FURTHER MYCOSPHAERELLA SPECIES ASSOCIATED WITH LEAF DISEASES OF EUCALYPTUS

Three new species of Mycosphaerella are described from diseased leaves of Eucalyptus growing in a species trial in south-eastern Australia: Mycosphaerella marksii sp. nov. was associated with circular to irregular, sometimes confluent lesions, bordered by a prominent red-brown margin on several species of Eucalyptus; M. grandis sp. nov. and M aggregata sp. nov. were associated with lesions confined to the leaf margin, extending from the tip almost back to the petiole, on leaves of E. grandis. It is likely that M grandis is a primary parasite and M aggregata a secondary invader. The species are distinguished mainly by their ascospore morphology and germination. Discrepancies between spore dimensions recorded in this and a previous study are explained by differences in the stains used.