小豆种质资源苗期抗旱性评价及抗旱资源筛选

Drought Resistance Evaluation of Adzuki Bean Germplasm at Seedling Stage and Screening of the Drought-resistant Resources

为了探讨小豆苗期抗旱性特点,建立抗旱性鉴定指标评价体系,筛选抗旱基因型材料,本研究以苗期盆栽控水方式,对不同来源的235份小豆种质资源进行了干旱胁迫试验。在测定其根系形态、株高、生物量和冠层萎蔫等15项指标的基础上,利用隶属函数值法、主成分分析和聚类分析对抗旱性进行了综合评价。结果表明,干旱胁迫条件下主根长、侧根长、总根长和根冠比值均比对照组高;主根表面积、侧根表面积、总根表面积、主根体积、侧根体积、总根体积、地上部干重、地下部干重、整株干重和株高值均低于对照组。各性状隶属函数值相关性分析表明隶属函数值平均值与总根表面积相关性最大。主成分分析将15个性状归纳成3个主成分(累积贡献率为82.8%),其中第Ⅰ主成分的载荷主要是根表面积,第Ⅱ主成分的载荷主要是干重,第Ⅲ主成分的载荷主要是主根长。聚类分析将235份小豆种质资源聚成抗旱型、中间型和敏感型3类,分别占供试材料的8%、63%、29%。根据隶属函数值法和主成分分析法结合不同类型根系形态,可将总根表面积作为小豆苗期抗旱性评价的主要指标。初步筛选出15份小豆耐旱资源材料,为进一步开展小豆抗旱育种和挖掘抗旱基因提供了基础材料。

To explore drought resistance characteristics of adzuki bean at the seedling stage,235 adzuki bean accessions from different regions were subjected for drought resistance tests upon drought stress treatment by pot cultivation assay.The root morphology,plant height,biomass and canopy wilting were measured,and the statistical analysis was conducted using the subordination function method,principal component analysis(PCA)and cluster analysis.Under drought treatment,the taproot length,lateral root length,total root length,and ratio of shoot dry mass to root dry mass were higher than those of the control groups,but taproot surface area,lateral root surface area,total root surface area,taproot volume,lateral root volume,total root volume,shoot dry mass,root dry mass,plant dry mass and plant height were lower than those of the controls.The correlation analysis on the subordination function values of each trait showed the correlation with the total root surface area.The first three principal components explained 82.8%of the phenotypic variations at 15 traits.The first,second and third principal components were mainly contributed by root surface area,dry mass,and taproot length,respectively.These accessions were classified into three types,composing of drought-resistant,intermediate and droughtsensitive,which accounted for 8%,63%and 29%of total accessions,respectively.According to the subordination function value,principal component analysis and root morphology of different types,the total root surface area served as a major index for the evaluation of drought resistance at the seedling stage.Moreover,15 droughttolerant accessions were identified being valuable for further drought-resistant breeding and gene mining in adzuki bean.