Taxonomy

Domain	Eukarya
Kingdom	Fungi
Phylum	Ascomycota
Subphylum	Pezizomycotina
Class	Sordariomycetes
Subclass	Hypocreomycetidae
Order	Glomerellales
Family	Glomerellaceae
Genus	Colletotrichum

Scientific Name

Colletotrichum capsici

Common Name

chili anthracnose

Author: Ke Zhang, University of Florida

Reviewed by: Jeffrey Rollins, University of Florida

Pathogen

Colletotrichum capsici is a fungal plant pathogen with a wide host range, including 121 host-genera in 45 plant families (4). The most widely known disease caused by this pathogen is anthracnose of chili. The disease is usually associate with leaf tip die-back symptoms. Symptoms on fruits make the fruit unmarketable (2). Colletotrichum capsici is widely distributed in most regions where cucurbits are grown. The sexual ascomycete form is rarely found in nature. Conidiophores are 3-45 × 2-6 µm, hyaline, cylindrical, unicellular or septate. Conidiogenous cells are 6-10 µm × 2.5-4 µm wide, hyaline, ellipsoidal to subglobose, conidia are 7-14 µm × 2.5-3.5 µm, one-celled, gluttulate, hyaline, fusiform with both ends pointed (4).

Symptoms and Signs

On chili fruits, anthracnose can cause extensive pre- and post-harvest damage, as well as pre-harvest symptoms on leaves and stems. Often, symptoms of the post-harvest disease do not develop until the fruit is ripe. Typical symptoms are circular or angular sunken lesions on fruits, with concentric rings of acervuli. Orange conidial masses are often produced in acervuli creating a surface that is wet and slimy. Lesions may coalesce under severe disease pressure (5).

Ecology and Spread

Colletotrichum capsici is an air-borne, seed-borne, and also soil-borne pathogen. It can survive in moist soil and plant debris for several years. The fungus can spread by rain splash and irrigation water. It can also spread by infected soil, farm tools, and shoes. The fungus can be carried by chilli seeds intraembryonally. Enzymes produced by C. capsici can disrupt seed tissues. Conidial masses generated from the acervuli can serve as a primary inoculum source. The fungus can spread from the seed to the placenta of the fruit, then penetrate the developing ovules or young seed. Infection of seeds can also occur directly from the mother plant. Conidia can remain dormant on the surface of the testa until seed germination (3).

Geographic Distribution

Colletotrichum capsici is widely distributed in Asia, Africa, Australia, North and Central America (1).

Management

Remove infected plant and plant debris.
Choose resistance cultivars.
Use certified seeds and do not use seeds from C. capsici infected fields.
Use fungicides during flowering. As small fruit begin to produce, use the standard fungicide to control anthracnose on pepper, Maneb (2).
Consult your local extension specialist for legal and efficacious fungicide products available in your state. Remember, the label is the law and the product applicator is responsible for reading and following all chemical labeling.

Diagnostic Procedures

Colletotrichum capsici can be isolated on common culture media such as PDA. Acervuli can be observed in mature lesions from leaves or fruits. Diagnostic features include:

white, effuse colony with orange conidial masses, the reverse side is brownish to black;
mycelia are branched and hyaline; and
conidia are hyaline, unicellullar, or cylindrical, 7-14 µm × 2.5-3.5 µm (4).

Resources and References

1. Farr, D.F., and Rossman, A.Y. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved April 1, 2014, from http://nt.ars-grin.gov/fungaldatabases/

2. Lewis Ivey, M. L., Nava-Diaz, C., and Miller, S. A. 2004. Identification and management of Colletotrichum acutatum on immature bell peppers. Plant disease 88: 1198-1204.

3. Nik, W., Zainun, W., and Meon, S. 1988. Seed-borne Infection and Development of Colletotrichum capsici in Naturally Infected Chili Seed. Pertanika 11: 341-344.

4. Shenoy, B. D., Jeewon, R., Lam, W. H., Bhat, D. J., Than, P. P., Taylor, P. W., and Hyde, K. D. 2007. Morpho-molecular characterisation and epitypification of Colletotrichum capsici (Glomerellaceae, Sordariomycetes), the causative agent of anthracnose in chilli. Fungal Diversity 27: 197-211.

5. Than, P. P., Prihastuti, H., Phoulivong, S., Taylor, P. W., & Hyde, K. D. 2008. Chilli anthracnose disease caused by Colletotrichum species. Journal of Zhejiang University Science B 9:764-778.

Acknowledgements

National Institute of Food and Agriculture, U.S. Department of Agriculture, under Agreement No. 2011-41530-30708 as part of "Diagnostic Image Series Development for Supporting IPM in the Southern Region" (USDA-NIFA-RIPM-003351)