Neopestalotiopsis rhododendri Qi Yang & Yong Wang bis, 2021

Yang, Qi, Zeng, Xiang-Yu, Yuan, Jun, Zhang, Qian, He, Yu-Ke & Wang, Yong, 2021, Two new species of Neopestalotiopsis from southern China, Biodiversity Data Journal 9, pp. 70446-70446 : 70446

Neopestalotiopsis rhododendri Qi Yang & Yong Wang bis sp. nov.

Materials

Type status: Holotype. Occurrence: recordedBy: Qi Yang; occurrenceID: GUCC 21504; Taxon : scientificName: Neopestalotiopsis rhododendri; order: Amphisphaeriales ; family: Sporocadaceae ; genus: Neopestalotiopsis ; Location : country: China; stateProvince: Yunnan; locality: Kunming ; verbatimCoordinates: 102°72' E, 25°05' N; Identification : identifiedBy: Qi Yang ; dateIdentified: 2021; Record Level : collectionID: HGUP 134 Type status: Other material. Occurrence: recordedBy: Qi Yang; occurrenceID: GUCC 21505; Taxon : scientificName: Neopestalotiopsis rhododendri; order: Amphisphaeriales ; family: Sporocadaceae ; genus: Neopestalotiopsis ; Location : country: China; stateProvince: Guizhou; locality: Kaili ; verbatimCoordinates: 107°97' E, 26°58' N; Identification: identifiedBy: Qi Yang; dateIdentified: 2021; Record Level: collectionID: HGUP 997

Description

Disease symptom: Associated with leaf spots of Rhododendron simsii . The leaf spots are small irregular to subcircular shape, brown, slightly sunken spots appear on surface leaves of R. simsii , which scattered on the surface leaves tip and eventually develops into a large lesion. Small off-white spots appeared initially and then gradually enlarged, changing to light brown circular ring spots with a dark brown border.

Colonies on PDA reaching 6.5-7 cm in diam. after 7 d at room temperature (28°C), under light 12 hr/dark. Hyphae white, colonies filamentous to circular, slightly undulate at the edge, with black fruiting bodies clustered, has filiform and fluffy margin, white from above and light yellow from the reverse. Sexual morph: undetermined. Asexual morph（Fig. 2 ）: Conidiomata 55-280 µm in diam., pycnidial, globose, solitary, black, semi-immersed on PDA, exuding brown to dark brown mass of conidia. Conidiophores often reduced to conidiogenous cell, regularly septate and branched at the base. Conidiogenous cells mostly integrated, ampulliform, cylindrical, hyaline to light brown, smooth-walled. Conidia (25.5-)30 × 5(-6) µm (x̄ = 27.6 × 5.5 µm, n = 30), fusiform to clavate, straight to slightly curved, 4-septate; basal cell obconic, hyaline, thin-walled, smooth, 3.5-6.5 µm (x̄ = 4.5 µm, n = 30); the three median cells 13.5-19.5 µm (x̄ = 16.3 µm, n = 30), light brown to dark brown, dark brown with septa darker than the rest of the cells, the second cell from base 4-6 µm (x̄ = 5 µm, n = 30); the third cell 3.5-5.5 µm (x̄ = 4.5 µm, n = 30); the fourth cell 4-6.5 µm (x̄ = 4.8 µm, n = 30); apical cell 3.5-6.3 µm (x̄ = 5 µm, n = 30), cylindrical to sub-cylindrical, hyaline, 1-3 (mostly 2) tubular apical appendages, arising from the apex of the apical cell each at different points, 21-38.5 µm (x̄ = 29.2 µm, n = 30); basal appendage present most of the time, single, tubular, unbranched, 6-11.5 µm (x̄ = 8.5 µm, n = 30).

Etymology

China, Yunnan Province, Kunming City, from leaves of Rhododendron simsii , 12 February 2018, Q. Zhang, HGUP 134, holotype, ex-type living culture GUCC 21504.

Notes

In the multi-gene analysis, strain GUCC 21504 formed a distinct clade with a sister strain GUCC 21505, but the node support values were 68/90/- (MP/ML/BI) and these two strains were close to N. protearum (CBS 114178). When comparing the polymorphic nucleotide differences of our two strains, there are 18 base pair differences, seven in ITS, two in tub2 and nine in tef1, but without obvious distinction (higher than 98.5%). Compared with N. protearum and our ex-type strain (GUCC 21504), there were six character differences with N. protearum in the ITS region, three character differences with N. protearum in the tub2 region, but 12 character differences from N. protearum in the tef1 region; thus the DNA base pair differences were mainly in the tef1 gene regions. The morphological differences between our strains and N. protearum were wider conidia ( N. protearum : 24.8 ± 1.5 × 8.5 ± 0.6 µm), more apical appendages ( N. protearum : 3-5) and shorter basal appendages ( N. protearum : 5-8 µm) ( Maharachchikumbura et al. 2014). Thus, Neopestalotiopsis rhododendri is introduced as a novel taxon, based on morphology and phylogeny.

Figures

Figure 2. Neopestalotiopsis rhododendri (GUCC 21504). a, b, c. Leaf spots of Neopestalotiopsis rhododendri; d, e. Culture on PDA (d - above, e - reverse); f. Colony sporulating on PDA; g-h. Conidia and conidiophores; i-m. Conidia. Scale bars: f = 1000 µm, g-m = 20 µm.