早、晚期水稻不育系、恢复系产量性状的配合力及遗传力分析

Analysis of combination ability and genetic difference between the early-stage and late-stage sterile lines and restorers in rice

为了解早、晚期不育系和恢复系的产量性状遗传差异,更好地指导杂交稻生产,本研究分别以9个有代表性的早、晚期恢复系和不育系按NCⅡ设计配制9×9不完全双列杂交研究了早、晚期杂交亲本的配合力基因型方差及遗传力间的差异,结果表明,①晚期恢复系除千粒重外的其它6个产量性状的一般配合力基因型方差都高于早期恢复系。晚期不育系的5个产量性状的一般配合力基因型方差与早期不育系没有差异,总粒数和穗重却明显低于早期不育系。②在产量性状非加性基因互作的利用上,后期恢复系配组的单株产量、不育系配组的单株产量、结实率、总粒数和实粒数等基因间的互作高于早期杂交组合。③早、晚期不育系及恢复系的产量性状的加性和非加性基因受环境影响因性状不同而异。④不同环境下不同组合都表现千粒重的遗传力最高和单株产量最低,其它产量性状的遗传力不尽相同。因此,要使杂交稻高产迈上一个新台阶,必须加强有突破性的不育系的培育和注重恢复系大粒的选育,同时重视非加性效应的利用以及调节不稳定基因的表达。

In order to understand the genetic difference of yield traits between the early-stage and late-stage sterile lines and restorers in rice and best direct production of hybrid rice,the difference of combination ability and heritability of yield traits were studied using 9 early-stage and late-stage sterile lines and restorers respectively designed in 9× 9 NC Ⅱ. The result showed as follows ： （1）The variances of general combination ability of 6 yield traits except 1000-grain weight of the late-stage restorers were significantly larger than those of the early-stage restor- ers. And no difference were exhibited in the variances of general combination ability of 5 yield traits between the late - stage and the earlystage sterile lines and even the variance of general combination ability of some traits such as spikdets per panicle and grain weight per panicle of the late-stage sterile lines were significantly little than those of the early-stage sterile lines. （ii）The variance of special combination ability of yield per plant of hybridized comblnation combined between late-stage restorers and sterile lines and those of 4 traits（yield per plant, spikelets per panicle,seed seeting rate,filled spikelets per panicle） of hybridized combination combined between late-stage sterile lines and restorers were significantly larger than those of responding traits of hybridized combination combined with early-stage restorers and early-stage sterile lines, （iii） It was different for the environment influence on the additive and non-additive genes of different yield traits between the late-stage restores （ sterile lines） and the early-stage restores （ sterile lines） in rice. （iv） The order of heritability of the rest yield traits except 1000- grain weight （ high heritability） and yield per plant （ low heritability） were not consistent completely in different hybridized combinations and in different environments. Consequently, to increase yield greatly, it was necessary to breed record-breaking sterile lines and novel restorers with large grains, and simultaneously to attach importance to the application of non-additive effect of special combination and to regulating the expression of unstable gene in cultural practices.