Application Studies Of In Situ Hybridization Technique In Chinese Cabbage And Cabbage

Chinese cabbage(Brassica campestris L. ssp. pekinensis ssn rapa)and cabbage(Brassica oleracea var. capitata L.)were vegetables grown extensively in Brassica, were important agriculture resource in our country. In this research, with the diploid of Chinese cabbage(AA, 2n=2x=20), the diploid(CC, 2n=2x=18)and three primary trisomics self-established of cabbage, allotriploid hybrid(ACC, 2n=3x=28)in Chinese cabbage and cabbage as materials, the distributing trait of 25S rDNA repeat sequence in chromosomes of Chinese cabbage and cabbage were analyzed, chromosomes were identified exactly, by FISH technique on metaphase and interphase. With Chinese cabbage genome and cabbage genome as probes respectively, GISH was made to analyse the signal trait, so as to discuss the relationship between A-genome and C-genome in the diploid of Chinese cabbage, the diploid of cabbage and allotriploid hybrid in Chinese cabbage and cabbage. The study results were as follows:1. The gene 25S rDNA was studied on diploid of Chinese cabbage using FISH. The result indicated that there were ten 25S rDNA signals in Chinese cabbage genome. They were located on the middle of long arm of chromosome 1, near the centromere of long arm of chromosome 2, 3 and 4, and on the satellite region of chromosome 10. The fluorescence intensity of hybridization signals was various on different chromosomes.2. 4 25S rDNA signals were detected on diploid of cabbage chromosome, they were located on the end of short arm of chromosome 3 and on the satellite region of chromosome 9; 4 25S rDNA signals were detected in Triplo4,Triplo5 and Triplo6, the chromosomes and the position that these signals were localized on were the same as on the diploid.3. 8 25S rDNA signals were detected in allotriploid hybrid in Chinese cabbage and cabbage. They were located on the end of short arm of chromosome 3 and on the satellite region of chromosome 9, near the centromere of long arm of chromosome 2,3 and 4 and on the satellite region of chromosome 10, The fluorescence intensity of hybridization signals was various on different chromosomes.4. The labeled genomic DNA of Chinese cabbage and cabbage were respectively hybridized to Chinese cabbage and cabbage, signals were detected on all chromosomes, but the fluorescence intensity of hybridization signals was various on different chromosomes.5. The labeled genomic DNA of Chinese cabbage was hybridized to allotriploid hybrid(ACC)in Chinese cabbage and cabbage. When blocking DNA was not used in GISH, clear and strong signals were detected on all chromosomes, the intensity of hybridization signals was various on different chromosomes; When blocking properly, weak signals were detected on 18 chromosomes, clear signals were detected in other 10 chromosomes, to certain extent, chromosomes of Chinese cabbage and cabbage could be discriminated; When blocking overly, all signals were very weak and could not be discriminated.6. The labeled genomic DNA of cabbage was hybridized to allotriploid hybrid(ACC)in Chinese cabbage and cabbage. When blocking DNA was not used in GISH, clear and strong signals were detected on all chromosomes, the intensity of hybridization signals was various on different chromosomes; When blocking properly, clear and strong signals were detected on 18 chromosomes, weak signals were detected in other 10 chromosomes, to certain extent, chromosomes of Chinese cabbage and cabbage could be discriminated; When blocking overly, all signals were very weak and could not be discriminated.