First Report of Colletotrichum truncatum Causing Anthracnose of Tomato in China

Abstract

growth was observed from surface sterilized tissues. Fungi were isolated, purified by single spore separation process, and subcultured to potato dextrose agar (PDA) plates. Growing on PDA, the surface of the colony was circular, fluffy, and shiny velvety-black, whereas the under surface was dark Prussian blue. Conidiophores were single or fascicled, brown to dark brown, rarely branched, multiseptate, and straight or often geniculate near the apex. Conidia were brown, smooth, fusiform, geniculate or hookshaped, 17.5 to 28.5 X 8.5 to 14.0 |im, and 3-septate, with the third cell from the base larger and darker than the others. Molecular identification was performed by analysis of the rDNA internal transcribed spacer region (ITS1-5.8S-ITS2). The rDNA-ITS region was amplified with primer pair ITSl and ITS4 (5), sequenced, and deposited in GenBank (Accession No. KC462186). The sequence of rDNA-ITS (KC462186) showed 100% identity with Cochliobolus lunatus R.R. Nelson & Haasis (JN943422) after BLAST. Based on the results of morphological and molecular analyses, the fungus isolated from infected leaves was identified as C. lunatus (anamorph: Curvularia Innata (Wakk.) Boedijn) (3). Pathogenicity tests were conducted three times by spraying a conidial suspension (1 x 10ŝ pores/ml) with 0.1% (v/v) Tween 20 on 12 healthy rice plants at late tillering stage. The same number of the healthy rice plants sprayed with sterilized water with 0.1% (v/v) Tween 20 were used as control. All plants were kept at 30°C and 75 to 85% relative humidity (RH) under a 12-h light/dark rotation. About 5 to 7 days after inoculation, green water-soaked streaks began to appear on inoculated plants. From 7 to 14 days after inoculation, the lesions developed quickly and the leaves began to wilt. After 14 days, inoculated plants showed symptoms similar to those originally observed in the field, while control plants (sprayed with sterilized water) remained healthy. C. lunatus was re-isolated from all inoculated plants, and re-identified by the same methods (morphological and molecular methods) as described above, thereby safisfying Koch's postulates, and confirming C. lunatus as the cause of the disease. C. lunatus is a pathogen of a wide range of plants and is common in paddy environments. It was reported as one of the causal agents of black kernel of rice (4) and rice spikelet rot disease (SRD) (1,2). The level of incidence observed in the affected fields suggest that this disease could potentially cause major losses under favorable weather conditions if susceptible cultivars are grown. To our knowledge, this is the first report of C. lunatus causing leaf blight of rice in China.

Colletotrichum species associated with chili anthracnose in Australia

“…Morphological characters of these isolates were consistent and showed very distinctive curved conidia typical of the species. Colletotrichum truncatum has been reported as a pathogen of chili in several countries and an important pathogenic species that infects other plant crops causing serious damage (Sharma et al, 2005;Than et al, 2008;Mongkolporn & Taylor, 2011;Diao et al, 2014). Microsatellite-based marker analysis of C. truncatum populations from chili-growing regions in Southeast Asia revealed a high allele flow within and between populations, showing a high adaptive capacity of this pathogen to overcome host resistance (Ranathunge et al, 2009(Ranathunge et al, , 2012.…”

Genetic differentiation and recombination among geographic populations of the fungal pathogen Colletotrichum truncatum from chili peppers in China

“…; Diao et al. ). In addition, C. truncatum can also cause mycotic keratitis and endophthalmitis in humans (Shivaprakash et al.…”

“…C. capsici) ). Aside from infecting peppers, C. truncatum has been reported to infect more than 460 plant species (http://nt.ars-grin.gov/fungaldatabases/) (Sutton et al 1992;Shenoy et al 2007;Damm et al 2009;Yang et al 2009;Wikee et al 2011;Huang et al 2013;Diao et al 2014). In addition, C. truncatum can also cause mycotic keratitis and endophthalmitis in humans (Shivaprakash et al 2011).…”

Detection of tomato anthracnose caused by Colletotrichum truncatum in India

“…truncatum as a causal agent of chilli anthracnose has been reported in India (Chethana et al 2015) and is reported to cause tomato anthracnose in China (Diao et al 2014). To our knowledge, this is the first report of tomato anthracnose caused by C. truncatum in India.…”