Sporulation of Drechslera graminea on barley straw extract agar

Abstract

A simple method was developed to induce sporulation in Drechslern graminea. Thirty-six isolates of D. graminea, gathered from Canada, Germany, Montana, and Syria, were cultured, developed vigorous colonies and produced abundant conidia. Sporulation 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 different 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 ultraviolet (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. graminea in culture. Twenty-one of the 36 isolates produced 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 isolates ranged from 72 to 99%.