Conidiocarpus caucasicus Woron.

Haituk, Supitchakorn Thungdee Sukanya, Withee, Patchareeya, Cheewangkoon, Ratchadawan, Suwannarach, Nakarin, Marasinghe, Diana S. & Hongsanan, Sinang, 2023, Unraveling Capnodiaceae species in Northern Thailand, Phytotaxa 620 (2), pp. 143-156 : 151-152

Conidiocarpus caucasicus Woron. , Key to fungi (fungi imperfecti) 2: 743 (1917)

Index Fungorum number: IF 803878; FIGURE 4

= Conidiocarpus asiaticus (Chomnunti & K.D. Hyde) T. Bose , in Bose, Reynolds & Burbee, Mycologia 106(4): 751 (2014)

= Conidiocarpus siamensis (Chomnunti & K.D. Hyde) T. Bose , in Bose, Reynolds & Burbee, Mycologia 106(4): 753 (2014)

Saprobic sooty mold-like, growing on living leaves Mangifera indica . Thallus thin, dark brown, reticulately branched, dense, easily removed from the host surface, composed of brown, septate hyphae. Sexual morph: Not observed. Asexual morph: Pycnidia 650–1080 × 40–60 μm (x = 875 × 50 μm, n = 10), solitary to gregarious, superficial, black to dark brown, subcylindrical, straight or variously curved, unbranched or branched, thick-walled, swollen, narrow globose, brown, cylindrical, long-stalked. Ostiole surrounded by hyaline, subulate, hyphal extensions tapering to apex. Conidia 4.2–4.7 × 2.0–2.6 μm (x = 4.5 × 2.3 μm, n = 10), small, ellipsoid, continuous, aseptate, hyaline, smooth-walled, arranged in a droplet at the apex of pycnidial neck.

Material examined: THAILAND, Payao Province, on living leaf of Mangifera indica (Anacardiaceae) , 4 November 2022, S Hongsanan SDBR-CMUMG01 = CMUB 40026, living culture SDBR-CMU 478.

Notes: Our collection of Conidiocarpus caucasicus ( SDBR-CMU 478) was collected in Thailand (Payao Province). We observed 1–2 carcasses of aphids on a single leaf of our specimen. The strain SDBR-CMU 478 is morphologically identical to Co. caucasicus in having dark brown, dense, thallus, long-stalked, black to dark brown pycnidia with hyaline, aseptate, ellipsoid conidia ( Abdollahzadeh et al. 2020). According to our phylogenetic analysis ( FIGURE 1 ), our strain ( SDBR-CMU 478) clustered together with Co. asiticus ( MFLUCC 10-0062), Co. caucasicus ( GUMH 937), and Co. siamensis ( MFLUCC 10-0064/10-0063). Moreover, our phylogenetic result is consistent with those of Abdollahzadeh et al. (2020), confirming that the strains of Co. asiticus , Co. caucasicus , and Co. siamensis were not well-separated taxa with significant phylogenetical interference. Herein, we synonymized these species under Co. caucasicus giving priority to the oldest name. Furthermore, the strain of Co. siamensis ( MFLUCC 10-0061) formed a distinct clade with Conidiocarpus sp. ( CPC 20464 and CPC 20468) to the basal of Conidiocarpus clade. This may be due to inconsistencies in the availability of gene regions. We observed that the ITS base pair difference between MFLUCC 10-0061 strain and other Co. siamensis strains lacks enough phylogenetic significance (1.4%) to delineate it as a distinct species.

Figures

FIGURE 1 Phylogram of the best-scoring ML consensus tree based on a combined dataset (LSU, ITS, tef-1α and rpb2) of Capnodiaceae. Sequences obtained in this study are indicated in red, and newly established species are indicated in yellow. Isolates from type materials are in bold. The ML ultrafast bootstrap and Bayesian PP values equal to or greater than 60% and 0.90 are shown at the nodes. The tree is rooted with Scorias leucadendri (CBS 131318) and S. spongiosa (CBS 325.33).

FIGURE 4 Conidiocarpus caucasicus (CMUB40026). a Sooty mold on the leaf surface of Mangifera indica. b, c Appearance of conidiomata on the host surface. f, g Pycnidia wall. h Ostiole surrounded by hyaline hyphae. i, j Network-like hyphae. k Conidia. l Germinating Conidia. Scale bars: d = 100 µm, e–i = 50 µm, k = 5 µm, j, l = 20 µm.