温敏雄性不育小麦BNS366花粉败育的细胞学观察

为了明确温敏雄性不育小麦BNS366雄性败育的细胞学机理,采用醋酸洋红染色法观察减数分裂和小孢子发育过程,用1%I2-KI溶液染色进行花粉育性统计;以温敏不育系BNS和常规品种扬麦13作为对照。结果表明,BNS366的减数分裂和小孢子发育过程与BNS完全一致,即:在减数分裂过程中,中期Ⅰ染色体出现滞后现象,在形成二分体和四分体时细胞质分裂不均匀,出现三孢现象;小孢子发育过程中,只观察到单核靠边期,最后核物质解体出现空孢现象。而扬麦13在减数分裂过程中染色体表现正常,小孢子发育过程中,观察到单核期→双核期→三核期。开花期,BNS366和BNS花粉均表现典败和圆败,扬麦13可育。减数分裂表现出的异常行为是导致BNS366花粉败育的原因之一,单核靠边期是其败育的关键时期。

Cytological Observation on Pollen Male Fertility Abortion of Thermo Sensitive Male sterile Wheat Line BNS366

In order to clarify the cytological mechanism of pollen abortion of thermo sensitive male sterile line wheat BNS366,the meiosis and the development process of microspore were observed by acetate carmine dyeing process and the pollen fertility was added up by staining with 1% I₂ KI and the thermo sensitive sterile line BNS and the conventional varieties Yangmai 13 were taken as check. The results showed that BNS366 and BNS was entirely consistent in meiosis and microspore development process. In the process of meiosis,the chromosomes appeared hysteresis phenomenon at metaphase I and the cytoplasmic division was uneven and three cell phenomenon appeared at dyad and tetrad stage. In the development process of microspore,only the late mononuclear stage was observed and nuclear matter melted finally and empty spore appeared. However,the chromosomes of Yangmai 13 were normal in the process of meiosis and mononuclear ,binuclear and trinuclear were observed successively in the development process of microspore.At flowering stage,the pollens of BNS366 and BNS showed abortion,which mainly belonged to spherical abortion type and typical abortion type,while Yangmai 13 showed male fertile. Abnormal meiosis is one cause of pollen abortion of BNS366,and late mononuclear period is the critical period of abortion.