State Key Laboratory of Crop Stress Biology in Arid Areas and College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Department of Plant Pathology and Microbiology, Iowa State University, Ames 50011.
Plant Dis. 2018 Jul;102(7):1273-1282. doi: 10.1094/PDIS-07-17-1027-RE. Epub 2018 Apr 23.
Alternaria spp. are pathogens of several diseases that pose significant threats to apple production. Several putative Alternaria sp. isolates were obtained from lesions of a disease commonly referred to as black dot on apple fruit in Shaanxi Province, China. Pathogenicity tests using mycelial plugs and conidial suspensions indicated that this isolate could cause leaf blotch, as well as moldy core and black dot on fruit. On the basis of sequence analysis of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), RNA polymerase second largest subunit, and translation elongation factor 1-α, an isolate clustered with the Alternaria sect. Ulocladioides. By combining GAPDH, major allergen Alta1, mating type protein 1-2-1, and the AGA1 gene sequence analysis and morphological description, the isolates were identified as a new species named Alternaria malicola. Our finding expands the documented diversity of apple pathogens within the genus Alternaria and clarifies the taxonomy of the pathogen assemblage that may be associated with three apple diseases.
交链格孢属（Alternaria spp.）是几种对苹果生产构成重大威胁的疾病的病原体。在中国陕西省，从一种通常被称为苹果果实黑斑病的病斑中分离出了几个假定的交链格孢属分离物。使用菌丝塞和分生孢子悬浮液进行的致病性测试表明，该分离物可引起叶片斑点病以及果实的霉变芯和黑斑病。基于甘油醛-3-磷酸脱氢酶（GAPDH）、RNA 聚合酶第二大亚基和翻译延伸因子 1-α的序列分析，分离物与交链格孢属的 Ulocladioides 节聚类。通过结合 GAPDH、主要过敏原 Alta1、交配型蛋白 1-2-1 和 AGA1 基因序列分析和形态描述，这些分离物被鉴定为一种新的名为苹果生交链格孢（Alternaria malicola）的物种。我们的发现扩展了苹果属内已记录的苹果病原体多样性，并阐明了可能与三种苹果疾病相关的病原体组合的分类学。
