Identification of factors affecting trait stability via factorial regression and environmental variance. II. Application to end-use quality of bread wheat.

摘要

The genetic stability of bread wheat still remains to be understood. Thus, factors affecting the stability of end-use quality in wheat were determined using a method developed in a companion paper [see FSTA 2008-02-Mj0541] that combines environmental variance and factorial regression. Kernel protein percentage, strength (W), tenacity (P) and extensibility (L) of dough were studied. 25 environmental covariates characterized grain formation and nitrogen yields, DM and nitrogen contents at anthesis, grain-filling and post-anthesis temp. Earliness was a genotypic covariate. For each trait, the factorial regression, introducing the 2 environmental covariates that best discriminated for stability and best explained the interaction, was selected. The best factorial regressions explained 31.5, 53.3, 49 and 46.3% of the interaction sum of squares for kernel protein percentage, W, P and L, respectively. The selected covariates indicated that nitrogen availability at anthesis, nitrogen grain-filling rate, and duration were involved in quality stability. The stable varieties appeared to use poor environments favourable to nitrogen accumulation, and behave well in unfavourable environments. It is suggested that such information will be of use in future breeding programmes.