Differential Organ Distribution, Pathogenicity and Benomyl Sensitivity of Colletotrichum spp. from Blackberry Plants in Northern Colombia

Abstract

Blackberry anthracnose, caused by Colletotrichum spp., is an important disease of cultivated blackberry in the world. In Colombia, it is the number one limiting factor for commercial production. This study was conducted to determine the species of Colletotrichum infecting blackberry plants as well as the organ distribution, pathogenicity and response to benomyl of the isolated strains. Sixty isolates from stems (n = 20), thorns (n = 20) and inflorescences (n = 20) were identified as Colletotrichum acutatum and Colletotrichum gloeosporioides by a species‐specific polymerase chain reaction (PCR). Both Colletotrichum species were found in the same plant but on different organs. Colletotrichum gloeosporioides species predominated in thorn lesions (n = 16) and C. acutatum in stems (n = 15) and inflorescence (n = 15). Pathogenicity assays on detached blackberry organs demonstrated differences between the two species with an average period of lesion development of 8.7 days for C. gloeosporioides and 10.3 days for C. acutatum. Wound inoculated organs had 90% disease development compared to 17.5% in non‐wounded. All C. acutatum isolates (n = 34) were benomyl tolerant, whereas C. gloeosporioides isolates (n = 26) were 30.7% sensitive and 69.2% moderately tolerant. Phylogenetic analysis with ITS sequences of a subset of 18 strains showed that strains classified as C. gloeosporioides had 100% identity to Colletotrichum kahawae, which belongs to the C. gloeosporioides species complex, whereas C. acutatum strains clustered into two different groups, with high similarity to the A2 and the A4 molecular groups. These data demonstrate for the first time the differential distribution of both species complexes in blackberry plant organs and further clarifies the taxonomy of the strains.

Poda drástica de verão e produção de cultivares de amoreira-preta em região subtropical

“…A poda drástica de verão pode ser uma opção para a diminuição dos inóculos, pois remove o total das hastes no verão. Perdas de produção de frutas, como resultado do efeito de antracnose, têm sido entre 50 e 76%, o que mostra a importância de melhorar o controle do patógeno (Rueda-Hernández et al, 2013).…”

“…Uma alternativa seria adotar manejos de poda diferentes em regiões subtropicais, em que as podas drásticas possam ser realizadas, para eliminar todas as hastes rentes ao solo, sem prejuízos à produção. São necessários apenas cinco meses, a contar da emissão das hastes do solo, para que as gemas se diferenciem e estejam prontas para a brotação e a emissão de flores (Moore, 1984;Clark et al, 2005). A poda drástica de verão, realizada logo após o término da colheita, foi testada por Campagnolo & Pio (2012c) …”

Molecular and phenotypic characterization of Colletotrichum species associated with anthracnose disease in peppers from Sichuan Province, China

“…The name C. gloeosporioides represents both C. gloeosporioides sensu lato, which encompasses the entire species complex, and C. gloeosporioides sensu stricto 18 . C. gloeosporioides sensu lato consists of at least 22 species, including C. gloeosporioides , C. siamense , and C. fructicola 1 18 25 26 41 . C. siamense and C. fructicola were originally known as opportunistic pathogens of Coffea arabica berries in Thailand 26 , and both of these species are non-host-specific.…”

Histone H3 gene is not a suitable marker to distinguish Alternaria tenuissima from A. alternata affecting potato

“…For example, populations of A. solani and A. alternata differed in resistance to azoxystrobin in the Columbia Basin of Washington [12]. This phenomenon was also found in Colletotrichum complex [13][14][15]. Fungicides could also have different intrinsic activity in species complex, i.e less activity of benomyl was found in C. acutatum compared to C. gloeosporioides [16,17].…”