不同氮肥水平下粳稻产量、氮素吸收差异及其基因型分类评价

Genotypic Differences and Evaluation of Yield and N Accumulation in Japonica Rice under Different N Fertilizer Levels

以南方早熟（125～135d）、中熟（136—145d）和迟熟（146～155d）中粳为材料，大田条件下研究4种氮肥水平即0、150、225、300kg/hm^2纯氮对水稻产量、氮素吸收的影响，并对产量和氮素吸收基因型差异进行评价。结果表明，不同生育期类型水稻平均产量和吸氮量随着施氮水平的增加而增加，在同一氮肥水平下，并随生育期的延长而增加；同一生育期类型，产量与吸氮量均存在显著或极显著基因型差异。采用组内最小平方和动态聚类法对3种类型水稻产量和总吸氮量及百千克籽粒吸氮量分别进行聚类分析，按从低到高的顺序均划分为Ⅰ、Ⅱ、Ⅲ、Ⅳ4种类型，方差分析表明，4种划分类型存在显著或极显著差异，每一划分类型基因型间变异系数大部分在0～5％波动。通过综合归类对各基因型水稻产量、总吸氮量及百千克籽粒吸氮量的分类标准吻合性进行评价，初步筛选出3种生育类型中高产高氮素吸收和低产低氮素吸收两种类型水稻基因型。

A field experiment with southern early （ 125 - 135 d）, medium （ 136 - 145 d） and late - maturing（ 146 - 155 d） Japonica rice was carried out in 2006 and 2007 on the farm of Yangzhou University ,Jiangsu Province ,China. The effects of different N levels including 0,150,225,300 kg/hm^2 N on rice grain yield and the N accumulation were analyzed. The results showed that, the grain yield and N absorption increased continuously with the increase of N application and rice growth duration prolonging. There were significant or highly significant genotypic differences in yield and N uptake under 4 N levels for the same growth type rice. The rice yield, total N accumulation and N absorption of 100 kg seeds were clustered into 4 types （ i, e. Ⅰ , Ⅱ, Ⅲand Ⅳ, Ⅰwas the lowest, Ⅳwas the highest） respectively by the Min - SSw method. There existed significant or highly significant genotypic differences among four types （Ⅰ , Ⅱ, Ⅲand Ⅳ） , the variation coefficient of which was all almost less than 5%. Two kinds of genotypes cultivars having high yield with high N accumulation and low yield with low N accumulation were selected primarily by synthetic analysis and evaluation on rice yield, total N accumulation, and N absorption of 100 kg seeds.