甘蓝型油菜种质氮素营养效率的鉴定及评价指标筛选

为建立甘蓝型油菜种质氮素营养效率的鉴定及评价方法，筛选合理的次级评价指标和氮素营养高效基因型，在田间小区试验条件下设置低氮(45 kg/hm2)、中氮(180 kg/hm2)和高氮(270 kg/hm2) 3个施氮水平，测定了416份不同生态类型甘蓝型油菜种质植株性状及氮素吸收效率(NAE)、氮素利用效率(NUE)和氮收获指数(NHI)。各性状在不同氮素水平下对氮的敏感性不同，低氮下第一次有效分枝数的变异程度表现为最大，单株籽粒重次之；中氮和高氮处理水平下单株籽粒重的变异程度均表现为最大，低氮胁迫加大了种质间的差异。油菜种质氮素营养效率基因型间差异明显，表现中效类型的种质最多，高效和低效的较少。油菜种质间成熟期NAE的鉴定与评价应选择在低氮处理下，以单株籽粒重、单株地上干重和株高为间接指标进行选择效果明显；油菜种质间成熟期NUE的鉴定与评价应选择在高氮处理下，以单株地上干重、第一次有效分枝数、单株籽粒重和每角粒数为间接指标进行选择效果明显；油菜种质间成熟期NHI的鉴定与评价应选择在低氮处理下，以单株籽粒重、单株地上干重和茎基粗为间接指标进行选择效果明显。

Identification and evaluation of nitrogen nutrition efficiency in rapeseed germplasms

To establish an efficient identification and evaluation method of rapeseed nitrogen nutrition efficiency. A field experiment was conducted using 416 germplasm accessions under 3 nitrogen levels (45, 180, 270 kg/hm2). 15 traits were measured to assess variations of nitrogen nutrition efficiencies including nitrogen absorption efficiency(NAE), nitrogen utilization efficiency (NUE) and nitrogen harvest index (NHI). The sensitivity of different traits to different nitrogen levels was different. Genetic variations of effective branch number under low nitrogen treatments(45 kg/hm2) were the greatest, genetic variations of seed weight per plant under low nitrogen treatments(45 kg/hm2) were the second greatest. Genetic variations of seed weight per plant under medium nitrogen (180 kg/hm2) and high nitrogen (270 kg/hm2) treatments were the greatest. Under low nitrogen stress, the differences increased among the accessions. Nitrogen nutrition efficiency of rapeseed genotypes at maturity stage existed significant difference. Distribution patterns showed that both high and low efficiency materials were few. Low nitrogen treatment (45 kg/hm2) was the best nitrogen application of identification and evaluation on NAE at maturity stage. The indirect indexes were seed weight per plant, aboveground plant dry weight and plant height. High nitrogen treatment (270 kg/hm2) was the best nitrogen application for identification and evaluation on NUE at rapeseed maturity stage. The indirect indexes was aboveground plant dry weight, effective branch number, seed weight per plant and seed number per pod. Low nitrogen treatment (45 kg/hm2) was the best nitrogen application for identification and evaluation on NHI at maturity stage. The indirect indexes were seed weight per plant, aboveground plant dry weight and basal stem diameter.