Diaporthe schimae C.M. Tian & Q. Yang, 2021

Yang, Qin, Jiang, Ning & Tian, Cheng-Ming, 2021, New species and records of Diaporthe from Jiangxi Province, China, MycoKeys 77, pp. 41-64 : 41

Diaporthe schimae C.M. Tian & Q. Yang sp. nov. Figure 7

Diagnosis.

Distinguished from the phylogenetically closely-related species D. sennae in having larger alpha conidia and longer beta conidia.

Etymology.

Named after the host genus Schima on which the fungus was isolated.

Description.

Leaf spots subcircular to irregular, pale brown, with dark brown at margin. Pycnidia solitary, scattered on the leaf surface. Pycnidial conidiomata in culture, globose, (150-)173-357(-373) µm in its widest diam., erumpent, single or clustered in groups of 3-5 pycnidia, coated with hyphae, cream to yellowish translucent conidial droplets exuded from ostioles. Conidiophores reduced to conidiogenous cells. Conidiogenous cells hyaline, unbranched, septate, straight, slightly tapering towards the apex. Alpha conidia scarce, hyaline, aseptate, ellipsoidal to spindle-shaped, four small guttulate, (7.5-)8-8.5(-9) × 2.5-3 μm. Beta conidia abundant, hyaline, aseptate, filiform, straight to sinuous at one end, eguttulate, (25-)27.5-38.5(-40.5) × 1-1.5 µm.

Culture characters.

Colony entirely white, with fluffy aerial mycelium, concentric zonation, margin fimbricate, reverse slightly yellowish.

Specimens examined.

China. Jiangxi Province: Ganzhou City, Fengshan Forest Park, on leaves of Schima superba , 25°44'22"N, 114°59'40"E, 15 May 2018, Q. Yang, Y. Liu & Y.M. Liang (holotype BJFC-S1661; ex-type culture: CFCC 53103); 24°40'51"N, 115°34'36"E, 15 May 2018, Q. Yang, Y. Liu & Y.M. Liang (BJFC-S1662; living culture: CFCC 53104); 24°40'52"N, 115°34'54"E, 15 May 2018, Q. Yang, Y. Liu & Y.M. Liang (BJFC-S1663; living culture: CFCC 53105).

Notes.

Diaporthe schimae occurs in an independent clade (Fig. 1 ) and was revealed to be phylogenetically distinct from D. sennae . Diaporhe schimae can be distinguished with D. sennae by 41 nucleotides in concatenated alignment, in which three were distinct in the ITS region, 20 in the tef1-α region and 18 in the tub2 region. Diaporthe schimae differs morphologically from D. sennae in having larger alpha conidia and longer beta conidia (8-8.5 × 2.5-3 vs. 5.5-6.3 × 1.5-1.7 µm in alpha conidia; 27.5-38.5 vs. 18.4-20 µm in beta conidia) ( Yang et al. 2017a).

Figures

Figure 1. Phylogram of Diaporthe from a Maximum Likelihood analysis based on combined ITS, cal, his 3, tef 1 and tub 2. Values above the branches indicate Maximum Likelihood bootstrap (left, ML BP ≥ 50 %) and Bayesian probabilities (right, BI PP ≥ 0.90). The tree is rooted with Diaporthella corylina. Strains in current study are in blue font and the ex-type cultures are in bold font.

Figure 7. Diaporthe schimae on Schima superba (BJFC-S 1661) a symptoms on leaves of host plant b the colony on PDA c conidiomata on PDA d conidiophores cells attached with beta conidia e Alpha conidia. Scale bars: 10 μm (d, e).