Characterization Of Fusarium Species Associated With Pineapple (Ananas Comosus (L.) Merr.) Fusariosis In Peninsular Malaysia

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dc.contributor.authorIBRAHIM, NURUL FAZIHA
dc.date.accessioned2016-11-24T02:29:52Z
dc.date.available2016-11-24T02:29:52Z
dc.date.issued2015-04
dc.description.abstractThe occurrence of a disease known as fusariosis in pineapple plantations in Johor, Penang, Selangor, Perak, Negeri Sembilan and Kedah were documented. From the present study, five species of Fusarium were identified morphologically as member of Fusarium fujikuroi species complex (FFSC), namely F. proliferatum (27.9%), F. fujikuroi (1.0%), F. verticillioides (1.0%), F. sacchari (2.2%) and F. subglutinans (4.8%). Other species identified were F. oxysporum (31.4%), F. solani (14.4%), F. semitectum (13.1%) and F. chlamydosporum (4.2%). For mating study, only FFSC isolates were used and the results showed that 76 isolates carried MAT-1 and 39 isolates carried MAT-2 alleles. In sexual crosses, 82 isolates of F. proliferatum were crossed fertile with mating population D (MP-D; Gibberella intermedia) and three isolates of F. verticillioides were crossed fertile with MP-A (G. moniliformis). Species confirmation was done using translation elongation factor-1 alpha (TEF-1α) and β-tubulin genes of which 26.3% were identified as F. proliferatum, 2.6% as F. fujikuroi, 1.0% as F. verticillioides, 3.5% as F. sacchari and 3.5% as F. subglutinans. Phylogenetic analysis from individual and combined datasets of TEF-1α and β-tubulin sequences using neighbor joining (NJ) and maximum parsimony (MP) methods showed that the isolates from the same species were clustered together in the same group. Intraspecific variations were observed within the isolates in the same species. In pathogenicity test, selected isolates from nine Fusarium species were pathogenic to pineapple leaves and fruits with different diseases severity index (D.S.I). Among the pineapple varieties, Josapine showed the highest susceptibility to fusariosis followed by Moris and Gandul. Fusarium proliferatum was the most virulent species causing fusariosis (D.S.I>66.67%) followed by F. fujikuroi, F. sacchari, F. subglutinans, F. oxysporum and F. semitectum with intermediate virulence (D.S.I, 50% - 66.67%), and F. verticillioides, F. solani and F. chlamydosporum was regarded as lowest virulence species (D.S.I<44.44%). The differences might be due to different virulent factors that involved in mycotoxins production. Among FFSC isolates, FUM1 gene was detected in F. proliferatum, F. fujikuroi and F. verticillioides isolates which indicated that the isolates can produce fumonisin B1 (FUM B1) in vitro. Analysis using ultra performance liquid chromatography (UPLC) showed that selected isolates of F. proliferatum, F. fujikuroi and F. verticillioides produced FUM B1 ranging from 0.47 to 71.84 μg/g. Fusarium sacchari and F. subglutinans isolates in which FUM1 gene was not detected, also did not produce FUM B1 in vitro. All FFSC isolates produced moniliformin (MON) ranging from 0.32 to 48.53 μg/g, and only F. verticillioides isolates and several isolates of F. proliferatum, F. fujikuroi and F. subglutinans can produce beauvericin (BEA) ranging from 7.54 to 44.86 μg/g. Characterization of Fusarium isolates and the information on the occurrence of pathogenic isolates and the ability of the isolates to produce mycotoxins associated with pineapple fusariosis is important to strategize fusariosis control and reduce the impact of mycotoxin exposure in pineapple commodities.en_US
dc.identifier.urihttp://hdl.handle.net/123456789/3192
dc.subjectCharacterization Of Fusarium Species Associated Withen_US
dc.subjectPineapple (Ananas Comosus (L.) Merr.) Fusariosis In Peninsular Malaysiaen_US
dc.titleCharacterization Of Fusarium Species Associated With Pineapple (Ananas Comosus (L.) Merr.) Fusariosis In Peninsular Malaysiaen_US
dc.typeThesisen_US
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