Nigrospora guangdongensis L.Y. Tian, 2020

Tian, Long-Yan, Zhang, Yan-Feng, Lian, Tao, Qin, Chang-Sheng & Xu, Jin-Zhu, 2020, Nigrospora guangdongensis sp. nov. from the needle of Cunninghamia lanceolata in China, Phytotaxa 449 (2), pp. 181-187 : 185

Nigrospora guangdongensis L.Y. Tian , sp. nov. FIGURE 2 .

MycoBank no: MB834489

Holotype:— BJFC-C006 .

Etymology:—In reference to the host genus Cunninghamia .

Host/distribution:—On the needles of C. lanceolata in China.

Hyphae smooth, hyaline to pale brown, branched, septate, 3.3–7.0 μm diam (av. = 4.81 μm, n = 50). Conidiophores reduced to conidiogenous cells. Conidiogenous cells dispersed on hyphae, monoblastic, discrete, solitary, hyaline or pale brown, determinate, doliiform to ampulliform, 6.5–10.9 × 7.1–9.9 μm (av. = 8.9 ± 1.4 × 8.4 ± 1.2 μm, n = 50). Conidia solitary, mostly globose or sub-globose, dark brown to black, shiny, smooth, 13.65–20.9 μm (av. = 16.8 ± 1.95 μm, n = 50).

Cultural characteristics—On PDA, colonies floccose, edge entire, initially white, becoming light brown to brown with age, reaching 9 cm diam after 5 d at 25 ° C, reverse smoke-grey with black spot, sporulating sparsely. On SNA, colonies flat, with some mycelia immersed, surface light brown. Colonies on OA, colonies flat, with sparse mycelia in early growth stage, reaching 9 cm diam after 6 d at 25 ° C, turning to light brown with age. Aerial mycelia were massive in the latter growth stage but covered with little conidia.

Materials examined:— China, Guangdong, Shaoguan city, Qujiang District Xiaokeng forest farm, 24°15’N, 113°35’ E, alt. 100-200 m, on needles of C. lanceolata (Lamb) . Hook ( Taxodiaceae ), L. Y. Tian, 6 Dec 2018 ( BJFCC 006, holotype; ex-type culture, CFCC 53917); Guangzhou, Tianhe District 23°12′00″N, 113°22′09″E, alt. 42 m, on needles of C. lanceolata, L.Y. Tian , 10 Dec 2018 (living culture, Tly 068).

Notes:—The N. guangdongensis sp. nov. constituted a distinct branch on concatenated gene trees with a high support value. It clustered in a clade with ex-type of N. musae ( CBS 319.34* and LC 6385), N. hainanensis ( CGMCC 3.18129* = LC 7030 and LC 6979), N. gorlenkoana ( CBS 480.73*), N. rubi ( CGMCC 3.18326* = LC 2698), N. bambusae ( CGMCC 3.18327* = LC 7114 and LC 7244) ( Fig. 1 ). Interestingly, these species were all found in south China, except for N. musae , which was from the fruit of Musa sapientum in Australia. Conidiophores of all these species usually reduced to subglobose to ampulliform conidiogenous cells. Nevertheless, conidia of N. guangdongensis sp. nov. (av. = 16.8 ± 1.95 μm) were much bigger than those of N. gorlenkoana (av. = 14.79 ± 1.21 μm), and N. rubi (av. = 14.23 ± 0.97 μm) ( Wang et al. 2017). It differs from N. hainanensis in having sparse conidiophores as oppose to abundant sporulation in N. hainanensis . Moreover, N. hainanensis differs from our species by having setae, and smaller conidia (spherical conidia (av. = 15.4 ± 1.04 μm) and ellipsoidal conidia (av. = 16.0 ± 0.98 × 12.1 ± 1.25 μm)), compared to the globose or sub-globose conidia of N. guangdongensis (av. = 16.8 ± 1.95 μm) ( Wang et al. 2017). Additionally, the growth rate of N. guangdongensis sp. nov. is fast than that of N. musae and N. bambusae , but almost same with N. hainanensis , N. gorlenkoana , and N. rubi ( Wang et al. 2017) . Besides, N. guangdongensis sp. nov. is difficulty in sporulation (Generally, the fungus can only form sporadic conidia on SNA at 30 days after cultivation and can not produce any conidium on PDA).

Figures

FIGURE 1. Phylogram of the best maximum likelihood tree from an analysis of the combined ITS-TUB2-TEF1-α matrix of Nigrospora, with Arthrinium malaysianum (CBS 102053) as the outgroup. MP/ML bootstrap support values greater than 50 % are shown at the nodes. Ex-type strains are marked with *.

FIGURE 2. Morphology of N. guangdongensis sp. nov. (BJFC-C006, holotype). A–C: Diseased needles of C. lanceolata. D: Colony morphology on PDA for 5 d. E–H: Conidiogenous cells and conidia. Scale bars: E–G = 20 μm