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以A2V4/B2V4为材料,对A2类型雄性不育系的减数分裂过程中染色体行为和花药发育过程中绒毡层的变化进行了细胞学观察研究。结果表明:高粱A2V4 CMS的染色体行为,在前期Ⅰ至中期Ⅰ无任何异常现象,从后期Ⅰ开始,染色体行为出现各种异常现象,同源染色体在走向两极时出现滞后或部分不分离、或在后期Ⅱ姐妹染色体不分离造成细胞内染色体多倍化,以致形成两极染色体数目不等、在一个细胞内有几个染色体团或核、三分体和“T”型、直线型排列的四分体;花药发育过程中也有大量异常现象,药室的绒毡层细胞不形成或提前解体,药室内的花粉母细胞不发育或小孢子液泡化,绒毡层细胞发育异常,出现巨型化而挤满整个药室或绒毡层细胞虽发育正常,但花粉母细胞发育异常,在造孢细胞时期即开始出现变形现象,随后发生粘连退化,绝大部分花粉母细胞不能完成正常的减数分裂过程而形成四分体,所有这些异常现象最终导致小孢子退化。
Using A2V4 / B2V4 as the material, the cytological observation of chromosome behavior and tapetal change during the meiosis of A2 type male sterile line was carried out. The results showed that the chromosomal behavior of sorghum A2V4 CMS did not show any abnormality in the first to the mid-term I, and all the abnormalities appeared in chromosome behavior from late stage Ⅰ. Homologous chromosomes showed some lagging or no separation when they reached the poles or Late stage Ⅱ sisters do not separate chromosomes resulting in chromosome doubling, resulting in bipolar chromosomes ranging from the number of chromosomes in a cell group or nucleus, trisomy and “T” type, the linear arrangement of the tetrad There was also a large number of anomalies during the development of anthers. The tapetum cells in the drug compartment did not form or disintegrate prematurely. The pollen mother cells in the drug compartment did not develop or the microspores vacuolization and the tapetal cells developed abnormally. Although the whole chamber or tapetum cells develop normally, pollen mother cells develop abnormally and begin to deform during the period of sporulation cells, then the adhesions degenerate, and most pollen mother cells can not complete the normal meiosis process Form a tetrad, all of these anomalies eventually leading to microspore degeneration.