Abstract
Colletotrichum acutatum is known to have a wide host range and has become an increasingly important pathogen on many economic crops worldwide. This is the first report of Colletotrichum acutatum on mango in Sri Lanka. Colletotrichum gloeosporiodes together with C. acutatum are considered as causal agents of this disease. Colletotrichum acutatum was characterized by fusiform conidia and white to orange colonies with slight shades of light mouse grey aerial mycelia. Colletotrichum gloeosporioides produced grey colonies with a dark mouse grey centre and conidia were cylindrical. The other differences between the mango isolate of C. acutatum and C. gloeosporioides were the slower growth rate and extremely high tolerance of C. acutatum to the fungicide carbendazim. Key words: Colletotrichum gloeosporioides, Hevea brasiliensis, carbendazim DOI: 10.4038/cjsbs.v38i1.1326 Cey. J. Sci. (Bio. Sci.) 38 (1): 31-34, 2009
Highlights
Colletotrichum acutatum (Simmonds ex Simmonds) is pathogenic on a number of economically important fruit and tree crops worldwide
Observations on the sensitivity of the two species to fungicides in vitro showed that C. gloeosporioides were extremely sensitive to carbendazim whereas more than a 1000 fold increase of fungicide concentration was needed to obtain 90-100% growth inhibition (EC 90-100) in C. acutatum (Table 1)
Colletotrichum gloeosporioides was believed to be the only cause of mango anthracnose in Sri Lanka. (Alahakoon & Brown, 1994), The culture and reproductive characteristics that have been previously utilized by various workers have been employed to distinguish between the two species (Adeskaveg & Hartin, 1997; Jayasinghe et al, 1997)
Summary
Colletotrichum acutatum (Simmonds ex Simmonds) is pathogenic on a number of economically important fruit and tree crops worldwide. The pathogen is declared as a quarantine pest in member countries of the European community (EC) and has become an increasingly important plant pathogenic fungus. Mangoes are an important export fruit for many tropical and sub-tropical countries. Anthracnose is one of the most widespread and common diseases, which causes premature fruit drop and direct reduction in quality of ripe fruits shortening the storage lifetime (Dodd et al, 1992). During epidemics it affects young leaves resulting severe spots and blackening of tips (Fig. 1a). The most conspicuous symptom of the disease is the circular, dark, sunken anthracnose lesions on ripe fruits (Fig. 1b)
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