水稻 細胞質的ㆍ遺傳的ㆍ雄性不稔系統 育成에 있어서의 組合能力檢定

Combining ability test in breeding of CGMS lines for hybrid rice

To access the combining ability problems encountered on the way of breeding the male sterile lines for hybrid rice utilizing ms-WA male sterility of rice, the F₁s of ms-maintainer × fertility restorer and F₁s of ms-line × fertility restorer were grown in 1983 and 1984 respectivly, and the combining ability for the grain yield were examined. They are summarized as follows ; 1. To express the combining ability of a breeding line in terms of productivity, the conceptions “Relative specific combining ability”(rsca), and “Relativ combining ability”(rca) were developed in addition to the conventionally used “General combining ability”(gca) and “Specific combining ability”(sca). Here the rsca designates the standard error of the mean of the hybrids which the concerned line is involved. The rca designates the sum amount of gca and rsca( rca = gca+rsca). 2. The relationship between the notes and Xik and the conception gca, rsca and rca were depicted with better comprehensions. 3. In comparison to the alien CGMS lines, the breeding CGMS lines showed lower combining ability especially showed lower rca. The alien lines showed higher gca and lower rsca while breeding lines showed very low gca and relatively low rsca. 4. From the similar two year’s results the feasibility to eliminate the poorly combining breeding ms-lines from the data of maintainer’s hybrid performance, with minimal risks, were infered. It is recognized that the exploitation of new techniques which effectively transfer the high combining ability of alien ms-lines on the way breed are required. 5. Discussions were extended to the comprehensive relationship of which ease the calculation and perception of combining ability of a group of breeding lines for hybrid varieties.