Identification Of Molecular Markers Linked To Multiple-allele Male-Sterile Gene In Heading Chinese Cabbage

Heading Chinese cabbage (Brassica campestris L. ssp. Pekinensis) is a special vegetable originated in China. Due to its genetic complex and difficult to transformation , the nucleus male sterile was only applied in few organizations. Molecular marker techniques provide a powerful tool to expand the utilization of male-sterile lines in the breeding process. In this resaerch, nine populations which contained the male sterility gene Ms supplied by the Chinese Cabbage research group of Northwest A&F University were used to study the rule of inheritance of male sterility gene and molecular markers linked to sterility gene Ms. The results are showed as following:1 According to multiple alleles hypothesis, it preliminary inferred that the genotype of 05S781 and 05S938 was MsfMsf , msms for 05S1719, msms and/or Msfms for 06J32.2 Eighty RAPD primers were used to amplify the DNA polymorphism in the fertility DNA pool and the sterility DNA pool of population 09H12. The results showed that each primer amplified 5 strips on average with a number of 387 for the total strips. Eight primers(S61,S145,S179,S258,S567,S761,S1250,S1398) of them couldn't get any strip both in the two pools,while 4 primers(S184,S927,S1211,S1327) could get differential band in them, but the differential band were lost in the repeating validation process. The amplification result showed that no difference was found between the fertility pool and the sterility pool among the other sixty-eight primers with total strips from 2 to 7.3 Nine populations were also used to test the suitability of five SCAR markers and the genotype of their fertile plants were identified by using these markers. The results showed that marker syau-scr01 had evident polymorphism while the polymorphism of other four markers were lost. The recombination frequency of syau-scr01 with male sterile gene Ms in population 09H12 was 2.97% with a genetic distance of 2.15cM calculated by software Mapmaker/Exp (Version 3.0b). It preliminary inferred that the genotype of the fertile plants in fertile segregation progeny of whole fertile 09H9 and 09H10 were MsfMs, while the fertile plants in the other four populations with segregation ratio 1:1 was msms.4 According to the genotype of 06J32, two proposals were designed to gain new male sterile lines. At the same time, fertile plants with sterility gene Ms were selected in the offsprings of 05S781 and 05S938 by using syau - scr01 marker in order to get new male sterile lines through the conventional breeding methods. New markers lingked to fetile gene ms or Msf were also be screened in the breeding process.