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Remarks (public):For a complete description including images see www.cababstractsplus.org/dfb 
Remarks (internal):Distinguished from conidial forms within the broad general concept of Glomerella cingulata (Stonem.) Spauld. & Schrenk (e.g. Colletotrichum phomoides) chiefly by size and shape of conidia and frequency of sclerotium formation. Generally considered to be a relatively minor pathogen or secondary invader provided that cultural conditions are good, but, where intensive cropping without rotation (as in some glasshouses) is practised, effects on crops can be very severe. In tomato breeding trials in Eire yields of some varieties were halved, whilst up to 14·8% of fruits were attacked in Byelorussia in a heavy rainfall year (35: 52; 45, 1203). In Austria and Java legislation, in the forms of seed potato certification schemes and quarantine regulations, has been imposed (34: 244; 18: 813). Mercurial disinfectants give some measure of control both when applied to tubers soon after lifting to combat storage infection (whose severity increases after frost damage, 34: 244), and when mixed with soil prior to planting (34: 480; 39: 274). Cultural methods such as prompt harvesting and burning of refuse are recommended for potato, whilst plastic or other mulching, and trellising when combined with fungicidal or mineral and organic manure treatments reduce tomato diseases (43, 1145, 1748, 1389; 45, 1203). Potassium deficiency promoted infection of potato in Denmark, but diseased plants with a high potassium content have also been recorded (18: 88; 33: 686). An association between C. coccodes and Heterodera schachtii and H. rostochiensis has long been suspected. In inoculation experiments with potato, the presence of C. coccodes in soil increased damage by Heterodera and Corticium solani; however, no interaction was found with H. rostochiensis on tomato (10: 203, 547; 43, 1416, 1835q; 45, 2686b). Reaction to strains of actinomycetes varies from stimulation of maturity and stromatal formation to inhibition of C. coccodes by several spore-forming aerobic bacteria isolated from field soil, although there are indications that eventually such antagonism may develop into synergism (35: 540; 38: 385).
 
Description type:Non-original description 
Description:Colletotrichum coccodes (Wallr.) Hughes, Can. J. Bot. 36: 754, 1958.
= Chaetomium coccodes Wallr., Flora Crypt. German. 2: 265, 1833.
[=Vermicularia atramentaria Berk. & Broome, 1850.
= Colletotrichum atramentarium (Berk. & Broome) Tauben., 1916.]
Acervuli on stems and roots, rounded or elongated, attaining approximately 300 µm diam.; acervular tissue intra- and sub-epidermal, disrupting the outer epidermal cell walls of host. Occasional cells of acervulus develop as setae which are brown, septate, slightly swollen at the base then tapered to the often slightly paler tip. Setose sclerotia common. Conidia cylindrical with obtuse ends, hyaline aseptate, 16-24 (av. 19,03) x 2,5-4,5 (av. 3,01) µm, formed from unicellular hyaline cylindrical phialidic conidiophores. Colonies on potato dextrose agar show sparse whitish aerial mycelium. Sclerotia usually abundant evenly distributed over the agar surface; when young, greyish and glabrous, rapidly becoming dark and setose. Acervuli formed in association with sclerotia or as separate aggregates of setose mycelium; solitary phialides often found on mycelium. Conidiophores sometimes septate and branched. Spore masses normally small, colourless to salmon orange. Conidia frequently shorter in proportion to their breadth than on host, many irregular forms occur. Reverse of colony grey, darker with age because of formation of appressoria. Appressoria very readily formed in slide cultures, cinnamon buff, ovate or obclavate to elliptical, occasionally irregularly lobed, 5-14 (av. 10,5) x 4-11 (av. 6,1) µm, borne on hyaline thin-walled sigmoid supporting hyphae.
Hosts: On Lycopersicon esculentum, Solanum tuberosum and over 35 other hosts, representing 13 families chiefly in the Cucurbitaceae, Leguminosae and Solanaceae (Cheaters & Hornby, 1965). Also on onion and strawberry on inoculation (36: 45).
Diseases: Black dot of potato and tomato, anthracnose of fruits of tomato, chilli (Capsicum) and squash. Causes a distinctive cortical brown rot of stems and roots of potato and tomato, chilli, eggplant and winter cherry (Solanum capsicastrum). The roots of other less susceptible hosts including chrysanthemum, white mustard, cress, cabbage, and lettuce are only lightly colonized, and the infected plants may be symptomless. Commonly causes destruction of cortical tissues of stems and roots of hosts, also fruit rot of tomato. On potato, black dot on stem root, and tuber, sometimes associated with leaf scorch (31: 574), skin necrosis (38: 621), rubbery tuber wilt (41: 670) and spindle sprout (35: 540, 918). Enzymes secreted by the pathogen are responsible for foot and root rot stages; wilting of aerial organs is a remote effect of operation of toxins (35: 541).
Geographical distribution: Widely distributed in Africa, Asia, Australasia, Europe, and N., C., and S. America. (CMI Map 190)
Transmission: Soil borne, but no rapid or extensive growth of hyphae through soil; survival probably only in decaying roots and other trash and on weed hosts. Infection occurs when living roots grow in contact with organic material harbouring the pathogen (32: 608; 36: 502, 719). Sclerotia overwinter on trash and develop into acervuli in spring (38: 478); they survive up to 84 wks. in greenhouse soil (45, 3066). In potato, transmission is from infected plants through the daughter tubers, and incidence of infection increases during storage; new plants are infected from dead material by conidia (35: 541; 34: 480). Persistence on weeds such as Solanum dulcamara and S. nigrum may be implicated in carry-over from potato to tomato crops (45, 1204).
Physiological specialization: A relatively unspecialized pathogen attacking a wide range of hosts from different families. There are indications that geographic races may occur (36: 502), but although a group of isolates from potato and tomato showed considerable variation all were pathogenic to both hosts (45, 1204).
Literature: Chesters & Hornby, Trans. Br. mycol. Soc. 48: 573-581, 583-594, 1965 (taxonomy and host range); Forlot, Bull. Ec. nat. sup. agron. Nancy 7(2): 122-144, 1965; Blakeman & Hornby, Trans. Br. mycol. Soc. 49: 227-240, 1966 (persistence in soil).

 
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