Cytology And Transcriptome Profiling Of Ogu CMS In Brassica Oleracea

Cabbage(Brassica oleracea var. Capitata) is an important leafy vegetable crop with a widely growing area in the world and is only second to Chinese cabbage(Brassica rapa) in China. It is an economic and efficient way to breeding hybrid cabbage generation using male sterile lines because Brassica oleracea has the obvious heterosis. Ogura cytoplasmic male sterile(OguCMS) is the most widely used, type with a complete and stable male sterility and is almost not affected by the environment.Using the anther of OguCMS Brassica oleracea R2P2 CMS with more than 8generation backcross descendant and its maintainer lines R2P2, we had done the following research:1.We observed the anther of R2P2 CMS and R2P2 by paraffin section using a microscope, and clarified the main sterile stages and characteristics of OguCMS.2.We identified and analyzed the differentially expressed gene related to stamen development by transcriptome analys,and explored the developmental pathway and mechanism of the male sterility,which provide theoretical basis for futher study.Main conclusions are listed as follows:1. Cytological analysis clarified that the main sterile stage of OguCMS Brassica oleracea is tetrad stage and the main characteristics is the abnormal activities of tapetal cells.2. RNA-seq data analysis showed that there were 1323 differentially expressed genes among the total of 36890 genes identified in this research with the filter conditions of Probability ≥ 0.8 and│log2Ratio(R2P2CMS/R2P2)│≥ 1. And307 genes were up-regulation and 1016 genes were down-regulation in R2P2 CMS compared with R2P2.3.In this study, we identified 24 genes related to pollen development and cell wall organization, 11 genes related to auxin and ethylene, 5 genes related to ATPase,31 genes related to heat-shock proteins,23 genes related to reactive oxygen species and 15 genes related to tapetum cells.4. This study support the AMS regulation pathway and Ca2+ participating in theMRR regulation pathway leading to cytoplasmic male sterility,and provide theoretical basis for futher study.