Morphological and molecular identification of two new Alternaria species (Ascomycota, Pleosporaceae) in section Radicina from China Author He, Lin Department of Plant Protection, College of Agriculture, Yangtze University, Jingzhou 434025, China & Forewarning and Management of Agricultural and Forestry Pests, Hubei Engineering Technology Center, Yangtze University, Jingzhou 434025, China Author Cheng, Hong Department of Plant Protection, College of Agriculture, Yangtze University, Jingzhou 434025, China & Forewarning and Management of Agricultural and Forestry Pests, Hubei Engineering Technology Center, Yangtze University, Jingzhou 434025, China Author Zhao, Lin Department of Plant Protection, College of Agriculture, Yangtze University, Jingzhou 434025, China & Forewarning and Management of Agricultural and Forestry Pests, Hubei Engineering Technology Center, Yangtze University, Jingzhou 434025, China Author Htun, Aye Aye Department of Plant Protection, College of Agriculture, Yangtze University, Jingzhou 434025, China & Forewarning and Management of Agricultural and Forestry Pests, Hubei Engineering Technology Center, Yangtze University, Jingzhou 434025, China Author Yu, Zhi He Department of Applied Microbiology, College of Life Sciences, Yangtze University, Jingzhou 434025, China Author Deng, Jian Xin https://orcid.org/0000-0001-7304-5603 Department of Plant Protection, College of Agriculture, Yangtze University, Jingzhou 434025, China & Forewarning and Management of Agricultural and Forestry Pests, Hubei Engineering Technology Center, Yangtze University, Jingzhou 434025, China djxin555@yangtzeu.edu.cn Author Li, Qi Li Institute of Plant Protection, Guangxi Academy of Agricultural Sciences and Guangxi Key Laboratory of Biology for Crop Diseases and Insect Pests, Nanning, Guangxi, 530007, China 65615384@qq.com text MycoKeys 2021 2021-04-09 78 187 198 http://dx.doi.org/10.3897/mycokeys.78.64853 journal article http://dx.doi.org/10.3897/mycokeys.78.64853 1314-4049-78-187 3C8E803BAD8A5A329FB0B6E372EFFFFE Alternaria divaricatae L. He & J.X. Deng sp. nov. Figure 2 Type . China , Sichuan Province , Chengdu City, Wenjiang District , Herb Garden of Chengdu University of Traditional Chinese Medicine , from leaf spot of Saposhnikovia divaricata . 17 June, 2015, J.X Deng , (YZU-H-0029, holotype ), ex-type culture YZU 151055 . Etymology. In reference to the host species name, Saposhnikovia divaricata . Description. Colonies on PDA (Fig. 2A ) vinaceous buff, hazel in the center, velvety, cottony, dark mouse grey to pale mouse grey in reverse, 56-64 mm in diam.; On PCA, conidiophores arising directly from lateral or apical of aerial hyphae or medium, lightly flexuous, sometimes geniculate at apex, smooth-walled, 9-36 x 3.5-6 μm , 1-3 transverse septa, the aerial hyphae sometimes up to 82-400 x 4-6 μm ; conidia solitary from apex or geniculate loci, short-ovoid, subglobose, ellipsoid, 21-38 x 12-26 μm , with 1-4 transverse septa and 1-4 longitudinal septa (Fig. 2B, D, E ); On V8A, conidiophores 10-26 (-53) x 3-4 μm , 1-7 transverse septa, conidia 22-39 x 13-24 μm , 1-4 transverse septa, 1-3 longitudinal or oblique between septa (Fig. 2C, F, G ). There was no secondary conidium production observed on PCA and V8A medium. Figure 2. Morphological characteristics of Alternaria divaricatae (strain: YZU 151055). Colony on PDA for 7 days at 25 °C ( A ); Conidia on PCA and V8A ( B, C ); Sporulation patterns from PCA and V8A ( D-G : D, E from PCA F, G from V8A); Scale bars: 25 µm ( B, C ); 2 µm ( D, F ); 50 µm ( E ); 100 µm ( G ). Additional isolate examined. China, Sichuan Province, Chengdu City, Wenjiang District, Herb Garden of Chengdu University of Traditional Chinese Medicine, from leaf spot of Saposhnikovia divaricata . 17 June, 2015, L He, living culture YZU 151059. Notes. Phylogenetically, Alternaria divaricatae forms a distinct clade in section Radicina , which appears to be sister to a clade including A. petroselini , A. selini and A. vulgarae (Fig. 1 ). Morphologically, A. divaricatae was different from A. petroselini , A. selini and A. vulgarae by producing smaller conidia (Table 2 ) and special sporulation from apex or geniculate loci of lateral or apical of aerial hyphae. Moreover, A. chlamydosporifera , A. glehniae and A. smyrnii grouped together and clustered as a sister clade with A. divaricatae , A. petroselini , A. selini and A. vulgarae (Fig. 1 ). Obviously, the conidia of A. divaricatae was smaller than A. smyrnii (Table 2 ) and A. divaricatae could be also easily differentiated from A. chlamydosporifera by the lack of chlamydospores in culture ( Marin-Felix et al. 2019 ). Meanwhile, A. glehniae was distinguished from A. divaricatae by its single conidium on apex of conidiophore (there was no geniculate sporulation loci) and production of secondary conidium ( Tao et al. 2019 ). In addition, A. radicina and A. carotiincultae were distinguished from present species by distant phylogenetic relationship in section Radicina . Table 2. Morphological comparison of the present species and other Altenraria species in section Altenraria Radicina
Species Conidia Conidia per chain Medium
Shape Size (μm) Septa
A. atrocariis Ovoid, ellipsoid 50-100 x 25-38 3-12 1-2 Hosta
A. divaricatae sp. nov. Short-ovoid,subglobose, ellipsoid 21-38 x 12-26 1-4 1 PCA d
22-39 x 13-24 1-4 V8A d
A. carotiincultae Long ovoid or ellipsoid 40-80 x 15-23 5-7 (-11) 1-3 PCA a
A. chlamydosporifera ellipsoidal or ovoid, occasionally, subglobose 12-41 x 7-20 1-3(-4) 1, occasionally 2 PCA b
A. glehniae Long ovoid, ellipsoid 20-40 (-48) x 10-20 3-7 1, occasionally 2 PCA c
A. petroselini Short-ovoid to subsphaeroid 35-62(-66) x 20-26 6-8 1, rarely to 2 PCA a
A. radicina Short-broad or long-narrow ellipsoid and ovoid 42-63 x 15-20 4-8 1, seldom up to 2 PCA a
A. selini Short-ovoid 32-42(-50) x 22-27 3-5 1-3 PCA a
Long-ellipsoid 48-65(-50) x 15-20 Up to 7
A. smyrnii Ovoid, obovoid 40-58 x 18-22 7-8(-10) 1-2 PCA a
Narrower ellipsoid 67-96 x 13-16
A. vulgarae sp. nov. Short-ovoid, ovoid or long-ellipsoid 25-50 (-70) x 16-27 1-5 1 PCA d
24-55 (-77) x 13-26 1-8 V8A d
a referenced from Simmons (2007) ; b referenced from Marin-Felix et al. (2019) ; c referenced from Tao et al. (2019) ; d determined in the present study.