Endorrhizal fungal symbiosis in aroids of the Western Ghats, southern India

Information of dark septate endophyte (DSE), arbuscular mycorrhizal (AM), and fine root endophyte (FRE) fungal symbioses of aroids in the Western Ghats region are very low. Therefore, we assessed the endorrhizal symbiosis in 25 aroid species belonging to 16 genera of Araceae from six different locations of the Western Ghats. The results revealed co-occurrence of the DSE and AM symbiosis in all the examined aroids, and FRE presence in seven aroids (Alocasia ´ amazonica, Alocasia sp., Anthurium andraeanum, Epipremnum aureum, Spathiphyllum sp., Syngonium podophyllum, and Zantedeschia aethiopica). We found variance in root length having AM (inter and intracellular hyphae, arbuscules, vesicles and arbusculate coils) and DSE (melanized septate hyphae, microsclerotia, and moniliform hyphae) fungal structures. Moreover, the AM fungal morphology of Arum-Paris type was widespread, and intermediate type morphology reported for the first time in five aroids. AM fungi colonized the roots of Philodendron xanadu the most, followed by DSE in Caladium bicolor, and FRE in Spathiphyllum sp. AM fungal spores were present in all aroid soils examined. The percentage of root length comprising FRE hyphae was significantly and positively correlated root length with FRE arbuscules, AM fungal spore numbers and total colonization. Our study revealed that, the aroids tend to form associations with various endorrhizal fungi.