ITS-based comparison of endophytic mycota in twigs of native Populus nigra and cultivated P. x euramericana (cv. I-214) stands in Northern Spain.

摘要

Context: The European black poplar (Populus nigra) is considered one of the most seriously endangered indigenous tree species. However, the total area covered by monoclonal plantations of hybrid poplar is growing, because of the high profitability of these trees. Aim: The aim of this study is to describe and compare the endophytic mycota in twigs from native poplar (P. nigra) and hybrid poplar plantations (P. x euramericana clone I-214). Methods: Twig endophytes were isolated from three native and three hybrid poplar stands in Palencia (N. Spain). Three trees were chosen at random within each stand sampled. Isolates were identified according to sequences of the internal transcribed spacer region of their rDNA. The study focused on dominant species. Results: A total of 13 species were found. Six species originated from P. nigra only (Stemphylium vesicarium, Alternaria spp., Aureobasidium pullulans, Fimetariella rabenhorstii, Plagiostoma fraxini and Cryptodiaporthe salicella) and four from P. x euramericana only (Cytospora chrysosperma, Athelia bombacina, Biscogniauxia mediterranea and Unidentified sp. 1), whereas three were found on both types of trees (Lewia infectoria, Alternaria alternata and Epicoccum nigrum). Conclusion: The results show that the endophyte community on poplar twigs differs between native and hybrid poplars.