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

Abstract

The anthracnose caused by Colletotrichum species is an important disease that primarily causes fruit rot in pepper. Eighty-eight strains representing seven species of Colletotrichum were obtained from rotten pepper fruits in Sichuan Province, China, and characterized according to morphology and the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) sequence. Fifty-two strains were chosen for identification by phylogenetic analyses of multi-locus sequences, including the nuclear ribosomal internal transcribed spacer (ITS) region and the β-tubulin (TUB2), actin (ACT), calmodulin (CAL) and GAPDH genes. Based on the combined datasets, the 88 strains were identified as Colletotrichum gloeosporioides, C. siamense, C. fructicola, C. truncatum, C. scovillei, and C. brevisporum, and one new species was detected, described as Colletotrichum sichuanensis. Notably, C. siamense and C. scovillei were recorded for the first time as the causes of anthracnose in peppers in China. In addition, with the exception of C. truncatum, this is the first report of all of the other Colletotrichum species studied in pepper from Sichuan. The fungal species were all non-host-specific, as the isolates were able to infect not only Capsicum spp. but also Pyrus pyrifolia in pathogenicity tests. These findings suggest that the fungal species associated with anthracnose in pepper may inoculate other hosts as initial inoculum.

Diversity, structure, and synteny of the cutinase gene ofColletotrichumspecies

“…Within C. truncatum sequences, the cutinase gene structure as cutinase 1 ( CUT1 ) was maintained as two exons with a single intervening intron which is spliced out during posttranscriptional modification resulting in a single splice variant based on comparative clustering. The relative positions of the two exons and the intervening intron varied within base pairs among Colletotrichum species and this is in keeping with the findings of Liu et al ().…”

“…The cutinase gene family in various genera of fungal genomes demonstrates a high degree of coding-sequence variation reflective of the diverse of roles attributed to cutinases and which perhaps, allowed adaptation to diverse ecological niches over time (Deng, Carbone, & Dean, 2007;Skamnioti et al, 2008). However, the relative degree of nucleotide and amino acid sequence diversity in addition to the role of these genes and their gene products in pathogenesis can vary (Liu et al, 2016;Skamnioti & Gurr, 2007;Sweigard, Chumley, & Valent, 1992). For example, in M. oryzae, CUT1 gene is essential for pathogenicity and CUT2 gene is required for cuticle sensing and formation of infection structures (Skamnioti et al, 2008).…”

“…Multilocus phylogeny revealed that the recently characterized Colletotrichum magnum species complex consists of nine closely-related species which includes C. brevisporum (Damm et al, 2019). C. brevisporum has also been reported as one of the causal agents of anthracnose disease in chili fruit in China and Brazil and in bell pepper fruit in Trinidad (De Silva, Crous, Ades, Hyde, & Taylor, 2017;Diao et al, 2017;Liu et al, 2016;Villafana et al, 2019). Sudan III was used to stain the cuticle an orange to red color for microscopic visualization (Yeung & Chan, 2015).…”

Colletotrichum species associated with cassava anthracnose in China

“…Colletotrichum plurivorum was first described as C. sichuanensis from Capsicum annuum in Sichuan Province, China (Liu et al, ). In a study by Douanla‐Meli, Unger, and Langer (), C. sichuanensis was regarded as a synonym of C. cliviicola (as C. cliviae ), while was found to in a study by Damm et al (), C. cliviicola and C. plurivorum were once again regarded as distinct species.…”

Morphological and molecular identification of Colletotrichum species associated with cassava anthracnose in Thailand

“…C. capsici isolate SRTLF01 (accession number KT222266) was best matched with C. capsici (syn. C. truncatum) sequences from the GenBank database (i.e., accession number KP748222, KX197403, AJ301945 and DQ454014) from peppers (Liu et al, 2016). And C. aeschynomene isolate NKSTKLS02 (accession number KT222267) was matched with C. aeschynomene sequences from the GenBank database (i.e., accession number JX131331 and JX010176) (Farr, Aime, Rossman, & Palm, 2006;Prihastuti, Cai, Chen, McKenzie, & Hyde, 2009;Wokocha et al, 2010).…”