Community structure of sporulating fungi on decaying litter of Shorea spp at Dramaga Research Forest, Bogor.

Abstract

Indonesian tropical rain forests are dominated by the Dipterocarpaceae. One of the most valuable Dipterocarpaceae is Shorea. Indonesia is a centre of endemic of Dipterocarpaceae and this tree is now being cultivated. In natural forests, Shorea spp. has an important role in maintaining the balance of the ecosystem because they produce abundant lignocellulosic rich substrates as a source of nutrients for the survival of microorganisms including saprobic fungi. Fungi have been known as the major wood and leaf decomposer organisms and they play an important role in the nutrient cycle in Shorea spp. plantation because they degrade lignocellulosic materials into a more simple compound. A few study on the community structure of litter degrading fungi on Shorea spp. has been done, but none from Indonesia. With highly diversity of Shorea spp. in Indonesia, survey on the fungal diversity on Shorea spp. litter is necessary in order to enrich the information regarding fungal community inhabiting Shorea spp. litter. Therefore, this study has two main objectives, as follows: (1) unreaveling the community structure of sporulating fungi on leaf and branch litter of Shorea that includes diversity, species richness and evenness of fungi; (2) to know the most abundant and dominant species of fungi in Shorea spp. litter. Leaf and branch litter samples were collected in 50 m x 50 m area at Dramaga Research Forest. Samples were placed in a zip lock plastic bag, sealed and labeled. Samples were then brought to the laboratory and moistened by placing wet tissue into these plastic bags. Samples were examined under microscopes to find fruiting bodies, and the microscopic features of the fungi were observed and noted. The fungi were mainly identified morphologically and those that can be isolated were identified further using molecular approach on the bases of the sequence of their ITS region. Of 260 samples, about 54.7% leaf litters and 45.3% branch litters were infested by the fungi and detected either in the form of spores or fruiting bodies. About 29 fungal species composed of 7 ascomycetes (24.1%) and 22 anamorphs that comprised of 12 coelomycetes (41.4%) and 10 hyphomycetes (34.5%) were identified. The ascomycetes are Annulohypoxylon purpureonitens, Diatrype chlorosarca, Didymosphaeria epidermidis, Lophiostoma sp., Lophodermium sp., Pemphidium sp., Valsa sp., The coelomycetes are Coniella musaiaensis, Coryneum betulinum, Hendersoniopsis thelebola, Lasiodiplodia theobromae, Lasmeniella guaranitica, Leptodothiorella sp., Massariothea themedae, Pestalotia guepinii, Pestalotiopsis sp., Pseudolachnea hispidula, Septoriella sp., Coelomycete sp 1., and the hyphomycetes are Beltraniella portoricensis, Cryptophialoidea fasciculata, Hermatomyces sphaericus, Kiliophora ubiensis, Minimidochium setosum, Monodisma fragilis, Nodulisporium sp., Stilbella fimetaria, Virgatospora echinofibrosa and Hyphomycete sp. 1. Of those species, 5 species can be isolated that were Annulohypoxylon purpureonitens, Beltraniella portoricensis, Cryptophialoidea fasciculata, Kiliophora ubiensis and Hyphomycete sp 1. Beltraniella portoricensis and Pemphidium sp. were the most frequent species found on leaf litter, while those of branch litter were Cryptophialoidea fasciculata and Lasiodiplodia theobromae. The fungal community was subtrate specific. The community on decaying branch litter was more diverse than those on leaf litter. C/N ratio of the substrate were closely related to the fungal community structure.