Pectolytic enzymes activity and pathogenicity ofGaeumannomyces graminis var.tritici and related Phialophora-like fungi

Gaeumannmyces graminis var.tritici (Ggt), Phialophora sp. (lobed hyphopodia) andPhialophora graminicola vere grown in a liquid medium with pectin and on autoclaved wheat roots (root media) and the activity of pectolytic enzymes in culture filtrates was measured. Most strains of the fungi exhibited polygalacturonate trans-eliminase activity but no pectin methylesterase activity was detected.Ggt polygalacturonase was found in culture filtrates from all the media used whilePhialophora sp. did not exhibit activity of this enzyme in the unbuffered root media. No polygalacturonase activity was demonstrated forP. graminicola. A correlation was found (r=0.548) betweenin vitro polygalacturonase activity and the pathogenicity ofGgt to wheat seedlings.