Sporulation of Mycosphaerella fijiensis in different culture media

Avaliou-se a esporulação de conídios de Mycosphaerella fijiensis (isolado LPM472) em sete meios de cultura (batata dextrose ágar, V8 ágar, V8 CaCO3 ágar, água de coco ágar, batata cenoura ágar, folha de banana ágar e micophil) sob quatro regimes de luminosidade (escuro contínuo, fotoperíodo de 12 h, luz contínua e seqüencial - dez dias no escuro e cinco dias sob luz contínua). O ensaio foi conduzido em delineamento inteiramente casualizado, com cinco repetições. A esporulação foi determinada em erlenmeyer de 125 ml, contendo 20 ml de seu respectivo meio de cultura e 0,5 ml de suspensão com 5 x 10(4) conídios de M. fijiensis/ml, mantidos a 25 ºC + 2 ºC, durante 15 dias. Não ocorreu esporulação em todos os meios de cultura sob regime de escuro contínuo, assim como no meio de folha de banana ágar, sob todos os regimes de luminosidade. No regime de fotoperíodo, ocorreu esporulação apenas nos meios V8 CaCO3 ágar e michophil, e no regime de luz contínua, apenas no micophil. No regime seqüencial, os meios de batata dextrose ágar e V8 CaCO3 ágar propiciaram as maiores produções de conídios.The conidial production of Mycosphaerella fijiensis (isolate LPM472) was evaluated on seven culture media (potato dextrose agar, V8 agar, V8 CaCO3 agar, coconut water agar, potato carrot agar, banana leaf extract agar and mycophil) under four different light exposure regimes (continuous darkness, 12-hour photoperiod, continuous light and ten days under continuous darkness followed by five days of continuous light). The experiment was arranged using a completely random factorial design with five replications with factor A being the four light regimes and factor B being the seven types of media. An erlenmeyer flask (125 ml) containing 20 ml of culture media and 0,5 ml of conidial suspension (5 x 10(4) conidia/ml) was considered as an experimental unit incubated at 25 ºC + 2 ºC for 15 days. Sporulation was quantified by counting the number of conidia in a Neubaeur chamber. No sporulation was observed under continuous darkness or for the banana leaf extract agar. Under the 12-hour- photoperiod regime, only mycophil and V8 CaCO3 agar provided sporulation while under continuous light, leave in mycophil resulted in sporulation. The best conidial production was obtained on PDA and V8 CaCO3 agar under the ten days of continuous darkness followed by five days of continuous light regime