Duration and rate of grain filling and subsequent grain protein content in selected winter wheat populations

• Main Author: Mou, Beiquan
• Other Authors: Kronstad, Warren E.
• Language: en_US
• Published: 2013
• Subjects: Winter wheat > Genetics; Winter wheat > Quality; Food > Protein content
• Online Access: http://hdl.handle.net/1957/36740

The lack of information regarding the inheritance of the duration and rate of grain filling, and the possible relationship between grain fill and grain protein content in wheat prompted this study. Early maturing Chinese cultivars, 'AI Feng 2' and 'CB 83-52', and late maturing cultivars adapted to Oregon, 'Stephens' and 'Yamhill Dwarf', were examined for vernalization and photoperiod responses. Progeny from a diallel cross of the genotypes was evaluated for grain filling parameters, grain protein content and other agronomic traits for two years. 'Yamhill Dwarf' required six weeks of vernalization, while other cultivars needed only four weeks. The two Oregon developed genotypes were more sensitive to photoperiod than Chinese genotypes. Variation in developmental patterns among genotypes was related to differences in leaf number, spikelet number, rate of spikelet initiation, and rate of grain fill. Compared to solid planting, space-planting reduced the grain filling period. Significant genotypic variation for grain filling rate, duration, and kernel weight was observed in both seasons. Genotype X year interaction was not significant for any of the grain filling traits. General combining ability effects for grain filling rate, duration, and kernel weight were much larger than specific combining ability effects. Additive gene action made the major contribution to the inheritance of the grain filling traits. However, dominance effects appeared also to be involved in the genetic control of grain filling duration and kernel weight. Narrow sense heritability estimates were high for all three grain filling traits. Results indicated that early generation selection for both duration and rate of grain fill should be effective in these populations. Rate, but not duration of grain fill was closely associated with kernel weight. There was an inverse relationship between duration and rate of grain filling. Kernel protein percentage was positively associated with duration, but negatively related to rate of the grain filling. Results suggest that starch and protein accumulations in the kernel are two highly independent processes and may not necessarily compete for assimilates or energy. It may be necessary under the environments of this study to increase the duration of the grain fill to obtain high protein content with acceptable grain yield. === Graduation date: 1993