Obtaining And Identification Of Chinese Cabbage Alien Addition Lines With Chromosome 3, 6 And 9 Of Cabbage

In order to creating the alien addition lines, the BC₁ and BC₂ plants which come from crosses of Chinese cabbage-cabbage sesquidiploid individual (ACC, 2n=3x=29) back to Chinese cabbage (AA, 2n=2x=20) diploid were used as testing materials. Morphologic, cytology and reproductive characters of the BC₁ and BC₂ plants and the addition chromosome types of BC₁ and BC₂ descendant by self were studied. 2 monosomic addition lines and 1 disomic alien addition lines with cabbage chromosome were identified by karyotype analysis. The study provided a material and theory basic for the substitution lines and the alien substitution lines and the translocation lines and also helped to research the relative of A and C genomes, the origin and evolution, gene mapping and express and variety genetic improvement. The main results were showed as follow:1. The chromosome number of BC₁ and BC₂ plants was identified by taking count of the chromosome number at anaphaseâ… and anaphaseâ…¡during meiosis diversion. The rate of 21 chromosomes and 22 chromosomes identified from 18 BC₁ plants and 11 BC₂ plants was 16.67%, 16.67%, 27.27% and 9.09% respectively.2. PMC meiotic chromosome behaviors of BC₁ and BC₂ plants were very complicated. Chromosomes from Chinese cabbage and cabbage can't be obviously divided into two parts at prophaseâ… during meosis; There were high frequently trivalent even quadrivalent, which indicated the heterogenons synapsis occared between Chinese cabbage and cabbage; There were dissociative chromosomes at methaphaseâ… ; There were distributions of 10-11,10-1-10,10-1-11,10-2-10 and so on at anaphaseâ… ; There were distributions of 10-11-10-11,10-1-10-11-10,10-10-10-12,11-11-11-11and so on at anaphaseâ…¡. The diversification of gametes suggested that it was possible to get a set of alien addition lines.3. The field traits of BC₁ and BC₂ plants showed a good deal of distinctness, including the plants with the same chromosomal number. The addition chromosomes plants seemed like the parent cabbage in certain aspects, which help to identify the type of addition chromosome according to plant field traits.4. The characters of pollen and leaves stoma, the podding set and seeding set by self were counted. The results showed that there was significant difference between BC₁ and BC₂ plants and Chinese cabbage diploid parent (CK). The relativity of the pollen amount and the pollen viability was tested. The result indicated that the relativity between the pollen amount and the pollen viability was significant correlation.5. The plant chromosome number of BC₁ and BC₂ descendant by self were identified with the routine planishing technique. Two monosomic addition lines with cabbage chromosome 6 and 9 and one disomic alien addition line with cabbage chromosome 3 were obtained by karyotype analysis.