Diversity of arbuscular mycorrhizal fungi (AMF) and root colonization trends along altitudinal gradient: a case study in Western Arunachal Pradesh

 Symbiotic association of Arbuscular Mycorrhizal Fungi (AMF) with roots of higher plants provides a better understanding about their ecological function in the mountain ecosystem. In the present study, we investigated the diversity of AMF genus and colonization efficiency of AMF in the selected five Representative Host Plants (RHPs) growing in the six different mountain forest types along an altitudinal gradient ranging from 1000 – 4500 m above msl in West Kameng district of Arunachal Pradesh. The selected RHP quantified for AMF colonization were, Anaphalis sp. (Asteraceae), Geranium pretense (Geraniaceae), Fragaria rubicola (Rosaceae), Plantago major (Plantaginaceae) and Primula sp. (Primulaceae) and they were selected on the basis of their occurrence throughout the study site. Additionally, colonization was also quantified in composite root samples collected from seven different sites. AMF colonization was observed in the five selected RHP throughout the altitudinal range of 1000 – 4500 m msl. It varied from 10 – 70% with the highest mean root colonization observed in P. major (30%). The maximum AMF colonization was observed in the RHP growing at mid-altitude range (2000 – 3000 m msl) whereas the minimum AMF colonization was observed in the RHP growing at the highest altitudinal range (4000 – 4500 m msl). The AMF colonization in composite root samples also showed the same trend. Our study suggests a significant effect of altitude on AMF species diversity and colonization association in the selected five host plant species investigated.