consisting of 28 single crosses, five test-crosses, four checks, and eight open-pollinated seed and seedlings. Twenty-three plant characteristics on stolon, petiole, leaf, and forage were examined on the eight clones diallel cross, five test-crosses, three checks, the eight parental clones of single crosses, and six parent clones of the test-crosses. These 14 parent clones for this study were assembled on the basis of diverse morphology and origin. Most seed and seedling vigor characteristics, except RQ values, and most plant characteristics, except internode length, LAR and diurnal ratio in SLW, expressed significant differences among and within most groups of progenies and parental clones. All seed and seedling vigor characteristics, except RQ values, responded primarily to the nonadditive type of gene action. This suggests that the plant breeder should design his breeding program to develop varieties where hybrid vigor can be used to advantage. Among the criteria used in this study to measure seed and seedling vigor, ATP content per seed was closely associated with seedling vigor index and with certain plant characteristics, including forage yield per plant. The associations of seed weight with other seed and seedling vigor characteristics were negative or poor. Most plant characteristics showed apparent hybrid vigor when progenies were compared with their respective mid-parents. With few exceptions, most plant characteristics, stolon, petiole, leaf and forage yield per plant, responded primarily to the nonadditive gene system. This indicated that the plant breeder may use the hybrid approach to white clover variety development. The exceptions were leaf ratio and SLW which responded primarily to additive gene action, and area and dry weight per leaf appeared to respond equally to additive and nonadditive gene action. Genetic differences were more readily identified for stolon number and length when measurements were taken after 70 days of growth. Yield components, such as number, length, and diameter of stolon, petiole length, number of leaves per plant, and dry weight per leaf were closely related to each other. The leaf components of yield, dry weight per leaf and number of leaves per plant, had the highest direct and indirect effects on forage yields per plant among the yield components. This study showed nonadditive gene action primarily responsible for most seed and plant characteristics. Considering the ease of vegetative propagation in this species along with the self-incompatibility, mechanisms, it is suggested that parent geneotypes may be developed by some recurrent selection procedure, then crossed on a two clone synthetic basis to form experimental lines for testing purposes. Close

• 26. [Article] Compensating effects and gene action estimates for the components of grain yield in winter wheat (Triticum aestivum, L. em Thell)

  Five winter wheat cultivars and their diallel crosses were evaluated for plant height, harvest index, deading-maturity duration, the components of yield, (spikes per plant, spikelets per spike, kernel ...

  Citation × Citation Citation Abstract Copy Title: Compensating effects and gene action estimates for the components of grain yield in winter wheat (Triticum aestivum, L. em Thell) Author: Abi-Antoun, Michel Five winter wheat cultivars and their diallel crosses were evaluated for plant height, harvest index, deading-maturity duration, the components of yield, (spikes per plant, spikelets per spike, kernel weight and kernels per spikelet)and total plant yield. Two diverse locations, Moro, a dryland site (250 mm annually) located in central Oregon and the Hyslop Agronomy Farm, a high rainfall site (over 1000 mm annually) located in the Willamette Valley, were utilized for one and two cropping seasons, respectively. Three rates of seeding were used as main plots in a split-plot design that was replicated four times. A modified blend method of seeding was used to simulate solid seeding conditions. Experimental seeds were planted 30.5 centimeters apart within the row over a filler cultivar in equally spaced (30.5 centimeters) rows. The data were analyzed by analysis of variance, Griffing's diallel analysis (Method 4, Model 1), correlation, path-coefficient analysis and by parent progeny regression. The correlation between grain yield, its components, harvest index, maturity-duration and plant height was dependent on the particula. r environment of the test. The re waspoorcorrelationbetween yield, tiller number and seed size under all the conditions of these studies. Negative associations between the components of yield indicated the sequential compensatory behavior of these characters under all environments. It would be very hard to select for large grain and short stature wheat because of the positive correlation between plant height and seed size within this population. The low correlations of yield with tiller number and seed size were mainly caused by indirect negative effects through one or more of the other yield components. Harvest index, maturity-duration and plant height had very small direct or indirect influences on grain yield. It was concluded that maximum yield would be obtained from a plant type which produces enough tillers to cover a particular unit of field area with large, fertile spikes, having medium to large kernels and semi-dwarf stature. No significant differences existed between parents and single crosses in the expression of the yield components. Nevertheless, hybrids outyielded their parents in grain yield and demonstrated that heterosis for complex traits was a consequence of multiplicative relationships among the components of these traits. Significant interactions between the genotypes and locations, seeding rates and years were observed in the expression of all characters studied. These interactions indicated that using data from non-competitive conditions to assess performance under competitive conditions could not be justified. Also, limiting the number of testing sites may lead to unsound generalizations and erroneous recommendations regarding gene action estimates of yield and the components of grain yield and three associated characters. Under non-competitive conditions, estimates of the additive type of gene action were more significant and contributed larger effects than the non-additive type for all traits. As competition increased at higher seeding rates, the effects of specific combining ability became more important in the expression of yield, number of spikes, spikelets per spike, and plant height. Heritability estimates confirmed these results except for yield. Of the agronomic characters, harvest index, maturity-duration and plant height, only harvest index showed some promise as a selection criterion under noncompetitive conditions. A breeding procedure utilizing the component approach consisted of selecting early generations under spaced planting with emphasis on avoiding extreme values in any of the components of yield. The balanced combinations of the components of yield should be tested under solid seeding conditions. Title: Compensating effects and gene action estimates for the components of grain yield in winter wheat (Triticum aestivum, L. em Thell) Author: Abi-Antoun, Michel Five winter wheat cultivars and their diallel crosses were evaluated for plant height, harvest index, deading-maturity duration, the components of yield, (spikes per plant, spikelets per spike, kernel weight and kernels per spikelet)and total plant yield. Two diverse locations, Moro, a dryland site (250 mm annually) located in central Oregon and the Hyslop Agronomy Farm, a high rainfall site (over 1000 mm annually) located in the Willamette Valley, were utilized for one and two cropping seasons, respectively. Three rates of seeding were used as main plots in a split-plot design that was replicated four times. A modified blend method of seeding was used to simulate solid seeding conditions. Experimental seeds were planted 30.5 centimeters apart within the row over a filler cultivar in equally spaced (30.5 centimeters) rows. The data were analyzed by analysis of variance, Griffing's diallel analysis (Method 4, Model 1), correlation, path-coefficient analysis and by parent progeny regression. The correlation between grain yield, its components, harvest index, maturity-duration and plant height was dependent on the particula. r environment of the test. The re waspoorcorrelationbetween yield, tiller number and seed size under all the conditions of these studies. Negative associations between the components of yield indicated the sequential compensatory behavior of these characters under all environments. It would be very hard to select for large grain and short stature wheat because of the positive correlation between plant height and seed size within this population. The low correlations of yield with tiller number and seed size were mainly caused by indirect negative effects through one or more of the other yield components. Harvest index, maturity-duration and plant height had very small direct or indirect influences on grain yield. It was concluded that maximum yield would be obtained from a plant type which produces enough tillers to cover a particular unit of field area with large, fertile spikes, having medium to large kernels and semi-dwarf stature. No significant differences existed between parents and single crosses in the expression of the yield components. Nevertheless, hybrids outyielded their parents in grain yield and demonstrated that heterosis for complex traits was a consequence of multiplicative relationships among the components of these traits. Significant interactions between the genotypes and locations, seeding rates and years were observed in the expression of all characters studied. These interactions indicated that using data from non-competitive conditions to assess performance under competitive conditions could not be justified. Also, limiting the number of testing sites may lead to unsound generalizations and erroneous recommendations regarding gene action estimates of yield and the components of grain yield and three associated characters. Under non-competitive conditions, estimates of the additive type of gene action were more significant and contributed larger effects than the non-additive type for all traits. As competition increased at higher seeding rates, the effects of specific combining ability became more important in the expression of yield, number of spikes, spikelets per spike, and plant height. Heritability estimates confirmed these results except for yield. Of the agronomic characters, harvest index, maturity-duration and plant height, only harvest index showed some promise as a selection criterion under noncompetitive conditions. A breeding procedure utilizing the component approach consisted of selecting early generations under spaced planting with emphasis on avoiding extreme values in any of the components of yield. The balanced combinations of the components of yield should be tested under solid seeding conditions. Close

• 27. [Article] The heritability of agronomic characteristics in tall fescue (Festuca arundinacea Schreb.)

  Three genotypes of tall fescue (Festuca arundinacea Schreb. cultivar Fawn and four genotypes from the cultivar Fortune were used as parents to form 15 of a possible 21 single crosses to study the heritability ...

  Citation × Citation Citation Abstract Copy Title: The heritability of agronomic characteristics in tall fescue (Festuca arundinacea Schreb.) Author: Subhanij, Thiravira Three genotypes of tall fescue (Festuca arundinacea Schreb. cultivar Fawn and four genotypes from the cultivar Fortune were used as parents to form 15 of a possible 21 single crosses to study the heritability of certain agronomic characteristics. The Fawn variety is considered to be tall in growth habit, vigorous and early in anthesis. The Fortune variety represents germ plasm with a shorter growth habit, less vigor and later anthesis. Crossing was accomplished by mutual pollination in the greenhouse during February 1972. A greenhouse experiment was started in June 1972 using the 15 single crosses in a randomized block with three replications. Plants were supplied with one half strength of a modified Hougland's solution twice weekly until August 3 followed with an application of the same nutrient solution every two weeks until they were taken to the field for establishment. Greenhouse data were collected on July 7, August 4 and September 11. These data indicated that the variation among single crosses for tiller numbers and dry weight were greater as the plant grew older. Nutrient stress affected dry matter yield by reducing the variation and mean performance of the single crosses. Differences among single crosses for shoot length, tiller number, and plant spread were still quite evident under the stress conditions. Shoot length showed significant general combining ability (GCA) with non significant specific combining ability effects (SCA) on July 7 and September 11. GCA effects for tiller numbers were evident on August 4 and September 11. Both GCA and SCA effects were significant for plant spread on September ii. GCA for dry weight were significant only on July 7. Based on the diallel analysis, additive gene action was primarily responsible for shoot length, tiller numbers and dry weight. Both additive and non additive gene action influenced plant spread. The field establishment included the 15 single crosses from greenhouse experiments and the seven parent clones, established in a randomized block design with three replications. From the diallel analysis, it was observed that the GCA:SCA mean square for the characters measured were: plant height (19:1), plant spread (2. 1:1), anthesis date (3.2:1), panicle number (1.4:1), panicle length(l2:1), number of primary pedicels per panicle (7.4:1), five panicle seed weight (0. 2:1), seed yield per plant (0. 4:1) and 100 seed weight (15.1:1). This indicated that additive gene action was of major importance in the expression of plant height, number of primary pedicels and 100 seed weight. Non additive gene action was contributed substantially more to the expression of five panicles seed weight and seed yield. Both additive and non additive gene action contributed to plant spread and anthesis. Inferences about gene action for panicle numbers and panicle length were not as evident. This is because of the low GCA:SCA ratio, a barely significant GCA for panicle number, and no significant GCA or SCA for panicle length. Single cross progeny were superior to mid parent for plant height (9.27 percent), plant spread (20. 33 percent), anthesis (20.90 percent, which suggested earlier anthesis than mid parent), panicle number (36. 69 percent), and panicle length (11. 44 percent). No apparent superiority of single cross progeny over their corresponding mid parent for number of primary pedicels and 100 seed weight was observed. Of all single crosses, only Fawn x Fortune crosses were inferior to mid parents for five panicle seed weight (65.93 percent) and seed yield (60. 22 percent). The Fawn x Fortune performance for both of these characters (0.4062 and 1.23 g per plant, respectively)was low, The diverse parentage of these crosses may have resulted in irregular meiotic behavior in the F₁ which in turn may have caused inviable gametes to be formed. This sterility would result in the low seed yields observed. This is a problem that should be cytologically investigated. Crosses between diverse germ plasm (Fawn x Fortune crosses) did result, however, in heterosis for all characteristics except number of primary pedicels and 100 seed weight. But Fortune x Fortune crosses, for certain characters such as plant height, plant spread, panicle numbers, panicle length,exhibited even more heterosis. No heterosis was observed in the Fawn x Fawn crosses. Medium to high heritability estimates were observed for 100 seed weight, plant spread, anthesis date, panicle number and panicle length, while medium to low heritability were observed for panicle length. Low heritable value was evident for plant height, number of primary pedicels, five panicle seed weight and seed yield. Heritability estimates were based on parent progeny relationships involving all single crosses and mid parents. The relationships among various plant characteristics and seed yield was studied. Five panicle seed weight and panicle numbers were significantly correlated with seed yield. However there was a non-significant association of panicle length with seed yield and number of primary pedicels with seed yield.These relationships suggest that higher yielding genotypes may be identified by observing only few panicles per plants. The panicle characteristics examined in this study (other than seed weight) were of little value in identifying high seed yield genotypes, but panicle seed weight was positively related to plant yield. Title: The heritability of agronomic characteristics in tall fescue (Festuca arundinacea Schreb.) Author: Subhanij, Thiravira Three genotypes of tall fescue (Festuca arundinacea Schreb. cultivar Fawn and four genotypes from the cultivar Fortune were used as parents to form 15 of a possible 21 single crosses to study the heritability of certain agronomic characteristics. The Fawn variety is considered to be tall in growth habit, vigorous and early in anthesis. The Fortune variety represents germ plasm with a shorter growth habit, less vigor and later anthesis. Crossing was accomplished by mutual pollination in the greenhouse during February 1972. A greenhouse experiment was started in June 1972 using the 15 single crosses in a randomized block with three replications. Plants were supplied with one half strength of a modified Hougland's solution twice weekly until August 3 followed with an application of the same nutrient solution every two weeks until they were taken to the field for establishment. Greenhouse data were collected on July 7, August 4 and September 11. These data indicated that the variation among single crosses for tiller numbers and dry weight were greater as the plant grew older. Nutrient stress affected dry matter yield by reducing the variation and mean performance of the single crosses. Differences among single crosses for shoot length, tiller number, and plant spread were still quite evident under the stress conditions. Shoot length showed significant general combining ability (GCA) with non significant specific combining ability effects (SCA) on July 7 and September 11. GCA effects for tiller numbers were evident on August 4 and September 11. Both GCA and SCA effects were significant for plant spread on September ii. GCA for dry weight were significant only on July 7. Based on the diallel analysis, additive gene action was primarily responsible for shoot length, tiller numbers and dry weight. Both additive and non additive gene action influenced plant spread. The field establishment included the 15 single crosses from greenhouse experiments and the seven parent clones, established in a randomized block design with three replications. From the diallel analysis, it was observed that the GCA:SCA mean square for the characters measured were: plant height (19:1), plant spread (2. 1:1), anthesis date (3.2:1), panicle number (1.4:1), panicle length(l2:1), number of primary pedicels per panicle (7.4:1), five panicle seed weight (0. 2:1), seed yield per plant (0. 4:1) and 100 seed weight (15.1:1). This indicated that additive gene action was of major importance in the expression of plant height, number of primary pedicels and 100 seed weight. Non additive gene action was contributed substantially more to the expression of five panicles seed weight and seed yield. Both additive and non additive gene action contributed to plant spread and anthesis. Inferences about gene action for panicle numbers and panicle length were not as evident. This is because of the low GCA:SCA ratio, a barely significant GCA for panicle number, and no significant GCA or SCA for panicle length. Single cross progeny were superior to mid parent for plant height (9.27 percent), plant spread (20. 33 percent), anthesis (20.90 percent, which suggested earlier anthesis than mid parent), panicle number (36. 69 percent), and panicle length (11. 44 percent). No apparent superiority of single cross progeny over their corresponding mid parent for number of primary pedicels and 100 seed weight was observed. Of all single crosses, only Fawn x Fortune crosses were inferior to mid parents for five panicle seed weight (65.93 percent) and seed yield (60. 22 percent). The Fawn x Fortune performance for both of these characters (0.4062 and 1.23 g per plant, respectively)was low, The diverse parentage of these crosses may have resulted in irregular meiotic behavior in the F₁ which in turn may have caused inviable gametes to be formed. This sterility would result in the low seed yields observed. This is a problem that should be cytologically investigated. Crosses between diverse germ plasm (Fawn x Fortune crosses) did result, however, in heterosis for all characteristics except number of primary pedicels and 100 seed weight. But Fortune x Fortune crosses, for certain characters such as plant height, plant spread, panicle numbers, panicle length,exhibited even more heterosis. No heterosis was observed in the Fawn x Fawn crosses. Medium to high heritability estimates were observed for 100 seed weight, plant spread, anthesis date, panicle number and panicle length, while medium to low heritability were observed for panicle length. Low heritable value was evident for plant height, number of primary pedicels, five panicle seed weight and seed yield. Heritability estimates were based on parent progeny relationships involving all single crosses and mid parents. The relationships among various plant characteristics and seed yield was studied. Five panicle seed weight and panicle numbers were significantly correlated with seed yield. However there was a non-significant association of panicle length with seed yield and number of primary pedicels with seed yield.These relationships suggest that higher yielding genotypes may be identified by observing only few panicles per plants. The panicle characteristics examined in this study (other than seed weight) were of little value in identifying high seed yield genotypes, but panicle seed weight was positively related to plant yield. Close

• 28. [Article] Conscience orientation in children and parental attitudes toward independence granting and achievement inducement

  This study focused on the relationship between parental attitudes and the conscience orientation of children, testing the hypotheses that (1) parents who had children with an external conscience orientation would ...

  Citation × Citation Citation Abstract Copy Title: Conscience orientation in children and parental attitudes toward independence granting and achievement inducement Author: Draper, Henry E. This study focused on the relationship between parental attitudes and the conscience orientation of children, testing the hypotheses that (1) parents who had children with an external conscience orientation would show significantly greater disparity between their independence granting and achievement inducement attitudes than parents whose children had conventional or humanistic orientations, (2) that parents who had children with a humanistic conscience orientation would show significantly less disparity between their independence granting and achievement inducement scores than parents whose children had external or conventional conscience orientations, and (3) that parents whose children had conventional conscience orientations would show a disparity between independence granting and achievement inducement scores which would fall midway between the parents of children with external or humanistic conscience orientations. Fifteen students representative of each of three conscience types were identified from 325 sixth grade children from various school districts in central and south eastern Utah. The identification and measurement of conscience orientations was achieved with a projective story completion battery adapted from a measure developed by Hoffman. Parental attitudes toward independence granting and achievement inducement were obtained by means of an interview, using the Parental Developmental Timetable, a paper and pencil instrument designed for this purpose by Torgoff . These instruments provided a single independence granting and single achievement inducement score for each parent. The achievement inducement score of each parent was divided into the independence granting score to obtain a ratio of these two variables (the I/A ratio). To determine if there was a significant difference in the I/A ratio scores of parents whose children held different conscience orientations, the parental data were treated by an analysis of variance. Using raw score data no differences were found in the I/A ratios between the three parental groupings, and the three hypotheses stated above were rejected. A derived score transformation technique of handling the data was then developed which permitted a more precise method of determining the difference between the relationship of independence granting to achievement inducement. The rationale permitted a high score theoretically to represent parents whose children had a humanistic conscience orientation, a low score to represent parents whose children had an external conscience orientation, and the scores in between to represent parents whose children had a conventional conscience orientation. When an analysis of variance was applied to these data, the hypotheses were again rejected. The data also were tested to determine the influence of the parental independence granting and achievement inducement variables independently on the conscience orientation of children. This analysis also revealed a lack of relationship between independence granting or achievement inducement orientations on the part of parents and the conscience orientation of children. It was concluded, within the limits of these data, that the independence granting and achievement orientations of parents are unrelated to the conscience orientations of sixth grade children from selected school districts in Utah. In an effort to account for the negative findings corning from the study, an examination of the sampling procedures, the measurement procedures, and the conceptual framework was undertaken. In spite of weakness in the sampling procedure, and the limitations of measurement, it is the opinion of the investigator that the major factor accounting for the negative findings was the inadequacy of the conceptual framework. Had a conceptual framework been developed which included a three-dimensional model, taking into account the influence of parental warmth in relation to the ratio of independence granting and achievement inducement, results in the direction predicted may have occurred. Title: Conscience orientation in children and parental attitudes toward independence granting and achievement inducement Author: Draper, Henry E. This study focused on the relationship between parental attitudes and the conscience orientation of children, testing the hypotheses that (1) parents who had children with an external conscience orientation would show significantly greater disparity between their independence granting and achievement inducement attitudes than parents whose children had conventional or humanistic orientations, (2) that parents who had children with a humanistic conscience orientation would show significantly less disparity between their independence granting and achievement inducement scores than parents whose children had external or conventional conscience orientations, and (3) that parents whose children had conventional conscience orientations would show a disparity between independence granting and achievement inducement scores which would fall midway between the parents of children with external or humanistic conscience orientations. Fifteen students representative of each of three conscience types were identified from 325 sixth grade children from various school districts in central and south eastern Utah. The identification and measurement of conscience orientations was achieved with a projective story completion battery adapted from a measure developed by Hoffman. Parental attitudes toward independence granting and achievement inducement were obtained by means of an interview, using the Parental Developmental Timetable, a paper and pencil instrument designed for this purpose by Torgoff . These instruments provided a single independence granting and single achievement inducement score for each parent. The achievement inducement score of each parent was divided into the independence granting score to obtain a ratio of these two variables (the I/A ratio). To determine if there was a significant difference in the I/A ratio scores of parents whose children held different conscience orientations, the parental data were treated by an analysis of variance. Using raw score data no differences were found in the I/A ratios between the three parental groupings, and the three hypotheses stated above were rejected. A derived score transformation technique of handling the data was then developed which permitted a more precise method of determining the difference between the relationship of independence granting to achievement inducement. The rationale permitted a high score theoretically to represent parents whose children had a humanistic conscience orientation, a low score to represent parents whose children had an external conscience orientation, and the scores in between to represent parents whose children had a conventional conscience orientation. When an analysis of variance was applied to these data, the hypotheses were again rejected. The data also were tested to determine the influence of the parental independence granting and achievement inducement variables independently on the conscience orientation of children. This analysis also revealed a lack of relationship between independence granting or achievement inducement orientations on the part of parents and the conscience orientation of children. It was concluded, within the limits of these data, that the independence granting and achievement orientations of parents are unrelated to the conscience orientations of sixth grade children from selected school districts in Utah. In an effort to account for the negative findings corning from the study, an examination of the sampling procedures, the measurement procedures, and the conceptual framework was undertaken. In spite of weakness in the sampling procedure, and the limitations of measurement, it is the opinion of the investigator that the major factor accounting for the negative findings was the inadequacy of the conceptual framework. Had a conceptual framework been developed which included a three-dimensional model, taking into account the influence of parental warmth in relation to the ratio of independence granting and achievement inducement, results in the direction predicted may have occurred. Close

• 29. [Article] Children's preceptions of parental responses to sibling quarrels and the qualities of sibling relationships

  Children in middle childhood were surveyed in elementary schools to explore possible associations between their perceptions about certain characteristics of their sibling relationships and the ways in ...

  Citation × Citation Citation Abstract Copy Title: Children's preceptions of parental responses to sibling quarrels and the qualities of sibling relationships Author: Ozretich, Rachel A. Children in middle childhood were surveyed in elementary schools to explore possible associations between their perceptions about certain characteristics of their sibling relationships and the ways in which their parents responded to sibling quarrels. An instrument was developed to measure perceptions of types of parental responses and the Sibling Relationship Questionnaire was used to assess sibling conflict, warmth/closeness, and perceptions of parental partiality. Factor analyses revealed that the parental responses of punishing, prohibiting, and group discipline were closely related, reflecting a single dimension (alpha=.81). Labeled restricting, regression analyses indicated that this type of parental response to sibling quarrels was a strong positive predictor of sibling conflict, a negative predictor of sibling warmth/closeness, and unrelated to perceptions of parental partiality. The contributions of the other types of parental responses to the aspects of sibling relationships studied were different for girls and boys. Parental referring to family rules contributed positively to girls' sibling conflict, and negatively to sibling warmth/closeness. Parental mediating conciliation, particularly by mothers, was a strong positive predictor of boys' sibling warmth/closeness. Parental mediating conciliation negatively contributed to boys' sibling conflict, particularly fathers' mediating conciliation. Nonintervention by parents, particularly fathers' nonintervention, was a strong positive predictor of boys' sibling conflict, and contributed positively to boys' perceptions of parental partiality, as well. However, among girls, fathers' nonintervention positively contributed to sibling warmth/closeness and negatively contributed to partiality. Boys perceived more sibling conflict than girls, but other sibling constellation and family structure variables did not contribute significantly to the aspects of sibling relationships studied. Title: Children's preceptions of parental responses to sibling quarrels and the qualities of sibling relationships Author: Ozretich, Rachel A. Children in middle childhood were surveyed in elementary schools to explore possible associations between their perceptions about certain characteristics of their sibling relationships and the ways in which their parents responded to sibling quarrels. An instrument was developed to measure perceptions of types of parental responses and the Sibling Relationship Questionnaire was used to assess sibling conflict, warmth/closeness, and perceptions of parental partiality. Factor analyses revealed that the parental responses of punishing, prohibiting, and group discipline were closely related, reflecting a single dimension (alpha=.81). Labeled restricting, regression analyses indicated that this type of parental response to sibling quarrels was a strong positive predictor of sibling conflict, a negative predictor of sibling warmth/closeness, and unrelated to perceptions of parental partiality. The contributions of the other types of parental responses to the aspects of sibling relationships studied were different for girls and boys. Parental referring to family rules contributed positively to girls' sibling conflict, and negatively to sibling warmth/closeness. Parental mediating conciliation, particularly by mothers, was a strong positive predictor of boys' sibling warmth/closeness. Parental mediating conciliation negatively contributed to boys' sibling conflict, particularly fathers' mediating conciliation. Nonintervention by parents, particularly fathers' nonintervention, was a strong positive predictor of boys' sibling conflict, and contributed positively to boys' perceptions of parental partiality, as well. However, among girls, fathers' nonintervention positively contributed to sibling warmth/closeness and negatively contributed to partiality. Boys perceived more sibling conflict than girls, but other sibling constellation and family structure variables did not contribute significantly to the aspects of sibling relationships studied. Close

• 30. [Article] Assessing the sex education attitudes and skills of parents of church attending preadolescents

  Four instruments were developed to assess sex education attitudes and skills of parents. The Parental Perception of Preadolescent Child (PPPC), Parental Attitudes Toward the Sex Education of Children (PATSEC), ...

  Citation × Citation Citation Abstract Copy Title: Assessing the sex education attitudes and skills of parents of church attending preadolescents Author: Kleffner, Carolyn Joyce Four instruments were developed to assess sex education attitudes and skills of parents. The Parental Perception of Preadolescent Child (PPPC), Parental Attitudes Toward the Sex Education of Children (PATSEC), Topic Checklist (TC) and Index of Challenging Questions for Parents of Preadolescents (ICQPP) provided measures on how parents perceive maturity and readiness for receiving information about sexual topics, and assessed a variety of parental sex education attitudes as well as competence, openness, and confidence in answering challenging questions from 9 - 12 year old children. After pretesting on a small sample of parents of preadolescents the instruments were then administered to a nonrandom parent sample of 65 residents of Linn and Benton Counties, Oregon. A majority of the 38 mothers and 27 fathers were married, college graduates, and attended church frequently. The questionnaire was administered at four Benton County churches. The four questionnaires and parental background data were analyzed by one and two way analysis of variance, Pearson Product Moment correlation, multiple and single response frequency tabulations, and a stepwise multiple regression test. Results indicated that parents held very positive attitudes toward the sex education of children and prefer being the primary source of information to them. Subjects were able to select the most developmentally appropriate response to children's challenging questions 75% of the time. The mean scores for fathers and mothers did not differ significantly in openness, attitude, or competence as measured on the TC, PATSEC, and ICQPP instruments. However, fathers were found to be more confident than mothers in responding to preadolescents' questions. A stepwise regression analysis showed a significant positive relationship between openness, competence and attitudes toward sex education of children. How mature a parent perceives a child to be was not significantly correlated to frequency of discussion on sexual topics. These findings were discussed and implications for providing sex education classes and parent-child discussion groups were made. Title: Assessing the sex education attitudes and skills of parents of church attending preadolescents Author: Kleffner, Carolyn Joyce Four instruments were developed to assess sex education attitudes and skills of parents. The Parental Perception of Preadolescent Child (PPPC), Parental Attitudes Toward the Sex Education of Children (PATSEC), Topic Checklist (TC) and Index of Challenging Questions for Parents of Preadolescents (ICQPP) provided measures on how parents perceive maturity and readiness for receiving information about sexual topics, and assessed a variety of parental sex education attitudes as well as competence, openness, and confidence in answering challenging questions from 9 - 12 year old children. After pretesting on a small sample of parents of preadolescents the instruments were then administered to a nonrandom parent sample of 65 residents of Linn and Benton Counties, Oregon. A majority of the 38 mothers and 27 fathers were married, college graduates, and attended church frequently. The questionnaire was administered at four Benton County churches. The four questionnaires and parental background data were analyzed by one and two way analysis of variance, Pearson Product Moment correlation, multiple and single response frequency tabulations, and a stepwise multiple regression test. Results indicated that parents held very positive attitudes toward the sex education of children and prefer being the primary source of information to them. Subjects were able to select the most developmentally appropriate response to children's challenging questions 75% of the time. The mean scores for fathers and mothers did not differ significantly in openness, attitude, or competence as measured on the TC, PATSEC, and ICQPP instruments. However, fathers were found to be more confident than mothers in responding to preadolescents' questions. A stepwise regression analysis showed a significant positive relationship between openness, competence and attitudes toward sex education of children. How mature a parent perceives a child to be was not significantly correlated to frequency of discussion on sexual topics. These findings were discussed and implications for providing sex education classes and parent-child discussion groups were made. Close