14份木薯种质的苗期耐旱性评价

Evaluation of cassava germplasm(14 cultivars) for drought tolerance at seedling stage

采用盆栽试验,比较水分胁迫下14份木薯种质苗期的耐旱性强弱。通过主成分分析、聚类分析、相关分析等方法,得出了14份木薯种质过氧化物酶（POD）活性、可溶性蛋白（Pr）含量、丙二醛（MDA）含量、游离脯氨酸（Pro）含量及株高、茎径等6个指标对应的耐旱系数变幅分别为0.14-4.00、0.12-3.28、0.55-1.76、0.33-1.70、0.68-1.09、0.62-1.05;按6个指标与综合主成分F值的相关系数排序,6个指标从大到小依次为POD活性、Pr含量、株高、Pro含量、茎径、MDA含量,其中,POD活性、Pr含量与F值呈极显著正相关,POD活性与Pr含量也呈极显著正相关。经综合比较,推荐将POD活性和Pr含量作为木薯幼苗耐旱性的主要评价指标。

Through potted plant experiments, drought tolerance of 14 cassava cultivars at seedling stage under water stress was measured. Comprehensive principal components analysis, cluster analysis and correlation analysis showed that the drought tolerance coefficient （DTC） of peroxidase （POD） activity, soluble protein content （Pr） content, malondialdehyde （MDA） content, free proline （Pro） content, plant height and stem diameter were 0.14-4.00, 0.12-3.28, 0.55-1.76, 0.33-1.70, 0.68-1.09 and 0.62-1.05, respectively. POD activity showed the largest correlation coefficient with F value （the comprehensive analysis）, followed by Pr content, plant height, stem diameter, Pro content and MDA content. POD activity and Pr content were very significantly positive correlated to F value, and there was very significantly positive correlation between POD activity and Pr content. After comprehensive comparison, POD activity and Pr content were recommended as the main indexes for evaluation of drought tolerance of cassava seedlings.