80份国际马铃薯中心引进的马铃薯种质资源抗旱性鉴定及评价指标的筛选

Identification of drought resistance and screening of evaluation indexes of 80 potato germplasm resources introduced by CIP

【目的】中国马铃薯种质资源相对缺乏,遗传背景单一,亲缘关系较近是制约我国马铃薯种质创新与优良新品种选育的重要原因。此外,干旱是马铃薯(Solanum tuberosum L.)生产的主要影响因素之一。因此,筛选出优良且抗旱的种质资源不仅能够有效应对干旱带来的马铃薯生产挑战,也将为解决中国马铃薯遗传背景狭窄和种质资源短缺提供重要的解决途径。【方法】以从国际马铃薯中心(CIP)表型观测评价的TON panel约300份高世代品系种质资源中筛选出80份表现良好的四倍体种质资源为试验材料,于甘肃省定西市马铃薯研究所进行田间试验,对正常灌溉(CK)和干旱处理(D)下的15个主要农艺性状、产量性状和品质性状进行测定。利用相关性分析、主成分分析、隶属函数分析、聚类分析和逐步回归等分析方法对80份马铃薯种质资源的抗旱性进行综合评价。【结果】通过计算各单项指标的抗旱系数(PI)和变异系数(CV)筛选到12个代表性指标进行后续分析。通过主成分分析,将12个单项指标的抗旱系数转换为6个相互独立的综合指标(累计贡献率达80.45%),根据综合评价值(D值)和聚类分析,可将80份马铃薯种质资源材料分为3类:B20、B40、B55等9个品系属于I类高度抗旱类型;B32、B77、B28等62个品系属于Ⅱ类中度抗旱类型;B73、B42、B19等9个品系属于Ⅲ类低抗类型。进一步利用逐步回归分析建立了抗旱性评价回归模型Y=-0.138+0.198PH+0.080RL+0.109LAI+0.144RFW+0.162TDW+0.079RSC(R2=0.917,P=0),估计精度均在86.6%以上,表明该模型可用于马铃薯抗旱种质资源筛选。【结论】B20、B40、B55等9个品系为高度抗旱品系,可作为优良的杂交亲本选育马铃薯抗旱品种。株高、总根长、叶面积指数、根总鲜重、单株薯块干重、还原糖含量可作为快速筛选抗旱马铃薯种质资源的预测指标,使马铃薯抗旱性评价鉴定工作更为便捷。

[Objective]The primary constraints that restricted the development and innovation of potato germplasm includes the relative scarcity of germplasm resources,the homozygous genetic background,and the close genetic relationships.In addition,drought poses a major threat to potato(Solanum tuberosum L.)production.Therefore,the selection of superior and drought-resistant germplasm resources can not only effectively deal with the challenges of potato production brought by drought,but also provide an important solution for alleviating the narrow genetic background and germplasm resource shortage of Chinese potato.[Method]In this study,80 tetraploid germplasm resources with good performance were selected from about 300 high-generation germplasm resources of TON panel evaluated by International Potato Center(CIP)phenotypic observation as experimental materials,and field experiments were conducted in Dingxi Potato Research Institute,Gansu Province.15 main traits including agronomic,yield and quality were measured under normal irrigation(CK)and drought treatment(D)condition in this study.The drought response levels of the 80 potato germplasm resources were evaluated by correlation analysis,principal component analysis,membership function analysis,cluster analysis and step regression analysis[.Result]12 representative indexes were selected by calculating the drought resistance coefficient(PI)and coefficient of variation(CV)of each index.The drought resistance coefficients of 12 separate variables were converted into 6 independent comprehensive indicators using principal component analysi(the cumulative contribution rate was 80.45%).Based on the comprehensive assessment value(D value)and cluster analysis,the 80 potato accessions were classified into 3 categories,with 9 accessions including B20,B40,B55 etc.clustered in Class I which were highly drought resistant,ClassⅡcontains 62 accessions including B32,B77 and B28,which was identified as moderate drought resistant,whiles ClassⅢconsisted of 9 accessions including B73,B42 and B19 belonging to drought sensitive types.Furthermore,a regression model for drought resistance evaluation was established by stepwise regression analysis,Y=-0.138+0.198PH+0.080RL+0.109LAI+0.144RFW+0.162TDW+0.079RSC(R2=0.917,P=0),and the estimated accuracy was above 86.6%.The results showed that the model could be used for the screening of drought-resistant potato germplasm resources.[Conclusion]Nine strains,including B20,B40 and B55,were highly resistant to drought and can be selected as hybrid parents to breed drought-resistant varieties of potato.Plant height,total root length,leaf area index,total fresh root weight,dry weight of potato block per plant and reducing sugar content can be used as predictive indexes for rapid selection of drought-resistant potato germplasm resources,making it easier to evaluate and identify potato drought resistance.