Distribution and diversity of arbuscular mycorrhizal fungi in grapevines from production vineyards along the eastern Adriatic coast

The colonisation and diversity of arbuscular mycorrhizal fungi (AMF) on roots of grapevines were investigated in production vineyards located along a 500-km-long stretch of karst along the coast of the Adriatic Sea. AMF communities on roots of grapevines were analysed using temporal temperature gel electrophoresis and sequencing of the 18S and internal transcribed spacer segments of the rDNA operon. The AMF colonisation of these grapevines roots was consistent along the whole of this east Adriatic karst region, at 64 to 82 % of fine roots. The comparison of the AMF communities on the roots of these grapevines showed that the fungal community associated with grapevine roots seems to be relatively stable, with inter-vineyard variability comparable to intra-vineyard variability. Some of the changes in the fungal communities were attributed to environmental factors (plant-available P) and location of the vineyard, although the latter could also have been influenced by an unmeasured environmental factor. A total of 27 taxa of fungi were identified, including taxa from Glomus group B, based on the sequencing of 18S rDNA. Sequencing of the internal transcribed spacer rDNA yielded 30 different fungal taxa, which comprised eight different Glomeromycota taxa, including Glomus sinuosum and Glomus indicum. To our knowledge, this is the first report of grapevine colonisation by G. indicum.