Identification And Genetic Analysis Of Wide Compatibility In Rice (Oryza Sativa L.)

Wide compatibility genes (WCG) is an essential tool for use of indica-japonica inter-subspecific heterosis in rice. Understanding the genetic mechanism of WCG is of great importance in application of wide compatibility (WC) for wide heterosis breeding. There are rich and various types of rice generis resources in Guangxi and, therefore, some of wide compatibility varieties(WCVs) may be abtained by screening the resources. Identicication and analysis for WC from Guangxi rice resouces will provide a solid theoretic and material foundation for the use of inter-subspecific heterosis.Forty rice varieties in Guangxi, some WC testers and WCG allelic testers were tested in this study. By fertility analysis in parents, FIS of testcrosses and three-way crosses, backcrosses and F2 populations, a series of WCVs were indentified from Guangxi varieties and genetis of WCGs were analyzed.The results of WC analysis indicated 20 WCVs in Guangxi varieties tested, like, Zhongdafei,Houshengheng,xingnogu,Hainanzan, Youzhiximi, Qiaizan, etc. Most of these WCVs belonged to intermidiate type between indica and japonica.The results of allelic analysis of WCGs showned at least two loci for the WC among the screen Guangxi WCVs, Zhongdaifei, Xingnogu, Houshengheng, Qiaizan,Hainanzan, JinglS and Youzhiximi. A single WCV might possess several WCGs and the genetic mechanism of the WCGs among varieties was different, indicating complicate genetic basis for the WC.Genetic study also indicated different genetic background among these WCV materials. Major gene effect for WC was significant and was modified by envirnment and minor genes. The WC was controlled by two or more loci and major gene effect was not significant in Houshengheng, Qiaizan, Zhongdafei and Xingnogu.