The Effect of Temperature on Spore Germination, Growth and Appressorium Formation of Colletotrichum Gloeosporioides and Dothiorella Aromatica

Conidial germination of Colletotrichum gloeosporioides and Dothiorella aromatica was affected by temperature. The optimal temperature for germination was between 25 and 30°C. No germination occurred at 5 and at 40°C respectively. C. gloeosporioides produced appressoria in vitro while D. aromatica produced long germ tubes without appressoria. Appresorium formation was more sensitive to temperature than was germination. Appressoria were produced at temperatures ranging from 10 to 30°C. Temperature requirements for mycelial growth of C. gloeosporioides and of D. aromatica were similar to those for conidial germination. The information is useful for the prediction of infection periods.