水稻不同基因型耐低氮能力差异评价

以水稻单株谷重及其氮素反应指数作为耐低氮能力指标，分析不同施氮水平下水稻种质资源的耐低氮能力以及单株谷重及其氮素反应指数与其他农艺性状的相关关系。结果表明，水稻种质资源的耐低氮能力在不同施氮水平间均有较大差异，多数农艺性状的表型差异顺序为未施氮〉施低氮〉普通施氮；不同施氮水平间单株谷重、单株草重和穗数的差异大于其他农艺性状。在不同施氮水平下，单株谷重与单株草重均呈极显著正相关；单株谷重的氮素反应指数与单株谷重、单株草重和谷草比均呈极显著正相关。在未施氮水平下，单株谷重与株高、穗数、穗粒数和单株草重的相关性以及单株谷重的氮素反应指数与穗数、单株谷重、单株草重和谷草比的相关性比施低氮或普通施氮水平更为密切。花峰稻、中作9059、旱稻9号、旱稻502和IRAT359等种质资源表现较迟钝的氮素反应，具有较强的耐低氮能力。

Evaluation of Tolerance to Low N-fertilized Level for Rice Type

Grain weight per plant and its response index to nitrogen was used as index of tolerance to low nitrogen in this study.Tolerance to low N-fertilized level for rice germplasm and coefficient correlation among grain weight per plant and its response index to nitrogen and main agronomic traits were analyzed.The results showed that the tolerance to low N-fertilized level was larger difference among rice materials under different N-fertilized levels,and the order of difference for most of agronomic traits were N-unfertilized >low N-fertilized >general N-fertilized.The difference of grain weight per plant,straw weight per plant and panicles per plant among different N-fertilized levels were larger than that of other agronomic traits.Grain weight per plant was positively correlated with straw weight per plant,response index to nitrogen for grain weight per plant was positively associated with grain weight per plant,straw weight per plant and ratio of grain to straw under all of different N-fertilized level.The correlation between grain weight per plant and plant height,panicles per plant ,spiklets per panicle,straw weight per plant,and between response index to nitrogen and panicles per plant,straw weight per plant,grain weight per plant and ratio of grain to straw under N-unfertilized level were higher than that of low or general N-fertilized level.Hwabongbyeo,Zhongzuo9059,Upland rice 9,Upland rice 502 and IRAT359 with higher tolerance to low N-fertilized level,which were nonsensitive to nitrogen.