Histological and ultrastructural observation of teliospore formation in Puccinia striiformis f. sp. tritici
小麦条锈菌冬孢子发生的组织学和超微结构研究

The ontogeny of teliospore of Puccinia striiformis f. sp. tritici (Pst), the causal agent of wheat stripe rust, was performed and observed by cryo-sectioning technique associated with light and electron microscopies. The observation showed that Pst teliospores derivated from binucleate sporogenous cells lining the base of telia. At the early stage, a spore-bud outgrew from one end of sporogenous cells and expanded to form septum and related structures such as teliospore initial, pedicel and primary teliospore cell resulted from bud division. The primary teliospore cell developed to be a two-celled teliospore with two nuclei in each cell after completion of the primary teliospore nuclear division and subsequent development of a septum. The matured teliospores were characterized by smooth surface, thickened cell wall, nuclear fusion, cytoplasmic condensing and accumulation of lipid droplets and glycogen-like substances. A lotus-shaped peridium structure around some telia was observed in some telia of Pst during telial formation.