Production and Identification of Interspecific Hybrids between Brassica Juncea and Purple-Caitai and the Utilization of the First Generation of Hybrid
|School||Huazhong Agricultural University|
|Keywords||Brassica juncea Purple-Caitai Distant hybridization Hybrididentification Hybrid heterosis Pickling Nutrients|
Purple-Caitai (B. campestris L.ssp Chinensis L.var. utilis Tsen et Lee.2n=2x=20) is a specialty vegetable in our country. Because of its good taste, crisp refreshing and rich nutrition,it becomes people’s favorite vegetable. Brassica juncea cytoplasmic male sterile line(hau CMS) was discovered in1999. It is a natural new type of cytoplasmic male sterility, containing the better sterile source. Through distant hybridization and backcrossing between Brassica juncea (Brassica juncea L.2n=4x=36) and Purple-Caitai, the male sterile cytoplasm in Brassica juncea can be transferred into Purple-Caitai, creating new Purple-Caitai cytoplasmic male sterile line and its intermediate materials, as well as providing materials of new varieties of Purple-Caitai.In this experiment, the interspecific hybrids was producted through the distant hybridization. Brassica juncea cytoplasmic male sterile line (hau CMS) was used as the female parent and Purple-Caitai was used as the recurrent parent to carry out the distant hybridization. The true interspecific hybrids between Brassica juncea and Purple-Caitai were identified by the botany traits observing, stigma chromosome counting, pollen viability observing and SSR molecular markers. The agronomic and quality traits of the true hybrids were investigated and the heterosis analysis of hybrids showed that the heterosis of agronomic traits was obvious. But the heterosis of quality was unobvious. Having investigated the chemical characteristics and nutrients changes during the process of hybrid progenies pickled, the study discussed the feasibility of rapid utilization about hybrid progenies. The main results were as follows:1. The observing of botanical characters of hybrids showed that botanical characters of hybrids tended to female parent, at the same time showed some of the characteristics of male parent. Hybrids had28chromosomes. The observing of Floral organs of hybrids showed that:the size of floral organs is between the female parent and male parent. The stamens degenerate into the petals or something similar to the petals. There is no pollen by microscopic examination.2.12pairs of primers were selected from48pairs of SSR primers used to identify the authenticity of hybrids with the DNA template of parents and F1plants. The PCR amplification maps of primers BnGMS0009in all F1plants of combination J×5showed that all plants can amplify the specific bands of parents. There is no specific bands of F1plants in the amplification maps. The PCR amplification maps of primers BRAS095in all F1plants of combination J×3showed the same result. As a result, all the F1plants were true. 3. The heterosis analysis of hybrids showed that the heterosis of agronomic traits was obvious, especially average weight per plant. Average weight per plant of F1plants from combination J×5is76.7%higher than that of the female parent, and is82.4%higher than that of X. Average weight per plant of F1plants from combination J×3is60%higher than that of the female parent,and is65.2%higher than that of X. The heterosis of quality was unobvious. Whether in agronomic or quality traits, hybrid combinations J×5outperformed hybrid combinations J×3.4. The analysis of investigating the chemical characteristics and nutrients changes during the process of hybrid progenies pickled showed that there was no significant difference between the first generation of hybrid and X. The analysis of tasting experiment showed that there was no significant difference in color, aroma and taste between the first generation of hybrid and X. So the first generation of hybrid can be used as pickles by the comprehensive evaluation.5. The yield of the first generation of hybrid was significantly higher than X. There was no significantly decrease of the chemical characteristics and nutrients content between the first generation of hybrid and X by the comprehensive evaluation. So the first generation of hybrid can be used as pickles and hybrid combinations J×5outperformed hybrid combinations J×3.