摘要
1988～1990年用常规的石蜡切片法和涂片法对有芽黄性状遗传标记的陆地棉 msc_7(81A)不育系和 msc_3不育系的小孢子发育过程进行了细胞学的研究。msc_7不育系小孢子的彻底败育主要在单核靠边期,它们不能产生雄配子体。但是在南京气侯异常温度较高的1988年,也观察到一些具双胞的可育花粉粒,这从细胞学上也证明 msc_7不育系小孢子发育可能具有温敏性。这种具有遗传标记的温敏性核雄性不育系在棉花杂优上具有较大的应用价值。msc_3不育系的小抱子败育从 PMC 形成过程开始一直持续到双胞花粉粒的初期。有相当多的初生造孢细胞不能发育成为成熟的花粉母细胞,PMC 的减数分裂异常也比较严重。由于染色体分离的错乱,胞质分裂的不完全,因而产生大量大小不一,形状各异的小孢子,大型的小孢子常具有多个微核。这一不育系花粉(小孢子)外壁不能长出刺。小孢子败育的主要时期是单核靠边期,个别的也能持续到双胞花粉粒初期。msc_3不育系小孢子的败育可能与它的绒毡层延缓解体有关。
Pollen abortion of msc_3 snd msc_7 genic male sterile lines is cytologically studied with the usually paraffin section and iron—propionate—carmine squash methods.Msc_7 male sterile mi- crospores were degenerated completely in the late mononucleate stage.However,in a few Iocules,some pollen grains developed normally and produced viable gametes under the abnor- mal climate condition in 1988.Since the development of microspores was overlapped with high temperature in Nanjing in 1988,the thermo—sensitivity of msc_7 male sterility was cytological- ly testified.The development of thermo—sensitive genic male sterile line with virescent marker character has a great significance for thetwo line system hybrid cotton breeding.Msc_3 male sterile pollen abortion began in the stage of pollen Mother Cell (PMC) production and lasts un- till the early bionucleate stage.Many msc_3 primary sporogenous cells degenerated and could not develop to be mature PMC.Mierospores released from the tetrad were in various sizes and ab- normal shape due to meiotic irregularities such as chromosome segregation disorder and cytoki- nesis failure.Spiny exine missed from the msc_3 aberrent pollen grains.As same as msc_7,some microgametophytes remained mononucleate,i,e.amitotic and degenerated although a few could develop into the early binucleate stage.Delayed degeneration of tapetum cell may be res ponsible for the breakdown of microsporogenesis.
出处
《棉花学报》
CSCD
北大核心
1991年第1期9-14,共6页
Cotton Science
基金
国家自然科学基金
江苏省科委资助项目
关键词
陆地棉
核雄性不育
细胞学
Gossypium Hirsutum L.
Genic male sterility
Cytology
Pollen abortion
Thermo-sensitivity
