عنوان مقاله [English]
Walnut anthracnose is the most common disease in common walnut, Juglans regia L., in Iran, caused by Gnomonia leptostyla. In current research, efficiency of various culture media including BAB, OMA, MA, NA, PDA, CMA, WLEA and WLEOMA in growth and sporulation of the fungus were studied. Three contaminated leaf samples from Miyaneh (No1), Marand (DV) and Karaj (Md1) areas were selected and after fungus isolation, they were
cultured on mentioned media with three replications. Cultures were incubated in 21oC, 50% RH and 12:12 (L:D) photoperiod and some traits such as maximal colony diameter, colony pattern, mycelium density, sexual and asexual reproduction were investigated after 2, 3, 6, 9, 14 and 21 days. For perithecia maturation, primordial perithecia consisted cultures were incubated in 4oC in darkness for 3 months. There was no significant difference between isolates in morphology, color and growth pattern, but in growth rates and sporulation. Md1 produced primordial perithecia on the culture without walnut leaf extract but the others were not able to do. No1 could not sporulate on PDA, WA, CMA and OMA media as much as other isolates. However all isolates could produce immature perithecia and acervuli on WLEA and WLEOMA. The weakest media was BAB and the most suitable media for fungus isolation was WA. Fungus growth rate was in maximum on OMA and the highest density of mycelium was obtained on PDA. Sexual and asexual reproduction has been occurred in best way on media with walnut leaf extract. However, any mature perithecia was not obtained in any culture after three month incubation.