Diversity of filamentous fungi on woody litter of five mangrove plant species from the southwest coast of India

Fungal diversity on decaying intertidal wood of five mangrove plant species (Acanthus ilicifolius, Avicennia officinalis, Bruguiera gymnorrhiza, Rhizophora mucronata and Sonneratia caseolaris) accumulated on the floor of Udyavara mangrove stand of southwest coast of India was investigated. Wood samples collected during the monsoon and summer season were incubated in moist chambers and observed once every two weeks for up to six months. Ninety-one fungi belonging to 68 genera were recovered. Terrestrial fungi were dominant during the monsoon season, while marine fungi were dominant during the summer. Fungal richness and diversity were higher during the monsoon season than the summer. Rhizophora mucronata showed the highest Simpson’s index at both seasons. The Shannon index was highest for Rhizophora mucronata in the monsoon season, while it was highest for Bruguiera gymnorrhiza during the summer. Rarefaction showed the highest expected number of species out of 150 identifications was from Rhizophora mucronata during the monsoon season (43 vs. 27-38 species), while it was highest in Sonneratia caseolaris during the summer (25 vs. 20-23 species). Maximum number of species per sample was observed on Bruguiera gymnorrhiza (monsoon, 2.9; summer, 3). Significant differences in the species diversity and expected number of species between the seasons were seen (t-test). Lignincola laevis, Savoryella lignicola and Trichocladium linderi were found in both seasons on all substrata. Lignincola laevis, Passeriniella mangrovei, Savoryella lignicola, S. paucispora, Trichocladium achrasporum and T. linderi were dominant during the monsoon season (>10%), while Cirrenalia pygmea, Lignincola laevis, Lulworthia grandispora, Nais sp., Savoryella lignicola and Zalerion varium were dominant during the summer. It is likely that terrestrial, freshwater and aero-aquatic fungi find ideal conditions for their development in mangroves during the monsoon season in the west coast of India.