Content area
Full Text
Phytoparasitica (2015) 43:3749 DOI 10.1007/s12600-014-0428-z
Characterization of Colletotrichum spp. causing anthracnose of bell pepper (Capsicum annuum L.) in Trinidad
Hema Ramdial & Sephra N. Rampersad
Received: 6 March 2014 /Accepted: 9 July 2014 /Published online: 15 July 2014 # Springer Science+Business Media Dordrecht 2014
Abstract Anthracnose fruit rot of pepper (Capsicum spp.) is an economically important disease in many countries worldwide. This study was conducted to identify and characterize the pathogens responsible for anthracnose disease in bell peppers (C. annuum L.) in Trinidad. Seventy-two percent of all isolates were Colletotrichum truncatum and 28% were C. gloeosporioides. Growth rate and conidia dimensions were reliable morphological markers that allowed differentiation betweenC. gloeosporioides and C. truncatum isolates. Benomyl sensitivity testing also distinguished between isolates ofC. gloeosporioides and C. truncatum. C. truncatum was resistant to benomyl at all concentrations tested whileC. gloeosporioides sensu lato was sensitive to concentrations above 0.1 g ml-1 . Pathogenicity tests demonstrated different levels of resistance to anthracnose in various Capsicum genotypes. C. gloeosporioides sensu lato isolates caused significantly greater damage thanC. truncatum isolates regardless of pepper cultivar. PCR with taxon- and species-specific primers produced amplicons of expected band sizes for all Colletotrichum species and only for C. gloeosporioides, respectively. Molecular analysis of ITS and -tubulin sequences positioned C. gloeosporioides sensu lato and C. truncatum isolates from bell pepper into separate species-specific clusters.
Keywords Capsicum spp . Fungicide resistance . Molecular identification . Pathogenicity
Introduction
Colletotrichum species are among the most destructive fungal plant pathogens worldwide. Member species cause the disease anthracnose which affects fruit and plant parts in a range of economically important host species including legumes, fruit trees and vegetables (Bailey et al. 1992). Anthracnose disease is one of the most devastating postharvest diseases affecting pepper (Capsicum spp.) production in the tropics and sub-tropics (Than et al. 2008a, b). Infection may occur as both pre- and posthar-vest fruit rots, which result in a considerable reduction of marketable yield. Losses between 50% and 100% have been reported in major producing countries such as Thailand (Than et al. 2008a, b) and the U.S.A. (Lewis-Ivey et al. 2004). Most of the peppers in Trinidad are harvested as fully sized green fruit, but red fruits of certain cultivars (e.g. cvs. Century and Canape) are also harvested and...