Fine Mapping Of Seed Color Gene In The Resynthesized Yellow-seed Barssica Napus

Yellow-seeded rapeseed (Brassica napus L) is characterized with thinner seed coat and lower hull percentage, which in turn is correlated with higher oil and protein compared to black-seeded rapeseed from the same genetic background.Based on advantages of yellow seeds character, studying yellow seed is being a hotspot of quality breeding in B. napus. In this research, through the resynthesized yellow-seed B. napus, two pairs near-isogenic lines were used as materials and the genomic information of B. rapa and Arabidopsis thaliana were utilized as references for fine mapping of gene related to seed coat color. The results were as follows:1) Bulked segregant analysis (BSA) and AFLP techniques were used to identify the markers linked to the gene of seed coat color. Twenty markers linked to the seed color in the resynthesized yellow-seed B. napus were obtained, and the nearest marker bracketed the the coat color gene at the distances of 1.2cM. In B. rapa population,52 markers were found.2) Eight all the fragments obtained from AFLP markers were cloned and sequenced. Then the specific PCR primers were designed based on the sequences. Results showed that the markers, EA15MG9 and EA6MG15, were successfully converted into SCAR markers which named as S159 and S615.The S159 was proformanced in B. napus population, and the S615 in B. rapa. population.3) The sequences of AFLP markers were submitted to the database of http://www.brassica-rapa.org/, the homologous sequences from B. rapa BAC were obtained through blast analysis.Then according to the sequences of BAC clones, SSR primer were designed.42 SSR markers were gained.4) Collected markers in the related region from genetic linkage maps published previously, we staked out initially. We screened 35 pairs of primers and ten valuable makers were obtained. 5) We designed 25 pairs ACGM primers base on the genomic information.There were 5 pairs showed polymorphisms in Brassica rapa population.But no polymorphisms were found in B. napus. Forthermore, one ACGM marker showed co-segregation with the target trait in B. rapa population.