Identification of an endophytic Nodulisporium sp from Quercus ilex in central Spain as the anamorph of Biscogniauxia mediterranea by rDNA sequence analysis and effect of different ecological factors on distribution of the fungus

Collado, J Platas, G Pelaez, F

J. Collado et al., Identification of an endophytic Nodulisporium sp from Quercus ilex in central Spain as the anamorph of Biscogniauxia mediterranea by rDNA sequence analysis and effect of different ecological factors on distribution of the fungus, MYCOLOGIA, 93(5), 2001, pp. 875-886

44

INGLESE

Article

Plant Sciences

MYCOLOGIA

0027-5514 → ACNP

93

5

2001

875 - 886

ISI

0027-5514(200109/10)93:5<875:IOAENS>2.0.ZU;2-K

A study of fungal endophytes from aerial parts of Quercus ilex ssp. ballota was carried out on 32 specimens sampled at three forests in Central Spain. Trunk bark, fresh leaves, and healthy and decaying twigs were surveyed. A Nodulisporium sp. was frequently recorded among the isolates. Sequence anal ysis of the internal transcribed spacer (ITS) region of the rDNA (including the 5.8S rRNA gene) was used for the identification of this fungus. The co mparison and phylogenetic analysis of the sequences from several representa tives of this endophytic species and a group of xylariaceous fungi with Nod ulisporium-like anamorphs revealed that the endophytic Nodulisporium sp. wa s conspecific with the phytopathogenic species Biscogniauxia mediterranea ( equivalent to Hypoxylon mediterraneum). Significant differences were found between the isolation frequencies of the fungus, relative to the geographic al origin of the samples. Also, the fungus was more frequent on samples col lected in the autumn, as compared to those collected in the spring. The gre atest degree of colonization was observed in twigs, while in leaves the fun gus was present in significantly lower amounts. The relative frequency of t his species in bark increased in the higher parts of the trunk. Tissue pref erence analysis revealed that this fungal species is exclusively located in bark, being absent from xylem of living twigs. The relative abundance of t he fungus in decaying twigs was remarkably higher than in healthy twigs.