水稻籼粳交亲籼型不育系的杂种优势利用

采用珍汕97B/秀水13的后代为材料,通过回交转育,育成系列亲籼型不育系.以Ⅱ-32A为对照,按8×6不完全双列杂交,分析各不育系产量性状的遗传效应与杂种优势,评价其育种价值.结果表明:(1)产量主要性状大多受加性效应和显性效应共同控制.单株重是一个复杂性状,受显性效应控制.株高、总粒数、生育期和有效穗与结实率的表型、遗传、加性和显性相关均呈负显著或极显著相关,育种上应注意上述性状的选择,提高后代结实率.(2)株高、主穗长、粒重及生育期的狭义遗传力较高,早期选择有效;而单株重、有效穗、总粒数及结实率的狭义遗传率低,分离世代长,需高世代鉴定.(3)42个籼粳交F1中有18个组合结实率高于80%,16个组合单株重超过Ⅱ优63,杂种优势表现在单株重、株高、穗粒数等性状.

Heterosis's application of indica-compatibility CMS lines of hybrids between indica and japonica in rice

A series of indica-compatibility CMS lines were bred by the population derived from Zhenshan 97B/Xiushui 13.Ⅱ-32A was chosen as the control CMS line.According to imperfection double cross design(6×8),the genetic effect and heterosis concerning yielding of the selected CMS line were analyzed,and their values in breeding were appraised too.The results indicate that:(1) The most main characters concerning yield in the hybrids are affected by additive effect and dominant effect of alleles.Yield is a complicated and integrated character.It was affected by dominant effect of alleles.Additive and dominance correlation exist among plant height,the main panicle length,1000-grain weight,growth period and seed setting rate,so these traits should be emphasized in breeding process to increase seed setting rate between indiaca and japonica hybrids.(2) The narrow-sense heritabilities of plant height,main ear length,total grain number and seed setting rate are higher,they can be selected effectively in early generation;but the narrow-sense heritability of grain weight per plant,panicle number,total grain number and seed setting rate are lower,they should be selected in later generations because of serious segregating.(3) The seed setting rate of 18 combinations are more than 80% in 42 indica-japonica combinations,and the grain weight per plant in 16 combinations are heavier than that of Ⅱ-you 63.The heterosis of indiaca and japonica is mainly embodied in weight per plant,plant height,total grain number,real grain number and total grain number per fringe.