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为研究旱地冬小麦品种更替过程中产量与光合特征对群体大小的响应,选择1940-2004年先后培育的7个冬小麦品种,于2011-2012年在陕西长武农业生态试验站进行田间试验,并设置3个播种密度(100、250、350粒/m~2)。在所有密度处理中,子粒产量均随着品种的更替而呈线性增长,年均遗传增益在0.65%到1.29%之间。1980年后培育的小麦品种的产量对于播种密度更不敏感,具备更好的群体调节能力。现代品种收获指数和千粒重的提高与其产量的提升呈显著正相关。品种更替过程中花期旗叶净光合速率和叶面积指数持续增长,并提高千粒重,最终增加产量。花期时冠层下可见天空比随着品种更替呈显著下降趋势。在黄土高原的冬小麦育种工作中,应将耐密性、大库容、高光效的理想株型作为重要的筛选指标。
In order to study the response of yield and photosynthetic characteristics of winter wheat cultivars to the population size in dryland, 7 winter wheat cultivars cultivated in succession from 1940 to 2004 were selected to carry out field experiments in Changwu Agricultural Ecology Experimental Station in Shaanxi Province from 2011 to 2012, 3 sowing density (100,250,350 grains / m ~ 2). In all density treatments, the grain yield increased linearly with the variety alternation, with an average annual genetic gain of 0.65% to 1.29%. The yield of wheat cultivated after 1980 is less sensitive to seeding density and has better population regulation. The improvement of harvest index and 1000-grain weight of modern cultivars was positively correlated with the increase of yield. During the process of variety alternation, the net photosynthetic rate and leaf area index of flag leaf continued to increase, and the 1000-grain weight was increased, which eventually increased the yield. During the flowering period, the visible sky ratio decreased significantly with the variety alternation. In the winter wheat breeding work in the Loess Plateau, the ideal plant type with tight tolerance, large storage capacity and high light efficiency should be taken as an important screening index.