Morphology of Sclerotium coffeicola, a tropical foliar pathogen

Abstract

HANLIN, R. T., and TORTOLERO, 0 . 1989. Morphology of Sclerotium coffeicola, a tropical foliar pathogen. Can. J. Bot. 67: 1852-1860.Sclerotium coffeicola, the cause of target-spot disease of coffee, is reported from Venezuela for the first time. Target spot is a foliar disease characterized by large brown lesions composed of a series of concentric rings. Columnar bundles of hyphae (propagules) form on the undersides of the leaves. Orange sclerotia are produced on infected host tissues and in culture. Hyphal septa are sparse and are of the dolipore type. The sclerotia develop from loose aggregations of interwoven hyphae that become more compact as the sclerotia mature. As the sclerotia develop, most interior hyphae enlarge into inflated, thin-walled cells that are interspersed with scattered, broad, thin-walled hyphae. Circular areas of pseudoparenchymatous cells form in the periphery of the sclerotia where they secrete liquid droplets. The outermost layer or two of cells have slightly thickened walls and are pigmented, but the interior of the sclerotium remains white. The entire sclerotium is covered by two thin layers of an amorphous material.HANLIN, R. T., et TORTOLERO, 0 . 1989. Morphology of Sclerotium coffeicola, a tropical foliar pathogen. Can. J. Bot. 67 : 1852-1860.Les auteurs rapportent pour la premiere fois au VCnCzuCla la presence du Sclerotium coffeicola, l'agent causal de la tache en forme de cible du cafk. La tache en forme de cible est une maladie foliaire caractCrisCe par de grandes lesions brunes montrant une sCrie d'anneaux concentriques. Des faisceaux columnaires d'hyphes (propagules) se foment sous la surface des feuilles. Des sclkrotes oranges se dCveloppent sur les tissus infect& de l'h6te ainsi qu'en culture. Les septations sont peu nombreuses le long des hyphes et montrent des dolipores. Les scltrotes se dCveloppent a partir d'aggregats ldches d'hyphes entrelacCs qui deviennent plus compactes avec la maturation du sclCrote. Avec la maturation du sclkrote, la plupart des hyphes internes s'accroissent en largeur pour former des hyphes gonflks a paroi mince qui sont dispersks parmi des hyphes trapus paroi mince. I1 se forme des rkgions circulaires de cellules pseudoparenchymatiques a la peripherie des sclCrotes, ou elles secrktent des gouttelettes de liquide. La premiere couche, ou les deux couches les plus externes de cellule ont des parois cellulaires 1Cgkrement kpaissies et sont pigmentkes, mais llintCrieur du sclkrote demeure blanc. L'ensemble du sclCrote est recouvert de deux minces couches de matkriel amorphe.[Traduit par la revue] Introduction While collecting plant disease fungi in the Tenitorio Federal Amazonas of southern Venezuela, leaves of Vismia sp. were encountered that had large, zonate, necrotic lesions. These leaves were taken into the laboratory where isolations yielded cultures of a rapidly growing fungus that formed large orange sclerotia. The same fungus was later found on leaves of Coffea canephora var. robusta (Lind.) Chev. (= C. robusta L. Linden) in the Temtorio Fede...

Three new records of plant parasitic phyllosphere fungi from Panama: Annellophora phoenicis, Cercospora corniculatae, and Sclerotium coffeicola

“…On leaf spots, only the lanceolate white propagules were observed, which agree to the description as "columnar bundles of hyphae" by Hanlin and Tortolero (1989), but mycelia or sclerotia also described by Hanlin and Tortolero (1989) were not found. The ITS sequence from the dried specimen from Panama had 99% similarity with that of the ex-type culture (CBS 115.19, GenBank NR_145331, Okabe and Matsumoto 2003) as well as with an unpublished sequence of S. coffeicola (GenBank KP176676), whereas the next similar sequences in the BLAST search were all from Athelia rolfsii (Curzi) C.C.…”

“…Sclerotium coffeicola is known from different host and Tortolero 1989), but did not include specimens from Sierra Leone deposited by F.C. Deighton in K. Our study of the specimen of S. coffeicola published by Deighton (1936) only revealed sclerotia so that we were unable to confirm the species identification.…”

“…7). Brazil, Costa Rica, Guyana, Puerto Rico, Suriname, Trinidad and Tobago, Venezuela (Hanlin and Tortolero 1989), Panama (new record), Sierra Leone (Deighton 1936).…”

“…Additional specimens, however, from the same locality collected by Deighton in 1949, contained the lanceolate propagules, so that we could confirm the identification of the African specimens as S. coffeicola. Hanlin and Tortolero (1989) compiled the knowledge about the geographic distribution, hosts, and heavy impact on coffee plantations, and among other new information, provided descriptions of the sclerotium development and ultrastructure. The ultrastructure indicated the basidiomycetous relationship, although a teleomorph is not yet known.…”

A new species of Ophiodothella on Casearia from Venezuela

“…One difference between the two genera, however, that is regarded as taxonomically significant is the apical ring in the ascus; in Phyllachora it is nonamyloid, whereas in Ophiodothella it stains blue in iodine (Hanlin 1990b). Additionally, the conidia (or spermatia) described for O. caseariae are very similar to those described for species of Diatrype, Diatrypella, Eutypa, and Eutypella of the Diatrypaceae (Xylariales) (Glawe and Rogers 1982a,b), although they tend to be somewhat smaller.…”