Colletotrichum: tales of forcible entry, stealth, transient confinement and breakout

Taxonomy: Imperfect, anamorphic fungus (subdivision Deuteromycotina, form-class Deuteromycetes, form-subclass Coelomycetidae, form-order Melanconiales, form-family Melanconiaceae) with 39 'accepted' species [Sutton, B. C. (1992) The genus Glom-erella and its anamorph Colletotrichum. In: Colletotrichum: Biology, Pathology and Control (Bailey, J. A. and Leger, M. J., eds). Wallingford, UK: CAB International, pp. 1-26.] which continue to be revised and clarified by molecular taxonomic techniques. Species complexes and subspecific groups have been proposed. Host range: Species of Colletotrichum attack a large number of important tropical and sub-tropical crop species and cause economically significant diseases of cereals, grain legumes, vegetables, forage legumes, fruit crops and perennial crops. Tropical and sub-tropical fruit production is significantly affected by postharvest anthracnose. Disease symptoms: Symptoms of the attack are commonly known as anthracnose and comprise dark, sunken, lenticular necrotic lesions containing the acervuli of the pathogen. Key attractions: A model fungus for research on host specificity, mycoherbicides, appressorial melanization, appressorial function, quiescent infection, fungal lifestyles, intracellular hemibiotrophy and the determinants of the switch from biotrophy to necrotrophy among others. Useful websites: http://www.uark.edu/depts/plant/, http://www.sorghumanthracnose.org/, http:// www.iacr.bbscr.ac.uk/ppi/staff/roc_rc.html