Ectomycorrhizal diversity of Alnus viridis (Chaix) DC from three subalpine sites in Slovenia M. Hrenko*, M. Bajc, T. Grebenc, H. Kraigher
Slovenian Forestry Institute, VeÄ?na pot 2, Ljubljana, Slovenia; * corresponding author (melita.hrenko@gozdis.si)
Background and aims The genus Alnus comprises in Slovenia three species, among which Alnus viridis (Chaix) DC (syn. A. alnobetula (Ehrh) Hartig) grows predominantly in the subalpine or high montane belt on acidified soils. Alders are the only genus from Betulaceae that has evolved root symbiotic relationships with nitrogen fixing actinomycetes (for a screening of these in Slovenia see Grebenc et al. 1999) as well as ectomycorrhizal and arbuscular mycorrhizae (Tedersoo et al. 2009). In Slovenia the ectomycorrhizal community of alders has not been studied yet. We present a pilot study of the ectomycorrhizal community of green alder at three subalpine sites in Slovenia. Methods The study sites were located in the Triglav national park at Lipanca, 1450 m a.s.l., acidified raw humus on limestone; in the Natura 2000 site on Smrekovec, 1650 m a.s.l., on volcanic andezite, and in the remnants of natural vegetation at the ski area Krvavec, 1500m a.s.l., on limestone. At each site 5 soil cores were taken quantitatively to reach 270 ml. After washing all roots were differentiated into non-woody-plant roots, non-ectomycorrhizal, non-turgescent and different vital ectomycorrhizal morphotypes, and counted. Morphotypes were briefly morphologically and anatomically characterized, the ITS region of rDNA was sequenced, and the identification is underway. Key results In total, 68.680 root tips were analysed, almost 31.000 in samples from Lipanca, almost 20.000 from Krvavec and almost 18.000 from Smrekovec. The non-turgescent types represented 76% of all alder roots from Lipanca, 42% from Krvavec and 55% from Smrekovec. Among vital types of ectomycorrhiza, 12 were found on Lipanca and 14 both at Krvavec and 11 on alder roots from Smrekovec. Some types have also been identified on spruce and pine roots. All identifications of fungi and roots yet need to be confirmed by molecular methods. Conclusions 30 different ectomycorrhizal morphotypes were differentiated on green alder from three sites in the Slovenian Alps. Although the number of roots from the volcanic ground rock material was smaller than from the other two plots, the number of different morphotypes was comparable. Also, the number of morphotypes from a heavily disturbed ski-area resort was high. Any alder- or site-specific types yet need to be confirmed after molecular identification. References Grebenc T., Rupnik M., Hacin J., Janc M. and Kraigher H. (1999). Phyton (Horn) 39 (3), 207-211. Tedersoo L., Suvi T., Jairus T., Ostonen I. and PĂľlme S. (2009). New Phytologist 182, 727-735.
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