Colletotrichum guangyuanense Y. X. Li & X. L. Fan, 2024

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

Colletotrichum guangyuanense Y. X. Li & X. L. Fan sp. nov.

Fig. 6

Etymology.

Named after the location where the fungal was first collected, which is Guangyuan City.

Typification.

China, Sichuan Province, Guangyuan City, Lizhou District , Shuiwo Village , 32 ° 23 ' 55 " N, 105 ° 39 ' 24 " E, from leaf of Juglans regia L., 11 Oct. 2023, Y. X. Li, L. Lin & X. L. Fan (holotype BJFC - S 2225 , ex-holotype culture CFCC 59902 ) .

Description.

Sexual morph not observed. Asexual morph developed on OA. Conidiomata acervular, color ranged from peach to light brown. Appressoria and Setae not observed on OA. Conidiophores hyaline, unbranched, approximately cylindrical, 22.2–35.1 × 3.2–5.3, mean ± SD = 27.4 ± 3.1 × 3.8 ± 0.5 µm, n = 50. Conidiogenous cells transparent, cylindrical, formed at the end or side of the hyphae. Conidia straight, hyaline, cylindrical, obtuse at the base, rounded at the apex, with smooth walls and granular contents, 9.7–17.7 × 3.9–6.9 µm, mean ± SD = 14.7 ± 1.9 × 5.5 ± 0.6 µm, L / W radio = 2.7, n = 100.

Culture characteristics.

Colonies on OA initially white, rapidly growing to 5 cm after 3 d at 25 ° C, and completely covering a 6 cm Petri dish after 7 d. The aerial mycelium white or gray, with a flocculent cotton like appearance, edge white, center pale greenish grey.

Additional materials examined.

China. • Sichuan Province, Guangyuan City , Lizhou District, Shuiwo Village, 32 ° 23 ' 31 " N, 105 ° 39 ' 22 " E, from leaf of Juglans regia L., 11 Oct. 2023, Y. X. Li, L. Lin & X. L. Fan ( BJFC - S 2226 , living culture CFCC 70249 ) . China. • Sichuan Province, Guangyuan City, Chaotian District, Longmen Valley Leisure Villa , 32 ° 39 ' 08 " N, 105 ° 58 ' 17 " E, from leaf of Juglans regia L., 10 Oct. 2023, Y. X. Li, L. Lin & X. L. Fan ( BJFC - S 2248 , living culture CFCC 59912 ) ; • Chaotian District, Longmen Valley Leisure Villa , 32 ° 39 ' 11 " N, 105 ° 55 ' 26 " E, from leaf of Juglans regia L., 10 Oct. 2023, Y. X. Li, L. Lin & X. L. Fan ( BJFC - S 2249 , living culture CFCC 70161 ) .

Notes.

In phylogenetic analyses, Colletotrichum guangyuanense forms a distinct clade within the C. gloeosporioides species complex, closely related to C. changpingense . Genetic differences between C. guangyuanense and the type strain of C. changpingense are observed at several loci: 4 bp in the ITS region, 3 bp in the act gene, 8 bp in the chs 1 gene, 6 bp in the gapdh gene, and 1 bp in the tub 2 gene ( Jayawardena et al. 2016 a). Morphologically, C. guangyuanense is distinguishable from C. changpingense by the absence of a distinct opaque region in the center of the conidia.

Figures

Figure 6. Colletotrichum guangyuanense (ex-holotype culture CFCC 59902) A symptom caused by Colletotrichum guangyuanense B colonies on OA media above and below after 5 days at 25 ° C C conidiomata on OA D conidiophores and conidia E, F conidia. Scale bars: 200 µm (C); 10 µm (D – F).