SEASONAL AND NEEDLE AGE-DEPENDENT CHANGES OF THE ENDOPHYTIC MYCOBIOTAIN PINUS-THUNBERGII AND PINUS-DENSIFLORA NEEDLES

Monthly changes in the endophytic mycobiota in Pinus thunbergii Parl. and Pinus densiflora Sieb. et Zucc. needles were detected by tissue cu lture. Endophytic mycobiota of these pine needles were dominated by fo ur taxa: the Leptostroma anamorph of the Lophodermium pinastri (Schrad . ex Hook.) Chev. complex, Phialocephala sp., Cenangium ferruginosum F r.:Fr., and an unidentified hyphomycete species (BrS). The mycobiota d iffered with host pine species, position on the needle, and needle age . Virtually no endophytes were detected in needles just after emergenc e, but most segments of the older needles harbored endophytes. The end ophytic mycobiota changed slowly with needle aging, except for the per iods of rapid increase in the detection frequency of leptostroma and P hialocephala sp. Detection frequency of leptostroma, the most frequent ly detected endophyte taxon in the needles of the two pine species, co ntinuously increased with needle aging, while that of Phialocephala sp ., the endophyte mainly detected from the basal segments of Pinus dens iflora a, slowly decreased with needle aging after a massive emergence in current-year needles.