大豆种质资源高温敏感性差异分析与优异种质筛选OA

High temperature severely constrains soybean growth and development,leading to significant yield losses.The development of high-temperature tolerant cultivars necessitates the identification of elite germplasm with such tolerance.Here,under natural conditions,comparative field experiments were conducted in Hefei(high-temperature treatment)and Xuzhou(control)from 2018 to 2020.A total of 608 soybean germplasm accessions were systematically evaluated for phenotypic variation in plant height,pod height at bottom,number of nodes on main stem,effective branch number,pod number per plant,seed weight per plant and 100-seed weight.The results showed that temperature was the major factor responsible for trait differences between the two locations,particularly affecting effective branch number,seed weight per plant and 100-seed weight.High temperature sensitivity among accessions was assessed by calculating high-temperature response coefficients(HTRC)and integrating principal component analysis,fuzzy membership function analysis and cluster analysis.Compared with the control group,the high temperature group exhibited a highly significant increase in the number of nodes on main stem.However,pod height at bottom,effective branch number,pod number per plant,seed weight per plant,and 100-seed weight decreased highly significantly.Based on HTRC,six traits were transformed into three principal components by principal component analysis,with a cumulative contribution rate of 74.23％.A comprehensive evaluation value(T value)was then calculated according to the weights of the principal components.Cluster analysis classified the 608 accessions into five sensitivity classes:extremely sensitive(9 accessions),slightly sensitive(123 accessions),moderately sensitive(309 accessions),mildly sensitive(158 accessions),and non-sensitive(9 accessions).Notably,foreign high temperature tolerance germplasms,including Kanto 102,Suzumaru,Bedford,and PI80828-1 were identified as insensitive to high temperature.These results provide valuable germplasm resources and a theoretical basis for breeding new heat-tolerant soybean cultivars.