Seven new species of Alternaria (Pleosporales, Pleosporaceae) associated with Chinese fir, based on morphological and molecular evidence Author He, Jiao https://orcid.org/0000-0002-4146-2223 Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China Author Li, De-Wei https://orcid.org/0000-0002-2788-7938 The Connecticut Agricultural Experiment Station Valley Laboratory, Windsor, CT 06095, USA Author Cui, Wen-Li https://orcid.org/0009-0005-7515-7672 Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China Author Huang, Lin https://orcid.org/0000-0001-7536-0914 Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, Jiangsu 210037, China lhuang@njfu.edu.cn text MycoKeys 2024 2024-01-05 101 1 44 http://dx.doi.org/10.3897/mycokeys.101.115370 journal article http://dx.doi.org/10.3897/mycokeys.101.115370 1314-4049-101-1 FBF8EACC1A7B50CA918E4C7D2FB08E8E Alternaria xinyangensis Lin Huang, Jiao He & D.W. Li sp. nov. Fig. 9 Holotype. China, Henan Province, Xinyang City, Zhenlei Mountain, 32°04'51"N , 114°07'23"E , isolated from leaf spots of Cunninghamia lanceolata , May 2017, Wen-Li Cui, (holotype: CFCC 59352). Holotype specimen is a living specimen being maintained via lyophilisation at the China Forestry Culture Collection Center (CFCC). Ex-type (ZLS1) is maintained at the Forest Pathology Laboratory, Nanjing Forestry University. Etymology. Epithet is after Xinyang City where the type specimen was collected. Host/distribution. From C. lanceolata in Zhenlei Mountain, Xinyang City, Henan Province, China. Description. Mycelium superficial on the PCA, composed of septate, branched, smooth, thin-walled, white to light brown hyphae. Conidiophores macronematous, mononematous, produced laterally or terminally on the hyphae, cylindrical, erect or ascending, simple or branched, geniculate, pale brown to dark brown, smooth, 1-7 septate, (9.4-)15.3-54.9(-80.4) x (2.9-)3.7-4.8(-5.2) μm , (mean +/- SD = 35.1 +/- 19.8 x 4.2 +/- 0.6 μm , n = 40). Conidiogenous cells apical or subapical, cylindrical, brown, smooth, (3.9-)5.3-9.6(-12.9) x (2.4-)3.3-4.9(-5.5) μm , (mean +/- SD = 7.5 +/- 2.2 x 4.1 +/- 0.8 μm , n = 39), mono- or polytretic, with conspicuous scars after conidia have seceded. Each conidiogenous locus bears a primary chain of 2-7 conidia; each primary chain usually has 1-3 branching chains of 1-3 conidia. Newly-developed conidia subhyaline or pale greyish, ellipsoidal or subacute, thin-walled, 1-3 septate, with few or no protuberance. Mature conidia brown to dark chocolate-brown, spheroidal or ellipsoid to long-ellipsoid, with 1-6 transverse septa and 1-5 longitudinal or oblique septa, (13.8-)19.9-31.8(-37.6) x (6.9-)8.6-12.9(-17.5) μm , (mean +/- SD = 25.9 +/- 6.0 x 10.7 +/- 2.1 μm , n = 37) in size. Secondary conidia commonly produced by means of a short apical or lateral secondary conidiophore, but rarely by conidia through an inconspicuous apical conidiogenous locus. In addition, false beaks (secondary conidiophores), unbranched, short, blunted, pale brown, (3.0-)5.3-16.0(-24.4) x (2.4-)2.8-4.1(-5.1) μm , (mean +/- SD = 10.6 +/- 5.4 x 3.4 +/- 0.7 μm , n = 31). Conidial beakless mostly with a conical cell at the apex. Chlamydospores not observed. Figure 9. Alternaria xinyangensis (ZLS1) A colony on PCA after 6 days at 25 °C in the dark B, C sporulation patterns D conidiophores and conidiogenouse cells E conidium. Scale bars: 50 μm ( B, C );10 μm ( D, E ). Culture characteristics. Colonies on PCA incubated at 25 °C in the dark growing at 7.2 mm/d; aerial hyphae cottony, olive green, with white margins; reverse centre black to greyish; sporulation abundant; diffusible pigment absent. Additional materials examined. China , Henan Province , Xinyang City , Zhenlei Mountain , 32°04'51"N , 114°07'23"E , isolated from leaf spots of Cunninghamia lanceolata , May 2017 , Wen-Li Cui, ZLS1-1, ZLS1-2, ZLS1-3, ZLS1-4 ; China , Henan Province , Xinyang City , Xinyang University , 32°08'20"N , 114°02'06"E , isolated from leaf spots of C. lanceolata , May 2017 , Wen-Li Cui, XYXY06, XYXY8-2, XYXY15, XYXY15-1, XYXY15-2, XYXY15-3, XYXY15-4, XYXY16 . Notes. The isolates of A. xinyangensis were phylogenetically close to A. dongshanqiaoensis (in this study, DSQ2-2), A. citri (ex-epitype, CBS 107.27), A. cinerariae (ex-epitype, CBS 612.72) and A. kikuchiana (ex-type, CBS 107.53) (Fig. 1 ). Between A. xinyangensis isolates and A. dongshanqiaoensis DSQ2-2, there were 1/453 differences in Alt a1, 1/510 in ITS, 8/664 in OPA10-2, 1/401 in endoPG, 1/757 in RPB2, 1/996 in SSU and 3/293 in TEF1. Between A. xinyangensis isolates and A. citri (ex-epitype, CBS 107.27), there were 1/453 differences in Alt a1, 3/510 in ITS, 8/664 in OPA10-2, 1/401 in endoPG, 1/996 in SSU and 3/293 in TEF1. Between A. xinyangensis isolates and A. cinerariae (ex-epitype, CBS 612.72), there were 1/453 differences in Alt a1, 3/510 in ITS, 8/664 in OPA10-2, 1/401 in endoPG, 1/996 in SSU and 3/293 in TEF1. Between A. xinyangensis isolates and A. kikuchiana (ex-type, CBS 107.53), there were 3/453 differences in Alt a1, 3/510 in ITS, 2/401 in endoPG, 1/757 in RPB2, 1/996 in SSU and 3/293 in TEF1. The PHI analysis showed that there was no significant recombination between A. xinyangensis isolates and their related species (Φw = 0.1647) (Fig. 2A ). Distinguishing characteristics of this new species and other similar species of Alternaria spp. are shown in Table 2 . Morphologically, conidial number in chains of the A. xinyangensis isolates were less than those of A. dongshanqiaoensis DSQ2-2 (2-7 conidia vs. 5-9 conidia). Conidia of the A. xinyangensis isolates were smaller than those of A. citri CBS 107.27 (ex-epitype) (19.9-31.8 x 8.6-12.9 μm vs. 25-40 x 15-25 μm ) ( Pierce 1902 ). Secondary conidiophores of the A. xinyangensis isolates were significantly shorter than those of A. cinerariae CBS 612.72 (ex-epitype) (5.3-16.0 x 2.8-4.1 μm vs. 80-159 x 5-9 μm ) ( Nishikawa and Nakashima 2020 ). Conidia in chains of the A. xinyangensis isolates were less than those of A. kikuchiana CBS 107.53 (ex-type) (2-7 conidia vs. 6-9 conidia) ( Nishikawa and Nakashima 2019 ). In conclusion, the phylogenetic and morphological evidence supports this fungus as being a new species within the Alternaria alternata species complex.