Genotypic And Ecological Effects On Grain Quality Formation In Winter Wheat

Wheat yield has increased significantly in recent years, yet wheat quality is not simultaneously improved in China. This severely influences production of superior quality wheats and improvement of marketing competitiveness of wheat industry. Quality formation of wheat depends on superior genotype, suitable environment and effective management. Thus, full investigations into the impact of genotype and eco-environment on wheat grain quality are of substantial importance for enriching wheat quality ecology and developing regulation technology of superior wheat production. In the present study, several experiments were conducted under different ecological environments and different sowing dates with the different cultivar types, and genotypic and ecological effects on grain quality formation, inter-relationships and underlying mechanisms were analyzed in the view of accumulation and distribution of carbon and nitrogen in wheat plant. The main results are summarized as follows.In Jiangsu Province, seven typical specialty winter wheat cultivars were sown at six representative ecological sites to investigate the variation in grain quality traits of different cultivars under different environments. All wheat quality traits were significantly affected by the main effects of genotype and environment, and the interactive effects between genotype and environment, except that grain starch content was not affected by the environment. The main effects of genotype on grain protein content and flour falling number were similar to those of environment, but were greater on the other quality traits than those of environment. It was indicated that both genetic improvement and intensive eco-zoning in grain quality were of importance for production of superior specialty wheats in Jiangsu Province. Also, different performances of grain quality traits were not unique at different environments. At Yandu, Jianmai 1 was the only variety qualified for weak gluten wheat, and the others were qualified for mid gluten wheat. Xuzhou 26 expressed mid to strong gluten quality at Xuzhou, but weak gluten quality at Hai'an. This indicates that theexpression of wheat quality in different varieties varies with eco-site, which leads to varied eco-zoning conclusions.Four representative eco-sites were selected in the Huang Huai Hai (3-H) Plain and Lower Yanzi River Plain to study the variation of yield and quality traits under different environments and its relationships with the major climatic factors during grain filling, by using six wheat genotypes differing in grain quality and using different sowing dates. Ecological condition (E), variety (V) and their interaction (EX V) had significant impact on grain yield, thousand kernels weight, contents of grain protein, wet gluten and starch, sedimentation volume, and falling number. At the four experiment sites, sowing dates (S) had highly significant effects on yield and starch content in spite of environment. The interaction of V XS significantly affected thousand kernels weight, falling number, starch content and sedimentation volume, and the interaction of E X V X S was also significant on yield, contents of wet gluten and starch and sedimentation volume. For four different eco-sites, the lowest protein and wet gluten content and the highest starch content were shown in Nanjing, the highest yield and thousand kernels weight were in Xuzhou,, the highest protein and wet gluten contents and lowest sedimentation value were in Tai'an , and the lowest yield and thousand kernels weight and highest sedimentation value were in Baoding. The contents of protein, wet gluten and starch, sedimentation value, and falling number under optimal and late sowing dates were all higher than those under early sowing date, which produced the highest yield and thousand kernels weight. For six different genotypes, the CV of falling number was largest and that of starch content was smallest under different eco-sites and sowing dates. Starch content was negatively linearly correlated, while grain yield, contents of grain protein and we...