유채의 목포CGMS 및 유지친 개발

Abstract

Rapeseed as a partial allogamous crop(allogamy rate : 25~75%) displays depression by continuous selfing. Therefore, it is essential to produce F hybrids with high yield using cytoplasmic genetic male sterility(CGMS). This breeding system needs to develop male sterile(MS) line, MS-maintainer and restorer line in order to increase commercial value of F hybrid seeds. MS and restorer lines can be easily obtained in rapeseed, but MS-maintainer is difficult to breed artifically or to discover from germplasm. Mokpo-CGMS is originated from the cross between Tower(♀) and Isuzu(??), and its stamens are degenerated by interacting of cyto- plasmic and nuclear genes. The Mokpo-CGMS line has good composition of oil with no erucic aicd. But the MS could be maintained by the cross between Mokpo-CGMS plants and fertile sister plants of the Mokpo-CGMS and 50% of the progeny show male sterility. To develop perfect maintainer which can produce 100% male sterile plants, a cross between Altex(normal cytoplasm and FF nuclear genotype) and fertile sister line of Mokpo-CGMS(sterile cytoplasm and FS nuclear genotype) was made. It was difficult to select the line with normal cytoplasm and male sterile nuclear gene in F generation because all phenotypes including heterozygous and homozygous types were expressed in the same plant type with fertility. Test cross was made between individual F plants and Mokpo-CGMS line in order to select maintainer. After backcrossing the F plant to the Mokpo-CGMS 14 times, a perfect maintainer producing 100% male sterile plants was identified in progenies.