两系亚种间杂交稻籽粒充实度的遗传研究

Genetic Studies on Grain Plumpness of Indica-Japonica Hybrids by Two Line Method

本研究选用了 10个籼型光温敏不育系作母本 ,10个粳型广亲和品种作父本 ,共配制籼粳亚种间杂交组合 5 3个。从两系亚种间杂交稻籽粒充实度的遗传方面进行研究 ,结果表明 :(1)两系亚种间杂种 F1的谷粒充实率与其本身的程氏指数相关不显著 ,相关系数仅为 - 0 .1818;与双亲的亲缘距离(程氏指数差值 )极显著负相关 ,相关系数为 - 0 .4 739* * 。 (2 )两系亚种间杂种 F1谷粒充实率与父本的谷粒充实率、母本谷粒充实率和双亲的平均谷粒充实率都为极显著正相关 ,相关系数分别是0 .4 979* *、 0 .5 90 2 * *和 0 .62 75 * *。 (3) 4× 8不完全双列杂交法配合力分析结果表明 ,亚种间杂种 F1谷粒充实率的表现中 ,父、母本的一般配合力效应和组合的特殊配合力效应都达到了显著差异 ;父、母本的一般配合力作用大于组合的特殊配合力作用 ,一般配合力方差占总基因型方差的 78.2 0 % ,特殊配合力方差占 2 1.80 %。在双亲的一般配合力作用中 ,父本即粳型广亲和品种的作用 (基因型方差为4 .86)大于母本即籼型光温敏两用核不育系的作用 (基因型方差为 2 .34 )。两系亚种间杂交稻的籽粒充实度的遗传主要是受基因作用的影响 ,其广义遗传率为 82 .10 % ,狭义遗传力为 76.0 6%。文章最后对两系亚种间杂种优势的利用和提高两系?

In this study, 53 intersubspecific combinations were obtained by crossing 10 pho to thermo sterilities ( indica ) with 10 wide compatibility va rieties ( jap onica ). The inheritance of grain plumpness for these materials was studied. Th e main results are as follows: 1) The genetic difference of two parents (differe nce in Cheng′s index) was very significant negatively correlated with grain plu mpness in intersubspecific combinations (F 1), and the correlation coefficient was -0.4739 ** .2) Grain plumpness of two parents (the male parentages, the female parentages and the mean of the two parents) was very significant positiv ely correlated with grain plumpness in intersubspecific hybrids (F 1), and the correlation coefficient was 0.4979 ** , 0.5902 ** and 0.6275 ** re spectively. 3) The difference in grain plumpness general combining ability (GCA) and special combining ability (SCA) of parents were very significant. The grain plumpness in F 1 intersubspecific hybrids was controlled by GCA and SCA of par ents, and GCA of parents especially the wide compatible restoring line ( japoni ca ) parents played a more important role. The heredity of grain plumpness in i ntersubspecific hybrid rice (F 1) by two line is majorly controlled by gene, a nd the h 2 B is 82.10%, the h 2 N is 76.06%. At last, breeding methods of im proving grain plumpness in intersubspecific hybrids(F 1) by two line system w ere discused.