玉米自交系氮高效指标的筛选及综合评价

以47个玉米自交系为材料,测定玉米自交系在低氮和正常氮处理下株高、穗位高、叶绿素SPAD值、吐丝期叶面积指数、吐丝期干重、全株干重、产量、子粒氮积累量、全株氮积累量和氮肥生产效率等10个指标,以耐低氮指数为参数,结合其变异系数,运用相关性分析、主成分分析和隶属函数法对其氮高效能力进行综合评价。结果表明,叶绿素、全株干重、产量、子粒氮积累量、全株氮积累量和氮肥生产效率等可作为玉米自交系氮高效能力的筛选指标。通过聚类分析,筛选得到PH6WC、郑58、PH6WC×郑58、PH6WC×D1798Z、D1798Z×521、HCL645×C7-2、HCL645×C7-2×单598、外杂二环系、美杂二环系×郑58、DH351×郑58、XL21×PH6WC共11个低氮高效型玉米自交系。

Indexes Screening and Evaluation for Nitrogen Use Efficiency in Maize Inbred Lines

This research was carried out with 47 maize inbred lines as test materials under no nitrogen(N0,0 kg/ha) and normal nitrogen(N180,180 kg/ha)levels.The values of ten indexes for each inbred line, including plant height, ear height, SPAD value, leaf area index(LAI) at silking stage, plant dry weight at silking and maturity stages, nitrogen uptake in grain, total nitrogen uptake and nitrogen use efficiency in grain production(NGPE) at maturity stage, were evaluated by correlation analysis, principal component analysis and membership function method, combined with the variation of coefficient. The results showed that SPAD value, total dry weight, yield, nitrogen uptake in grain, total nitrogen uptake and NGPE were recommended as screening indexes for nitrogen use efficient. Thus using clustering analysis, 11 maize inbred lines were determined as materials with higher nitrogen use efficiency at low nitrogen level.