Diversity of root-associated mycobiome of Betula utilis D. Don: a treeline species in Kashmir Himalaya.

Treelines and treeline species are being studied the world over because of their sensitivity to climate change but most of these studies have not focused on the essential belowground mutualists which could influence the outcome of the interaction between treeline species and climate change, such as the treeline shift. To fill this knowledge gap, we processed 27 root samples of Betula utilis from two sites in the Kashmir Himalaya and identified 590 species of root-associated fungi belonging to 158 genera, 80 families, 38 orders, 15 classes and 3 phyla from a total of 9157 quality reads. Most of the identified species belonged to Basidiomycetes. Papiliotrema, Humaria, Sphaerobolus, Sebicina, Inocybe, Cryptococcus, Lactarius and Laccaria were the dominant taxa. Symbiotroph, Saproptroph-Symbiotroph and Saprotrophs were the dominant trophic modes of the identified root-associated fungi and most of the identified species belonged to the Ectomycorrhizae (ECM) guild. Differences in the species richness between the two sites were noted and a total of 511 taxa were recovered from root samples at the Sinthan Top site in south Kashmir whereas only 302 taxa were recovered from root samples at the Apharwat site in north Kashmir. Papiliotrema and Inocybe with > 75% prevalence represented the core microbiome. Our study provides the first detailed and comprehensive account of the diversity of fungi associated with the roots of B. utilis and paves way for exploring their functional role in the growth of this treeline species, particularly under changing climate. [ABSTRACT FROM AUTHOR]