甘蓝型油菜与播娘蒿原生质体融合杂种后代的遗传

Genetical Studies on Progenies of Somatic Hybrids between Brassica napus and Descurainia sophia

甘蓝型油菜(2n=38)与播娘蒿(2n=28)原生质体融合杂种F1连续自交3代,获得F2、F3和F4后代。用细胞学和SSR分子标记方法,分析杂种后代的染色体数目变异、减数分裂行为以及播娘蒿遗传成分的保留情况。结果表明在F2、F3和F4代中,根尖细胞染色体平均数分别为38.47±3.17、37.65±3.23和36.66±2.95,随着自交世代增加呈减少趋势;在杂种后代减数分裂中,观察到染色体桥、染色体落后、染色体周期不同步、不均等分离等现象;杂种后代F2、F3和F4代中检测到播娘蒿特征条带的平均频率分别为9.62%、2.99%和0.31%,呈减少趋势。因此要实现播娘蒿种质向油菜渗入应该重视F2世代的选择。

Somatic hybridization is an available way to create new germplasm and enrich breeding materials. Somatic hybridization between B. napus and D. sophia has been finished by the authors in 2005. Present research is to continue progeny studies of the somatic hybrids with the objective of carrying out desirable genes transfer from D. sophia to B. napus. Fertile progenies of the somatic hybrids between Brassica napus （2n=38） and Descurainia sophia （2n=38） selfed in three consecutive generations, resulting in F2, F3, and F4 populations. The number of somatic chromosome, chromosome behavior and genetic components from D. sophia in these progenies were observed and analyzed by cytological and SSR analyse. The average number of chromosomes in F2, F3, and F4 populations were 38.47±3.17, 37.65±3.23, and 36.66±2.95, respectively, and the maximum number was 56, 50, and 45, respectively, showing that chromosome number tended to reduction with the generation progression. Abnormal chromosome behaviors such as chromosome bridges, lagging chromosomes, meiotic cycle asynchrony, chromosome unequal distribution at meiosis stage were often observed in the three populations. SSR marker detections with 22 pairs of primers showed that the average frequency of plants with bands characteristic of D. sophia in the F2, F3, and F4 populations was 9.62%, 2.99%, and 0.31%, respectively. Therefore, achieving germplasm of D. sophia filter into B. napus should attach importance to select progenies of the somatic hybrid in F2 population.