Colletotrichum species_Alignments

Colletotrichum is a cosmopolitan fungal genus known for its important role as a plant pathogen. Its species cause diseases such as anthracnose, leaf spots, blights, and rots, impacting a wide range of hosts. Colletotrichum species also exhibit endophytic and saprobic life modes. The genus comprises species complexes, many of which include cryptic species that are morphologically similar but phylogenetically distinct. The genus is characterized by hyaline and aseptate ascospores and conidia, with the ascospores being cylindrical to oval or fusiform, and the conidia mostly ellipsoidal to ovoid. As part of ongoing research on phytopathogenic fungi, we gathered diseased leaves and pods with spots, blight and blotches from Chiang Mai, Chiang Rai, and Tak provinces in Thailand. For species identification and delimitation, we employed a biphasic approach incorporating morphological data and multigene phylogenetic analyses of the locus of the internal Transcribed Spacer (ITS, nuclear rDNA consisting of ITS1-5.8S-ITS2), and the genes encoding for glyceraldehyde-3-phosphate dehydrogenase (GAPDH), chitin Synthase 1 (CHS1), actin (ACT), beta-tubulin 2 (TUB2), histone (H3), and calmodulin (CAM). We obtained 20 Colletotrichum isolates representing eight species, among which we propose two new species: Colletotrichum dendrobii (from Dendrobium sp.) and C. musichiangmaiense (from Musa sp.). We also establish 13 new host records (for six species): C. castaneae (on Jasminum grandiflorum), C. chrysophilum (on Terminalia sp.), C. endophyticum (on Artocarpus heterophyllus, Begonia luxurians, Cassia sp., Castanopsis sp., Ficus auriculata, and Schefflera sp.), C. fructicola (on Castanea sp., Hedychium sp., and Rhododendron sp.), C. jiangxiense (on Artocarpus sp.), and C. schimae (on Jasminum sp.). In addition, this is the first study to present the sexual morph of C. endophyticum and to synonymize C. noveboracense under C. chrysophilum.