Characterization of endophytic fungi from Garcinia atroviridis with antagonistic effect against Colletotrichum gloeosporioides / Nur Afeeqah Mohamed Zanudin

Fungal endophytes produce a broad variety of bioactive compounds with potential to address some of the unmet human needs. Medicinal plants have an important role to play in the search for new strains of endophytes fungi, as it is possible that their beneficial characteristics are as a result of the metabolites produced by their endophytic community. However, inspite of this potential as repositories of bioactive compounds, the fungal endophytes of Malaysian medicinal plants remain largely underexplored. This thesis reports on studies that were conducted to bioprospect for endophytic fungi with antagonistic activity against Collectrichum gloeosporioides hosted by the plants Garcinia atroviridis used in Malaysian traditional medicine. The endophytic fungus isolates were isolated from different parts of the host plant (fruits, leaves and branches), where the samples were collected from two different geographical location in Nasuha Herbs Farm, Muar. A total of 243 endophytic fungi were isolated from 600 G. atrovidis segments. Overall, fungal isolation rate in G. atrovidis segments was 0.41 and colonization rate was 71.5% and the highest being found in the higher location. The colonization rate was higher in the leaf (50.2%) than the branch (33.3%) and fruit (16.5%). The fungal richness was also higher in leaf as compared to in other parts. Morphological analysis grouped these isolates into 21 distinct groups. Further, ITS gene sequencing analysis identified these isolates as Annulohypoxylon sp, Colletotrichum gloeosporioides, Pestalotiopsis sp., Pestalotiopsis sp., Diaporthe sp., Lasiodiplodi theobromae, Pestalotiopsis neglecta, Bjerkandera adusta, Nigrospora sphaerica and Colletotrichum sp. The effect of different cultivation medium on fungal growth revealed that the growth requirements of each endophyte fungi isolate significantly (p<0.05) differs from each other. Potato Dextrose Agar (PDA) exhibited the most suitable medium to growth endophyte fungus with highest radial growth compared to Malt Extract Agar (MAE) and Water Extract Agar (WA).