Abstract
Anther ontogeny in an exotic cytoplasmic male-sterile (CMS) Iine 'Nadadores' and that in six indigenous CMS Iines obtained through crosses with the former have been compared. In the exotic CMS Iine, pollen abortion was associated with nondegenerating and persistant tapetum. Similar abnormalities were recorded in the indigenous CMS Iines also. Besides a few other tapetal abnormalities like degeneration of tapetum in premeiotic stages, tapetal hypertrophy in both pre and post-meiotic stages and pseudo-periplasmodium formation were also recorded. It is concluded on the basis of these observations that malfunctioning tapeta of various types are caused by inhibition of vascular tissue of the anther connective.
