摘要

缺水是世界上一些马铃薯种植区的主要制约因素。缺水影响在块茎化阶段最为严重，导致产量降低。因此，为了加速育种工作，需要对哥伦比亚种质中因缺水而产生的遗传和表型变异进行评估。研究了马铃薯群体中因缺水而产生的表型变异。利用哥伦比亚国立大学马铃薯育种项目工作收集的104个基因型进行了块茎形成阶段的逐步缺水试验。通过相对叶绿素含量（CC）、PSII最大量子效率（Fv/Fm）、相对含水量（RWC）、叶片含糖量、单株块茎数（TN）和单株块茎鲜重（TW）来评估对水分亏缺条件的反应。采用主成分分析（PCA）和聚类分析，计算变量和基因型的耐旱指数（DTI）。叶片可溶性糖含量在亏缺条件下显著增加，在两种水分处理下与产量的相关性较弱。主成分分析结果显示，生理、生化和产量构成变量具有广泛的变异，而产量构成变量比生理和生化变量更能区分耐病基因型和感病基因型。基于DTI的主成分分析和聚类分析揭示了104个基因型的不同耐水性水平。这些结果为今后研究马铃薯耐水分亏缺的分子机制提供了基础。 

关键词：产量构成——水分亏缺；耐水分亏缺；糖分积累——水分不足；二倍体马铃薯；耐旱指数

Physiological, Biochemical and Yield-Component Responses of Solanum tuberosum L. Group Phureja Genotypes to a Water Deficit 

Abstract

Water deficits are the major constraint in some potato-growing areas of the world. The effect is most severe at the tuberization stage, resulting in lower yield. Therefore, an assessment of genetic and phenotypic variations resulting from water deficits in Colombia germplasm is required to accelerate breeding efforts. Phenotypic variations in response to a water deficit were studied in a collection of Solanum tuberosum Group Phureja. A progressive water deficit experiment on the tuberization stage was undertaken using 104 genotypes belonging to the Working Collection of the Potato Breeding Program at the Universidad Nacional de Colombia. The response to water deficit conditions was assessed with the relative chlorophyll content (CC), maximum quantum efficiency of PSII (Fv/Fm), relative water content (RWC), leaf sugar content, tuber number per plant (TN) and tuber fresh weight per plant (TW). Principal Component Analysis (PCA) and cluster analysis were used, and the Drought Tolerance Index (DTI) was calculated for the variables and genotypes. The soluble sugar contents increased significantly under the deficit conditions in the leaves, with a weak correlation with yield under both water treatments. The PCA results revealed that the physiological, biochemical and yield-component variables had broad variation, while the yield-component variables more powerfully distinguished between the tolerant and susceptible genotypes than the physiological and biochemical variables. The PCA and cluster analysis based on the DTI revealed different levels of water deficit tolerance for the 104 genotypes. These results provide a foundation for future research directed at understanding the molecular mechanisms underlying potato tolerance to water deficits.  

Keywords: yield component–water deficit; water deficit tolerance; sugar accumulation–water-deficit; diploid potato; Drought Tolerance Index