COMPARISONS OF EXTRACELLULAR ENZYME ACTIVITIES AND OXALATE PRODUCTION AMONG CRYPHONECTRIA PARASITIC A ISOLATES WITH DIFFERENT VIRULENCE LEVELS
栗疫病菌不同毒力菌株胞外酶活性和草酸产量的比较

All isolats of Cryphonectria parasitica did not secrete amylast in cul -ture. Virulent isolates could secrete laccase, polygalacturonase, protease, cellulase and lipase, but hypovirulent isolates did not secrete these extracellular enzymes or the activities of these enzymes were weak in hypovirulent isolates. All isolates produced oxalate in culture, but varying among isolates with different virulence levels. The oxalate productions of virulent isolates were higher markedly than those of hypovirulent isolates. There are no correlation of mycelial dry weights with oxalate production. The polygalaturonase of C. parasitica did not hydrolyze calcium polypectate except in the presence of oxalate ions.