Occurrence of <i>Phomopsis castanea</i> as an endophyte in chestnut trees

Abstract

Epidemiological studies on Phomopsis nutrot disease of chestnuts in New Zealand revealed that the fungus Phomopsis castanea occurred as an endophyte in stems (except xylem) leaves flowers and immature burrs of chestnut trees Apparently healthy trees from nurseries grower properties and research orchards as well as wild trees in the North and South Island were sampled and P castanea was isolated from 92 of the trees Among the four edible chestnut species and several commercial cultivars tested the incidence was highest for trees of European chestnut (Castanea sativa) and cultivar 1002 and lowest in Japanese chestnut (Castanea crenata) The incidence of plant parts yielding P castanea was also lowest for young trees from nurseries Dieback and necrosis of male catkins and leaf spot symptoms caused by P castanea were observed in some trees of C sativa and American chestnut (Castanea dentata) Spore sampling techniques failed to recover any airborne propagules from November 1999 to March 2000