陆地棉1355A和104—7A不育系的细胞学研究

细胞学观察表明，陆地棉１３５５Ａ核雄性不育系小孢子败育从收缩期、小孢子外壁发育到双核期早期都有发生，但是其主要的败育时期是单核早期，这一不育系的外壁不能正常发育而长出刺，它和美国鉴定的ｍｓ２不育系小孢子败育过程相类似。这从细胞学上证实了我们先前的遗传学研究结果，即它是ｍｓ２的等位基因。１０４－７Ａ胞质不了系花药分化正常，但是很多在花纷母细胞的形成过程中退化解体。一些花粉母细胞能进一步发育成熟并开始减数分裂，但都仅停留在减数分裂的前期Ⅰ。该不育系绒毡层的提早解体可能与花粉母细胞的解体有关。它和美国培育的Ｃ．ｈａｒｋｎｅｓｓｉｉ胞质不育系的败育进程基本一致。

Cytolgic Studies on 1355A Genic and 104-A Cytoplasmic Malesterile Lines in UplandCotton

Cytologic observation indicated that the meiosis appears normal for 1355Agenicmale sterile line. There is a regular tetrad formation and seperation of microspores. The mi-crospores degenerate during the development of the pollen wall.In this line,exine spine cannot be produced. However, in a few locules,some microspores develop and preduce vacuolatemicrospores or early binucleate pollen. As for 104-7A cytoplasmic male sterile line, there is anormal differentiation of the archesporial cell and anther walls. In the majority of cases,thesporogenous tissues collapse and coalesce during the premeiotic stages of development. caca-sionally, a few Pollen Mother Cells(PMCs)are formed and meiosis progresses in some locules,but these cells degenerate during the early stages of Prophase I. The collapse of the tapetumis responsible for the abortion of PMCs. The abortion events of 104-7A are much similar tothose of the G. harknessii cytoplasmic male sterile lines.