Characterization of Ustilago tritici and U. nuda on wheat and barley. I. Teliospore morphology

Morphology of teliospores of Ustilago tritici and U. nuda pathogenic on wheat and barley were studied by using light and electron microscopy. The data on teliospore length and width subjected to ANOVA showed significant differences at 1% level between the two species, whereas UPGMA Cluster analysis was not able to separate the two species. The ultrastructure of the two species was found to be substantially similar. In SEM, teliospores of U tritici showed echinulation with more prominent spines than those of U nuda. It is concluded that based only on teliosore morphology, it is difficult to separate the two species, thus making it imperative to use approaches involving DNA polymorphism for species separation.