牡山羊草细胞质雄性不育小麦败育的生物学特性和细胞学研究
Biological characteristics and cytological studies on abortion of Aegilops juvenalis cytoplasmic male sterile line

为明确牡山羊草细胞质雄性不育小麦的染色体组成及雄性败育特点,采用分子标记技术和酸性聚丙烯酰胺凝胶电泳技术对牡山羊草细胞质雄性不育小麦是否含有1BL/1RS易位染色体进行了鉴定。另外,为揭示牡山羊草细胞质雄性不育小麦败育发生的时期和败育的细胞学机理,以牡山羊草细胞质雄性不育小麦(Ju87B1-706A)和其同型保持系(706B)为供试材料,采用I2-K染色、醋酸洋红染色、DAPI染色和石蜡切片法对其花药形态特征及小孢子形成和发育过程进行细胞学观察。结果表明:Ju87B1-706A具有黑麦1RS的特异扩增条带(1 500 bp),但缺少1BS的特异扩增条带(220 bp),与其在A-PAGE结果的ω区与黑麦特异蛋白谱带的结果相对应,从而说明牡山羊草细胞质雄性不育小麦Ju87B1-706A为1BL/1RS雄性不育小麦类型;I2-K染色说明Ju87B1-706A的败育类型为典败和染败; Ju87B1-706A能正常进行减数分裂形成小孢子,到单核晚期时能形成正常的核但细胞皱缩,二核期细胞形态不规则能形成正常的精核但有些营养核不清晰,三核期精核呈圆形不能形成梭形的精核并发生部分空胞化;其单核晚期花药中绒毡层的延迟解离以及二核期三核期细胞团侵入药室造成小孢子败育,从而推测单核晚期是其雄性不育发生的关键时期,可能与绒毡层异常有关。
To clarify the chromosome constitution of Aegilops juvenalis cytoplasmic male sterile line and its male sterile characteristics, 1BL/1RS translocation chromosome was identified by molecular marker techniques and acidic polyacrylamide gel electrophoresis (A-PAGE) and the pollen abortion type, cytological mechanism and morphological characteristics were also observed.The results showed that Ju87B1-706A contained the expected band of 1 500 bp in rye chromosome 1RS, but did not have the expected band of 220 bp in wheat chromosome 1BS, which was corresponded with the results from A-PAGE analysis.Ju87B1-706A was confirmed with the wheat-rye translocation chromosome 1BL/1RS and thus grouped as 1BL/1RS male sterile type.I2-KI staining revealed that the pollen abortion of Ju87B1-706A was the typical and stainable abortion type.Ju87B1-706A could precede normal meiosis to the formation of the anther, and small spores had normal formation of the nucleus but their shape was Irregular at the late uninucleate stage.The spores could form normal sperm nucleus but some vegetative nucleus were not clear and the shape of spores was still irregular at the binucleate stage.The sperm nucleus was round-shaped instead of the spindle-shaped and some spores were empty at trinucleate stage.Dissociation of anther's tapetum delayed in the late uninucleate stage and the invasion of cell mass could cause the abortion of microspore at the dinucleate and trinucleate stage.We speculated that the late uninucleate stage was the key period of the occurrence of male sterility, and the male sterility was associated with abnormal dissociation of the tapetum.