小麦大拇指矮的穗发芽抗性研究

Study on Preharvest Sprouting Resistance of Tom Thurmb in Wheat

以小麦大拇指矮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 8.2 6 %、 1 1 .4 7%和 56 .37%、 6 6 .87%。群体中穗发芽率分离明显 ,赤霉酸反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芽率高。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 .6 56 2、 0 .81 0 3和0 .6 4 35、 0 .8581和 0 .892 8,均达极显著水平。Rht3、Gai3通过降低 α-淀粉酶活性而增强了抗穗发芽性。

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.