239份长果种黄麻种质资源萌发期耐镉性评价及耐镉资源筛选

Evaluation of cadmium tolerance in germination stage of 239 dark jute (Corchorus olitorius L.) germplasm resources and screening of cadmium tolerance resources

镉污染是重金属污染中最严重的类型之一,筛选耐镉性强的黄麻种质资源对改良土壤环境有重要意义。为鉴定评价长果种黄麻种质资源萌发期耐镉性,本研究对239份来源不同的长果种黄麻种质萌发期进行0 mg L^(-1)、5mgL^(-1)和25 mg L^(-1)镉胁迫处理,测定计算发芽率、发芽势、根长、芽长、发芽指数、活力指数和相对镉害率等7个指标,结果显示对照组和处理组的7个指标间存在不同程度的差异。采用主成分分析、隶属函数分析和系统聚类分析等综合分析方法对长果种黄麻萌发期耐镉性进行综合评价,将239份长果种黄麻种质资源依据D值大小划分成5类:镉敏感型材料72份、镉较敏感材料52份、中度耐镉材料56份、耐镉材料50份、高耐镉材料9份,其中以CoODKCG为代表的9份高耐镉材料可作为长果种黄麻耐镉育种的优异种质资源。通过逐步回归分析方程建立5mgL^(-1)与25 mg L^(-1)胁迫下长果种黄麻耐镉性综合评价数学模型:D_(1)=0.029+0.060×GR+0.036×GI+0.122×VI+0.066×RL+0.148×BL+0.047×RCDR(R_(1)^(2)=0.833),D_(2)=0.064+0.098×GR+0.146×GI+0.133×VI+0.113×RL+0.087×BL+0.056×RCDR(R_(2)^(2)=0.801)。结合主成分分析、相关性分析和逐步回归分析筛选出发芽指数、活力指数和根长作为长果种黄麻萌发期综合耐镉鉴定指标。本研究为长果黄麻耐镉品种的培育和优异基因资源的挖掘奠定了基础。

Cadmium is one of the most serious types of heavy metal pollution.It is of great significance to screen the germplasm resources of dark jute(Corchorus olitorius L.)with high tolerance cadmium varieties to improve the soil environment.In order to identify and evaluate the cadmium tolerance of dark jute germplasm resources at germination stage,239 dark jute germplasm resources from different sources were subjected to cadmium stress treatment at germination stage of 0,5,and 25 mg L^(-1).The germination rate,germination energy,root length,shoot length,germination index,vital index,and relative cadmium damage rate were measured at germination stage.The results showed that there were different degrees between the control group and the treatment group.Principal component analysis,membership function analysis,and systematic cluster analysis were used to com-prehensively evaluate the cadmium tolerance of dark jute varieties at germination stage.239 dark jute germplasms were clustered into five grades according to D-value including 72 cadmium sensitive materials,52 sensitive materials,56 medium resistance materials,50 cadmium resistance materials,and 9 high cadmium resistance materials.Among them,9 varieties such as CoODKCG had the higher resistance to cadmium,which could be used as excellent resources for dark jute germplasms.A com-prehensive evaluation mathematical model[D_(1)=0.029+0.060×GR+0.036×GI+0.122×VI+0.066×RL+0.148×BL+0.047×RCDR(R_(1)^(2)=0.833),D_(2)=0.064+0.098×GR+0.146×GI+0.133×VI+0.113×RL+0.087×BL+0.056×RCDR(R_(2)^(2)=0.801)]for the comprehen-sive evaluation of cadmium tolerance in dark jute was established by the stepwise regression analysis.Combined with principal component analysis,correlation analysis,and stepped-regression analysis,selected the germination index,vigor index,and root length as the comprehensive cadmium tolerance indexes of dark jute at germination stage.This study laid a foundation for the evaluation and screening of cadmium tolerance in dark jute.