Influence of Temperature and Species Origin on Fusarium spp. and Microdochium nivale Pathogenicity to Wheat Seedlings

摘要

The influence of temperature and species origin on the in vitro growth rate and pathogenicity of Fusarium and Microdochium nivale (F. avenaceum, F. culmorum, F. graminearum, F. poae, and M. nivale) to wheat seedlings was examined. The mycelial growth of Fusarium avenaceum, F. culmorum, F. graminearum, and F. poae was the fastest at 25 degrees C, and of M. nivale at 15 degrees C. The isolates of F. culmorum, F. graminearum and F. poae originating from mountain regions grew significantly faster at 15 degrees C than those from flatland regions. The isolates from flatland regions grew significantly faster at 25 degrees C than those from mountain regions. F. culmorum and F. graminearum were the most pathogenic species to the root development. The retardation of wheat grain germination caused by the tested species was assessed in descending order: F. culmorum, F. graminearum, M. nivale, F. avenaceum, F. poae. The biomass growth retardation at 15 degrees C was assessed in descending order: F. culmorum, F. graminearum, M. nivale, F. avenaceum, F. poae; at 25 degrees C as follows: F. graminearum, F. culmorum, F. avenaceum, M. nivale, F. poae. The isolates of M. nivale and F. poae originating from mountain regions were significantly more pathogenic than those from flatland regions. The results suggest that there exist different temperature ecotypes and pathotypes of Fusarium species and Microdochium nivale across the territory of the Slovak Republic.