AFLP Analysis Of Cytoplasmic Male Sterility And Buds Phytohormones Research In Heading Chinese Cabbage

The research about mechanism of male sterility has got more progress with biotechnology methods improved, but there is still a long way to discover their inherent mechanism of male sterility completely. Compared with genic male sterility, CMS could get more effects on hybrid seeds production.The CMS research lagged, mainly due to the CMS more complex, involving nucleo-cytoplasmic inter-reaction, and being effected by environmental factors. The CMS was studied at two aspects: First, the AFLP molecular marker technique and near-isogenic lines were used to screen markers closely linked to CMS in Chinese cabbage for the future molecular assisted breeding; Second, the changes of endogenous hormones contents in buds of different development stages of radish were tested for exploring the internal relationship between endogenous hormones and the male sterility.The main results are as follows:1.The pool sample of DNA pool digested with PstⅠand MseⅠ,and then the adapter was added, finally screened with AFLP primers.Among the1024 pairs AFLP primers, only primer p12/m33 and p16/m50 amplified special bands in fertile DNA pool but no bands in sterile DNA pools.The test with individual plants that constructed the DNA pool comfirmed the result. The two special bands were retrieved and sequenced. The band length form the primer p12/m33 was 73bp, while the other from the p16/m50 was 61bp. These two bands were too short to design new primers, or to scar markers.2. Twenty five fertile and twenty five sterile plants of F2 were tested with the two pair primers. The result showed that there were two recombinant plants with p12/m33, while three recombinant plants with p16/m50. The genetic distance between the markers and fertility gene were 2.489cM and 5.513cM respectively.3. At initial stage of the male sterile phenomenon to appear, the contents of IAA and JA in male sterile buds were 12.47% and 16.18% higher than that in the normal fertile buds respectively; while the contents of IAA, ZR and GA dropped to 14.00%, 23.04% and 45.68% as nomal bud respectively. The decline of IAA, ZR and GA₃ might be one of the reasons that lead to the male sterility.4. During the process of buds development, the ratios of IAA/ABA, IAA/ZR, GA₃/ABA and IAA/GA₃ showed large difference and different change tendency between sterile plants and fertile plants. When the sterile phenomenon began to appear, the male sterility might be related to the inbanalance of IAA/ABA, IAA/GA₃ and GA₃/ABA.