Characterization Of Fungi Associated With Leaf Spot Of Mango (Mangifera indica L.)
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Date
2016-02
Authors
Omar, Nurul Husna
Journal Title
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Publisher
Universiti Sains Malaysia
Abstract
Mango (Mangifera indica L.) is a popular fruit crop in Malaysia and is susceptible to leaf spot disease caused by diverse groups of Ascomycete and mitosporic fungi. The disease will interrupt photosynthesis and reduce the growth of mango trees. The present study was conducted to identify and characterize fungi associated with leaf spot of mango. Pathogenicity test was performed to determine the causal pathogen of the disease. Based on morphological identification, 264 fungal isolates were tentatively identified into 11 genera and 18 species, namely Colletotrichum (n = 93, C. acutatum and C. gloeosporioides), Fusarium (n = 90, F. proliferatum, F. semitectum, F. mangiferae, F. solani and F. chlamydosporum), Pestalotiopsis (n = 28, P. theae and P. mangiferae), Phomopsis (n = 13, Phomopsis sp.), Curvularia (n = 12, Cur. geniculata and Cur. lunata), Guignardia (n = 9, G. mangiferae), Lasiodiplodia (n = 9, L. theobromae), Nigrospora (n = 5; N. sphaerica), Botryosphaeria (n = 3, B. dothidea), Nodulisporium (n = 1, Nodulisporium sp.) and Corynespora (n = 1, Cor. cassiicola). A total of 151 fungal isolates within the same species that showed similar morphological characteristics were chosen as representative isolates for molecular identification. Depending on the fungal genera, DNA sequencing and phylogenetic analysis of Internal Transcribed Spacer (ITS) region, β-tubulin and Translation Elongation Factor 1α (TEF-1α) genes were used for species confirmation. Two Colletotrichum species complex, C. acutatum species complex (n = 33) and C. gloeosporioides species complex (n = 22) were identified based on ITS and β-tubulin sequences. Phylogenetic analysis showed that none of the isolates morphologically identified as C. acutatum and C. gloeosporioides from leaf spot of mango were grouped with C. acutatum and C. gloeosporioides epitype strains. ITS sequences confirmed the identity of morphologically identified P. mangiferae (n = 12), P. theae (n = 8), Phomopsis sp. (n = 8), Ph. glabrae (n = 2), L. theobromae (n = 7), G. mangiferae (n = 5), B. dothidea (n = 3), Cur. geniculata (n = 4), Cur. lunata (n = 2), N. sphaerica (n = 5), Nodulisporium sp. (n = 1) and Cor. cassiicola (n =1). Phylogenetic analysis using ITS region showed that the isolates from the same species were clustered in the same clade. Molecular identification of five Fusarium species, namely F. proliferatum (n = 18), F. semitectum (n = 11), F. mangiferae (n = 3), F. solani (n = 2) and F. chlamydosporum (n = 1) were done using TEF-1α sequences and the result of phylogenetic analysis showed that the isolates from the same species were grouped in the same clade. Results of pathogenicity test indicated that 50 selected isolates from each of the species were pathogenic towards mango leaves except F. solani and F. mangiferae. The present study showed that diverse groups of fungal genera were associated with leaf spot of mango.
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Keywords
Mango