Obtaining Of Chinese Cabbage-cabbage Translocation Lines By Pollen Irradiation

In order to create Chinese cabbage-cabbage translocation lines, the pollens of Chinesecabbage-cabbage addition lines （AC1and AC3） were irradiated with⁶⁰Co-γrays. Thentheirradiated lines were selfed and were backcrossed with diploid parent Chinese cabbage.Through identification on morphology, cytology, and molecular makers, three Chinesecabbage-cabbage translocation lines （AT1-31, AT1-32and AT1-11） were identified fomAC1, and two Chinese cabbage-cabbage translocation lines （AT3-9and AT3-12） wereidentified from AC3. This research will provide important genetic materials for geneticimprovement in breeding Chinese cabbage, for mapping alien genes of Cabbage, and forexploring the relationship between genome A and C. The main results are shown asfollows:1．The pollens of Chinese cabbage-cabbage line#1AC1were irradiated with30Gy⁶⁰Co-γ rays. The M1seeds were then obtained by selfing and backcrossing withdiploid Chinese cabbage. M1plants were identified using specific SSR primers oflinkage group NO.3in cabbage compared with Chinese cabbage, three progeny plantswith specific cabbage bands were selected. These three progeny plants have normalmeiosis and20chromosomes, which were preliminarily identified as translocation lines.2．Through identification by specific SSR and InDel markers and meiosis observation onthe progeny plants of translocation lines, three translocation lines were identified andnamed AT1-31, AT1-32and AT1-11. PMC meiosis behavior of three translocation linesshowed that the chromosome configurations at diakinesis and metaphase I is2n=10II,without multivalent and univalent. Chromosomes of anaphase I and II can be separatedregularly, showing that the two translocation lines can be inherited stably in cytology.Seed set of selfed progeny plants from three translocation lines was counted, indicatingthat seed set of progeny from translocation lines were significantly lower than fromChinese cabbage.3．The pollens of AC3were irradiated with45Gy⁶⁰Co-γ rays. The M1seeds were thenobtained by selfing and backcrossing with diploid Chinese cabbage. M1plants wereidentified using specific SSR primers of linkage group NO.3and NO.2in cabbagecompared with Chinese cabbage,11progeny plants with specific cabbage bands wereselected. Two Chinese cabbage-cabbage translocation lines AT3-9and AT3-12with20chromosomes were obtained through observing meiosis from those11progeny plants.4. Seed set of selfed progeny plants of two translocation lines was counted, indicating that seed set of progeny from AT3-9and AT3-12was significantly lower than fromChinese cabbage. Seed set of AT3-12progeny was only12.82%.