甘蓝型油菜种质萌发期耐砷性综合评价与筛选

Comprehensive Evaluation and Screening of Arsenic Toxicity Tolerance at Germination Stage in Brassica napus

为了探究重金属砷对不同基因型甘蓝型油菜种子萌发期的影响,选育出萌发期耐砷毒的甘蓝型油菜种质资源。本研究利用不同遗传来源的甘蓝型油菜品种(系)为材料,通过对萌发期油菜耐砷性单项指标系数(AC)、平均隶属函数值(ASF值)及砷毒耐性综合评价值(A值)等指标进行相关性分析、主成分分析、逐步回归方程和聚类分析,以获得萌发期耐砷性油菜品种(系),并建立综合耐砷评价体系对材料耐砷性进行鉴定。本试验测定5份供试材料在不同浓度As3+处理下的根长,以不同品种(系)间根长变化差异性为基础,基于方差分析确定最佳处理浓度为15 mg/L;在15 mg/L浓度处理下,发现134份甘蓝型油菜的根长、下胚轴长、鲜重、干重、株高和含水量6个指标均达到差异显著性,并存在不同程度的相关性。研究发现,通过主成分和逐步回归方程分析,根长、下胚轴长和株高可作为有效快速评价甘蓝型油菜萌发期耐砷性的重要指示性状。基于A值聚类分析可将供试种质划分为4类耐性等级,筛选到B472、B358和B4503份材料为强耐砷性品种。本试验将为萌发期甘蓝型油菜高耐砷性分子机理研究和育种材料筛选提供重要的研究基础。

In order to explore t he effects of heavy metal arsenic on seed germination of different genotypes of Brassica napus,germplasm resources resistant to arsenic were selected.In this study,we used rapeseed varieties(lines)of different genetic origins as materials,the rapeseed varieties(lines)with high arsenic tolerance in germination period were obtained by correlation analysis,principal component analysis,stepwise regression equation and cluster analysis of single index coefficient(AC),average subordinate function value(ASF value)and comprehensive evaluation value(A value)of arsenic tolerance;and a comprehensive arsenic resistance evaluation system was established for identifying the arsenic resistance of rapeseed during seed germination.Firstly,in this experiment,the root length among five rapeseed varieties(lines)under different arsenic treatment was measured.Based on the variation of root length among different varieties(lines),the optimal treatment concentration was determined to be 15 mg/L based on variance analysis.Subsequently,we investigated the germination parameters of 134 rapeseed germplasm,including root length,hypocotyls length,fresh weight,dry weight,plant height and water contents,which showed the significant differences and positively correlation.It was found that the root length,hypocotyls length and plant height could be suitable evaluation and identification indexes to evaluate the arsenic tolerance of rapeseed during germination by principal component analysis and stepwise regression equation analysis.Additionally,all tested germplasm could be divided into 4 types of tolerance grades according to the A-value,of these,B472,B358 and B450 were selected as strong arsenic resistant varieties.This experiment would provide an important research basis for the study of molecular mechanism of high arsenic tolerance and breeding utilization screening of rapeseed.