籼粳重组自交系亲本籼粳特性与杂种优势的关系

为了提高两系杂交稻亚种间杂种优势利用的预见性,以5个两用核不育系和9个籼粳程度不同的重组自交系为材料,研究了亲本籼粳特性与杂种优势的关系。结果表明,F1杂种产量优势与亲本籼粳特性之间以第1~2穗节长鉴定的籼粳特性较好地表现出籼粳差异与产量优势的关系,父本籼粳特性是以籼性越强的杂种优势越大,母本则以粳性越强的杂种优势越大;粳性的增强是有利于每穗实粒数、有效穗数、结实率和千粒重优势的提高,而籼性的增强是有利于每穗总粒数和着粒密度优势的提高;籼粳亚种杂种优势的利用应以培育粳型亲籼系不育系和优良的籼型恢复系(父本系),采用粳母籼父配组方式的利用途径。

Correlation between the Parental Indica-japonica Characteristics of Recombinant Inbred Lines from an Indica-japonica Cross and Heterosis

In order to enhance the foresightedness of the heterosis utilization in two-line hybrid rice subspecies,with 5 dual-purpose genic male sterile lines and 9 recombinant inbred lines with different indica-japonica degrees as materials,the correlation between parental indica-japonica characteristics and heterosis was studied.The results showed that the indica-japonica characteristics identified with the 1st～2nd ear-node lengths of hybrid F1 showed the correlation between indica-japonica difference and yield heterosis better.The stronger the indica characteristic of male parent was,the bigger its heterosis was and the stronger the japonica characteristic of female parent was,the bigger its heterosis was.The increment of japonica characteristic was in favor of enhancing the heterosis on full grains per ear,available ears,seed setting rate and 1 000-seed weight and the increment of indica characteristic was in favor of enhancing the heterosis on total grains per ear and seed setting density.The utilization of heterosis of indica-japonica subspecies should regard the breeding of indica compatible japonica male sterile lines and good indica restorer lines(male parental lines) as the main objects and use the combination mode with japonica female parent and indica male parent.