Characterisation And Toxicity Studies Of Fusarium Isolates

• Main Author: Ismail, Nor Azliza
• Format: Thesis
• Language: English
• Published: 2016
• Subjects: QH1 Natural history (General - Including nature conservation, geographical distribution)
• Online Access: http://eprints.usm.my/31958/1/NOR_AZLIZA_BINTI_ISMAIL_24%28NN%29.pdf; http://eprints.usm.my/31958/

Spesies di dalam genus Fusarium merupakan kulat patogenik kepada pelbagai tumbuhan di seluruh dunia. Beberapa spesies mampu menghasilkan fumonisin B1 (FB1) sejenis mikotoksin yang berbahaya kepada manusia dan haiwan. Tujuan kajian ini adalah untuk mengenal pasti dan menciri spesies Fusarium yang berassosiasi dengan sembilan perumah di Malaysia, menentukan hubungan filogenetik di antara spesies, menentukan kebolehan spesies ini menghasilkan FB1 dan toksisiti ekstrak kasar kulat mengandungi FB1 terhadap anak pokok padi dan larva nyamuk Aedes. Di dalam kajian ini, 125 pencilan daripada sembilan perumah dikenalpasti sebagai F. verticillioides (12 pencilan), F. proliferatum (51 pencilan), F. fujikuroi (24 pencilan), F. andiyazi (enam pencilan) dan F. oxysporum (32 pencilan) menggunakan jujukan TEF-1α. Pohon filogenetik parsimoni maksimum mnggunakan jujukan TEF-1α dan β-tubulin memisahkan kelima-lima spesies kepada lima klad berbeza di mana pencilan daripada spesies yang sama dikelompokkan dalam klad yang sama. Species in the genus Fusarium are pathogenic fungi to a wide variety of plants worldwide. Some species are able to produce fumonisin B1 (FB1), a mycotoxin that is harmful to humans and animals. The aims of this present study were to accurately identify and characterise Fusarium species associated with nine hosts in Malaysia, to determine the phylogenetic relationship between the species, to determine the ability of these species to produce FB1 and to test the toxicity of fungal crude extract containing FB1 on rice seedlings and mosquito larvae. In this study, 125 isolates of Fusarium species from nine hosts were identified as F. verticillioides (12 isolates), F. proliferatum (51 isolates), F. fujikuroi (24 isolates), F. andiyazi (six isolates) and F. oxysporum (32 isolates) using TEF-1α sequences. Maximum parsimony phylogenetic tree using TEF-1α and β-tubulin sequences resolved the species into five different clades of which the isolates from the same species were grouped in the same clade.