氮素高效吸收型粳稻品种源库指标的基本特点

群体水培条件下,以国内、外不同年代育成的94个常规粳稻品种为供试材料,测定植株叶面积、各器官干物重和含氮率、库容量和产量等,采用组内最小平方和的动态聚类方法将供试品种按吸氮量的大小从低到高依次分为A、B、C、D、E、F等6类,研究氮素高效吸收型粳稻品种源库指标的基本特点。结果表明:①供试品种间吸氮量的差异很大,成熟期总吸氮量最大品种为最小品种的2.94倍(2008年)和2.59倍(2009年),成熟期单穗吸氮量最大的品种为最小品种的4.67倍(2008年)和3.51倍(2009年);②氮素高效吸收型品种抽穗期、成熟期群体叶面积系数和单穗叶面积较大;③氮素高效吸收型粳稻品种抽穗期绿叶重、净同化率较大,但比叶重无明显优势;④氮素高效吸收型品种群体库容量与单穗库容量均大于氮素低效吸收型品种;⑤叶面积系数和库容量对粳稻品种总吸氮量均有重要的影响,库容量的作用大于叶面积系数。增源扩库是粳稻品种增加氮素累积量,实现高产更高产的重要途径。

Study on the characteristics of source and sink in conventional japonica rice cultivars with high nitrogen uptake efficiency

To investigate the characteristics of source and sink in conventional japonica rice cultivars with high nitrogen uptake efficiency,94 conventional japonica rice cultivars were solution-cultured.Leaf area index(LAI),dry matter weight and nitrogen content,sink potential and grain yield were measured.Based on the amount of nitrogen absorption(ANA),these rice cultivars were clustered into 6 types in the alignment from low to high(A,B,C,D,E and F) by the MinSSw(dynamic clustering method-minimum sum of squares within groups) method.Results were as follows: ① Great differences in ANA were detected among all tested cultivars.The maximum ANA was 2.94 and 2.59 times higher than the minimum ANA in 2008 and 2009,respectively,and the maximum ANA per panicle was 4.67 and 3.51 times higher than the minimum ANA per panicle in 2008 and 2009,respectively;② LAI and leaf area per panicle at heading and mature stages in rice cultivars with high nitrogen uptake efficiency were both larger than those in rice cultivars with low nitrogen uptake efficiency;③ The rice cultivars with high nitrogen uptake efficiency had higher green leaf weight at heading stage and higher net assimilation rate than those with low nitrogen uptake efficiency,while there was no significant difference in green leaf weight per unit leaf area among different types;④ Sink potential and sink potential per panicle in rice cultivars with high nitrogen uptake were both greater than those in rice cultivars with low nitrogen uptake efficiency;⑤ Both the LAI and sink potential had important influence on the ANA,and the influence of sink potential was stronger than the LAI.Therefore,improving the LAI and sink potential was beneficial to the elevation of the ANA,and importantapproach for higher yield.