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• 1. [Article] Effect of moisture stress on yield and quality of winter wheat seed

  Two experiments were conducted to determine the effects of moisture stress on physiological changes that occur during the vegetative and reproductive stages of the wheat (Triticum aestivum L.) plant, and ...

  Citation × Citation Citation Abstract Copy Title: Effect of moisture stress on yield and quality of winter wheat seed Author: Assuncao, Marcos Vinicius Two experiments were conducted to determine the effects of moisture stress on physiological changes that occur during the vegetative and reproductive stages of the wheat (Triticum aestivum L.) plant, and to relate these effects to seed yield, quality and performance. In a field experiment, different levels of moisture stress were obtained by establishing plots in two rainfall areas, and by planting on three different dates in the dryland area. Seed development and maturation occurred under extreme moisture stress in Moro (254mm annual rainfall), while stress at Corvallis (1020 mm annual rainfall) was low. Plants from the early fall planting were subjected to the most stress because of the greater fall growth which removed much of the soil moisture. Lowest seed yields occurred under the greatest moisture stress conditions, primarily because of a reduced number of seeds per spike. Seed size was the quality component most affected by moisture stress. Smaller seed size was associated with lower soil water potential, higher leaf area index during vegetative growth, and higher specific leaf weight and water soluble carbohydrate content of the plants after anthesis. Water soluble carbohydrate content was particularly high in the rachises of the most severely stressed plants, indicating a reduced rate of translocation to the developing seeds. Embryo weight was also reduced in the more stressed plants in proportioa to the reduction in seed weight. The protein contents of seeds from all three moisture stress levels at Moro were similar. Seeds developed under the most severe water stress had the highest respiratory quotient and lowest glutamic acid decarboxylase activity. The growth rate of seedlings produced by these seeds was 29% lower than that from seeds from the less stressed plots. A greenhouse experiment was conducted to study the effects of water stress under controlled conditions. Plants were grown under three moisture regimes (600, 300 and 150 ml water/pot/day) from the time awns were first visible on the main stem until maturity. Water-stressed plants had smaller leaf area and leaf dry weight, higher specific leaf weight, earlier leaf senescence, lower dry weight, and lower seed yield. On the other hand, water-stressed plants produced larger seeds, with heavier embryos, higher protein content, lower CO₂ evolution and lower respiratory quotient. These seeds in turn produced seedlings with greater vigor in terms of seedling growth rate. Because of the compensation ability of the wheat plant, development of management practices to decrease certain yield components in favor of enhanced seed quality is worthy of further study. Title: Effect of moisture stress on yield and quality of winter wheat seed Author: Assuncao, Marcos Vinicius Two experiments were conducted to determine the effects of moisture stress on physiological changes that occur during the vegetative and reproductive stages of the wheat (Triticum aestivum L.) plant, and to relate these effects to seed yield, quality and performance. In a field experiment, different levels of moisture stress were obtained by establishing plots in two rainfall areas, and by planting on three different dates in the dryland area. Seed development and maturation occurred under extreme moisture stress in Moro (254mm annual rainfall), while stress at Corvallis (1020 mm annual rainfall) was low. Plants from the early fall planting were subjected to the most stress because of the greater fall growth which removed much of the soil moisture. Lowest seed yields occurred under the greatest moisture stress conditions, primarily because of a reduced number of seeds per spike. Seed size was the quality component most affected by moisture stress. Smaller seed size was associated with lower soil water potential, higher leaf area index during vegetative growth, and higher specific leaf weight and water soluble carbohydrate content of the plants after anthesis. Water soluble carbohydrate content was particularly high in the rachises of the most severely stressed plants, indicating a reduced rate of translocation to the developing seeds. Embryo weight was also reduced in the more stressed plants in proportioa to the reduction in seed weight. The protein contents of seeds from all three moisture stress levels at Moro were similar. Seeds developed under the most severe water stress had the highest respiratory quotient and lowest glutamic acid decarboxylase activity. The growth rate of seedlings produced by these seeds was 29% lower than that from seeds from the less stressed plots. A greenhouse experiment was conducted to study the effects of water stress under controlled conditions. Plants were grown under three moisture regimes (600, 300 and 150 ml water/pot/day) from the time awns were first visible on the main stem until maturity. Water-stressed plants had smaller leaf area and leaf dry weight, higher specific leaf weight, earlier leaf senescence, lower dry weight, and lower seed yield. On the other hand, water-stressed plants produced larger seeds, with heavier embryos, higher protein content, lower CO₂ evolution and lower respiratory quotient. These seeds in turn produced seedlings with greater vigor in terms of seedling growth rate. Because of the compensation ability of the wheat plant, development of management practices to decrease certain yield components in favor of enhanced seed quality is worthy of further study. Close

• 2. [Article] Estimates of heterosis for five agronomic traits in selected winter x spring and winter x winter wheat crosses (Triticum aestivum L. em Thell)

  Concern regarding the lack of genetic variability and the apparent yield plateau reached in wheat breeding have prompted this investigation. The systematic crossing of spring and winter wheat types which ...

  Citation × Citation Citation Abstract Copy Title: Estimates of heterosis for five agronomic traits in selected winter x spring and winter x winter wheat crosses (Triticum aestivum L. em Thell) Author: Brajcich, P. Concern regarding the lack of genetic variability and the apparent yield plateau reached in wheat breeding have prompted this investigation. The systematic crossing of spring and winter wheat types which have evolved to form somewhat different gene pools, may provide a source of additional usable genetic variability for future yield increases. Five winter and five spring wheat cultivars with different degrees of genetic similarities in their pedigrees were crossed to obtain F1's and F2's. The parents plus winter x spring F1's were planted in two growing seasons at Hyslop Agronomy Farm near Corvallis, Oregon. During the second season the winter x spring F2 and winter x winter F1 crosses were also included. Agronomic traits were measured on an individual plant basis. These traits were plant height, number of tillers per plant, 100 kernel weight, number of kernels per spike and grain yield. Analyses of variance were conducted for each trait. Estimates of the amount of usable genetic variation were determined by heterosis values, inbreeding depression and parent-progeny standard regressions. Possible interactions between years and the above five characters were determined for the winter x spring F1's. Evidence of non-additive gene action was found in the expression of heterosis and subsequent inbreeding depression which depended on the specific trait measured and the parents involved in the cross. The greatest heterosis values were noted for grain yield per plant. Crosses with the winter parent, Weique Red Mace, resulted in the highest estimates for grain yield. This was due to the late maturity of these hybrids and to the diverse genetic background of this winter parent compared to the five spring parents. Parent-progeny regressions indicated that a large amount of additive genetic variance was present for plant height, 100 kernel weight and grain yield an intermediate amount for kernels per spike and tillers per plant. Winter x spring F1 crosses resulted in higher heterosis estimates and a wider range of values between crosses than winter x winter F1 crosses. Parent-progeny regression estimates were similar in value for the two types of F1 populations. Thus, these results indicate that the systematic crossing between winter and spring wheats will produce greater total genetic variability for further wheat improvement. This is true for the development of hybrid wheat (non-additive) and may also be promising for conventional breeding programs when only the additive portion of the total genetic variance can be used. The data support the general conclusion that the amount of heterosis is a function of genetic diversity between the two parents. Those breeders working on hybrid wheat may wish to look at winter x spring crosses as a means of maximizing heterosis. However, since a significant interaction between years x F1's was noted for the traits measured, more than one year of evaluation will be necessary if winter x spring crosses are employed. Title: Estimates of heterosis for five agronomic traits in selected winter x spring and winter x winter wheat crosses (Triticum aestivum L. em Thell) Author: Brajcich, P. Concern regarding the lack of genetic variability and the apparent yield plateau reached in wheat breeding have prompted this investigation. The systematic crossing of spring and winter wheat types which have evolved to form somewhat different gene pools, may provide a source of additional usable genetic variability for future yield increases. Five winter and five spring wheat cultivars with different degrees of genetic similarities in their pedigrees were crossed to obtain F1's and F2's. The parents plus winter x spring F1's were planted in two growing seasons at Hyslop Agronomy Farm near Corvallis, Oregon. During the second season the winter x spring F2 and winter x winter F1 crosses were also included. Agronomic traits were measured on an individual plant basis. These traits were plant height, number of tillers per plant, 100 kernel weight, number of kernels per spike and grain yield. Analyses of variance were conducted for each trait. Estimates of the amount of usable genetic variation were determined by heterosis values, inbreeding depression and parent-progeny standard regressions. Possible interactions between years and the above five characters were determined for the winter x spring F1's. Evidence of non-additive gene action was found in the expression of heterosis and subsequent inbreeding depression which depended on the specific trait measured and the parents involved in the cross. The greatest heterosis values were noted for grain yield per plant. Crosses with the winter parent, Weique Red Mace, resulted in the highest estimates for grain yield. This was due to the late maturity of these hybrids and to the diverse genetic background of this winter parent compared to the five spring parents. Parent-progeny regressions indicated that a large amount of additive genetic variance was present for plant height, 100 kernel weight and grain yield an intermediate amount for kernels per spike and tillers per plant. Winter x spring F1 crosses resulted in higher heterosis estimates and a wider range of values between crosses than winter x winter F1 crosses. Parent-progeny regression estimates were similar in value for the two types of F1 populations. Thus, these results indicate that the systematic crossing between winter and spring wheats will produce greater total genetic variability for further wheat improvement. This is true for the development of hybrid wheat (non-additive) and may also be promising for conventional breeding programs when only the additive portion of the total genetic variance can be used. The data support the general conclusion that the amount of heterosis is a function of genetic diversity between the two parents. Those breeders working on hybrid wheat may wish to look at winter x spring crosses as a means of maximizing heterosis. However, since a significant interaction between years x F1's was noted for the traits measured, more than one year of evaluation will be necessary if winter x spring crosses are employed. Close

• 3. [Article] Association between length of grain filling period and grain yield in two wheat populations (Triticum aestivum L. em Thell.)

  The objective of this study was to determine interrelationships among agronomic traits in early and late maturing populations. Two populations were obtained from the crosses, Roussalka/Tesopaco 76 and ...

  Citation × Citation Citation Abstract Copy Title: Association between length of grain filling period and grain yield in two wheat populations (Triticum aestivum L. em Thell.) Author: Min, Hwang Kee The objective of this study was to determine interrelationships among agronomic traits in early and late maturing populations. Two populations were obtained from the crosses, Roussalka/Tesopaco 76 and Yamhill/Aspen. Seeds were space planted with split plot design and nine agronomic traits were observed. In comparative studies between early and late populations, the early population was earlier in heading date, maturity date, longer maturity duration, heavier kernel weight, and higher harvest index. However, it was shorter in plant height, had fewer tillers, kernels and lower grain yield than the late population. Grain filling duration expressed positive relationships with grain yield in both crosses, although the correlation coefficient with grain yield was very low compared to other agronomic traits. Grain filling duration showed consistent positive relationships with kernel weight in both populations and with kernel number in the late population. No relationship was found between grain filling duration and tiller number. Grain filling duration influenced grain yield mainly by the indirect effects of kernel weight and kernel number. Yield components generally showed high positive relationships with grain yield; tiller number being the most important, followed by kernel number, and kernel weight. Competition among yield components was minimal in this space planted study. Heading date showed a negative association while plant height and harvest index expressed high positive relationships with grain yield. Title: Association between length of grain filling period and grain yield in two wheat populations (Triticum aestivum L. em Thell.) Author: Min, Hwang Kee The objective of this study was to determine interrelationships among agronomic traits in early and late maturing populations. Two populations were obtained from the crosses, Roussalka/Tesopaco 76 and Yamhill/Aspen. Seeds were space planted with split plot design and nine agronomic traits were observed. In comparative studies between early and late populations, the early population was earlier in heading date, maturity date, longer maturity duration, heavier kernel weight, and higher harvest index. However, it was shorter in plant height, had fewer tillers, kernels and lower grain yield than the late population. Grain filling duration expressed positive relationships with grain yield in both crosses, although the correlation coefficient with grain yield was very low compared to other agronomic traits. Grain filling duration showed consistent positive relationships with kernel weight in both populations and with kernel number in the late population. No relationship was found between grain filling duration and tiller number. Grain filling duration influenced grain yield mainly by the indirect effects of kernel weight and kernel number. Yield components generally showed high positive relationships with grain yield; tiller number being the most important, followed by kernel number, and kernel weight. Competition among yield components was minimal in this space planted study. Heading date showed a negative association while plant height and harvest index expressed high positive relationships with grain yield. Close

• 4. [Article] The influence on winter wheat yields of competitive weedy species

  A study was conducted to compare the competitive ability with weeds of the short-strawed Gaines variety wheat and taller growing varieties under different fertility levels at three experimental locations. ...

  Citation × Citation Citation Abstract Copy Title: The influence on winter wheat yields of competitive weedy species Author: Albeke, William Edgar A study was conducted to compare the competitive ability with weeds of the short-strawed Gaines variety wheat and taller growing varieties under different fertility levels at three experimental locations. The experiments were designed so that the effects of variety, nitrogen fertilization, and weed competition could be evaluated. The interactions between these factors were also studied. Ryegrass (Loolium app.) and downy brome (Bromus tectorum) were the two weed species studied. Under high winter rainfall and ryegrass competition yields of wheat were seriously impaired in both the short and tall growing wheat varieties tested. As rates of nitrogen increased yields of wheat did not increase where a medium or heavy stand of ryegrass was present. Yield of wheat was reduced under high nitrogen and high ryegrass competition. A response to 60 pounds of nitrogen per acre was noted where no ryegrass competition was present. One hundred twenty pounds of nitrogen did not increase yields appreciably, especially in the Gaines variety. In the two remaining experiments, response to nitrogen fertilization was not as prominent due to lack of moisture throughout the growing season. However, downy brome competition decreased yields at one location under all three fertility levels. At the other location a poor stand of downy brome and arid conditions accounted for the lack of competitive effects. No differences were noted in competing abilities of the tall vs. the short growing varieties. In general it was concluded that in order to get maximum response from nitrogen fertilization in wheat, weeds would have to be controlled. Title: The influence on winter wheat yields of competitive weedy species Author: Albeke, William Edgar A study was conducted to compare the competitive ability with weeds of the short-strawed Gaines variety wheat and taller growing varieties under different fertility levels at three experimental locations. The experiments were designed so that the effects of variety, nitrogen fertilization, and weed competition could be evaluated. The interactions between these factors were also studied. Ryegrass (Loolium app.) and downy brome (Bromus tectorum) were the two weed species studied. Under high winter rainfall and ryegrass competition yields of wheat were seriously impaired in both the short and tall growing wheat varieties tested. As rates of nitrogen increased yields of wheat did not increase where a medium or heavy stand of ryegrass was present. Yield of wheat was reduced under high nitrogen and high ryegrass competition. A response to 60 pounds of nitrogen per acre was noted where no ryegrass competition was present. One hundred twenty pounds of nitrogen did not increase yields appreciably, especially in the Gaines variety. In the two remaining experiments, response to nitrogen fertilization was not as prominent due to lack of moisture throughout the growing season. However, downy brome competition decreased yields at one location under all three fertility levels. At the other location a poor stand of downy brome and arid conditions accounted for the lack of competitive effects. No differences were noted in competing abilities of the tall vs. the short growing varieties. In general it was concluded that in order to get maximum response from nitrogen fertilization in wheat, weeds would have to be controlled. Close

• 5. [Article] Evaluation of parental performance for grain yield in two populations of wheat (Triticum aestivum Vill., Host)

  Six winter wheat cultivars were evaluated for their breeding value in transmitting superior genetic factors for grain yield to subsequent progeny. The cultivars were selected on the basis of their potential ...

  Citation × Citation Citation Abstract Copy Title: Evaluation of parental performance for grain yield in two populations of wheat (Triticum aestivum Vill., Host) Author: Alcala de Stefano, Maximino Six winter wheat cultivars were evaluated for their breeding value in transmitting superior genetic factors for grain yield to subsequent progeny. The cultivars were selected on the basis of their potential grain yield and divided into two populations. Population I was comprised of three cultivars which have been in commercial production for several years and are regarded as intermediate for grain yield. Population II was represented by three recently developed cultivars which have superior grain yielding potential. Each of the three parents within each population were crossed in a diallel manner Hence, the parents and subsequent F₁, F₂, and BC progeny made up the experimental populations. These populations were grown at two environmentally diverse sites within the state of Oregon. Morphological characters measured were: (1) tillers per plant; (2) kernels per spike; (3) plant height; (4) weight of 300 kernels; and (5) grain yield. To detect which parental combination had the greatest potential for transmitting superior performance to the subsequent progeny for the components of yield and grain yield, the following parameters were determined for both populations: (1) the amount and nature of the genetic variance associated with each population; (2) average combining ability of each parent within the populations; (3) estimates of heterosis and heterobeltiosis in the F₁ and (4) the possible influence of the genotype-environmental interactions on the parameters measured. Also information concerning the desirability of using top crosses and double crosses rather than single crosses was obtained. In an effort to compare the relative performance between the populations, Pullman Selection 101, which is a good general combining winter wheat cultivar, was used as a tester for both populations. The values obtained in this investigation reflect the properties of the populations studied and should not be interpreted as applying to all wheat populations. Considerable genetic variability was found within both populations for the characters studied. This variability was largely due to genetic factors which were additive. Tillers per plant and grain yield were influenced by both additive and nonadditive genetic variance. The higher yielding parents in Population II were found to be higher in their average combining ability for kernels per spike and grain yield per plant whereas the lower yielding parents in Population I were higher for tiller number, weight of 300 kernels and plant height. Parental combinations identified as being promising, for grain yield in a conventional program, where nearly homozygous lines are desired, were also the same parental combinations which resulted in a maximum expression of heterobeltiosis and would be of most interest in a hybrid program. The desirability of using multiple crosses to maximize the number of favorable factors need further study inctuding additional parents and different combinations plus an evaluation of the performance of such crosses in later generations. In this investigation, the single crosses appeared to be the most promising; however, inbreeding depression due to segregation within top and double crosses influenced the values obtained. Also, the population sizes should be increased to measure the total potential of such crosses. Significant genotype-environmental interactions were observed between locations for plant height and weight of 300 kernels. The estimates obtained for average combining ability, heterosis and heterobeltiosis for the other characters measured also suggested that it will be necessary to identify the most promising hybrid combinations based on the performance of the parents at the specific location. To make the most rapid progress in developing high yielding cultivars in either conventional or hybrid programs, the wheat breeder needs to emphasize crosses between unrelated high yielding cultivars. However, the need to provide superior parental lines which include such factors as disease resistance, should be evaluated. The development of elite germ plasm by geneticists will be mandatory if plant breeders are to continue to improve grain yield. Title: Evaluation of parental performance for grain yield in two populations of wheat (Triticum aestivum Vill., Host) Author: Alcala de Stefano, Maximino Six winter wheat cultivars were evaluated for their breeding value in transmitting superior genetic factors for grain yield to subsequent progeny. The cultivars were selected on the basis of their potential grain yield and divided into two populations. Population I was comprised of three cultivars which have been in commercial production for several years and are regarded as intermediate for grain yield. Population II was represented by three recently developed cultivars which have superior grain yielding potential. Each of the three parents within each population were crossed in a diallel manner Hence, the parents and subsequent F₁, F₂, and BC progeny made up the experimental populations. These populations were grown at two environmentally diverse sites within the state of Oregon. Morphological characters measured were: (1) tillers per plant; (2) kernels per spike; (3) plant height; (4) weight of 300 kernels; and (5) grain yield. To detect which parental combination had the greatest potential for transmitting superior performance to the subsequent progeny for the components of yield and grain yield, the following parameters were determined for both populations: (1) the amount and nature of the genetic variance associated with each population; (2) average combining ability of each parent within the populations; (3) estimates of heterosis and heterobeltiosis in the F₁ and (4) the possible influence of the genotype-environmental interactions on the parameters measured. Also information concerning the desirability of using top crosses and double crosses rather than single crosses was obtained. In an effort to compare the relative performance between the populations, Pullman Selection 101, which is a good general combining winter wheat cultivar, was used as a tester for both populations. The values obtained in this investigation reflect the properties of the populations studied and should not be interpreted as applying to all wheat populations. Considerable genetic variability was found within both populations for the characters studied. This variability was largely due to genetic factors which were additive. Tillers per plant and grain yield were influenced by both additive and nonadditive genetic variance. The higher yielding parents in Population II were found to be higher in their average combining ability for kernels per spike and grain yield per plant whereas the lower yielding parents in Population I were higher for tiller number, weight of 300 kernels and plant height. Parental combinations identified as being promising, for grain yield in a conventional program, where nearly homozygous lines are desired, were also the same parental combinations which resulted in a maximum expression of heterobeltiosis and would be of most interest in a hybrid program. The desirability of using multiple crosses to maximize the number of favorable factors need further study inctuding additional parents and different combinations plus an evaluation of the performance of such crosses in later generations. In this investigation, the single crosses appeared to be the most promising; however, inbreeding depression due to segregation within top and double crosses influenced the values obtained. Also, the population sizes should be increased to measure the total potential of such crosses. Significant genotype-environmental interactions were observed between locations for plant height and weight of 300 kernels. The estimates obtained for average combining ability, heterosis and heterobeltiosis for the other characters measured also suggested that it will be necessary to identify the most promising hybrid combinations based on the performance of the parents at the specific location. To make the most rapid progress in developing high yielding cultivars in either conventional or hybrid programs, the wheat breeder needs to emphasize crosses between unrelated high yielding cultivars. However, the need to provide superior parental lines which include such factors as disease resistance, should be evaluated. The development of elite germ plasm by geneticists will be mandatory if plant breeders are to continue to improve grain yield. Close

• 6. [Article] Influence of Soft Wheat Characteristics on Quality of Batter-based Products

  Wheat is a globally traded staple crop. Wheat is important in human diets because of its agronomic adaptability, physical characteristics, functionality for the production of leavened products and nutritional ...

  Citation × Citation Citation Abstract Copy Title: Influence of Soft Wheat Characteristics on Quality of Batter-based Products Author: Fajardo Centeno, Carlos A. Wheat is a globally traded staple crop. Wheat is important in human diets because of its agronomic adaptability, physical characteristics, functionality for the production of leavened products and nutritional value. Two significant characteristics make wheat an important staple food-crop. First, the proteins present in wheat endosperm have attributes that enable gas retention after the proteins are hydrated and mechanically worked during dough production. Second, a wider variety of products can be made out of wheat compared to other cereals. Wheat quality is defined in terms of suitability for specific end-uses. This is important for breeders, farmers, flour millers, and food producers and consumers. In the U.S. Pacific Northwest (PNW) climatic conditions favor production of soft wheat. Three soft wheat types are planted in the PNW, soft white winter (SWW), soft white spring (SWS), and club (CLUB). Batter-based products are important applications for soft wheats and include a wide range of products such as pancakes and waffles, cakes, and coatings. Pancakes are produced from fluid batters using a single step mixing process and contain sugar concentrations < 30% in their formulations. Cakes are complex food systems where their classification is based on mixing process to produce the batters and the sugar-flour ratio concentrations in their formulations. This dissertation is focused on the functionality, analysis, and selection of soft wheat quality traits that affect end-product performance and also developing a methodology to rapidly predict cake quality. The first study (Chapter 3) was concerned with the functionality of SWW wheats in pancake making. The aim of this study was to observe the differences in genotype and protein concentration on batter flow and pancake making performance of a collection of SWW wheats. Two formulations were used in the study: one based on Finnie et al (2006) called "old" and another based on the AACC-I Approved Method 10-80.01 called "new". The "new" lean formulation had an improved ability to distinguish the performance of different flours compared with the “old” as a result of wider range of pancake diameters. This study showed that pancake making performance would not be optimized by conventional superior high-quality soft wheat flours with soft kernel texture, high break flour yield, and low water-, carbonate-, and sucrose SRCs. From our results it appears that for unchlorinated flours, at least for thicker pancakes, the most appropriate flour would have higher water and sucrose SRCs and be grown under management conditions conductive to higher protein. The second study (Chapter 4) was a meta-analysis of data collected by the USDA Western Wheat Quality Laboratory (Pullman, WA). This study was done to advance understanding soft wheat quality traits that differentially affect sugar-snap cookie diameter (CODI) and Japanese sponge cake (SC) volume (CAVOL). Principal component analysis (PCA) and partial least square (PLS) regression models were used to obtain useful actionable information from the data. The overall data showed that break flour yield (BKFY) was the single most important trait positively associated with both CAVOL and CODI. SWW wheats showed CVs > 10% for kernel hardness (SKHRD), grain and flour protein concentrations, ash, sucrose-, and lactic acid SRCs. These observations suggested that hardness, protein, ash, and the two SRCs were more sensitive to G&E effects than were the end-product traits that had CVs < 10%. The third study (Chapter 5) was built on the second study by adding two additional quality tests, oxidative gelation capacity (PeakOXI) and median particle size, to the potential prediction of CODI and CAVOL. Similar to the second study, BKFY was the single most important trait positively associated with both CAVOL and CODI. Virtual selection of SWWs based on either BKFY or SKHRD alone showed (in both the second and third studies) that using these enabled a gain of 134 mL for CAVOL and 0.6 cm for CODI using SKHRD and 122 mL for CAVOL and 0.58 cm for CODI using BKFY (Chapter 5). PeakOXI was significantly correlated with CODI but not with CAVOL. This contrasted with our hypothesis that PeakOXI would affect both products similarly. Notably 13 SWW samples had PeakOXI values higher than 800 cP. PeakOXI values this high have never been observed in soft wheats prior to this study. This is a valuable genetic resource for further studies that may lead to ways to better exploit oxidative gelation. The fourth study (Chapter 6) expanded the concepts in previous studies and included the use of a test to measure cake-batter viscosity in an attempt to predict cake quality. This study investigated the relationships between wheat quality traits, cake batters, and cake making quality in three cake types: SC, layer cake (LC), and pound cake (PoC). This study differed from the studies in Chapters 4 and 5 and was similar to Chapter 3 as the samples were fewer but specifically chosen to span the entire range of typical SWW quality. In this study we also developed a viscosity-based method to predict SC and LC quality that takes only eight minutes. This could be useful for screening or selection for cake quality in soft wheat breeding programs. In SC, there were no significant differences in cake quality traits between varieties. However, SC volume had a strong negative association with PeakOXI. For LC, the variety Tubbs, with harder kernel and higher absorption characteristics, had the largest LC volume. In contrast to SC, LC volume was significantly and positively associated with PeakOXI. In PoC, Kaseburg, with the highest protein content, had the largest cake volume. PoC was significantly and positively associated with flour protein concentration suggesting that flour proteins were important for larger volumes and confirming other observations in the literature. In contrast to LC and SC, PoC was not significantly associated with PeakOXI. The overall impact of the studies reported is: - For pancakes, the most important soft wheat trait is flour protein concentration. Water-, and sucrose SRCs were potentially useful parameters for predicting pancake quality. - For SC and sugar-snap cookies, break flour yield was the most important single trait in predicting higher SC volumes and larger cookie diameters. Therefore, selection in soft wheat breeding should be focused on kernel hardness and break flour yields as primary factors. Title: Influence of Soft Wheat Characteristics on Quality of Batter-based Products Author: Fajardo Centeno, Carlos A. Wheat is a globally traded staple crop. Wheat is important in human diets because of its agronomic adaptability, physical characteristics, functionality for the production of leavened products and nutritional value. Two significant characteristics make wheat an important staple food-crop. First, the proteins present in wheat endosperm have attributes that enable gas retention after the proteins are hydrated and mechanically worked during dough production. Second, a wider variety of products can be made out of wheat compared to other cereals. Wheat quality is defined in terms of suitability for specific end-uses. This is important for breeders, farmers, flour millers, and food producers and consumers. In the U.S. Pacific Northwest (PNW) climatic conditions favor production of soft wheat. Three soft wheat types are planted in the PNW, soft white winter (SWW), soft white spring (SWS), and club (CLUB). Batter-based products are important applications for soft wheats and include a wide range of products such as pancakes and waffles, cakes, and coatings. Pancakes are produced from fluid batters using a single step mixing process and contain sugar concentrations < 30% in their formulations. Cakes are complex food systems where their classification is based on mixing process to produce the batters and the sugar-flour ratio concentrations in their formulations. This dissertation is focused on the functionality, analysis, and selection of soft wheat quality traits that affect end-product performance and also developing a methodology to rapidly predict cake quality. The first study (Chapter 3) was concerned with the functionality of SWW wheats in pancake making. The aim of this study was to observe the differences in genotype and protein concentration on batter flow and pancake making performance of a collection of SWW wheats. Two formulations were used in the study: one based on Finnie et al (2006) called "old" and another based on the AACC-I Approved Method 10-80.01 called "new". The "new" lean formulation had an improved ability to distinguish the performance of different flours compared with the “old” as a result of wider range of pancake diameters. This study showed that pancake making performance would not be optimized by conventional superior high-quality soft wheat flours with soft kernel texture, high break flour yield, and low water-, carbonate-, and sucrose SRCs. From our results it appears that for unchlorinated flours, at least for thicker pancakes, the most appropriate flour would have higher water and sucrose SRCs and be grown under management conditions conductive to higher protein. The second study (Chapter 4) was a meta-analysis of data collected by the USDA Western Wheat Quality Laboratory (Pullman, WA). This study was done to advance understanding soft wheat quality traits that differentially affect sugar-snap cookie diameter (CODI) and Japanese sponge cake (SC) volume (CAVOL). Principal component analysis (PCA) and partial least square (PLS) regression models were used to obtain useful actionable information from the data. The overall data showed that break flour yield (BKFY) was the single most important trait positively associated with both CAVOL and CODI. SWW wheats showed CVs > 10% for kernel hardness (SKHRD), grain and flour protein concentrations, ash, sucrose-, and lactic acid SRCs. These observations suggested that hardness, protein, ash, and the two SRCs were more sensitive to G&E effects than were the end-product traits that had CVs < 10%. The third study (Chapter 5) was built on the second study by adding two additional quality tests, oxidative gelation capacity (PeakOXI) and median particle size, to the potential prediction of CODI and CAVOL. Similar to the second study, BKFY was the single most important trait positively associated with both CAVOL and CODI. Virtual selection of SWWs based on either BKFY or SKHRD alone showed (in both the second and third studies) that using these enabled a gain of 134 mL for CAVOL and 0.6 cm for CODI using SKHRD and 122 mL for CAVOL and 0.58 cm for CODI using BKFY (Chapter 5). PeakOXI was significantly correlated with CODI but not with CAVOL. This contrasted with our hypothesis that PeakOXI would affect both products similarly. Notably 13 SWW samples had PeakOXI values higher than 800 cP. PeakOXI values this high have never been observed in soft wheats prior to this study. This is a valuable genetic resource for further studies that may lead to ways to better exploit oxidative gelation. The fourth study (Chapter 6) expanded the concepts in previous studies and included the use of a test to measure cake-batter viscosity in an attempt to predict cake quality. This study investigated the relationships between wheat quality traits, cake batters, and cake making quality in three cake types: SC, layer cake (LC), and pound cake (PoC). This study differed from the studies in Chapters 4 and 5 and was similar to Chapter 3 as the samples were fewer but specifically chosen to span the entire range of typical SWW quality. In this study we also developed a viscosity-based method to predict SC and LC quality that takes only eight minutes. This could be useful for screening or selection for cake quality in soft wheat breeding programs. In SC, there were no significant differences in cake quality traits between varieties. However, SC volume had a strong negative association with PeakOXI. For LC, the variety Tubbs, with harder kernel and higher absorption characteristics, had the largest LC volume. In contrast to SC, LC volume was significantly and positively associated with PeakOXI. In PoC, Kaseburg, with the highest protein content, had the largest cake volume. PoC was significantly and positively associated with flour protein concentration suggesting that flour proteins were important for larger volumes and confirming other observations in the literature. In contrast to LC and SC, PoC was not significantly associated with PeakOXI. The overall impact of the studies reported is: - For pancakes, the most important soft wheat trait is flour protein concentration. Water-, and sucrose SRCs were potentially useful parameters for predicting pancake quality. - For SC and sugar-snap cookies, break flour yield was the most important single trait in predicting higher SC volumes and larger cookie diameters. Therefore, selection in soft wheat breeding should be focused on kernel hardness and break flour yields as primary factors. Close

• 7. [Article] Growth rate and phosphorus uptake of wheat (Triticum aestivum VILL., Host) as a function of soil water suction and soil temperature

  The effect of soil temperature and soil water suction on the rate of phosphorus uptake and growth rate of wheat (Triticum aestivum VILL. , Host) was studied. Plants were grown in perlite slabs separated ...

  Citation × Citation Citation Abstract Copy Title: Growth rate and phosphorus uptake of wheat (Triticum aestivum VILL., Host) as a function of soil water suction and soil temperature Author: Fazilat, Mohammad The effect of soil temperature and soil water suction on the rate of phosphorus uptake and growth rate of wheat (Triticum aestivum VILL. , Host) was studied. Plants were grown in perlite slabs separated from an osmotic solution by a semi-permeable membrane. Measurements were made at temperatures of 10.0, 18.3, 23.9, 32.2, and 35.0°C, and soil water suctions of 0.35 and 2.5 bars. Five week old wheat seedlings were exposed to these conditions. The dry weight of shoots and roots was determined at two day intervals. Plant material extracted was analyzed for phosphorus concentration. The color intensity was measured on a Bausch and Lomb spectronic 20 spectrophotometer of 420 millimicrons. In general, a constant growth rate, which was approached exponentially during the experimental period was found in all treatment combinations. Growth rate for both shoots and roots was slow at low root temperatures and had a maximum rate at a root temperature of 24.0°C. High soil water suction was a limiting factor in growth rate. Phosphorus concentration of shoots and roots was found to approach a constant value during the experimental period according to the equation y = a+be[superscript]-0.07t[superscript]3/2 where y is the phosphorus concentration, t is the time in days, and a and b are constants. Over the entire range of soil temperatures considered the phosphorus concentration of the shoots increased linearlly with the root temperature, but the phosphorus concentration of the roots slightly decreased by increasing soil temperature and did not increase until the root temperature was about 32.0°C. There was no evidence of much variation in percent of total phosphorus uptake transported to the shoot in the experiments. Trans location of phosphorus from roots to shoots did not appear to be a limiting factor for phosphorus uptake at the low root temperature. It was suggested that the low rates of phosphorus uptake at the low root temperatures resulted from the low level of metabolic activity. Title: Growth rate and phosphorus uptake of wheat (Triticum aestivum VILL., Host) as a function of soil water suction and soil temperature Author: Fazilat, Mohammad The effect of soil temperature and soil water suction on the rate of phosphorus uptake and growth rate of wheat (Triticum aestivum VILL. , Host) was studied. Plants were grown in perlite slabs separated from an osmotic solution by a semi-permeable membrane. Measurements were made at temperatures of 10.0, 18.3, 23.9, 32.2, and 35.0°C, and soil water suctions of 0.35 and 2.5 bars. Five week old wheat seedlings were exposed to these conditions. The dry weight of shoots and roots was determined at two day intervals. Plant material extracted was analyzed for phosphorus concentration. The color intensity was measured on a Bausch and Lomb spectronic 20 spectrophotometer of 420 millimicrons. In general, a constant growth rate, which was approached exponentially during the experimental period was found in all treatment combinations. Growth rate for both shoots and roots was slow at low root temperatures and had a maximum rate at a root temperature of 24.0°C. High soil water suction was a limiting factor in growth rate. Phosphorus concentration of shoots and roots was found to approach a constant value during the experimental period according to the equation y = a+be[superscript]-0.07t[superscript]3/2 where y is the phosphorus concentration, t is the time in days, and a and b are constants. Over the entire range of soil temperatures considered the phosphorus concentration of the shoots increased linearlly with the root temperature, but the phosphorus concentration of the roots slightly decreased by increasing soil temperature and did not increase until the root temperature was about 32.0°C. There was no evidence of much variation in percent of total phosphorus uptake transported to the shoot in the experiments. Trans location of phosphorus from roots to shoots did not appear to be a limiting factor for phosphorus uptake at the low root temperature. It was suggested that the low rates of phosphorus uptake at the low root temperatures resulted from the low level of metabolic activity. Close

• 8. [Article] Yield and other agronomic characters of winter wheat cultivars as affected by five seeding rates and three different environmental conditions

  Five newly released and two Eastern European winter wheat cultivars were grown under five different seeding rates (80, 160, 240, 320, 400 seeds per m²). Four of these newly released cultivars were grown ...

  Citation × Citation Citation Abstract Copy Title: Yield and other agronomic characters of winter wheat cultivars as affected by five seeding rates and three different environmental conditions Author: Güler, Mengü Five newly released and two Eastern European winter wheat cultivars were grown under five different seeding rates (80, 160, 240, 320, 400 seeds per m²). Four of these newly released cultivars were grown at three different locations which have different environmental conditions. Data were obtained on grain yield, tiller number per plant, 1000 kernel weight, seed number per spike, plant and spike number per unit area, plant height, heading and maturity dates. At the lowest rate of seeding the grain yield was significantly lower at all three locations. Although there were no significant differences for grain yield for all the other seeding rates, maximum yields were obtained from lower seeding rates at Ryan while at Hyslop and Madras, which had better moisture conditions, maximum yields were obtained at higher seeding rates. This situation was not observed for the Yamhill cultivar in which maximum yields were obtained at 160 seeds per m² seeding rate at all three locations. Tillers per plant value decreased as the seeding rate increased. Hyslop and McDermid produced significantly higher number of tillers per plant from the other cultivars. Significantly highest 1000 kernel weight values were obtained at the lowest seeding rate. Yamhill produced the highest significant 1000 kernel weight while Paha produced the lowest. Seeds per spike value followed the same order as tillers per plant and 1000 kernel weight showing a continuous decrease with the increased rates of seeding. The number of plants per m² was a direct linear function of seeding rate. The number of spikes per m² increased curvilinearly with the increased seeding rate. Hyslop and McDermid produced the highest significant number of spikes per m² because of their higher tillering ability. Plant height increased with increased rates of seeding because of the increased competition for light. Yamhill and Paha were significantly the tallest cultivars. The tallest plants were observed at Hyslop. There was a decrease in the number of days in heading and maturity as the rates of seeding increased. The cultivars ranked in the order Paha > Yamhill > Hyslop > McDermid for heading and maturity dates. Heading first occurred at Hyslop followed by Ryan and Madras while maturity occurred first at Ryan followed by Hyslop and Madras. Highly positive correlations were observed among plants per m², spikes per m and seeding rate while these factors correlated negatively with tillers per plant, 1000 kernel weight and seeds per spike. The regression equations showed that maturity date, heading date and spikes per m² values were the most important factors for predicting yield. Title: Yield and other agronomic characters of winter wheat cultivars as affected by five seeding rates and three different environmental conditions Author: Güler, Mengü Five newly released and two Eastern European winter wheat cultivars were grown under five different seeding rates (80, 160, 240, 320, 400 seeds per m²). Four of these newly released cultivars were grown at three different locations which have different environmental conditions. Data were obtained on grain yield, tiller number per plant, 1000 kernel weight, seed number per spike, plant and spike number per unit area, plant height, heading and maturity dates. At the lowest rate of seeding the grain yield was significantly lower at all three locations. Although there were no significant differences for grain yield for all the other seeding rates, maximum yields were obtained from lower seeding rates at Ryan while at Hyslop and Madras, which had better moisture conditions, maximum yields were obtained at higher seeding rates. This situation was not observed for the Yamhill cultivar in which maximum yields were obtained at 160 seeds per m² seeding rate at all three locations. Tillers per plant value decreased as the seeding rate increased. Hyslop and McDermid produced significantly higher number of tillers per plant from the other cultivars. Significantly highest 1000 kernel weight values were obtained at the lowest seeding rate. Yamhill produced the highest significant 1000 kernel weight while Paha produced the lowest. Seeds per spike value followed the same order as tillers per plant and 1000 kernel weight showing a continuous decrease with the increased rates of seeding. The number of plants per m² was a direct linear function of seeding rate. The number of spikes per m² increased curvilinearly with the increased seeding rate. Hyslop and McDermid produced the highest significant number of spikes per m² because of their higher tillering ability. Plant height increased with increased rates of seeding because of the increased competition for light. Yamhill and Paha were significantly the tallest cultivars. The tallest plants were observed at Hyslop. There was a decrease in the number of days in heading and maturity as the rates of seeding increased. The cultivars ranked in the order Paha > Yamhill > Hyslop > McDermid for heading and maturity dates. Heading first occurred at Hyslop followed by Ryan and Madras while maturity occurred first at Ryan followed by Hyslop and Madras. Highly positive correlations were observed among plants per m², spikes per m and seeding rate while these factors correlated negatively with tillers per plant, 1000 kernel weight and seeds per spike. The regression equations showed that maturity date, heading date and spikes per m² values were the most important factors for predicting yield. Close

• 9. [Article] Effects of irrigation frequency on yields of winter wheat

  Deliberately underirrigating a crop may yield economic benefits. The optimal use of water by an irrigator should be achieved under a deficit irrigation regime. It is important to know how water deficits ...

  Citation × Citation Citation Abstract Copy Title: Effects of irrigation frequency on yields of winter wheat Author: Nakamura, Brian Clifford Deliberately underirrigating a crop may yield economic benefits. The optimal use of water by an irrigator should be achieved under a deficit irrigation regime. It is important to know how water deficits affect yields and the interaction of the deficits with the scheduling of irrigations. A field experiment was conducted during the 1981 irrigation season to investigate the effects of high and low frequency deficit irrigation on yields of winter wheat. Yield and water use data were used to construct three production functions. The relationship between the level of water use and the resulting yield were determined for three irrigation frequency regimes. Field plots under daily (high frequency), weekly (normal frequency), and stress (reduced frequency) regimes were included in the field experiment as well as two dryland production plots. The relationships derived from this project were characterized by a large degree of scatter in the results. Highly favorable weather conditions offset the effects of irrigation deficits on plant yields throughout the irrigation season. At this time, a second year of data is in the process of compilation. The results of a regression analysis showed no statistically significant difference in the water use-yield relationships of the three irrigation frequency regimes. The effect of frequency did not lead to any readily apparent differences in the three production functions. The efficiency of water use of the different irrigation frequencies increases with decreasing amount of applied water for the 1981 crop year. The most efficient treatment, i.e., least water use per unit of yield, was the pre-plant irrigated, dryfarmed plots. The density of the wheat, a measure of crop quality also increased with decreased water use in this experiment. The optimal irrigation treatment (measured by production and quality) was the two-week frequency set. Title: Effects of irrigation frequency on yields of winter wheat Author: Nakamura, Brian Clifford Deliberately underirrigating a crop may yield economic benefits. The optimal use of water by an irrigator should be achieved under a deficit irrigation regime. It is important to know how water deficits affect yields and the interaction of the deficits with the scheduling of irrigations. A field experiment was conducted during the 1981 irrigation season to investigate the effects of high and low frequency deficit irrigation on yields of winter wheat. Yield and water use data were used to construct three production functions. The relationship between the level of water use and the resulting yield were determined for three irrigation frequency regimes. Field plots under daily (high frequency), weekly (normal frequency), and stress (reduced frequency) regimes were included in the field experiment as well as two dryland production plots. The relationships derived from this project were characterized by a large degree of scatter in the results. Highly favorable weather conditions offset the effects of irrigation deficits on plant yields throughout the irrigation season. At this time, a second year of data is in the process of compilation. The results of a regression analysis showed no statistically significant difference in the water use-yield relationships of the three irrigation frequency regimes. The effect of frequency did not lead to any readily apparent differences in the three production functions. The efficiency of water use of the different irrigation frequencies increases with decreasing amount of applied water for the 1981 crop year. The most efficient treatment, i.e., least water use per unit of yield, was the pre-plant irrigated, dryfarmed plots. The density of the wheat, a measure of crop quality also increased with decreased water use in this experiment. The optimal irrigation treatment (measured by production and quality) was the two-week frequency set. Close

• 10. [Article] Sulfhydryl and disulfide changes in young wheat seedlings during vernalization

  A study of the SH and SS content levels during vernalization of wheat was made. In order to carry out the study, a rapid analytical technique was worked out which allowed fast sequential analyses of the ...

  Citation × Citation Citation Abstract Copy Title: Sulfhydryl and disulfide changes in young wheat seedlings during vernalization Author: Ellis, Robert William A study of the SH and SS content levels during vernalization of wheat was made. In order to carry out the study, a rapid analytical technique was worked out which allowed fast sequential analyses of the samples of wheat tissue. Two techniques were used: a) an amperometric titration method and b) a fluorescence quenching method. The amperometric titration method consisted of adding aliquots of samples of wheat tissue homogenate to the system and noting the decrease in current, due to a tie-up of Ag⁺ by the SH groups of the sample. The system consisted of a rotating platinum electrode connected to a mercury-mercuric oxide reference cell. The supporting electrolyte was a 0.14M solution of tris at pH 7.4. The fluorescence quenching method consisted of adding aliquots of sample to a solution of fluorescien mercuric acetate (FMA) in a 1N NaOH media. The SH and SS groups reacted with FMA in a one:one ratio. The reacted FMA was unable to fluoresce, thus making possible a quantitative assay for SH and SS groups in solution. Red Bobs, a spring wheat, and Elgin, a winter wheat, were grown in the dark at 3° C. and at 20° C. The SH and SS contents of the shoots were measured throughout a period of five weeks in the group grown at 3° C. and a period of 48 hours in the group grown at 20° C. The results of the analyses showed that the SH, SS, and SH+SS contents based on fresh weights were present in greater quantities in the tissues of Red Bobs grown at 20° than in the Elgin tissues grown at 20°. The high SH and SS concentrations present in the warm-grown Red Bobs tissues were due to a high concentration of protein extracted from that tissue. The SH, SS, and SH+SS contents per fresh weight were quite similar in the cold-grown tissues of both varieties during the growth period. These constituents present in the cold-grown tissues occurred in quantities that were less than those found in warm-grown Red Bobs tissues and greater than those present in the warm-grown Elgin tissues. Both varieties grown at both temperatures showed a similar decrease in SH and SS contents based on fresh weights as maturation progressed. The analyses indicated that SH, SS, and SH+SS contents based on protein levels were similar in Elgin and Red Bobs tissues grown at 20°. Both varieties grown at 3° contained greater concentrations of SH, SS, and SH+SS groups based on protein levels than those present in the tissues grown at 20°. The Elgin tissues at 3° underwent a fluctuation of these values as growth progressed, while the Red Bobs tissues at 3° maintained relatively constant levels of SH, SS, and SH+SS contents based on protein levels present during the growth period. It was concluded that the levels or patterns of SH and SS groups in young spring and winter wheat shoots were not correlated with the capacity of these plants to flower. Title: Sulfhydryl and disulfide changes in young wheat seedlings during vernalization Author: Ellis, Robert William A study of the SH and SS content levels during vernalization of wheat was made. In order to carry out the study, a rapid analytical technique was worked out which allowed fast sequential analyses of the samples of wheat tissue. Two techniques were used: a) an amperometric titration method and b) a fluorescence quenching method. The amperometric titration method consisted of adding aliquots of samples of wheat tissue homogenate to the system and noting the decrease in current, due to a tie-up of Ag⁺ by the SH groups of the sample. The system consisted of a rotating platinum electrode connected to a mercury-mercuric oxide reference cell. The supporting electrolyte was a 0.14M solution of tris at pH 7.4. The fluorescence quenching method consisted of adding aliquots of sample to a solution of fluorescien mercuric acetate (FMA) in a 1N NaOH media. The SH and SS groups reacted with FMA in a one:one ratio. The reacted FMA was unable to fluoresce, thus making possible a quantitative assay for SH and SS groups in solution. Red Bobs, a spring wheat, and Elgin, a winter wheat, were grown in the dark at 3° C. and at 20° C. The SH and SS contents of the shoots were measured throughout a period of five weeks in the group grown at 3° C. and a period of 48 hours in the group grown at 20° C. The results of the analyses showed that the SH, SS, and SH+SS contents based on fresh weights were present in greater quantities in the tissues of Red Bobs grown at 20° than in the Elgin tissues grown at 20°. The high SH and SS concentrations present in the warm-grown Red Bobs tissues were due to a high concentration of protein extracted from that tissue. The SH, SS, and SH+SS contents per fresh weight were quite similar in the cold-grown tissues of both varieties during the growth period. These constituents present in the cold-grown tissues occurred in quantities that were less than those found in warm-grown Red Bobs tissues and greater than those present in the warm-grown Elgin tissues. Both varieties grown at both temperatures showed a similar decrease in SH and SS contents based on fresh weights as maturation progressed. The analyses indicated that SH, SS, and SH+SS contents based on protein levels were similar in Elgin and Red Bobs tissues grown at 20°. Both varieties grown at 3° contained greater concentrations of SH, SS, and SH+SS groups based on protein levels than those present in the tissues grown at 20°. The Elgin tissues at 3° underwent a fluctuation of these values as growth progressed, while the Red Bobs tissues at 3° maintained relatively constant levels of SH, SS, and SH+SS contents based on protein levels present during the growth period. It was concluded that the levels or patterns of SH and SS groups in young spring and winter wheat shoots were not correlated with the capacity of these plants to flower. Close