Department of Biology, Colorado State University, Fort Collins, Colorado 80523-1878 USA;
Am J Bot. 2000 Aug;87(8):1193-201.
Two recessive male-sterile mutants of maize with similar patterns of pollen abortion were studied. Genetic studies showed that one of the two mutations was allelic with a previously identified male-sterility locus (ms23) and the other mutation was in a newly identified male-sterility locus (ms32). Cytological characterization of homozygous mutants and fertile heterozygous control siblings was performed using brightfield, fluorescence, and electron microscopy. During normal anther development, the final anther wall periclinal division divides the secondary parietal anther wall layer into the middle layer and tapetum, forming an anther with four wall layers. This is followed by differentiation of the tapetal cells into protoplastic binucleate, secretory tissue. In both the ms23 and ms32 mutants, the prospective tapetal layer divided into two layers, termed t1 and t2, forming an anther with five wall layers. Neither the t1 nor the t2 layers differentiated normally into tapetal layers, as determined by examination of cell walls, nucleus number, and cytoplasmic organization. Pollen mother cells aborted after the onset of prophase I of meiosis, suggesting that an early developmental coordination may exist between tapetum and pollen mother cells.
我们研究了两个具有相似花粉败育模式的隐性雄性不育玉米突变体。遗传研究表明，这两个突变中的一个与先前鉴定的雄性不育基因座（ms23）等位，另一个突变位于一个新鉴定的雄性不育基因座（ms32）。使用明场、荧光和电子显微镜对纯合突变体和可育杂合对照同胞进行了细胞学特征分析。在正常花药发育过程中，终末花药壁周缘分裂将次级壁层的花药壁层分为中层和绒毡层，形成具有四个壁层的花药。随后，绒毡层细胞分化为原生质双核、分泌组织。在 ms23 和 ms32 突变体中，预期的绒毡层分为两层，称为 t1 和 t2，形成具有五个壁层的花药。通过细胞壁、核数和细胞质组织的检查，t1 和 t2 层均不能正常分化为绒毡层。花粉母细胞在减数分裂前期 I 开始后败育，这表明绒毡层和花粉母细胞之间可能存在早期发育协调。
