水稻品种间穗重构成因子的差异性研究

STUDIES ON VARIETAL DIFFERENCES IN COMPONENTS OF PANICLE WEIGHT IN RICE

在盆栽条件下,研究不同穗重型水稻品种稻穗不同部位颖花数、结实率、千粒重的变化趋势及根系性状的差异。结果表明:①一次枝梗颖花数占全穗颖花数的百分率,穗重大的品种全穗及其上、中、下部均小于穗重小的品种,以中部下降幅度最大;二次枝梗颖花数占全穗颖花数的百分率,穗重大的品种全穗及其中、下部均大于穗重小的品种,以下部增加幅度较大。②籼稻品种一次枝梗颖花数占全穗颖花数的比例相对较小,二次枝梗颖花占全穗颖花数的比例相对较大,粳稻品种变化趋势与此相反。③同一品种一、二次枝梗结实率及饱粒千粒重的差异,粳稻大于籼稻。④增加每穗颖花数、结实率和饱粒千粒重均能提高穗重,以每穗颖花数(尤其是二次枝梗颖花数)的促进效果最显著。⑤发达的根系性状是重穗型品种一个重要的特征。

The differences in panicle weight components, including number of spikelets, seed setting percentage and 1000-grain weight at different part along the panicle, among rice varieties with different ear-type and root traits were studied in pot experiment. The factors influencing panicle weight were analysed. Results were as follows: ①The ratios of primary spikelets to spikelets of whole panicle (Rp) in three locations along the panicle (i.e. upper, middle, lower) in large-ear type variety were lower than those in small-ear type variety, especially in the middle part, while the ratios of the secondary spikelets to whole panicle spikelets (Rs) at middle and lower parts in large-ear type variety were higher than those in small-ear type variety. ②The Rp was lower and Rs was higher in Indica rice, but the reverse trend appeared in Japonica rice. ③The differences of grain setting percentage and 1000-grain weight in primary and secondary spikelets were larger in Japonica varieties than those in Indica varieties.④Panicle weight could be enhanced by increasing the number of spikelets per panicle, seed setting rate and 1000-grain weight, among which the number of spikelets per panicle, especially in the secondary branches, was more effective.⑤Developed root traits were the important characteristics in weight-ear type rice varieties.