小麦大拇指矮的穗发芽抗性研究

以小麦大拇指数的近等基因系及其分离群体为材料，分析了大拇指矮的矮秆基因Ｒht3和赤霉酸不敏感基因Gai3对穗发芽的影响，结果表明Ｒht3和Gai3与抗穗发芽密切相关，高矮亲本间穗发芽差异明显，矮扬３和矮苏３及它们的轮回亲本的穗发芽率分别为８．２６％、１１．４７％和５６．３７％、６６．８７％、。群体中穗发芽率分离明显，赤霉酸拓应不敏感的矮秆和半矮秆类型植株穗发芽率低，赤霉酸反应敏感的高秆类型植株穗发牙率高，两分离群体中株高、赤霉酸反应、α淀粉酶活性与穗发芽率的相关系数分别为０．８５８５和０．６５６２、０．８１０３和０．６４３５、０．８５８１和０．８９２６８，均达极显著水平，Ｒht3、Gai３通过低α－淀粉酶活性而增强了抗穗发芽性。

Study on Preharvest Sprouting Resistance of Tom Thurmb in Wheat

Near isogenic lines from Tom Thurmb and their segregating populations were analyzed for resistance to preharvest sprouting resulted from dwarf gene Rht3 and gibberellic acid insensitive gene Gai3. The result showed that Rht3 and Gai3 were closely associated with preharvest sprouting resistance. Resistance to preharvest sprouting was apparently different in parents.The germinating percentage of dwarf Yangmai3 and dwarf Sumai3 were 8.26% and 11.47%,and the percentage of their recurrent parent Yangmai3 and Sumai3 were 56.37% and 66.87%,respectively.Germinating percentage in segregating populations also showed differently.Dwarf or semidwarf plants with gibberellic acid insensitivity exhibited lower sprouting percentage,but the tall plants of gibberellic acid sensitivity had high sprouting percentage.Correlation coefficients between plant height,gibberellic acid,α-amylase activity and preharvest germinating percentage in two segregating population were 0.8585 and 0.6562, 0.8103 and 0.6435, 0.8585 and 0.8928 at dominantly significant level. Rht3 and Gai3 could reduce α-amylase activity and hence enchanced the resistance to preharvest sprouting.