Diversity and molecular phylogeny of entomopathogenic fungi of Sabah

Mohammad Hafiz Syukri Kassim (2022) Diversity and molecular phylogeny of entomopathogenic fungi of Sabah. Masters thesis, Universiti Malaysia Sabah.

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Abstract

Entomopathogenic fungi or widely known as “Zombie Fungi” are group of parasitic fungi that infect wide range of insect host and then evolved to exploit by manipulating and kill the insects. This study was done to assess the diversity, to isolate, characterize and curate the parasitic fungi using molecular and morphological method and to infer the evolutionary relationship and phylogenetic classification of known lineage of entomopathogenic fungi which is the Ophiocordycipitaceae. The effects of elevation and disturbances were also studied. All samples were collected using opportunistic sampling and were conducted at 14 sampling sites around Sabah with different forest vegetations and habitats and the isolation of the fungi were done. All the collected fungi samples were identified based on their morphology by studying their size, colour, physical structures of ascoma and perithecia and their micro-morphology with the help of molecular analysis for further confirmation. A total of 93 specimens were collected in this study and representing nine genera and 14 species. The most dominant genera collected was Ophiocorydyceps sp. then followed by Cordyceps spp., Isaria spp., Hirsutella spp., Aspergillus, Hevansia and Metarhizium respectively. Most of the specimens were collected from under-leaf habitats (67%) and dominated by the genus Ophiocordyceps. Other habitats recorded were on the forest floor (19%), buried under soil (10%), on understorey tree leaf (2%), and some collected biting on tree branches (2%). In this study, the most infected insect host is from the order of Hymenoptera (61%) and then followed by Hemiptera (11%), Lepidoptera (10%), Araneae (4%), Coleoptera (4%), Blattodea (2%), Orthoptera (1%), and 7% was unidentified host respectively. The diversity analysis showed different pattern where the agricultural area has the highest diversity in Simpson analysis (Simpson (1-D)=4.4984) and evenness index (Evenness (eH/S)= 0.2602) while undisturbed forest is highest in Shannon analysis (Shannon (H)= 1.7839) than disturbed forests and agricultural area respectively. The elevational and disturbance effect on EPF were statistically significant (Elevation; t=4.94, p= 0.001; Disturbance; t=-3.21, p=0.02). The results suggests that the increase in elevations will increase the species abundances and from the undisturbed forests to disturbed forest and agricultural area, the species abundances were decreasing, respectively. 42 successful sequences (ITS: 21 and LSU: 21) were generated. The sequences were identified into eleven species consist of Ophiocordyceps unilateralis, Hirsutella rhossiliensis, Hirsutella citriformis, Isaria cicadae, Cordyceps javanica, Cordyceps cylindrica, Hevansia websteri, Purpureocillium lilacinum, Metarhizium granulamotis, Aspergillus oryzae and Beuveria brongniartii. 58 total sequences of ITS and 49 total LSU sequences were collected from the Genbank with Xylaria bambusicola as an outgroup. Phylogenetic trees of ML and BI were generated. ML tree within the Ophiocordycipitaceae with four sequences (ITS:4 and LSU:4) were generated with addition of 27 Genbank sequences and Nectria cinnabarina as an outgroup. Three phylogenetic datasets were generated include ITS Dataset, nITS + LSU dataset and nITS + LSU dataset of O. unilateralis s.l. The Ophiocordycipitaceae ML tree were shown that a new species of Ophiocordyceps sp. nov. were recorded from Borneo. Favourable environment with elevations, cool atmosphere, relatively high humidity and high diversity of insects is a suitable environment that promotes the high diversity of entomopathogenic fungi recorded in Sabah. The classical method with addition of advance molecular analysis and technologies used in this study, offered rapid and more accurate species identification and alleviated the evolutionary relationships of this unique fungus in Sabah.

Item Type:	Thesis (Masters)
Keyword:	Entomopathogenic fungi, Insetcs, Diversity, Morphology, Phylogeny, Classification
Subjects:	Q Science > QK Botany > QK1-989 Botany > QK504-(638) Cryptogams
Department:	INSTITUTE > Institute for Tropical Biology and Conservation
Depositing User:	DG MASNIAH AHMAD -
Date Deposited:	13 Sep 2024 10:34
Last Modified:	13 Sep 2024 10:34
URI:	https://eprints.ums.edu.my/id/eprint/40990

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