• Korean Journal Plant Pathology
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• v.13 no.4
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• pp.215-218
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• 1997

The environmental factors affecting maturity of pseudothecia overwintered in iufected leaves by Mycosphaserella nawae was investigated. The pseudothecia in the overwinteringinfected leaves were matured at the end of April when the average temperature was $14^{\circ}C$ and precipitation was enough. Pseudothecia initiation was preceded by the fungal biomass development in a given host. The maturity of the pseudothecia from the leaves defoliated in early October was earlier and higher than those defoliated in November of the previous year. Pseudothecia development was also positively affected by low temperature. The maturity time, as determined by percentage of matured pseudothecia out of prematured ones, was also 20 days earlier, and the rate of maturity was higher for the leaves overwintered in door, than for those kept in greenhouse. We have providedevidence that the conidia play a significant role in the epidemiology of this pathogen. Many pseudothecia were developed in the leaves infected by artificially inoculated conidia and maturation rate of the pseudothecia was not different from that of the typical symptom by ascospores infection of Mycosphaerella nawae.