^(60)Co-γ辐射小麦M_3代种子和幼苗抗旱性的变异

Studies on Variation to Drought Resistance of Wheat M_3 Population Radiated by ^(60)CO-γ Ray at Seedling Stage

为了探讨利用物理诱变技术创制小麦抗旱种质资源的可行性,采用60 Co-γ射线辐射诱变小麦品种涡9722,用30%PEG-6000溶液模拟干旱胁迫,对227个M3代株行进行发芽试验和幼苗生长试验,测定发芽指标和幼苗的生长指标、生理指标。结果表明,发芽势、发芽率、发芽指数、苗高、叶数、根数、主根长、根干重、地上部分干重、根冠比、根含水率、苗含水率、脯氨酸含量、可溶性糖含量、叶绿素含量等15个指标在M3代株行间差异极显著。以综合抗旱系数评价抗旱性,M3群体株行抗旱性的变异倾向于正偏态分布,抗旱性低于亲本的株行占61.2%,高于亲本的株行占38.8%。以超过M3群体株行综合抗旱系数均值±2×标准差筛选变异株行,有9个株行发生正向变异,其中株行176的综合抗旱性表现突出,抗旱萌发和抗旱生长的能力均较好。用类平均法对227个M3代株行进行聚类,当遗传距离为1.59时,M3代株行的抗旱性变异类型可分为6大类。

To explore the drought resistant resources of wheat innovated by physical mutation,the 227 M3 lines of Wheat GUO 9722 irradiated by ^60Coγ-ray were treated under drought stress in 30% PEG-6000 solution at germination and seedling stages,the traits of germination,seedling growth and physiology were tested.The results showed that there were significant variations in the germination potentiality,germination rate,germination index,plant height,leaf number,root number,main root length,root dry weight,shoot dry weight,root/shoot ratio,root moisture content,shoot moisture content,proline content,soluble sugar content and chlorophyll content among the 227 M3 lines.The complex drought resistance coefficient was used to identify the drought resistance of the M3 lines;the variation of M3 population tends to be positive normal distribution.The drought resistance of 61.2% M3 lines were less than that of wild type,and the drought resistance of 38.8% M3 lines were higher than that of wild type.According to the mean±2×standard deviation of complex drought resistance coefficient of M3 population,positive variation occurred in 9 lines.Line 176 was significant performance in drought resistance with better seed germination and seedling growth under drought stress.The cluster analysis showed that when the genetic distance was set at 1.59,the 227 lines of M3 could be divided into 6 groups.