水稻根系性状的遗传研究

采用双回交试验设计系统研究了水稻６个根系性状的遗传。结果表明：各性状表现为数量遗传，只受细胞核基因控制。６个性状的加性效应及显性效应均达显以上统计水平，其中平均根长、根数、根基粗的加性率较高达４０％左右。上位性效应对各性状尤其是根重、根中粗具有不可忽视的影响，其中又以加性×加性、显性×显性的贡献较大，只有平均根长符合加性－显性模型。各性状的显性及上位性效应值基本上均为正值。因而既可以利用各根系性

A STUDY ON THE INHERITANCE OF RICE ROOT CHARACTEISTICS

A genetic study of six rice root characteristics was carried out systematically by mean ofdouble backcross experiment design. The results indicate that each characteristics appears asquantitative inheritance and is controlled by the gerie of the cell nucleus. The additive and dom-inant effects of six root characteristics reach remarkable statistical level,among which the addi-tive effects of mean root length, root number and root-base thickness attain the high proportionof 40%.The epistatic effect has noticeable inflence on every characteristics,especially on rootdry weight and root-middle thickness,yet the crossing between additive and additive varieties,dominant and dominant varieties has a greater contribution to the characteristics. Only meanroot length accords with the additive-dominant pattern. Dominant and epistatic effects of rootcharacteristics essentially is positive,so not only positive heterosis of every root characteristicmay be used.but also it is possible to breed pure-line varieties of well-developed rootsystem.Heritability in the narrow sense of mean root length, root number and root-basethickness is about 55%,which is of good selection effect in rice breeding;but that of root-middle thickness,maxium root length and root dry weight is about 40%,which is of potential-ity in heterosis utilization,It is proper to select better characteristics from high generations inthe breeding scheme of pure-line varieties.