Molecular Markers Linked To Orange Color Of Leaf Head Gene And Purity Identification Of Hybrid In Chinese Cabbage

Bulked segregant analysis (BSA) was employed to screen molecular markers linked to orange color of leaf head gene based on RAPD in Chinese cabbage with 196 F2 population. By testing the special RAPD markers with 196 F2 individual plants, one RAPD marker linked closely to orange leaf head gene were identified and transferred into SCAR marker. The two DNA fingerprints of which are Guanchun hybrid seeds combining with their parents and Jinguan No.2 hybrid seeds combining with their parents respectively were established. The technique of molecular marker-assisted-selection for breeding orange leaf head Chinese cabbage cultivars was established. The DNA fingerprints of hybrids beneficial to plant broadly in case of theoretical substantiate. The chief results are as follow:1. Orange leaf head expression of four groups, white leaf head lines and orange leaf head lines and their hybrids generations (F1 and F2 and BC1) were investigated. According to the segregating results of leaf-head color in F2 population and orange genotype were proved to be controlled by a pair of recessive genes.2. The method of DNA extraction was explored. DNA extracted in this method was very complete and reliable PCR amplification can be obtained.3. By screening polymorphism between orange pool and white pool which were established by 196 F2 plants and F3 family with 400 S RAPD 10-mer-primers, primer S82 showed polymorphic between two pools. One RAPD marker S82-591 produced by primer S82 (GTTTCGCTCC)was observed in every plants of orange leaf head pool and disappeared in every plants of white leaf head pool. Identical results were obtained in three times repetition, therefore S82-591 was thought to be linked to orange leaf head gene.4. The specific DNA marker S82 amplified in orange pool was recovered the specific band was cloned and sequenced and a pair of 19-base specific primers was designed. The SCAR analysis of F2 population displayed that the result of amplification with SCAR is identical with that of RAPD. The accuracy in comparing the head leaf color and the S82...