Phomopsis castanea, a Seed-borne Endophyte in Chestnut Trees

Abstract

Phomopsis castanea(Sacc.) Höhn was found to occur endophytically in plant parts of European chestnut including flowers, leaves, shoots and fruits, when apparently healthy trees of four cultivars were sampled seven times throughout 1 year. This fungus is associated with the important post-harvest disease Phomopsis nut rot. The fungus was also shown to be endophytic in seedlings of the cultivar Perton’s Pride, and seed transmitted. There were apparent differences in the incidence of P. castanea isolated between the four cultivars and the two sites tested. The incidence of plant parts yielding P. castanea was highest for cultivar Marone at both sites, and lower for cultivars Sword, Buffalo Queen and Lucente. The plant parts with the highest incidence of P. castanea were the burr, the male flower, the stigma and style, and 1-year-old and 2-year-old shoots; those with the lowest incidence were the 3-year-old and 4-year-old xylem, the inner peduncle and the nut kernel. There were no apparent trends in the incidence of the fungus recovered from plant parts at different times of the year.