耐低钾山羊草基因型的筛选与鉴定

为研究小麦近缘属种的耐低钾特性,分析不同山羊草(Aegilops)耐低钾胁迫下各生理指标的差异,筛选和鉴定耐低钾基因型。本试验通过砂培法,以9种不同基因型山羊草为供试材料,采用改进的Hoagland营养液,设低钾(0.02mmol·L~(-1) KCl)和正常供钾(2.0mmol·L~(-1) KCl)两个水平进行试验。对相对根冠比、相对根长、相对地上部干重、相对钾积累量和相对钾利用效率5个指标进行相关分析和主成分分析,筛选出3个综合指标进行山羊草耐低钾基因型的鉴定。结果发现,不同基因型山羊草对低钾胁迫存在显著的差异。地上部干重、钾积累量和钾利用效率可以作为苗期耐低钾种质筛选的重要指标。综合评价结果表明:双角山羊草(Ae.bicornis)、偏凸山羊草(Ae.ventricosa)、粗厚山羊草(Ae.crassa)、拟斯卑尔托山羊草(Ae.speltoides)、尾状山羊草(Ae.caudata)、粘果山羊草(Ae.kotschyi)、易变山羊草(Ae.variabilis)、欧山羊草(Ae.biuncialis)、小伞山羊草(Ae.umbellulata)的综合评价值(D值)分别为0.383,0.898,0.327,0.516,0.007,0.682,0.338,0.346,0.655。由此可知,其中偏凸山羊草耐低钾胁迫能力最强,其次是粘果山羊草,尾状山羊草耐低钾胁迫能力最弱。通过本试验,初步建立了山羊草耐低钾种质的评价指标,为进一步研究山羊草的耐低钾分子机制,以及小麦育种上利用耐低钾山羊草种质提供了材料和理论依据。

Screening and Identification of Aegilops Germplasm for Tolerance to Low Potassium Stress

Nine different genotypes of Aegilops were used to study the low potassium tolerance and the differences of physiological indexes in low potassium stress.Under two levels of low potassium (0.02 mmol · L-1 KCl) and normal potassium (2.0 mmol · L-1 KCl),the correlation analysis and principal component analysis of five indexes,namely the relative values of root length,dry weight,potassium accumulation and potassium use efficiency were carried out.Three comprehensive indexes were screened for the identification of the low potassium tolerance of Aegilops.The results showed that there were significant differences in the low potassium tolerance among Aegilops.In seedling stage,the dry weight,potassium accumulation and potassium use efficiency could be used as the important indicators of low potassium tolerance.Comprehensive evaluation showed D values of the Ae.bicornis,Ae.ventricosa,Ae.crassa,Ae.speltoides,Ae.caudata,Ae.kotschyi,Ae.variabilis,Ae.biuncialis,and Ae.umbellulata were 0.383,0.898,0.277,0.516,0.007,0.682,0.388,0.336 and 0.655,respectively.So Ae.ventricosa had the strongest ability of low potassium tolerance.The next was Ae.kotschyi,and the last was Ae.caudata.Evaluation indexes of the low potassium tolerance of Aegilops were preliminarily established in this study.It will provide the low potassium tolerance germplasm of Aegilops for wheat breeding,and theoretical basis for the further study of molecular mechanism of low potassium tolerance of Aegilops.