Linkage Map Construction Of DH Population Of Brassica Alboglabra Bailey×Brassica Oleracea L.var.italica Planch

Both Chinese kale and broccoli are important vegetable crops in China. Genetic maps in some Brassica species have been constructed. Linkage maps of Chinese kaleb x roccoli have not reported until now. In the present study, F1-derived doubled haploid (DH) populations obtained from Brassica alboglabra Bailey X Brassica oleracea L. var. italica Planch were used to construct molecular linkage maps. The main results were as follows:It was found that the template DNA concentration affected on pre-amplification significantly. Bands were obtained in pre-amplification when the template DNA concentration was from 10ng/μl to 50ng/μl But the best pre-amplification was obtained with 30ng/μl template DNA concentration. The product of pre-amplification was not so good when the template DNA concentration was too high or too low.A total of 96 primer combinations were initially screened with both parents by AFLP and Li-cor fluorescence technique, of which 46 primer combinations showed polymorphism between the two parents. Based on the selection of primer, 46 DH individuals were analyzed and 421 AFLP polymorphic markers were detected. By using JionMap Version 3.0 software, a total of 327 molecular marker loci were mapped to 9 main linkage groups and 2 small groups. The linkage groups span 801.5cM with an average marker interval of 3.6cM. The AFLP markers were not well-distributed on the linkage maps with some makers on the same locus.DH population was widely used in linkage map construction. To obtain the DH population, plant regenerated from isolated microspores is one of the key steps. In this study, several experiments were conducted. The isolated microspores of five genotypes of Chinese kale were cultured in the NLN-13 liquid medium. It was found that genotypes had important impact on embryo formation. Only one genotype could produce embryo from microspores, though microspores of other two genotypes could reach the cell division phase. Culture method affected the embryos development. It was demonstrated that shakingculture could promote the development of embryos and increase frequency of cotyledon embryos significantly. Regenerated plants were obtained when cotyledon embryos were sub-cultured in both MS and B5 media.