Primary Mapping Of The Leaf Color Gene In Brassica Napus

In order to utilize GMS-based hybrids efficiently,it is required to remove about 50% male fertile plants from the female plants.To identify the male fertile plants timely and accurately,and also to reduce the workload in the field,it is necessary to develope marker gene linked to purple leaf gene,it will be a effectual morphological marker in crossbreeding.the purple leaf color and purple stem color traits were stable,make the purple leaf plants crossed with green ones,F1 and showed purple vein and no separations were found,while BC1 showed separations of purple vein plants and green ones,the ratios of purle vein leaf:green leaf is 1:1,inferring thai the purple leaf color gene is incomplete dominant;we also make the purple stem plants and green ones crossed with each other,F1 showed purple stem and no separations were found,while BC1 showed separations of purple stem plants and green ones,the segregation ratio of purle stem:green stem is 1:1,inferring thai the purple stem gene is dominant.in order to prove the result above in a molecular way,the BC₁ population from purple leaf(green stem)×green leaf(purple stem) was investigated by BSA(Bulked Segregant Analysis).we found 5 AFLP fragments produced polymorphic bands linked to the purple leaf gene and they are P03MC01,P08MC01,P10MC03,P11MC15 and P14MC114,and four linked to the green leaf gene and they are P05MC04,P06MC06,P16MC05å’ŒP10MC10.None was found linked to the purple stem gene.We sequenced those nine AFLP fragments showed polymorphism.According to the sequence,we designed SCAR primers and then contrasted those fagments'sequences with that of Arabidopsis'.The results from BLAST analysis told us that three makers had homologous sequences in the genome of Arabidopsis,and they could be located on the chromosome3,chromosome4,and chromosome5.