甘蓝型油菜373S温敏不育基因在可育细胞质背景下的表达

旨在明确甘蓝型油菜温敏不育系373S温敏不育基因表达与特定细胞质之间的关系。以甘蓝型油菜373S（微粉）为父本，以具有cam细胞质的Shaan 2B为母本，杂交、回交及自交得到BC₁及F₂代群体。结果表明，在上述具有cam细胞质的BC₁及F₂中，可育株与不育株的分离比分别符合3∶1与15∶1，表明该群体中不育性状受2对基因控制。分离群体中的不育株表现出温敏不育特征，其不育花形态与373S没有明显差别；与373S比较，该分离群体中的不育植株结实角果数及自交结实率有不同程度的降低，不育期时间率（不育期时间所占百分比）无显著差异；花冠直径、四强花药长度、二弱花药长度无明显差异，花柄长度、花瓣长度、花瓣宽度、四强雄蕊长度、二弱雄蕊长度略有增加。细胞学观察表明，该分离群体中的不育株小孢子的发育过程、染色体形态、胼胝质沉积与373S无明显差异，均在花粉母细胞时期出现异常。本研究成功地将373S温敏不育基因从pol细胞质导入cam细胞质，说明该温敏不育性状是由细胞核内温敏不育基因导致，与细胞质背景无关。

Expression of Thermo-sensitive Male Sterility Gene in Normal Cytoplasmic Type Derived from TGMS Line 373S (Brassica napus)

This study investigated the relationship between the thermo-sensitive male sterile gene and specific cytoplasmic type in thermo-sensitive genic male sterile (TGMS) line 373S in Brassica napus L.,with the aim of advancing the understanding of its male sterility mechanism and utilization in two-line hybrid breeding.This study used the female parent line Shaan 2B with normal cytoplasmic type cam and the TGMS line 373S as the male parent,in a cross,resulting in the separation ratios of fertile and sterile plants at 3∶1 and 15∶1 in BC₁ and F₂ population,respectively,suggesting that the male sterility trait was controlled by two pairs of recessive genes in this population. The sterile plants in the BC₁ and F₂ populations exhibited thermo-sensitive sterility.Compared with the line 373S,the seed-setting rate of male sterile plants slightly decreased,and the male sterile period had no significant difference in the segregated populations. Additionally,there were no significant differences in the corolla diameter,length of four stronger stamens’ anther,and length of two weaker stamens’ anther,while a slightly increase was observed in the length of stalk,length of petal,width of petal,length of four stronger stamens and length of two weaker stamens in the segregated populations. Cytological observation revealed abnormal microspores at pollen mother cell stage in male sterile plants in the segregated populations in terms of anther development stage,chromosome morphology and callose deposition,with no differences compared with the line 373S. These findings suggest that the TGMS gene(s) in the line 373S is successfully introduced from pol to cam cytoplasm,and the TGMS trait of 373S is caused by the TGMS gene(s) in the nucleus,independent of the cytoplasmic background.