水稻越冬品系的杂种优势及配合力分析

对3个越冬品系与4个籼稻品种配制的16个正反交F1代主要农艺性状的杂种优势、母体效应值和按不完全双列杂交配制的12个正交组合及亲本主要农艺性状的配合力、遗传力进行了分析,结果表明:(1)所有组合的播始历期、株高和结实率具有超亲优势,千粒重接近中亲值.(2)所有组合的播始历期、每穗总粒数和结实率的母体效应值较高.(3)亲本SW-1 和R195的一般配合力(GCA)较好,其所配制组合的特殊配合力(SCA)效应值也较高;而SW-3和R128的GCA也较好,其所配制组合的SCA效应值却偏低;表明亲本的GCA效应与组合的SCA效应关联不大.(4)亲本的播始历期、株高、结实率、谷粒长、谷粒长宽比、千粒重6个性状的GCA基因型方差在基因型总方差中比重大于60%,且它们的H2N也均大于60%,说明这些性状遗传主要受基因加性效应的影响;而单株产量的SCA方差对总方差的贡献率大于60%,且它的H2N仅为18.83%,说明其遗传主要受基因非加性效应的影响.父本和母本对GCA方差的贡献率在所有性状表现上相差较大,母本GCA方差的贡献率远大于父本,且双亲的互作效应不明显.(5)利用越冬品系进行品种选育应注重对杂交后代株高、结实率和千粒重等性状的选择.

Analysis on Heterosis and Combining Ability of Surviving in Winter (SW) Lines in Rice

An analysis on the heterosis and maternal effect of the agronomic characters of sixteen hybrids produced by reciprocal cross of three surviving-in-winter(SW) lines and four cultivars,and on the combining ability,heritability of the agronomic characters of the parents and twelve combinations produced by incomplete diallel cross of them was conducted.The results showed that(1) the characters such as days from sowing to initial heading(DSIH),plant height(PL) and seed setting rate(SSR) had over-parent heterosis,and the value of thousand-grain weight(TGW) was near to that of the mid-parent heterosis in all the combinations;(2)the maternal effect values of spikelets per panicle(SPP),DH,and SSR were relatively high,which indicated that the phenotypes were meanly controlled by their own genotypes;(3)the parents such as SW-1,R195 had good general combining ability(GCA),and the value of specific combining ability(SCA) effect of the combinations produced by them were relatively high;the parents such as SW-3,R128 also had good GCA,but the values of SCA effect of the combinations produced by them were relatively low',which suggested that the relativity between the parents' GCA and their combinations' SCA was not high;(4) GCA genotypic variance of the six characters,namely,DSIH,PL,SSR,TSW,grain length(GL),and the ratio of grain length to width(GL/W) within parents was higher than 60 percent of the total genotypic variance,and their narrow heritability(H2N) was beyond 60 percent,which showed that these characters were affected by additive gene effects;SCA genotypic variance of the yield of single plant(YSP) within all the combinations was higher than 60 percent of the total genotypic variance,and it's narrow heritability(H2N) was only 18.83 percent,which suggested that non-additive gene effects played a greater role for this trait;the contribution rate of GCA genotype variance of the paternal-parent differed greatly from that of the maternal-parent,and SCA genotype variance occupied less of the total variance within most of the traits,and the interaction effect between the paternal-parent and the maternal-parent was not distinguished;(5)it is of importance to focus on selection of characters such as PL,SSR and GW of progenies from hybridization by using surviving-in-winter(SW) lines.