甘蓝型油菜苗期耐酸性综合评价及耐酸种质筛选

Comprehensive evaluation of acid-tolerance and screening of acid-tolerant germplasm in Brassica napus at seedling stage

为探究在酸性土壤环境下油菜苗期耐酸特性,采用盆栽试验对113份油菜品种进行酸胁迫处理和酸性土壤改良处理,在苗期测定根长、株高、地上部鲜质量、根系鲜质量、总鲜质量、地上部干质量、根系干质量、总干质量、根冠比和SPAD共10项性状指标,利用相关性分析、主成分分析、隶属函数法、聚类分析、灰色关联度和逐步回归分析对不同油菜品种进行耐酸综合评价,建立油菜耐酸评价模型并筛选耐酸油菜品种。结果显示:113份油菜品种在2个处理下10个性状均呈现极显著差异;10项指标的变异系数范围为10.09%~78.68%,将10个单项指标转换成4个相互独立的综合指标,代表了原始指标88.688%的信息量;基于113份油菜的耐酸综合评价值(D值)聚类分析,将油菜品种分为5个类群,分别为极耐酸型(2份)、耐酸型(16份)、中间型(41份)、敏感型(50份)、极敏感型(4份);通过D值和10项指标构建最优回归方程:D=-0.075+0.0403X_(总干质量)+0.100X_(根系鲜质量)+0.188XSPAD+0.099X_(株高)+0.092X_(根系干质量)(R^(2)=0.982,F=1154.562^(***)),筛选出适宜的油菜苗期耐酸鉴定指标。综上,酸胁迫会严重抑制油菜苗期的生长,不同油菜品种耐酸性存在较大差异,通过测定总干质量、根系鲜质量、SPAD、株高、根系干质量并结合回归方程可评价判断油菜耐酸性。

In order to explore the characteristics of acid tolerance of rapeseed at the seedling stage in acidic soil environment,113 rapeseed varieties were treated with acid stress and acid soil improvement by pot experiment.10 traits including root length,plant height,shoot fresh mass,root fresh mass,total fresh mass,shoot dry mass,root dry mass,total dry mass,root/shoot ratio and SPAD were measured at the seedling stage.The acid resistance of different rapeseed varieties were evaluated by correlation analysis,principal component analysis,membership function method,cluster analysis,grey correlation degree and stepwise regression analysis,the acid-resistant evaluation model was established and the acid-tolerant rapeseed varieties were screened.The results showed that 113 rapeseed varieties showed extremely significant differences in 10 traits under two treatments.The coefficient of variation of 10 indicators ranged from 10.09%to 78.68%.The 10 indicators were converted into 4 independent comprehensive indicators,representing 88.688%of the information content of the original indicators.Based on the cluster analysis of the comprehensive evaluation value of acid tolerance(D value)of 113 varieties,they were divided into 5 groups,namely,extremely acid-resistant type(2 samples),acid-resistant type(16 samples),intermediate type(41 samples),sensitive type(50 samples)and extremely sensitive type(4 samples).The optimal regression equation was constructed using D value and 10 indicators:D=-0.075+0.0403X_(total dry weight)+0.100X _(root fresh weight)+0.188XSPAD+0.099X_(plant height)+0.092X_(root dry weight)(R^(2)=0.982,F=1154.562^(***)),and the suitable identification index of acid tolerance in rapeseed at seedling stage was screened out.In conclusion,acid stress could seriously inhibit the growth of rapeseed at the seedling stage,and there were great differences in acid tolerance among different rapeseed varieties.The acid tolerance of rapeseed could be evaluated by measuring total dry mass,root fresh mass,SPAD,plant height,root dry mass and combining with regression equation.