title: New insights into the characterization of Colletotrichum species associated with apple diseases in southern Brazil and Uruguay.
abstract: Colletotrichum species are associated with Apple bitter rot (ABR) and Glomerella leaf spot (GLS). Whereas both apple diseases occur frequently in Brazil, only the former has been reported in Uruguay. This work was aimed at identifying and comparing morpho-cultural characteristics and pathogenic variability of thirty-nine Colletotrichum isolates from both countries. Sequencing of the internal transcribed spacer (ITS) rDNA, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and β-tubulin (TUB2) allowed the identification of three species causing ABR and GLS in Brazil, i.e., Colletotrichum fructicola, Colletotrichum karstii, and Colletotrichum nymphaeae; and three species causing ABR in Uruguay, i.e., C. fructicola, Colletotrichum theobromicola, and Colletotrichum melonis. Six groups of colony colours were recorded with group 1 (mycelium white to pink and in reverse pinkish) and group 2 (mycelium white to grey and in reverse pinkish) the most frequent. Isolates of C. fructicola and C. theobromicola were sensitive to benomyl, while C. karstii, C. nymphaeae, and C. melonis were resistant. Conidia were predominantly cylindrical for C. fructicola and C. karstii, fusiform for C. nymphaeae and C. melonis, and obclavate for C. theobromicola. Brazilian isolates caused ABR in wounded fruits, but only five in non-wounded ones. Uruguayan isolates produced symptoms in fruits with or without previous wounding. All Brazilian isolates from GLS and twelve from ABR were able to cause GLS symptoms, while a sole Uruguayan ABR-isolate caused leaf spot symptoms. This study gives a better insight on the new species causing apple disease in both countries and discusses their pathogenic potential.
authors: Laboratory of Plant Pathology, Agricultural Science Center, Federal University of Santa Catarina, Rod. Admar Gonzaga 1346, 88034-001 Florianópolis, SC, Brazil.
authors: Aline Cristina
authors: AC
authors: Velho
authors: Department of Plant Protection, Faculty of Agronomy, University of the Republic, Av. Garzón 780, CP 12900 Montevideo, Uruguay.
authors: Sandra
authors: S
authors: Alaniz
authors: Department of Plant Protection, Faculty of Agronomy, University of the Republic, Av. Garzón 780, CP 12900 Montevideo, Uruguay.
authors: Leticia
authors: L
authors: Casanova
authors: Department of Plant Protection, Faculty of Agronomy, University of the Republic, Av. Garzón 780, CP 12900 Montevideo, Uruguay.
authors: Pedro
authors: P
authors: Mondino
authors: Laboratory of Plant Pathology, Agricultural Science Center, Federal University of Santa Catarina, Rod. Admar Gonzaga 1346, 88034-001 Florianópolis, SC, Brazil. Electronic address: marciel.stadnik@ufsc.br.
authors: Marciel J
authors: MJ
authors: Stadnik
mesh_terms: D001938:Brazil; D016000:Cluster Analysis; D020231:Colletotrichum / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification*; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) / Q000235:genetics; D027845:Malus / Q000382:microbiology*; D008969:Molecular Sequence Data; D025282:Mycelium / Q000166:cytology; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D013172:Spores, Fungal / Q000166:cytology; D014404:Tubulin / Q000235:genetics; D014583:Uruguay
chemical_list: D021903:DNA, Ribosomal Spacer; D014404:Tubulin; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating)
keywords: Apple bitter rot; Colletotrichum spp.; Glomerella leaf spot; Morphology; Pathogenicity; Phylogeny