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• 1. [Article] Evaluation of methods of progeny testing in tall fescue seed production (Festuca arundinacea, Schreb.)

  Seventeen parental clones were selected, from 9,000 plants, on the basis of self-sterility, seed and forage yield potential using phenotypic ratings, crude protein and chromogen content. The parental clones ...

  Citation × Citation Citation Abstract Copy Title: Evaluation of methods of progeny testing in tall fescue seed production (Festuca arundinacea, Schreb.) Author: Thomas, Johnny Ray Seventeen parental clones were selected, from 9,000 plants, on the basis of self-sterility, seed and forage yield potential using phenotypic ratings, crude protein and chromogen content. The parental clones were divided into two populations based on date of maturity. Group I was intermediate in maturity and had nine parental clones, while group E was early maturing and had eight parental clones. Six progeny testing methods (vegetative cuttings of parental clones, first generation selfed-seed (S₁ progeny), open-pollinated progeny, polycross progeny, seed from all possible single crosses, and selfed seed from the single-crosses or F₂ progeny) were compared using simple correlation coefficients between the progeny test and by comparing the rankings of the clones on the basis of each progeny test. The actual polycross performance was compared with the theoretical polycross performance or average of all possible single crosses, to see if equal and random fertilization occurred in the actual polycross. The results from the comparison of the six progeny testing methods indicated the vegetative cuttings of the parental clones and the single-cross progeny tests are the two most effective progeny testing methods when considering all four traits and both populations of plants. The open pollinated and polycross progeny tests were generally undesirable, because frequently there was no significant difference among their progeny. The S₁ progeny test was generally not desirable in group I; however, it appeared to be the most satisfactory test for seed yield when both populations of plants were considered. The results illustrate why there are inconsistencies in the literature concerning the effectiveness of the progeny testing methods. The effectiveness of the six progeny tests varied, to some extent, from trait to trait and for the two populations. For all four traits there was much less agreement among the six progeny tests in group E than in group I. In all four traits the F₂ generation showed a great inbreeding depression. The average of the single crosses was lower than the parents for tiller number, plant height, and 100 seed weight, but equalled the parents in yield per plant. The S₁ progeny were usually approximately equal to the average of the single cross progeny. The open-pollinated and polycross progeny were generally the highest for all four traits. The results from the comparison of the actual polycross with the theoretical polycross indicated that equal and random fertilization did not occur in the actual polycross. The more desirable clones appeared to contribute the majority of the pollen, since the actual polycross performance was usually greater than the theoretical polycross performance. Title: Evaluation of methods of progeny testing in tall fescue seed production (Festuca arundinacea, Schreb.) Author: Thomas, Johnny Ray Seventeen parental clones were selected, from 9,000 plants, on the basis of self-sterility, seed and forage yield potential using phenotypic ratings, crude protein and chromogen content. The parental clones were divided into two populations based on date of maturity. Group I was intermediate in maturity and had nine parental clones, while group E was early maturing and had eight parental clones. Six progeny testing methods (vegetative cuttings of parental clones, first generation selfed-seed (S₁ progeny), open-pollinated progeny, polycross progeny, seed from all possible single crosses, and selfed seed from the single-crosses or F₂ progeny) were compared using simple correlation coefficients between the progeny test and by comparing the rankings of the clones on the basis of each progeny test. The actual polycross performance was compared with the theoretical polycross performance or average of all possible single crosses, to see if equal and random fertilization occurred in the actual polycross. The results from the comparison of the six progeny testing methods indicated the vegetative cuttings of the parental clones and the single-cross progeny tests are the two most effective progeny testing methods when considering all four traits and both populations of plants. The open pollinated and polycross progeny tests were generally undesirable, because frequently there was no significant difference among their progeny. The S₁ progeny test was generally not desirable in group I; however, it appeared to be the most satisfactory test for seed yield when both populations of plants were considered. The results illustrate why there are inconsistencies in the literature concerning the effectiveness of the progeny testing methods. The effectiveness of the six progeny tests varied, to some extent, from trait to trait and for the two populations. For all four traits there was much less agreement among the six progeny tests in group E than in group I. In all four traits the F₂ generation showed a great inbreeding depression. The average of the single crosses was lower than the parents for tiller number, plant height, and 100 seed weight, but equalled the parents in yield per plant. The S₁ progeny were usually approximately equal to the average of the single cross progeny. The open-pollinated and polycross progeny were generally the highest for all four traits. The results from the comparison of the actual polycross with the theoretical polycross indicated that equal and random fertilization did not occur in the actual polycross. The more desirable clones appeared to contribute the majority of the pollen, since the actual polycross performance was usually greater than the theoretical polycross performance. Close

• 2. [Article] Single cross progeny evaluation in tall fescue, Festuca arundinacea, Schreb

  All possible single crosses from three different maturity groups of 27 selected parental genotypes of tall fescue were established in a randomized block experiment to be evaluated in 1962 for five agronomic ...

  Citation × Citation Citation Abstract Copy Title: Single cross progeny evaluation in tall fescue, Festuca arundinacea, Schreb Author: Cáceres, Oscar All possible single crosses from three different maturity groups of 27 selected parental genotypes of tall fescue were established in a randomized block experiment to be evaluated in 1962 for five agronomic characters: height, width and maturity per plant; self -seed yield per plant; and forage yield per plant. For each character, general and specific combining ability effects, relationship among these characters and heritability estimates based on mean square expectations were obtained. Results of this study indicate that genetic diversity present in the original parental population resulted in significant differences among maturity groups for the characters measured, with the exception of self-seed yield. The variability within each group was small and significant only for maturity and self-seed yield in the intermediate group and for height and maturity in the late group, indicating that the progenies were quite uniform for the other characters. Significant correlation coefficients were noted between forage yield with height and width of the plant. This significant association was observed in all three maturity groups. Estimates of heritability in narrow sense for maturity and self-seed yield in the intermediate maturity group were 0.19 and 0.46, respectively. With the preponderance of additive gene effects for self-seed yield, the value of breeding material for this character may be indicated early in a breeding program. Title: Single cross progeny evaluation in tall fescue, Festuca arundinacea, Schreb Author: Cáceres, Oscar All possible single crosses from three different maturity groups of 27 selected parental genotypes of tall fescue were established in a randomized block experiment to be evaluated in 1962 for five agronomic characters: height, width and maturity per plant; self -seed yield per plant; and forage yield per plant. For each character, general and specific combining ability effects, relationship among these characters and heritability estimates based on mean square expectations were obtained. Results of this study indicate that genetic diversity present in the original parental population resulted in significant differences among maturity groups for the characters measured, with the exception of self-seed yield. The variability within each group was small and significant only for maturity and self-seed yield in the intermediate group and for height and maturity in the late group, indicating that the progenies were quite uniform for the other characters. Significant correlation coefficients were noted between forage yield with height and width of the plant. This significant association was observed in all three maturity groups. Estimates of heritability in narrow sense for maturity and self-seed yield in the intermediate maturity group were 0.19 and 0.46, respectively. With the preponderance of additive gene effects for self-seed yield, the value of breeding material for this character may be indicated early in a breeding program. Close

• 3. [Article] The breeding behavior of forage yield in two populations of tall fescue, (Festuca arundinacea, Schreb.)

  The single-cross and most F₂ progenies of 19 genotypes of tall fescue (Festuca arundinacea, Schreb. ) were used to study the breeding behavior of forage yield. Parental genotypes were selected for high ...

  Citation × Citation Citation Abstract Copy Title: The breeding behavior of forage yield in two populations of tall fescue, (Festuca arundinacea, Schreb.) Author: Matheson, Keith Isom The single-cross and most F₂ progenies of 19 genotypes of tall fescue (Festuca arundinacea, Schreb. ) were used to study the breeding behavior of forage yield. Parental genotypes were selected for high self-sterility, high chromogen and high crude protein. These were studied in two groups of nine intermediate and ten late-flowering genotypes. Progenies were grown on the Hyslop Agronomy Farm, Corvallis, Oregon as plants spaced one foot apart with three feet between rows. Ten plants of each cross for each generation were arranged in a randomized block design with four replications. Variables measured were plant width, natural plant height, plant spread, leaf length, total plant height of regrowth tissue, plant density and forage yield. The collected data were converted to plant means. Broad- and narrow-sense estimates of heritability were obtained from expected mean squares according to Griffing's analysis (random model, method four) and compared with estimates of heritability obtained by F₂-single-cross regression. General and specific combining ability effects were observed and the single-cross-F₂ inbreeding depressions were studied. The F₂ families were obtained by the self-pollination of five single-cross plants. General combining ability mean squares averaged from two to nine times greater than the mean squares for specific combining ability, with the largest difference being 54.7 times greater. The two populations responded similarly for the variables measured except for total plant height and plant spread. Greater progress from selection could be expected in the late- maturing group with the exception of these two traits. In most cases, single-cross progenies performed better than their corresponding F₂ progenies. The average of all single-crosses differed from the average of all F₂ progenies in 12 of 20 analyses in 1963, but in only 2 of 12 in 1964. The inbreeding characteristic was most pronounced for forage yield. High-performing single-crosses for the traits studied tended to produce high-performing F₂ progenies. Little or no heterosis was expressed and the expression of inbreeding depression appeared to be influenced greatly by the environment. Heritability estimates indicated that most traits could be studied more effectively after the second year of plant establishment. The environmental influence appeared to be less pronounced at that time. Where the coefficient of determination was high between the single-cross and F₂ generations, traits were less influenced by the environment and the disparity between the estimates of heritability was less. When used on cross-pollinated polyploid grasses, the method of diallel analysis proposed by Griffing does not appear to remove all environmental influence and thus overestimates heritability. Forage yield in the two populations of tall fescue studied was governed principally by additive gene action. Heterosis expressed was mostly in crosses involving low-performing parents. Title: The breeding behavior of forage yield in two populations of tall fescue, (Festuca arundinacea, Schreb.) Author: Matheson, Keith Isom The single-cross and most F₂ progenies of 19 genotypes of tall fescue (Festuca arundinacea, Schreb. ) were used to study the breeding behavior of forage yield. Parental genotypes were selected for high self-sterility, high chromogen and high crude protein. These were studied in two groups of nine intermediate and ten late-flowering genotypes. Progenies were grown on the Hyslop Agronomy Farm, Corvallis, Oregon as plants spaced one foot apart with three feet between rows. Ten plants of each cross for each generation were arranged in a randomized block design with four replications. Variables measured were plant width, natural plant height, plant spread, leaf length, total plant height of regrowth tissue, plant density and forage yield. The collected data were converted to plant means. Broad- and narrow-sense estimates of heritability were obtained from expected mean squares according to Griffing's analysis (random model, method four) and compared with estimates of heritability obtained by F₂-single-cross regression. General and specific combining ability effects were observed and the single-cross-F₂ inbreeding depressions were studied. The F₂ families were obtained by the self-pollination of five single-cross plants. General combining ability mean squares averaged from two to nine times greater than the mean squares for specific combining ability, with the largest difference being 54.7 times greater. The two populations responded similarly for the variables measured except for total plant height and plant spread. Greater progress from selection could be expected in the late- maturing group with the exception of these two traits. In most cases, single-cross progenies performed better than their corresponding F₂ progenies. The average of all single-crosses differed from the average of all F₂ progenies in 12 of 20 analyses in 1963, but in only 2 of 12 in 1964. The inbreeding characteristic was most pronounced for forage yield. High-performing single-crosses for the traits studied tended to produce high-performing F₂ progenies. Little or no heterosis was expressed and the expression of inbreeding depression appeared to be influenced greatly by the environment. Heritability estimates indicated that most traits could be studied more effectively after the second year of plant establishment. The environmental influence appeared to be less pronounced at that time. Where the coefficient of determination was high between the single-cross and F₂ generations, traits were less influenced by the environment and the disparity between the estimates of heritability was less. When used on cross-pollinated polyploid grasses, the method of diallel analysis proposed by Griffing does not appear to remove all environmental influence and thus overestimates heritability. Forage yield in the two populations of tall fescue studied was governed principally by additive gene action. Heterosis expressed was mostly in crosses involving low-performing parents. Close