52份豌豆种质萌发期耐铝毒性的综合评价与筛选

随着土壤酸化的日益加重,铝毒成为影响作物种子萌发质量以及产量的重要胁迫因子之一。本研究采用单项耐铝毒系数(AC值)、综合耐铝毒系数(CAC值)、平均隶属函数值(ASF值)、耐性综合评价值(A值)等指标及相关分析、主成分分析、聚类分析和逐步回归分析等方法,综合评价豌豆种质萌发期铝毒耐性,建立综合筛选评价体系,并筛选萌发期耐铝毒豌豆种质。利用筛选出的适宜浓度40 mg L–1Al3+处理52份豌豆品种(系)种子,结果显示,萌发期8个相关性状在处理组及对照组品种间均存在显著差异,遗传多样性指数分别介于1.43～2.03和1.51～2.06之间。基于AC值聚类分析, 52份豌豆种质可被分为3个耐性级别,其中,第I级含2份,为耐铝毒品种(系);第II级含19份,为敏感品种(系);第III级含31份,为铝毒极敏感性品种(系)。利用豌豆种子发芽率、发芽势、发芽指数、芽长、根长、芽干重、根干重7项指标,结合最优回归方程可初步鉴定豌豆萌发期耐铝毒特性。通过综合评价和聚类分析,筛选出萌发期铝毒耐性极强的种质C175和C145,可作为豌豆铝毒耐性育种和耐性机制研究的重要资源。

Screening and comprehensive evaluation of aluminum-toxicity tolerance during germination stage in 52 varieties (lines) of pea germplasm

With increasing acidification of soil, aluminum toxicity has become one of the important stress factors affecting seed germination quality and crop yield. The purpose of this study is to explore the characteristics of aluminum toxicity tolerance in different genotypes of Pisum sativum, and establish the comprehensive evaluation system for screening and breeding new varieties with aluminum toxicity tolerance. The identification of tolerance at germination stage was performed according to the comprehensive tolerance coefficient of aluminum toxicity (CAC) value, the average subordinate function value (ASF value), the comprehensive evaluation value of aluminum toxicity tolerance (A-value) in correlation analysis, frequency analysis, principal component analysis, cluster analysis and stepwise regression analysis. Fifty-two pea varieties collected from different places were treated with 40 mg L ^-1 Al ³⁺ screened in the pretest. There were significant differences between treatment and control groups in germination rate, germination energy, germination index, root length, bud length, root dry weight, bud dry weight, root-shoot ratio, and the genetic diversity index ranging from 1.43-2.03 and 1.51-2.06, respectively, showing extensive genetic variation. Cluster analysis was carried out based on A value, exhibiting that the tested cultivars were roughly divided into groups with three aluminum toxicity tolerance grades. The first group including two varieties is tolerant to aluminum toxicity, the second group including 19 varieties is sensitive to aluminum toxicity, and the last group containing 31 other varieties is very sensitive to aluminum toxicity. Combined with the optimal regression equation, seven indexes of pea seed germination rate, germination potential, germination index, bud length, root length, bud dry weight and root dry weight were used to comprehensively evaluate and identify the aluminum toxicity tolerance of pea during germination period. Through comprehensive evaluation and cluster analysis, germplasm C175 and C145 were screened out with strong tolerance to aluminum toxicity in germinating stage, which can be used as important resources for breeding near varieties and studying the mechanism of tolerance to aluminum toxicity in pea.