109 - Tilletiopsis Derx ex Derx

Abstract

This chapter focuses on Tilletiopsis genus and its member species. The hyphae of this genus are regularly branched, narrow, septate, hyaline, monokaryotic, usually partly lysed, and come with retraction septa. Ballistoconidia are bilaterally symmetrical, allantoid, falcate or cylindrical, and are formed on sterigmata. Chlamydospores are sometimes present and the colonies are cream-colored, pinkish-cream, pinkish-yellow, yellow-brown, or brown. The member species of this genus are Tilletiopsis albescens, Tilletiopsis flava, Tilletiopsis fulvescens, Tilletiopsis minor, Tilletiopsis pallescens, and Tilletiopsis washingtonensis. After undergoing growth on 5% malt extract agar for five days at 17° C, the hyphae of Tilletiopsis albescens appear as regularly branched, narrow, and with retraction. The colonies of this species appear as tough, flat, glabrous or pruinose, dull, whitish-cream, and with an eroded margin. The hyphae of Tilletiopsis flava, after undergoing growth on 5% malt extract agar for five days at 17° C, appear as regularly branched, narrow, with cells measuring and with retraction septa. Ballistoconidia in this species are allantoid, falcate, or cylindrical. The hypae ofTilletiopsi fulvescens, after undergoing growth on 5% malt extract agar for five days at 17° C, become regularly branched, narrow, cylindrical, along with retraction septa. The colonies of this species become soft to rather dry, flat, warty or reticulate, glabrous or pruinose, dull, yellow-brown, and with an entire or eroded margin. Chlamydospores in Tilletiopsis minor, after undergoing growth at 5% malt extract agar for five days at 17° C, occur as terminally or intercalarily, and are ellipsoidal, subglobose, fusiform, or cylindrical. The colonies of this species are tough, glabrous, and pruinose or covered with slender fascicles, shiny or dull, cream to yellow-brown, and with an entire oreroded margin.