以29份“吉单”号玉米杂交种为材料，以先玉335(耐低氮)为对照，在正常氮和低氮水平处理下进行苗期水培试验，测定根部和生物量相关的14个指标。利用耐低氮系数进行相关性分析、主成分分析、聚类分析和回归分析等方法鉴定和筛选具有耐低氮特性的玉米杂交种。结果表明，不同氮处理下，玉米杂交种苗期各项指标均有显著影响，但影响程度在各杂交种和指标间均有不同。主成分分析将14个单项指标转化为4个综合指标，经杂交种耐低氮综合评价，通过聚类分析将供试玉米杂交种分为3种类型，其中，耐低氮型4份、中间型14份、低氮敏感型12份。通过逐步回归分析得出，叶绿素含量、株高、地上部鲜重、地下部鲜重、根尖数和根冠比的耐低氮系数可作为鉴定玉米自交系苗期耐低氮特性的主要指标。

This study used 29 "Jidan" hybrid maize varieties as materials and Xianyu335(low-nitrogen tolerance) as controls. Hydroponics tests were conducted at the seedling stage under normal and low-nitrogen levels, and 14 indexes related to root and biomass were determined. Correlation analysis, principal component analysis, cluster analysis and regression analysis were used to identify and screen maize hybrids with low-nitrogen tolerance. The results showed that all indexes of maize hybrids at the seedling stage were significantly affected, but the degree of influence was different between self-hybrids and indexes. The 14 individual indexes were converted into 4 comprehensive indexes by principal component analysis. After comprehensive evaluation of low-nitrogen tolerance, the tested maize hybrids were divided into 3 types by cluster analysis, among which 4 were low nitrogen tolerant, 14 were intermediate and 12 were low-nitrogen sensitive. The low nitrogen tolerance coefficients of chlorophyll content, plant height, above ground fresh weight, below ground fresh weight, number of root tips and root to shoot ratio can be used as the main indexes to identify the low nitrogen tolerance characteristics of maize inbred lines at the seedling stage.

S513.037

吉林省科技发展计划项目(20210101018JC)、第四批吉林省青年科技人才托举工程项目(QT202016)