Nemania oryzae S. Absalan, S. Lumyong and K. D. Hyde, 2025

Absalan, Sahar, Armand, Alireza, Jayawardena, Ruvishika S., Suwannarach, Nakarin, Monkai, Jutamart, Jungkhun, Nootjarin, Lumyong, Saisamorn & Hyde, Kevin D., 2025, Endophytic xylariaceous fungi from rice in northern Thailand: discovery of novel species and new host records, MycoKeys 120, pp. 1-34 : 1-34

Nemania oryzae S. Absalan, S. Lumyong and K. D. Hyde sp. nov.

Fig. 10

Holotype.

MFLU 25-0027

Etymology.

Oryzae refers to the host genus Oryza from which it was isolated.

Description.

Endophytic from healthy panicle of Oryza sativa . Sexual morph: Not observed. Asexual morph: Hyphomycetous. Hyphae 1.5–2.5 µm wide, straight, branched, septate, hyaline. Conidiophores 3–3.5 µm wide, unbranched, septate, occasionally enlarged towards the upper part, pale brown to hyaline. Conidiogenous cells 2.5–3.5 µm wide, cylindrical, pale brown to hyaline. Conidia 4.5–7 × 3–4 µm (x ̄ = 6 × 3.5 µm, n = 20), obovoid, smooth, hyaline. Chlamydospores scarce, thick-walled, hyaline, globose to ellipsoidal.

Culture characteristics.

Colonies on PDA reaching 65–68 mm in diameter after 7 days at 28 ° C, cotton white, circular, medium dense, velvety to felty, with undulate margins; reverse white.

Material examined.

Thailand • Chiang Rai Province, Phan District , from healthy tissue part of the rice panicle, 9 November 2021, Nootjarin Jungkhun (NS 24-1 a = MFLU 25-0027 ) (ex-type, living culture MFLUCC 24-0508 ) .

GenBank numbers.

MFLUCC 24-0508 : ITS = PV 241499, LSU = N / A, rpb 2 = PV 275682, tub 2 = PV 275686.

Notes.

Nemania oryzae is proposed here as a new species based on multi-gene phylogenetic analyses. Our strain ( MFLUCC 24-0508 ) clustered in a separate lineage, distinct from N. primolutea , N. aquilariae , and N. feicuiensis , with 100 % ML and 1.00 PP bootstrap support (Fig. 9 ). A comparison of the nucleotide differences between N. oryzae and the closely related species, N. aquilariae , revealed 0.28 % (across 357 nucleotides), 4 % (across 886 nucleotides), and 5.2 % (across 327 nucleotides) base pair differences in ITS, rpb 2, and tub 2 gene regions, respectively. Nemania aquilariae ( KUMCC 20-0268 ) was isolated from the wood of Aquilaria sinensis as an endophytic fungus and did not sporulate on the culture media ( Tibpromma et al. 2021). Hence, morphological comparisons are not feasible due to the absence of micro-morphological details in N. aquilariae ’ s description. Sequence comparison between N. oryzae and N. feicuiensis showed base pair differences of 2.5 % (across 357 nucleotides), 9.2 % (across 886 nucleotides), and 13.4 % (across 327 nucleotides) in the ITS, rpb 2, and tub 2 gene regions, respectively. Morphological distinction between the two species is also not feasible, as N. feicuiensis has only been documented as a sexual morph ( Pi et al. 2021).

Figures

Figure 9. Phylogram of ML analysis based on combined ITS, LSU, rpb 2, and tub 2 sequence data. ML bootstrap support values equal to or higher than 60 % and Bayesian probability values (PP) equal to or above 0.80 are given at the nodes (ML / PP). The tree is rooted to Rosellinia britannica (MFLU 17-302). The isolate from the current study is highlighted in red, and type strains are indicated in bold black.

Figure 10. Nemania oryzae (MFLUCC 24-0508, ex-type). a. Front and reverse of the colony on PDA; b – e. Conidiophore and conidiogenous cells; f. Chlamydospore; g. Conidia. Scale bars: 10 μm (b – g).