Neopestalotiopsis saprophytica (Maharachch. & K.D. Hyde) Maharachch., K.D. Hyde & Crous,

Koodalugodaarachchi, Vidyamali, Thilini Chethana, K. W., Jayawardena, Ruvishika S., Bundhun, Digvijayini, Aluthmuhandiram, Janith V. S., Suwannarach, Nakarin, Manawasinghe, Ishara S. & Lumyong, Saisamorn, 2024, New records of Pestalotioid species associated with leaf spot disease on Camellia sinensis from northern Thailand, Phytotaxa 647 (1), pp. 91-114 : 101-103

Neopestalotiopsis saprophytica (Maharachch. & K.D. Hyde) Maharachch., K.D. Hyde & Crous, Stud. Mycol. 79: 148 (2014)

MycoBank: MB 809780, Faces of fungi number: FoF 13405, Figure 3

Description:—Associated with lesions of the diseased leaves of Camellia sinensis var. assamica . Appearing as black spots on dead tissues of the leaf epidermis. Asexual morph: Conidiomata pycnidial on PDA, 111–475 μm diam. (x̅ = 293 μm), aggregated, mostly globose, reniform or oblong, exuding black slimy, glistening conidial masses. Conidiophores unbranched, aseptate, often reduced to conidiogenous cell. Conidiogenous cells 9–26 × 3–8 μm (x̅ = 17 × 5 μm, n = 20), discrete, annellidic, clavate, oblong-cylindrical, hyaline to pale yellow, smooth, thin-walled. Conidia 19.4–50.9 × 4.6–12.6 μm (x̅ = 29.2× 6.6 μm, n = 20), fusoid to fusiform, straight to slightly curved, 4-septate, initially hyaline to pale yellow, later turning to olivaceous, smooth, thin-walled at maturity; basal cell 1–6 μm long (x̅ = 4.9 μm, n = 20), acute conic, hyaline, infrequently light yellow, thin-walled, smooth; three median cells each 2.5–7.6 μm long (x̅ = 4.9 μm, n = 20), doliiform, olivaceous, concolorous, verruculose, periclinal walls darker than the rest of the cell; second cell from base 4.4–7.6 μm long; third cell 3.5–6.4 μm long; fourth cell 2.5–6.3 μm long; apical cell 1.8–5.0 μm long (x̅ = 3.5 μm, n = 20), hyaline, subcylindrical to obconic, with 2–4 (often 3) tubular appendages arising from the apex of the apical cell, unbranched, flexuous, filiform, 4.1–29.9 μm (x̅ = 13.8 μm, n = 20); basal appendage single, tubular, unbranched, centric, 2.3–11.2 μm long, (x̅ = 3 μm, n = 20). Sexual morph: Not observed.

Culture characteristics:—Colonies on PDA filamentous to circular, slightly undulate to filiform margin, attaining 30–40 mm diam. after 7 days at 25 ° C, surface white, cottony, aerial mycelium on surface, flat elevation, reverse white to pale yellowish. Sporulates after 10 days; conidiomata black, gregarious.

Known hosts:—Saprobic on leaves of Magnolia sp. ( Magnoliaceae ) and on fruits of Litsea rotundifolia ( Maharachchikumbura et al. 2012, 2014); pathogenic causing leaf spots on Oil palm ( Elaeis guineensis ( Ismail et al. 2017) , Paphiopedilum micranthum ( Qin et al. 2020) , and Erythropalum scandens ( Yang et al. 2021) , leaf blight on Roystonea regia ( Ismail et al. 2022) , fruit rot on Persimmon ( Diospyros kaki ) ( Qin et al. 2023), associated with diseased leaves of Camellia sinensis var. assamica (this study); endophytic on leaves of Cordia dichotoma ( Reddy et al. 2016) .

Known distribution:— China ( Maharachchikumbura et al. 2012, 2014, Qin et al. 2020, 2023, Yang et al. 2021), Malaysia ( Ismail et al. 2017, 2022), India ( Reddy et al. 2016), Thailand (this study).

Materials examined:— Thailand, Chiang Mai Province, Mae Taeng District, Ban Pang Makluay Community Forest, alt. 530 m, on symptomatic leaf of Camellia sinensis var. assamica ( Theaceae ), 28 September 2022, V. Koodalugodaarchchi P6 ( MFLU 23-0396), living culture MFLUCC 23-0259; ibid., P11 ( MFLU 23-0397), living culture MFLUCC 23-0260.

Notes:— Neopestalotiopsis saprophytica was introduced by Maharachchikumbura et al. (2012) as Pestalotiopsis saprophyta Maharachchikumbura & K.D. Hyde , a saprobe on the leaves of Magnolia sp. , Yunnan Province, China ( Maharachchikumbura et al. 2012). During the revision of Pestalotiopsis , P. saprophyta was synonymised to N. saprophytica by Maharachchikumbura et al. (2014) based on the multi-gene phylogeny of ITS, tub2 and tef1-α. Our strains ( MFLUCC 23-0259 and MFLUCC 23-0260) share similar conidial characteristics with N. saprophytica ( MFLUCC 12-0282) by having same conidial length to width ratio (4.4), with three median cells that are dark brown to olivaceous, and 2–4, long apical appendages (13.8 vs 13.6 μm). However, conidial sizes of our isolates (19.4–50.9 × 4.6–12.6 μm) show significant differences from those of N. saprophytica ( MFLUCC 12-0282) (22–30 × 5–6 μm) ( Maharachchikumbura et al. 2012), along with median cell length (2.5–7.6 μm vs 4–6 μm) and conidial colour (concoloured olivaceous vs versicoloured dark brown to olivaceous). According to the multi-locus phylogeny, N. saprophytica (CBS 115452) clustered with MFLUCC 23-0259 with 98% MLBS, 56% MPBS, 0.99 BYPP, and MFLUCC 23-0259 with 91% MLBS, 45% MPBS and 0.51 BYPP. Base pair comparison between N. saprophytica (CBS 115452) and our isolate MFLUCC 23-0259 demonstrated insignificant nucleotide differences only in the tub2 (0.13%) region, while the isolate MFLUCC 23-0260 showed slight nucleotide differences in tub2 (0.27%) and tef1-α (0.67%) regions. Thus, we identify our strains as N. saprophytica , a new record on Camellia sinensis var. assamica in Thailand, following the species recognition guidelines provided by Chethana et al. (2021) and Maharachchikumbura et al. (2021).

Figures

FIGURE 3. Neopestalotiopsis saprophytica (MFLU 23-0396 (a, b), MFLU 23-0397 (c, d), MFLUCC 23-0259 (e, j, p), MFLUCC 23- 0260 (f–h, k–n, p) new host record). a, c Diseased leaves of Camellia sinensis var. assamica. b, d Close-up of lesions. e Upper and reverse views of the PDA (MFLUCC 23-0259) (at 25 °C). f Upper and reverse views of the PDA (MFLUCC 23-0260) (at 25 °C). On culture: g–i Pycnidial conidiomata. j Mycelium. k, l Conidial attachment to conidiogenous cells. k–l Conidiogenous cells. m–p Conidia. Scale bars: h = 50 μm, j–p = 20 μm.