The Research And Utilization Of The Eru Cytoplasmic Male Sterility Line In Flowering Chinese Cabbage (Brassica Campestris L. Ssp. Chinensis Var. Utilis Tsen Et Lee)

Flowering Chinese cabbage (Brassica campestris L.ssp.chinensis var. utilis Tsen et Lee) or Tsai-tai, is a variant of Chinese cabbage, which vast majority of edible parts are tender flower stalk and morphologic features is similar with other Chinese cabbage vegetables. In the study of flowering Chinese cabbage breeding, Our group has bred six cytoplasmic male sterility lines in flowering Chinese cabbage (EruCMS) by using the bred cytoplasmic male sterility line in purple cai-tai which sterility expresses stable, Leaf avoids yellowing in seedling stage under low temperature, nectary is normal, Sterility strain rate and the fertility degrees are100%crossed and backcross ed for three years with six inbred lines of flowering Chinese cabbage.In this study, the anther development of the new cytoplasmic male sterility line and its maintainer line in flowering Chinese cabbage were observed by using paraffin sections, in order to determine the stage and pattern of anther abortion. A6×6incomplete diallel cross design was used with six cytoplasmic male sterility lines in flowering Chinese cabbage and six inbred lines, and36hybrids were obtained. Heterosis on main agronomic traits, yield related traits and quality traits were investigated with36hybrids. While SSR technologies was used to analysis genetic diversity of the12inbreed lines and estimation of genetic distance. Further analysis the correlation between genetic distance and heterosis, primary discuss the feasibility of the prediction of heterosis with genetic distance. The main results were as follows:1. The abortion occurred at the early stage of uninucleate microspore, the abortion of the uninucleate microspore was caused by the squeezing of tapetal cell which showed highly vacuolization and exceptionally radial expansion. The uninucleate microspore sticked together and could’t make the viable pollen grains.2.73pairs of SSR primers screened out from520pairs SSR primers for amplifying clear and repeating bands were used for DNA polymorphism analysis.229polymorphic bands were amplified in total, each pair of primers could amplify one to six polymorphic bands. The calculation of genetic similarity coefficient and genetic distance and cluster analysis were accomplished by software NTSYSpc2.1, cluster analysis based on UPGMA(unweighted pair-group method with arithmetic means) showed that:the genetic similarity coefficient ranged from0.51to0.72. When the coefficient was0.55, the12parents were divided into four categories.3. Heterosis analysis on main agronomic traits, yield related traits and quality traits showed that:combination showed significantly positive average performance in the mid-parents heterosis on13traits of agronomic traits and yield traits. Soluble sugar content and fibres showed positive average performance in mid-parents heterosis, soluble protein content and VitaminC showed negative average performance in mid-parents heterosis.4. The parent which had a value of application was screened by analysis of combination ability. The CMS line3had the greatest negative effect on the growth period, it can be used as breeding parents of early maturing variety; CMS line5and male parent23showed high general combining ability(GCA) on yield-related traits, they could be used in high-yield breeding; CMS line D and male parent15showed high GCA on quality traits, they could be used for quality breeding; CMS line A and male parent13showed high GCA on stalk-leaf ratio, they could be used to improve commodity of flowering Chinese cabbage.5. Genetic distance showed a highly significant linear positive correlation with F1phenotypic values in12traits of agronomic traits and yield related traits, except that leaf width showed significant linear positive correlation with F1phenotypic values; as for heterosis, there was significant linear correlation between Genetic distance and mid-parent heterosis only in petiole width; as for special combining ability(SCA), there was no significant linear correlation between genetic distance and SCA except in petiole length. The use of genetic distance based on molecular markers for prediction of heterosis needs to make more in-depth inquiry.