Aspergillus lannaensis N. Suwannarach, S. Khuna & S. Lumyong, sp. nov.
Index Fungorum number: IF 838058; MycoBank number: MB 838058; Facesoffungi number: FoF 09955; Fig. 1
Etymology – “lannaensis” referring to Lanna, the old name of the region including Chiang Mai Province, northern Thailand, where soil containing the new fungus was collected.
Holotype – SDBR-CMUO8
Culture characteristics – Colonies growing after 7 days at 25 °C on the following agar: CYA 45–48 mm, MEA 46–49 mm, and CREA 41–43 mm. Slow growth was observed on CYA, MEA, and CREA are 18–20, 12–14 and 13–15 mm, respectively after 7 days at 37 °C. On all agar media the colonies first white, gradually becoming light yellow from entre outwards, then conidiophores are produced, conidial areas are light yellow to olive drab on MEA and CREA; light yellow to dark yellow on CYA. Reverse yellowish-brown on CYA and CREA; light yellow on MEA. On CREA thin colonies with poor sporulation and no acid production. Conidiophores produced abundantly on MEA. Conidial heads 35–137 µm diam., globose, light yellow when young, olive drab in age, radiate, commonly splitting into columns with age. Stipes 190–800×7–15 µm wide near vesicle, short, smooth, thick walled, hyaline (light yellowish-brown pigment on upper portion near vesicle). Vesicles globose or nearly so, 14–46 µm in diam.; uni-seriate. Phialides 8–15×2–3 µm, pyriform and covering the entire surface of the vesicle. Conidia 3–6×2–3 µm wide, oval or ellipsoidal, light yellow, with smooth-walled, and arranged in long chains.
Material examined – THAILAND, Chiang Mai Province, Mae Wang District, (18°36′46″ N 98°46′30″ E), isolated from soil of longan orchard, 8 August 2017, S. Khuna, dried culture: SDBR-CMUO8, holotype; Chiang Mai Province, Mae Wang District, (18°36′46″ N 98°46′30″ E), isolated from soil of longan orchard, 8 August 2017, S. Khuna, living culture, SDBR-CMUO6.
GenBank numbers – SDBR-CMUO6: Cam MW219780, BenA = MW219782, RPB2 = MW219784; SDBRCMUO8: Cam = MW219781, BenA = MW219783, RPB2=MW219785.
Notes – A concatenated phylogenetic tree (cam, benA, and RPB2) revealed that Aspergillus lannaensis forms distinct lineages sister to A. funiculosus with 100% MLBS, 1.00 BYPP support (Fig. 2). However, A. lannaensis can be distinguished from A. funiculosus in shapes and sizes of conidia and phialides (Smith 1956). Therefore, we introduce a new species Aspergillus lannaensis (Fig. 1) based on morphology coupled with phylogenetic evidence.
Figure 1 – Aspergillus lannaensis (SDBR-CMUO8, holotype). Colonies incubated at 25 °C for 7 days. a Colony on CYA. b Colony on MEA. c Colony on CREA. d Conidiophores. e Conidia arranged in long chains. f Oval or ellipsoidal conidia. Scale bars: a–c=10 mm, d, e=20 µm, f=10 µm
Figure 2 – Phylogenetic tree derived from maximum likelihood analysis of a combined Cam, BenA and RPB2 genes of 22 sequences and the aligned dataset was comprised of 2360 characters including gaps (Cam: 1–792, BenA: 793–1310 and RPB2: 1311–2360). The average standard deviation of the split frequencies of the BI analysis was 0.004276. A best scoring RAxML tree was established with a final ML optimization likelihood value of − 13462.8650. The matrix had 1055 distinct alignment patterns with 21.67% undetermined characters or gaps. Estimated base frequencies were found to be: A=0.2500, C=0.2468, G=0.2390, T=0.2642; substitution rates AC=1.0520, AG=3.4446, AT=1.0037, CG=0.6646, CT=5.3732, GT=1.0000; proportion of invariable sites=0.1320 and gamma distribution=0.6870. Aspergillus fructus NRRL 239 and Aspergillus versicolor CBS 583.65 were used as outgroup. Numbers above branches are the bootstrap statistics percentages (left) and Bayesian posterior probabilities (right). Branches with bootstrap values equal to or greater than 70% are shown at each branch and the bar represents 0.1 substitutions per nucleotide position. Hyphen (-) represents support values equal to or greater than 70%/0.95. Ex-type strains are in bold and newly generated sequences are in blue