CHARACTERIZATION OF A POLYGALACTURONASE INHIBITORY PROTEIN  GENE BcPGIP IN CHINESE CABBAGEPAKCHOI (Brassica campestris L. ssp. chinensis Makino) Effect of Hormones on the Regeneration of Different Explants of GMS Line in Brassica campestris L. ssp. chinensis cDNA-AFLP Analysis on Genes Associated with Vernalization in Vitro inBrassica campestris ssp. chinensis cDNA-AFLP Analysis on Genes Associated with Vernalization in Vitro inBrassica campestris ssp. chinensis Effects of Silenc ing BcMF3 by RNAi on Pollen Development of FloweringChinese Cabbage Effect of Hormones on the Regeneration of Different Explants of GMS Line in Brassica campestris L. ssp. chinensis