不同种质资源南瓜苗期耐低钾性鉴定及筛选

Identification and screening of low potassium tolerance of pumpkin seedlings from different germplasm resources

为明确不同种质资源南瓜苗期耐低钾特性,筛选耐低钾南瓜种质资源。本研究以39个南瓜种质资源为材料,采用水培法,分析适钾(6.0 mmol·L^(-1)K^(+))和低钾(0.1 mmol·L^(-1)K^(+))处理下南瓜苗期的12个生长指标和耐低钾系数,并利用多元分析方法对不同南瓜种质资源耐低钾能力进行综合评价。结果表明:除根系干重和根冠比外,不同种质资源南瓜的其他指标变异系数较大。通过主成分分析将12个指标转化成3个相互独立的综合指标,其累计贡献率达91.12%。利用南瓜苗期性状指标和主成分分析结果将地上部鲜重和根系钾积累量作为南瓜苗期耐低钾性评价指标,并基于热图的分层聚类将不同南瓜种质资源分为3类。采用隶属函数分析和聚类分析将39个南瓜种质资源进一步划分为4个类群:耐低钾型、中等耐低钾型、偏弱耐低钾型和低钾敏感型,分别占总南瓜种质资源的5.13%、33.33%、23.08%和38.46%。综合分析来看,TMG0091和CM0091为耐低钾型南瓜, 14个品种为低钾敏感型南瓜。

To clarify the low potassium tolerance characteristics of different germplasm resources of pumpkin(Cucurbita moschata) at seedling stage, the germplasm resources of low potassium tolerance pumpkin were screened. In this study, 39 pumpkin germplasm resources were used as materials, and 12growth indexes and low potassium tolerance coefficient of pumpkin seedlings under suitable potassium(6.0 mmol·L^(-1)K^(+)) and low potassium(0.1 mmol·L^(-1)K^(+)) treatments were analyzed by hydroponic method.Multivariate analysis was used to comprehensively evaluate the low potassium tolerance of different pumpkin germplasm resources. The results showed that except for root dry weight and root-shoot ratio,the variation coefficient of other indexes of pumpkin from different germplasm resources was larger. The 12 indexes were transformed into three independent comprehensive indexes by principal component analysis, and the cumulative contribution rate was 91.12%. The fresh weight of shoot and K accumulation in root were used as the evaluation indexes of low potassium tolerance of pumpkin seedlings based on the traits of pumpkin seedlings and the results of principal component analysis, and different pumpkin germplasm resources were divided into three categories by hierarchical clustering on heat maps. The 39 pumpkin germplasm resources were further divided into four groups by membership function analysis and cluster analysis: low-potassium tolerance, medium-low-potassium tolerance, weak-low-potassium tolerance and low-potassium sensitivity, accounting for 5.13%, 33.33%, 23.08% and 38.46% of the total pumpkin germplasm resources, respectively. Comprehensive analysis showed that TMG0091 and CM0091 were low-potassium tolerant pumpkins, and 14 varieties were low-potassium sensitive pumpkins.