Sporulation of Drechslera graminea on Barley Straw Extract Agar

Abstract

A simple method was developed to induce sporulation in Drechslera graminea. Thirty-six isolates of D. graminea, gathered from Canada, Germany, Montana, and Syria, were cultured, developed vigor- ous colonies and produced abundant conidia. Spor- ulation of the fungus was induced using straw extract from the barley cultivars Arta, Bowman, Bracken, Clark, Gallatin, and Salmas. There were significant differences in sporulation among isolates from dif- ferent areas as well as among isolates originating from the same barley field. Incubating the culture plates at 16 C under fluorescent light (12 h light/12 h dark) for 5 d following incubation under near ul- traviolet (NUV) light for 7 d resulted in 40% higher conidia production. Extract of seed, green straw or green leaves of barley as well as extract of mature wheat straw did not induce sporulation in D. grami- nea in culture. Twenty-one of the 36 isolates pro- duced pycnidia following the 7-day incubation under NUV light. Five of 25 isolates grown on V8-juice agar failed to sporulate. Germination of conidia of 12 iso- lates ranged from 72 to 99%.