Gentic Analysis And Application On Bolting Traits And Establishment Of Fingerprinting Of Non-heading Chinese Cabbage

Non-heading Chinese cabbage is one of the widely cultivated vegetable crops in China, occupying an important position in the annual supply of vegetables. However the bolting problem results huge losses in yield production, so the research of inheritance of bolting trait and the resistance of bolting breeding becomes an important direction in breeding process. Non-heading Chinese cabbage has strong heterosis, so we can use hybridization and backcross to get new germplasm. With the continuous enriching of germplasm resources, the using of molecular markers to establish the SSR digital fingerprinting for the identification and protection of breeds becomes a new research direction. In this study, a late bolting non-heading Chinese cabbage line and an early bolting non-heading Chinese cabbage line were used to formulate the P1、P2、F1、B1、B2and F2 six generations, then used the mixed major gene plus poly-gene genetic model to analysis the inheritance of bolting time, and the bolting resistance trait was used for new breeding. The early bolting and heat-resistant non-heading Chinese cabbage and the Flowering Chinese cabbage cytoplasmic male sterile line were used to hybridizate and backcross to obtain two new heat-resistant non-heading Chinese cabbage cytoplasmic male sterile line, the variations of the agronomic traits, physiological and biochemical indexs were analyzed, and the infertility and the heat resistance of the new non-heading Chinese cabbage cytoplasmic male sterile line were identified. At the same time, the SSR primers were used to establish the digital fingerprinting of twenty-eight non-heading Chinese cabbage.The main results are as follows:1. The bolting trait of six non-heading Chinese cabbage generations was analyzed by the mixed major gene plus poly gene inheritance model.The result showed that the inheritance of bolting trait was controlled by two additive-dominance-epistatic effects major gene plus additive-dominance effects poly-gene.The additive effects of the two major genes were-9.0784 and-7.2804 respectively, the dominance effects were 0.7812and-20.8587 respectively. The heritability of major genes in B1, B2 and F2 generations were 81.04%, 77.59%, 87.58% respectively and the poly genes heritability were 7.41%,3.51% and 6.47% respectively. The variance of environment in B1 was higher than other generations. The inheritance of bolting trait of non-heading Chinese cabbage was dominated by major genes and the variance of environment was low in total variance. It is fit for early selection. The new germplasm with better agronomic traits and bolting trait was obtained by hybridization.2. By investigating the cultivation and pollination time of the stertile source and the paternal, a new efficient transfer method was established, and two non-heading Chinese cabbage cytoplasmic male sterile lines were obtained by artificial selection. The agronomic and biochemical traits of the parents and backcross generations were investigated, the results showed that many characters were close to the recurrent parent gradually with the increasing of the backcross generation. The new non-heading Chinese cabbage cytoplasmic male sterile line obtained efficient heat resistance, high soluble sugar content and low cellulose content.3. The botanical traits of new non-heading Chinese cabbage cytoplasmic male sterile line were investigated. The results showed that the sterility was stable and complete.Through specific PCR primers amplification, the Ogu CMS was amplified in the new non-heading Chinese cabbage cytoplasmic male sterile line the sterility gene has been successfully transferred into the non-heading Chinese cabbage. The new non-heading Chinese cabbage cytoplasmic male sterile line showed lower conductivity and MDA content than the comparison, which indicated they have good heat resistance.4. Sixteen SSR primer with high polymorphism, clear amplified bands, good repeatability were screened. Each primer pair amplified 3 to 6 alleles, polymorphism information value range from 0.77 to 0.94.Four pairs of primers BRAS-067, cnu-m316 a,Bn GMS491, cnu-286 were selected to construct the digital fingerprinting of 28non-heading Chinese cabbage materials.