Abstract: To study the biological characters of Pestalotiopsis versicolor， one of the agents of bayberry twig blight disease， the effects of media type， carbon （C） and nitrogen （N） sources， temperature， pH， and light on P. versicolor were examined to determine optimal conditions for mycelial growth and sporulation. Three independent isolates showed a similar trend of growth and sporulation with different C and N sources. However， the growth rates varied significantly among seven agar media. Fungal growth rates were the highest on potato dextrose agar （PDA） and potato sucrose agar （PSA）. The fungi grew fast on bayberry fruit extract agar （BFA） but sparsely. Growth rates were moderate on oatmeal agar （OMA） and Czapek\|Dox agar （CDA）， and low on bayberry leaf extract agar （BLA） and bayberry branch extract agar （BBA）. Sucrose， dextrose， maltose， lactose， mannose， levulose， sorbose， and starch were optimal carbon sources， whereas glycerol and ribose were moderate， and xylose was poor for the fungus. Potassium nitrate， ammonium nitrate， urea， and all of the amino acids tested （i.e. cysteine， glycine， tyrosine， histidine， alanine， arginine， glutamate， and proline）， were good sources of nitrogen for the fungus. Growth occurred between 10 and 30℃ and was optimal between 25 and 28℃. Growth was normal and no significant difference between pH 5 to 10 was found. The quantity of conidia from two isolates （XJ27 and XJ42） on PDA after 10 days growth under light was significantly greater （P< 0001） than that under darkness. In contrast， sporulation of the other isolate， RA2\|1， was unaffected by light. P. versicolor has wide adaptivity to media， carbon， nitrogen， temperature and pH， while light influences sporulation of some isolates. These results will be helpful to understand the epidemiology of the disease and to develop a reasonable disease management strategy in reforestation areas.

Key words: Pestalotiopsis versicolor, media, carbon sources, nitrogen sources, temperature, pH, light