Colletotrichum siamense Prihastuti, L. Cai & K. D. Hyde

Li, Yixuan, Lin, Lu, Cao, Jing, Gan, Mingxu & Fan, Xinlei, 2024, Three new species of Colletotrichum (Glomerellales, Glomerellaceae) associated with walnut (Juglans regia) anthracnose from China, MycoKeys 108, pp. 147-167 : 147-167

publication ID	https://doi.org/ 10.3897/mycokeys.108.125382
DOI	https://doi.org/10.5281/zenodo.13645552
persistent identifier	https://treatment.plazi.org/id/EE1B963D-283B-5E18-A125-5CB4A340083F
treatment provided by	MycoKeys by Pensoft
scientific name	Colletotrichum siamense Prihastuti, L. Cai & K. D. Hyde
status

Treatment

Colletotrichum siamense Prihastuti, L. Cai & K. D. Hyde , Fungal Divers. 39: 98 (2009)

Materials examined.

China. • Sichuan Province, Guangyuan City, Chaotian District, Zhongzi Town , 32 ° 41 ' 05 " N, 106 ° 02 ' 08 " E, from leaf of Juglans regia L., 10 Oct. 2023, Y. X. Li, L. Lin & X. L. Fan ( BJFC - S 2231 , living culture CFCC 59601 ; BJFC - S 2233 , living culture CFCC 59625 ; BJFC - S 2235 , living culture CFCC 59964 ) GoogleMaps ; • 32 ° 41 ' 34 " N, 106 ° 02 ' 23 " E, from leaf of Juglans regia L., 10 Oct. 2023, Y. X. Li, L. Lin & X. L. Fan (holotype BJFC - S 2234 , living culture CFCC 59909 ) GoogleMaps

Notes.

Colletotrichum siamense was first described as a species in association with Coffea arabica by Prihastuti et al. (2009). The broader concept of C. siamense sensu lato has been a subject of considerable debate, as noted by Weir et al. (2012) and Sharma et al. (2015), due to the application of the Genealogical Concordance Phylogenetic Species Recognition ( GCPSR) approach. Liu et al. (2016) concluded that C. siamense is a single species, not a species complex. Based on phylogenetic evidence, Zhang et al. (2022) proposed that C. menglaense , C. pandanicola , and C. parvisporum are synonyms of C. siamense . More recent studies have further synonymized the closely related species C. rhizophorae and C. thailandica with C. siamense , considering morphological characteristics, phylogenetic analyses, and GCPSR ( Aumentado et al. 2024). In this study, C. siamense was isolated from walnut leaf spots affected by walnut anthracnose. The four isolates our study examined while forming a distinct lineage were found within the C. siamense clade in our phylogenetic analysis. Moreover, our isolate ( CFCC 59909) is similar to the holotype of C. siamense ( ICMP 18578). While the conidia of our isolate ( CFCC 59909) are wider than strain ICMP 18578 (12.3–14.5 × 4.9–6.4 vs. 7–18.3 × 3–4.3 μm) ( Prihastuti et al. 2009). Based on this evidence, we identify our isolate as C. siamense .