Studies On Inheritance Of GMP Content And Its Relations To Quality And Agronomic Characters In Wheat

A set of diallel crosses involving 6 wheat parents, according to the model of Grilling Method II, was made to study the combining ability, heterossis, heritability and genetic model of glutenin macropolymer (GMP) content and study the relation- ships between GMP content and agronomic characters. 261 wheat germplasm materials were used to study the correlations between GMP content and baking quality characters. 5 wheat varieties growing in 4 localities were used to study the correlations between GMP content and environment. The results indicated that (1) GMP content was significantly and positively correlated to protein content and sedimentation value. The effect of GMP content was less influenced by protein content using partial correlation analysis. It was feasible to predict the baking quality of flour using GMP content as a reliable crite- rion. (2) The percentage of germplasms with GMP content lower than 3%, 4%, and higher than 4% in total germplasms was 54.02%, 92.33% and 7.67% respectively. The domestic germplasms with higher GMP content were limited in number compa- red with foreign germplasms. (3) The correlations between GMP content and plant height, head length, biomass per plant, kernel weight per plant, 1000-kernel weight, kernel number per plant and harvest index were not significant. It was likely to gain lines with high GMP content, high baking quality, desirable agronomic characters and high yield potential, so high yield and high quality were harmoniously associated by crossing parents and selecting progeny correctly. (4) The effect variance of the general combining ability or the special combining ability of the GMP content of different crosses was very significant, The general combining ability effect variance was larger than that of the special combining ability. The order of the general combining effect value was in a same trend with the order of parent values on the whole. Most of the special combining effect values were negative, most of the average heterosis were negative in effect. The heredity of GMP content trended towards low value parent. (5) The gene inheritance of GMP content was fitted to additive-dominant model and was mainly controlled by additive effect. Dominant effect performed pa- rtial dominance. Recessive allels controlled high GMP content, dominant allels controlled low GMP content. The heritability of GMP content was high, it was lik- ely to gain varieties with higher GMP content by using crossing high parents and s- electing progenies. (6) The difference of GMP content among different varieties was controlled mainly by inheritence. Environment factors had certain influence ott it. The GMP content of wheat kernals could be increasd by breeding high quality varieties and providing with desirable cultivation measure, its quality were improved accordingly.