The etiological agent of cotton ramulosis represents a single phylogenetic lineage within the Colletotrichum gloeosporioides species complex

Abstract

Ramulosis of cotton, caused by Colletotrichum gossypii var. cephalosporioides (CGC), is an important disease of cotton in Brazil. The main objective of this work was to test whether CGC is a phylogenetic species inside the Colletotrichum gloeosporioides species complex. A Bayesian inference phylogenetic analysis of a combined ITS and TUB2 dataset was conducted with 21 strains identified as CGC and five strains of Colletotrichum gossypii (CG), associated with cotton anthracnose, obtained from diseased plants from different regions of Brazil. All CGC strains formed a highly supported lineage inside the clade of Colletotrichum theobromicola, a member of the C. gloeosporioides species complex. CG strains formed another lineage in the same clade. These findings were supported by a second analysis conducted with three genes (ITS+TUB2+GAPDH) and a subset of five CGC and three CG strains. During pathogenicity tests, all five CGC strains tested induced typical symptoms of ramulosis on inoculated plants, including foliar necrosis, death of apical meristems and over sprouting. Plants inoculated with CG strains exhibited foliar necrotic spots two months after inoculation. These results give phylogenetic support for the placement of CGC in the C. gloeosporioides species complex, and the distinction between the ramulosis and anthracnose pathogens of cotton in Brazil.

Near infrared hyperspectral images and pattern recognition techniques used to identify etiological agents of cotton anthracnose and ramulosis

“…Although controversy regarding no consistent reports of morphological and molecular markers to differentiate cotton anthracnose and ramulosis fungi exists, 10,11 our study corroborates studies conducted by Silva-Mann et al 9 and Salustiano et al, 12 who used molecular DNA techniques to distinguish successfully CG and CGC fungi. The technique proposed in this work, compared with molecular DNA techniques used to differentiate CG and CGC, is a rapid and low-cost method for accurate identification of these fungi and a non-destructive technique requiring minimal or no sample preparation.…”

“…Some authors have considered C. gossypii to be a synonym of C. gloeosporioides, but this taxon was not accepted by Sutton. 11 Recently, a molecular phylogenetic analysis conducted by Salustiano et al 12 showed that C. gossypii and C. gossypii var. cephalosporioides formed distinct lineages inside the clade of Colletotrichum theobromicola, a member of the C. gloeosporioides species complex, which allows distinction between the ramulosis and anthracnose pathogens of cotton.…”

“…Molecular techniques have been successfully used in the differentiation of species in a wide range of genera of pathogenic fungi, including Colletotrichum. 9,12,13 These techniques, however, are complex, slow, laborious and costly compared to spectral techniques, such as hyperspectral imaging near infrared (HSI-NIR) technology. HSI-NIR is an analytical tool with broad analytical capability for the verification and quantification of analytical compounds in biological systems.…”

Colletotrichum fructicola is the dominant and one of the most aggressive species causing bitter rot of apple in Uruguay

“…Damm et al (2012a, b) and Weir et al (2012) suggested that GAPD H, BTUB2 or glutamine synthetase are among the most effective genes to distinguish single Colletotrichum species that are phylogenetically related. As previously reported (Rodrigues et al 2014;Salustiano et al 2014;Velho et al 2015), multilocus phylogenetic analysis of ITS, GAPDH and BTUB2 allowed for the successful identification of a collection of Colletotrichum spp. obtained from apple.…”

Crotalaria Como Hospedeira Alternativa E Fonte De Inóculo De Fungos Fitopatogênicos

“…O gênero é o causador da antracnose da soja (COSTA, 2006), da ramulose (SILVA et al, 2010) e também a antracnose (SALUSTIANO, 2014) em algodão e da antrocnose do colmo e foliar do milho (COÊLHO et al, 2001).…”