Studies On Isenzyme And Cytology Of Cabbage Male Sterile Materials "Ms2008076"

Cabbage(Brassica oleracea var. capitata L.) is one of the important vegetable crops and is widely grown in China for its great nutritional and economic values. Heterosis is the universal phenomena in Cabbage, and the hereditary basis of heterosis in cabbage has been extensively studied. In present, most of the cabbage varieties were obtained through the heterosis approach. There are many approaches to product the hybrid of cabbage, but the male sterility is the most classic approach. In this study, a new nuclear recessive male sterile material'Ms2008076',whose mechanism of infertility were studied from morphology, cytology and isoenzyme. Results were as follows:1. Studies on Morphology:No significant differences were observed between of Ms2008076 from germination to bolls stage. However, in flowering stage, the petals were normal and with many golden and full pollens from fertile, but the filaments from sterile plants were withered, short, yellowish-white with little brown, without pollens and obvious shorter stamen than pistils.2. Studies on Cytology:Microscopic observations on anther development process of male sterile materials Ms2008076 showed that Ms2008076 anther development was failed at the stage of pollen mother cell differentiation. The main characteristic is that the tapetal cells developed abnormally and pollen mother cell degradated rapidly, which result to the anthers were abortive completely.3. Studies on Isoenzyme:Five isoenzymes including SOD, POD, CAT, ATP and AMY were studied. Results showed that the isoenzyme bands and activities were different between the sterile and fertile plants of Ms2008076.a. After blotting, increased SOD. POD and CAT activity were recognized in both sterile and fertile Ms2008076 plants leaves compared with those in leaves before bolting, in sterile plants the activity of SOD, POD and ATP were higher, the CAT activity was lower and no significant difference in AMY activity compared with fertile plants before bolting. After bolting, in sterile plants the activity of SOD, POD and CAT were higher than in fertile plants, no significant difference in ATP and AMY were found between the two materials. Before bolting, the sterile plants leaves have the same bands with the fertile plants. After bolting, the band numbers for four isoenzymes including POD, CAT, ATP and amylase in sterile plants were the same with the fertile plants. However, two more SOD bands with Rf 0.55 and Rf 0.61 respectively in fertile plants were detected.b. In the development process of bud, the activity of SOD, POD and CAT in bud of sterile plants declined straightly, and the POD activity of fertile plants has the same pattern. However, SOD and CAT activities of fertile plants increased first and then decreased. Compared with fertile plants, POD and CAT of sterile plants, in small bud stage, expressed higher activity, and there was no significant difference in SOD,ATP and AMY activity. In big bud stage, in sterile plants the activity of SOD, CAT,ATP and AMY were lower than in fertile plants, POD activity was higher. While the POD and CAT of the bud showed higher activity on sterile than fertile plants in the flowering period, SOD and ATP activities were on the contrary, and no significant change in AMY activity was found between them. In addition, CAT isoenzyme of fertile plants have one more specific-band (Rf 0.23) than sterility in big flower bud stage. SOD isoenzyme of fertile plants have three more (Rf 0.61,0.65 and 0.74) specific-bands with stronger activity than sterility in both big flower bud and blooming flower bud stages.