Diaporthe meliae C.M. Tian & Q. Yang, 2022

Cao, Lingxue, Luo, Dun, Lin, Wu, Yang, Qin & Deng, Xiaojun, 2022, Four new species of Diaporthe (Diaporthaceae, Diaporthales) from forest plants in China, MycoKeys 91, pp. 25-47 : 25

Diaporthe meliae C.M. Tian & Q. Yang sp. nov.

Fig. 3

Diagnosis.

Distinguished from the phylogenetically closely-related species, D. podocarpi-macrophylli , in shorter alpha conidia.

Etymology.

Named after the host genus on which it was collected, Melia .

Description.

Conidiomata pycnidial, immersed in the host bark, scattered, erumpent through the bark surface, discoid, with a single locule. Ectostromatic disc dark brown, one ostiole per disc, (325-)330-375(-385) μm (n = 30) diam. Locule undivided, 420-640 × 385-515 μm (n = 30). Conidiophores reduced to conidiogenous cells. Conidiogenous cells (13.5-)15-26.5(-28) × 1.3-2.1(-2.3) μm (n = 30), L/W = 8.5-15.5, cylindrical, hyaline, branched, straight or slightly curved, tapering towards the apex. Alpha conidia hyaline, aseptate, fusiform, multi-guttulate, (6.7-)8-9.5(-10) × (2-)2.1-2.3 μm (n = 30), L/W = 3.4-4.5. Beta conidia not observed.

Culture characters.

Colony originally flat with white felty aerial mycelium, becoming auburn furcate mycelium with age, with irregular margin, conidiomata absent.

Specimens examined.

China, Shandong Province: Rizhao City , on branches of Melia azedarach , 20 April 2018, N. Jiang (holotype BJFC-S1668; ex-type living culture: CFCC 53089; living culture: CFCC 53090) .

Notes.

Two strains representing Diaporthe meliae cluster in a well-supported clade (ML/BI = 100/1), and appear closely related to D. podocarpi-macrophylli . Diaporthe meliae can be distinguished based on ITS, his3, tef-1α, and tub2 loci from D. podocarpi-macrophylli (4/459 in ITS, 15/455 in his3, 25/349 in tef-1α, and 14/401 in tub2). Morphologically, D. meliae can be distinguished from D. podocarpi-macrophylli by its longer conidiogenous cells (15-26.5 vs. 6-18 μm) and alpha conidia (8-9.5 vs. 3.5-8.5 μm) ( Gao et al. 2017).

Figures

Figure 3. Diaporthe meliae (BJFC-S 1668) a, b habit of conidiomata on twig c transverse section through conidiomata d longitudinal section through conidiomata e, f conidiogenous cells g alpha conidia. Scale bars: 1 mm (b); 200 μm (c, d); 10 μm (e-g).