水稻谷粒密度的杂种优势及配合力分析

Analysis on Heterosis and Combining Ability of Grain Density in Rice

以5个不育系与4个恢复系按NCⅡ交配设计,配制20个杂交水稻组合,研究了谷粒密度的杂种优势、遗传力和配合力。结果表明：杂交组合谷粒密度的中亲优势都为正值,中亲优势率0.57%~6.55%,且大部分（80%）杂交组合具超亲优势;杂交组合谷粒密度主要受不育系以及父母本互作效应的影响;杂交稻谷粒密度广义遗传力为88.41%,狭义遗传力为51.92%;在参试亲本中,就提高杂交组合谷粒密度而言,28H130是理想恢复系,龙S和中3A为较理想的不育系亲本。

20 F1rice hybrids derived from five male sterile lines and four restorer lines by the incomplete diallel cross（ NCⅡ） design were used to study on the heterosis,combining ability and heritability of rice grain density. The results showed that all hybrids had a positive mid-parent heterosis ranging from 0. 57% ~ 6. 55%,and most of them（ 80%） showed a high-parent heterosis in grain density. The grain density of F1hybrids was mainly affected by the female parent and the male-female interaction. The broad-sense heritability（ h2 B） and narrow-sense heritability（ h2 N） of grain density were 88. 41% and 51. 92%,respectively. Among the tested parents,28H130 was the best restorer line,and Long S and Zhong 3 A were better male sterile lines in breeding of rice hybrids with high grain density.