Monday, August 3, 2009

PS 17-138: Root-associated fungal communities colonizing two dominant semiarid grasses: Hilaria sp. and Stipa sp

Miriam I. Hutchinson1, Jayne Belnap2, Jose Herrera3, Robert Sinsabaugh1, and Andrea Porras-Alfaro1. (1) University of New Mexico, (2) U.S. Geological Survey, (3) Truman State University

Background/Question/Methods

We conducted a preliminary survey of the fungal communities associated with roots of Stipa hymenoides and Hilaria jamesii, two grasses native to the southwestern United States. Root samples from 10 different plants were collected at a semiarid grassland in Utah. Fungal communities were assessed using microscopic and molecular methods. Roots were cleared with KOH and stained using blue ink to visualize mycorrhizal and endophytic fungi. A total of 100 root segments were surface sterilized and plated on malt extract agar with antibiotics.  Fungal endophytes were identified using nrITS primers.
Results/Conclusions

Microscopic analyses showed that all root samples from both Hillaria and Stipa were colonized by dark septate and arbuscular mycorrhizal fungi.  Vesicles and hyaline hyphae also were observed in all the roots.  Sclerotia, a characteristic structure of some dark septate fungi were also found. Approximately 75 fungi were isolated representing at least 45 morphotypes. Molecular identification showed that both grasses are colonized by endophytes in the orders Pleosporales, Hypocreales, and Sordariales commonly found in semiarid grasses, liverworts, and mosses.