Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/19/1998
Publication Date: N/A
Technical Abstract: Tilletia indica, the causal agent of Karnal or partial bunt of wheat, produces large brown, tuberculate teliospores. Morphologically based identification of similar looking species of Tilletia can be difficult without accurate knowledge of the host, especially when few teliospores are present. In this study, herbarium and fresh specimens of T. indica, T. horrida, T. lolii, T. eragrostidis, and an apparently undescribed Tilletia from bunted Lolium spp. seeds were examined. Teliospores were characterized using light and scanning electron microscopy. Shape, size, ornamentation and color of the teliospores were analyzed. Mature T. indica teliospores, ranging from 30.2-63.8 um diam, were dark red-brown often opaque, with a densely ornamented exospore. Teliospores of the Tilletia from Lolium were 26.2-44.4 um diam, ranging in color from pale yellowish-or golden-brown to dark brown, with a more coarsely ornamented exospore. Tilletia horrida and dT. eragrostidis, with spores ranging from 21.9-41.4 um and 26.9-43.3 um, respectively, and T. lolii were distinguished from T. indica mainly by exospore ornamentation. Molecular confirmation will be helpful in cases when the host is uncertain and certain morphological characters overlap or when the stage of maturity of the teliospore is not known.