Genetic Analysis Of Bolting Tolerance In Cabbage (Brassica Oleracea Var.capitata) And Research On Physiological And Biochemical Indices In Vernalization Process

Cabbage (Brassica oleracea L. var. capitata L.) is an important vegetable crop of Cruciferous crops and is growed widely in the world. It has an important position in vegetable production in China. In cabbage production, premature bolting occurred frequently, which has been the important issues in the spring cabbage production. The efficient measure to solve this problem is to develop bolting-resistant varieties and germplasms.Research on the genetics of premature bolting and appropriate breeding methods will help to improve breeding efficiency and speed up the breeding process. In this paper, including agronomic traits associated with bolting traits of cabbage, the change of physiological and biochemical in vernalization process and associated with bolting traits as well as combining ability and heritability analysis of bolting stage in cabbage were studied using different bolting-resistant cabbage inbred lines, the results are as follows:1. Analysis of variable multiple regression was performed using the number of outer leaves sphericity index,firmness of head,proportion of head weight,length of interior stem as independent variables, and bolting stage as the dependent variable.Then the correlation coefficient and path coefficient were Obtained. The results showed that the greatest impact on the bolting is firmness of head, correlation coefficient reached a significant positive correlation. Length of interior stem was significant negative correlation with bolting, but other traits were little effect on bolting.2. Four inbred lines were used to analyze the combining ability and heritability of bolting time by Griffing complete diallel crossing I. the results showed that the general combining ability and special combining ability of inbred lines LN-0901 and LN-0913 were higher, which are suitable for heterosis-cross-breeding approach.The broad-sense heritability and narrow-sense heritability of bolting characters were 96.42% and 67.68% respectively, and mainly affected by additive genes.The selection will be effective in early generations to the bolting characters of cabbage.3. Relative to the same indicators,4 materials showed that basically the same trends in the whole process. In vernalization process, three indicators are showing upward.but in the process of room temperature treatment, it's t decreased first and then increased. In addition, cabbage varieties with different bolting-resistant were different in terms of soluble protein,soluble suga,and free amino acid content.The soluble protein and soluble free amino acid content of bolting-resistant cabbage varieties were lower than the easy bolting cabbage varieties. In the process of low temperature treatment.the content of soluble sugar in the easy bolting cabbage varieties was lower than bolting-resistant cabbage varieties,but it was the opposite situation under the room temperature treatment.4. Path analysis showed three indicators were highly significant correlation between physiological and biochemical indicator and vernalization time. But the path coefficient between physiological and biochemical indicator and vernalization time is great different depend on cabbage varieties, and the determination coefficients were great differences also.