Studies on Molecular Marker-assisted Selection for Sterile Line and Maintainer Line in Welsh Onion (Allium fistulosum L.)
Gai Shupeng 1* Meng Xiangdong 2 Xu Lijuan 1 1 Department of Life Science, Laiyang Agricultural College, Laiyang, 265200 2 College of Horticulture, Shandong Agricultural University, Taian, 271018
Cytoplasmic male sterility(CMS) plays an important role in welsh onion heterosis utilization. Selection based on the markers would be more efficient provided there was tightly linkage between the marker and the trait of interest. In this study, we tried to develop technique system for markers assisted selection to facilitate breeding for male-sterile and maintainer line, finally shorten breeding years and accelerate step to heterosis utilization in welsh onion. Linkage analysis was made between S13 2800 , S38 960 , S72 300 , S73 1100 , S200 2400 and cytoplasmic types, whose recombination ranged from 0 to 7.5%. S13 2800 and S200 2400 , markers with no recombination found, could distinguish N and S cytoplasm in several cultivars. And great veracity and value would be achieved if the markers were utilized to cytoplasm identification in CMS breeding. Southern blotting analysis testified polymorphism between N and S cytoplasm using S13 2800 and S200 2400 as probe and restricted fragments of mtDNA from both sterile line and maintainer line, which indicated the two fragments be correlated with CMS in welsh onion. Furthermore, they were cloned to pGEM-T-easy vector, sequenced and converted to SCAR markers considering limiting factors of RAPD markers. Fortunately S13 2800 was successfully converted to SCAR marker and the new marker could differentiate cytoplasmic types correctly. But it failed to display polymorphism when S200 2400 was converted to SCAR marker. Simplified detecting technique of SCAR amplified products was then made to decrease the cost. The applications of RAPD and SCAR markers were expected to accelerate breeding progress and enhance breeding efficiency of sterile and maintainer line in welsh onion.
【CateGory Index】： S633.1