Determination, Cloning And Sequence Analysis Of Specific AFLP Fragments Of Chinese Cabbage-Pak-Choi (Brassica Campestris L.ssp.Chinensis Makino) AB Lines

Chinese cabbage-pak-choi (Brassica campestris L. ssp. chinensis Makino) is a typical allogamy plant and is of attractive heterosis. And, it is also one of the most popular leafy vegetables, especially in the South China. Much attention, for which, has been paid to the research of male sterility mechanism and its application in it inthe past several decades. Now, with the help of progressing molecular biotechnology, it has become possible of explaining the molecular mechanism of male sterility.'Aijiaohuang' used in this study is a representative genie male sterile AB lines in Chinese cabbage-pak-choi, and it is also an optimal plant material in the research of male sterility mechanism. In order to compare the differences of genomic DNA between the fertile line and the sterile line with AFLP technique, genomic DNA bulks of the fertile and the sterile lines of which were built up. By using different primer combinations, some polymorphism bands were determined. Meanwhile, the cloning and sequencing of which was also performed .and the main results were as follows:(1) Only two obvious polymorphism bands were obtained in the fertile line from selective PCR amplification with 64 pairs E+3/M+ rimer combinations, and which were named as MF-14 and MF-24, respectively. Moreover the polymorphism band MF-14 was cloned successfully.(2) It proved that there should be nucleotides sequence similar to MF-14 in the sterile line by the Southern hybridization using the fragment MF-14 as probe. Basing that, the mutation of nucleotides sequence in the region related to fertile gene was discussed.(3) Nucleotides sequencing revealed that the fragment MF-14 consists of 289 base pairs. Comparison of sequences similarity between MF-14 and other specific fragment or genes (S107, CYP86MF, BCMF1, BCMF2, BCMF3, BCMF4), which got in the previous research of male sterile, show that all the similarity between them were below 50%. So MF-14 was believed to be a newly specific DNA fragment, according to which, in the fertile line in 'Aijiaohuang'.(4) The sequence characterized amplified region marker about the specific fragment MF-14 was discussed.