Mycodiversity and biotechnological potential of endophytic fungi isolated from hydrophytes

Foliar endophytic fungi were isolated from regular hydrophytic plants such as Eichhornia crassipes (Pontederiaceae), Nymphaea nouchali (Nymphaeaceae), Vallisneria spiralis (Hydrocharitaceae) growing in a pond in the Anna Zoological Park, Chennai, Tamil Nadu. Five
hundred leaf segments from each plant species were inoculated in Potato Dextrose Agar (PDA) medium. A total of 18 different endophytic fungi could be isolated from three host surveyed. Hyphomycetes group was the most prevalent endophyte than ascomycetes, coelomycetes, and sterile form. Nymphaea nouchali had more endophytic fungi (18 species) followed by Eichhornia crassipes (12 species), and Vallisneria spiralis (11 species). To our knowledge Vallisneria spiralis is studied for endophytic fungi diversity for the first time. Among the 18 endophytic fungi isolated, nine were present in all three hosts investigated for endophytic fungi. Curvularia lunata, Chaetomium indicum, Nigrospora oryzae, Pestalotiopsis sp. showed <5% of colonization frequency in all three host species studied. The culture filtrate of Curvularia lunata, Nigrospora
oryzae, Chaetomium indicum and Pestalotiopsis microspora investigated contained alkaloids, flavonoids, terpenoids, tannins and steroids. The dominant endophytic fungi were tested for production of extracellular enzymes like amylase, cellulase, L- asparaginase, laccase and protease.
Curvularia lunata, Chaetomium indicum and Pestalotiopsis microspora produced all the enzymes tested, whereas Nigrospora oryzae did not produce L- asparaginase. The culture filtrate of Chaetomium indicum and Pestalotiopsis microspora significantly increased the cell division in
Allium cepa root meristem and the radical plumule length in AD8 rice variety.