Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2008
Publication Date: 7/1/2008
Citation: Carris, L.M., Castlebury, L.A. 2008. Biology and phylogenetic analysis of Tilletia maclaganii, a pathogen of switchgrass (Panicum virgatum). Meeting Abstract. Inoculum 2008 59(4):23
Technical Abstract: Switchgrass (Panicum virgatum) is a native, warm-season perennial grass grown for forage and biofuels in the U.S. One of the most serious diseases of switchgrass is smut caused by Tilletia maclaganii. This pathogen causes significant biomass reduction and complete loss of seed production in infected switchgrass plants. None of the widely-grown cultivars have resistance to T. maclaganii, and no effective control measures are available; yet little is known about the biology or phylogenetic relationships of T. maclaganii. A study of T. maclaganii strains from cultivated switchgrass showed that teliospore germination occurs in less than 24 hours at room temperature, the fastest known for any species of Tilletia. Teliospores germinated to form rudimentary basidia with 5-7 fusiform, multinucleate, and non-conjugating basidiospores. Germ tube-like structures were frequently observed emerging directly from basidia. Basidiospores germinated to produce hyphae on which cylindrical passively dispersed secondary sporidia were formed. Forcibly discharged secondary sporidia, characteristic of most species of Tilletia that have been studied, were not produced by T. maclaganii. Implications for control of T. maclaganii based on its unusual germination and growth characteristics, and phylogenetic analysis of T. maclaganii and other Tilletia spp. infecting Panicoid grasses will be presented.