结球甘蓝不同初级三体n+1配子的形成及传递率研究

Study on Formation and Transmission of n+1 Gametes of Primary Trisomics of Cabbage

【目的】n+1配子传递率是进行三体遗传分析的重要参数。测定结球甘蓝"初级三体系"不同三体的n+1配子传递率为利用该"初级三体系"进行基因定位等遗传研究创造条件。【方法】结球甘蓝各初级三体分别与其二倍体亲本-9601进行相互杂交,杂交种子接种到MS培养基上培养繁殖成单株无性系;根尖染色体计数法鉴定杂交子代植株的染色体数目,用鉴定出的三体(2n+1=19)株数占鉴定植株总数的百分比表示n+1配子的传递率。【结果】各初级三体的n+1雌配子的传递率分别为15.28%(Tri-1)、12.68%(Tri-2)、12.31%(Tri-3)、30.51%(Tri-4)、22.81%(Tri-5)、7.46%(Tri-6)、5.36%(Tri-7)、42.37%(Tri-8)、9.23%(Tri-9);n+1雄配子的传递率分别为12.12%(Tri-1)、12.33%(Tri-2)、7.81%(Tri-3)、4.76%(Tri-4)、8.93%(Tri-5)、10.94%(Tri-6)、1.54%(Tri-7)、2.94%(Tri-8)、13.04%(Tri-9)。影响n+1雄配子形成和传递的因素主要有减数分裂前期Ⅰ三价体形成的频率、后期Ⅱ9/9/10/10分离的频率和花粉的生活力等。【结论】结球甘蓝各初级三体的额外染色体通过雌、雄配子均能传递给子代。

【Objective】 Transmission rate of n＋1 gametes is an important parameter for genetic analysis of trisomics. In order to correctly use the trisomics of the cabbage to carry out gene mapping and other genetic studies, it is significant to determine the n＋1 gamete transmission rate.【Method】The hybrid seeds of each primary trisomics （2n＋1） ×2n parent-9601 and 2n parent-9601×each primary trisomics （2n＋1） were respectively cultured on MS medium to propagate the clones which were used for chromosome number identification by root tip squash method. The ratio of （2n＋1） plants to total plants identified from progenies of 2n＋1×2n was denoted as the female n＋1 gamete transmission rate, and that from 2n×2n＋1 was denoted as the male n＋1 gamete transmission rate. 【Result】The female n＋1 gamete transmission rates were 15.28% for tri-1, 12.68% for tri-2, 12.31% for tri-3, 30.51% for tri-4, 22.81% for tri-5, 7.46% for tri-6, 5.36% for tri-7, 42.37% for tri-8, and 9.23% for tri-9. The male n＋1 gamete transmission rates were 12.12% for tri-1, 12.33% for tri-2, 7.81% for tri-3, 4.76% for tri-4, 8.93% for tri-5, 10.94% for tri-6, 1.54% for tri-7, 2.94% for tri-8, and 13.04% for tri-9.The main affecting factors on male n＋1 gamete formation and transmission were the rates of trivalent formation at prophaseⅠ, 9/9/10/10 division at anaphase and pollen viability. Ⅱ 【Conclusion】n＋1 gametes of the cabbage trisomics can be transmitted through female and male parents.