甘蓝型油菜种质苗期氮素营养效率的鉴定与评价

Identification and evaluation of nitrogen nutrition efficiency in rapeseed germplasm at seedling stage

为建立快速简便高效的油菜氮素营养效率的鉴定与评价方法,温室盆栽条件下设置土壤低氮(0.05g/kg)、中氮(0.2g/kg)和高氮(0.3g/kg)3个水平,测定了75份不同生态类型甘蓝型油菜种质的苗期形态性状及氮素吸收效率(NAE)和氮素利用效率(NUE)。结果表明:苗期各性状在不同氮素水平下对氮的敏感性不同,3个不同氮处理水平下单株根表面积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间存在明显的基因型差异,表现为高效和低效的较少,表现中效类型的种质最多;NAE和NUE间的相关性未达显著水平。以NAE作为氮素营养效率指标来鉴定与评价种质间苗期氮素营养效率差异应选择在低氮处理下,以单株地上干重和根冠比为间接指标进行选择效果明显。以NUE作为氮素营养效率指标来鉴定与评价种质间苗期氮素营养效率差异应选择在高氮处理下,以单株地上干重为间接指标进行选择效果明显。

To establish an efficient identification and evaluation method of rapeseed nitrogen nutrition efficiency,greenhouse pot experiment was conducted using 75 germplasm accessions under 3 nitrogen levels in soil（ 0. 05,0. 2,0. 3 g / kg）. 15 seedling traits were measured to assess variations of nitrogen nutrition efficiencies including nitrogen absorption efficiency（ NAE） and nitrogen utilization efficiency（ NUE）. Results showed that the sensitivity of different traits to different nitrogen levels was different. Genetic variations of root surface area under different nitrogen treatments were the greatest. Under low nitrogen stress,the differences increased among the accessions. Nitrogen nutrition efficiency of rapeseed genotypes at seedling stage showed significant difference. Distribution patterns showed that both high and low efficiency materials were rare. Low nitrogen treatment（ 0. 05 g / kg） was the best nitrogen application for identification and evaluation on NAE at seedling stage. The indirect indexes were aboveground plant dry weight and root- shoot rate. High nitrogen treatment（ 0. 3 g / kg） was the best nitrogen application for identification and evaluation on NUE at rapeseed seedling stage. The indirect index was aboveground plant dry weight.