A comparative study of endophytic fungi in needles, bark, and xylem of Pinus tabulaeformis.

摘要

Endophytic fungi associated with Chinese oil pine (Pinus tabulaeformis Carr.) from two distinct climatic sites, Fenghuangshan and Lingyuan in northeast China, were investigated. A total of 2065 fungal isolates were recovered from 4320 tissue segments consisting of needles, bark, and xylem from 30 mature trees for each site. Twenty-one fungal taxa were identified; the remaining 205 isolates (11% of total isolates) did not sporulate and could not be identified. There were higher overall colonization and isolation rates of endophytic fungi from the Fenghuangshan than from the Lingyuan site. At the Fenghuangshan site, the colonization and isolation rates significantly increased with the age of the needles and xylem, but not of the bark. At the Lingyuan site, the colonization and isolation rates significantly increased with the age of the xylem; however, there were no significant differences between 2- and 3-year-old needles and bark, except that they both contained fewer endophytes in 1-year-old by comparison with 2- and 3-year-old needles and bark. Alternaria alternata (Fr.) Keissler, Phoma sp.1, Phomopsis archeri B.C. Sutton, and Leptostroma sp. were the dominant taxa in the bark and needles. There was a high Sorenson's coefficient (0.89) of endophyte composition similarity between the Fenghuangshan and Lingyuan sites. We conclude that some fungi show a degree of tissue recurrence or specificity and that the composition of endophyte assemblages is not greatly influenced by geographical or climatic factors.