大豆苗期耐铝毒特性综合评价及种质筛选

Comprehensive Evaluation of Aluminum Toxicity Tolerance and Screening of Germplasms During Seedling Stage in Soybean

铝毒是酸性土壤中一种主要的非生物胁迫,严重影响大豆的生长与产量形成,筛选耐铝毒大豆种质对耐铝毒研究具有重要意义。为筛选苗期铝毒处理适宜浓度,采用6种铝离子浓度(0, 50, 100, 150, 200和300μmol·L^(-1))处理7种大豆种质;使用已筛选适宜铝毒浓度处理256份遗传变异广泛的大豆种质,以主根相对伸长率、相对总根长、相对总根表面积、相对平均根直径、相对总根尖数为评价指标,采用相关性分析、主成分分析、隶属函数值和聚类分析方法综合评价各种质苗期耐铝毒性。结果表明:在100μmol·L^(-1)处理下,主根伸长量、总根长分别较对照(0μmol·L^(-1))下降19.10%和32.00%,150μmol·L^(-1)抑制程度过大,选择适宜铝毒处理浓度为100μmol·L^(-1)。铝毒胁迫对不同大豆种质各单项耐铝毒指数存在不同程度影响,与对照相比,主根伸长量、总根长、总根表面积和总根尖数平均值分别下降了33.24%、43.75%、37.52%和42.06%,平均根直径增加了6.05%。基于综合评价值聚类分析,将256份大豆种质分为5个耐性等级,分别为耐铝毒性强种质(23份)、耐铝毒中等种质(53份)、耐铝毒一般种质(128份)、铝毒敏感种质(41份)、铝毒强敏感种质(11份)。本研究筛选出的耐铝毒性强与铝毒强敏感大豆种质,可为大豆耐铝毒性育种和耐性机制研究提供种质资源。

Aluminum(Al) toxicity is a major abiotic stress in acidic soils, which seriously affects the growth and yield formation of soybean. It is great significance for the research of Al toxicity tolerance by screening of Al-tolerant soybean germplasms. In this study, to screen the optimum Al3+concentration during seedling stage, seven soybean germplasms were treated with six different concentration(0, 50, 100, 150, 200 and 300 μmol·L^(-1)). Then, 256 soybean germplasms with extensive genetic variation were treated with the optimum concentration. The relative main root elongation, relative total root length, relative total root surface area, relative average root diameter, and relative total root tip number were used as evaluation indicators for comprehensive evaluation of Al toxicity tolerance during seedling stage by correlation analysis, principal component analysis, principal component analysis and cluster analysis. The results showed that the main root elongation and total root length were respectively decreased by 19.10% and 32.00% under 100 μmol·L^(-1)compared with the control(0 μmol·L^(-1)), and 150 μmol·L^(-1)inhibited too great, so 100 μmol·L^(-1)was the optimum concentration for germplasms treatment. Al toxicity stress had different degrees of influence on the individual Al tolerance index of different soybean germplasms at seedling stage. Compared with the control, the main root elongation, total root length, total root surface area, total root tip number decreased by 33.24%, 43.75%, 37.52% and 42.06%, and the average root diameter increased by 6.05%. Based on the cluster analysis of comprehensive evaluation values, 256 soybean germplasms were divided into five tolerance grades, which were the strong Al toxicity tolerance germplams(23 accessions), the medium Al toxicity tolerance germplams(53 accessions), the normal Al toxicity tolerance germplams(128 accessions), the Al toxicity sensitive accessions(41 accessions), and the highly Al toxicity sensitive accessions(11 accessions). In this study, the soybean germplasms with strong aluminum toxicity resistance and strong aluminum toxicity sensitivity was screened, which can provide germplasm resources for the breeding and resistance mechanism study of aluminum toxicity of soybean.