Tsai W S, Shih S L, Lee L M, Dolores L M, Kenyon L
AVRDC - The World Vegetable Center, Shanhua, Tainan, 74151 Taiwan.
Institute of Plant Breeding, Cop Science Cluster (CSC), College of Agriculture (CA), University of the Philippines Los Baños (UPLB), College, Laguna, Philippines.
Plant Dis. 2014 May;98(5):701. doi: 10.1094/PDIS-10-13-1025-PDN.
Browne's Blechum (Blechum pyramidatum) is a common weed found in fields and waste grounds in the Philippines. A disease was observed causing begomovirus-like yellow/chlorotic leaf veins and shortened internodes of Browne's Blechum plants on the island of Luzon, Philippines; disease incidence ranged from 10 to 50% in fields in 2012. Samples were collected from two plants with symptoms from each of Laguna and Quezon provinces and one plant without symptoms from Laguna Province. All four samples from plants with symptoms tested positive for begomovirus by PCR using primer pair PAL1v1978B/PAR1c715H (2), but the symptomless plant sample did not. However, no virus DNA-B component was detected in any of the samples using either general detection primer pair DNABLC1/DNABLV2 or DNABLC2/DNABLV2 (1). Using abutting primers AFPH12W1-R2F (TCTGGATCCATTGTTGAACGAGT) and AFPH12W1-R2R (CCGGGATCCCACATTGTTAAACA), a complete DNA-A component sequence was obtained for a Laguna isolate (GenBank Accession No. KF446659) and for a Quezon isolate (KF446660). The Laguna and Quezon isolate sequences were 2,764 and 2,756 nucleotides, respectively, and shared 90.6% nucleotide sequence identity. Both had six open reading frames (ORFs)-two in the virus sense (V1 and V2) and four in the complementary sense (C1 to C4)-and the geminivirus conserved sequence (TAATATTAC). Based on BLASTn searching of GenBank and sequence analysis using MEGALIGN (DNASTAR), both isolates should be considered as a new begomovirus (tentatively named Blechum yellow vein virus, BlYVV) since their DNA-A sequences share less than 89% nucleotide identity with any other begomovirus. Both DNA sequences had the highest nucleotide identity (84.8 to 87.6%) with Papaya leaf curl Guangdong virus isolates (AJ558122, AY650283, FJ495184, FJ869907, and JN703795). To our knowledge, this is the first report of a previously unidentified begomovirus associated with yellow vein disease of this species. References: (1) S. K. Green et al. Plant Dis. 85:1286, 2001. (2) W. S. Tsai et al. Plant Pathol. 60:787, 2011.
布朗氏腺毛草（Blechum pyramidatum）是一种常见杂草，在菲律宾的田野和荒地中均可发现。在菲律宾吕宋岛，人们观察到一种病害，导致布朗氏腺毛草植株出现类似菜豆金色花叶病毒的黄色/褪绿叶脉以及节间缩短的症状；2012年，田间发病率在10%至50%之间。从拉古纳省和奎松省各采集了两株有症状的植株样本，以及一株来自拉古纳省无症状的植株样本。使用引物对PAL1v1978B/PAR1c715H进行PCR检测，所有四株有症状植株的样本均检测出菜豆金色花叶病毒呈阳性（2），但无症状植株样本检测结果为阴性。然而，使用通用检测引物对DNABLC1/DNABLV2或DNABLC2/DNABLV2（1）在任何样本中均未检测到病毒DNA - B组分。使用相邻引物AFPH12W1 - R2F（TCTGGATCCATTGTTGAACGAGT）和AFPH12W1 - R2R（CCGGGATCCCACATTGTTAAACA），获得了来自拉古纳分离株（GenBank登录号KF446659）和奎松分离株（KF446660）的完整DNA - A组分序列。拉古纳分离株和奎松分离株的序列分别为2764和2756个核苷酸，核苷酸序列同一性为90.6%。两者均有六个开放阅读框（ORF）——两个在病毒链（V1和V2），四个在互补链（C1至C4）——以及双生病毒保守序列（TAATATTAC）。基于对GenBank的BLASTn搜索以及使用MEGALIGN（DNASTAR）进行的序列分析，这两个分离株均应被视为一种新的菜豆金色花叶病毒（暂定名为腺毛草黄脉病毒，BlYVV），因为它们的DNA - A序列与任何其他菜豆金色花叶病毒的核苷酸同一性均低于89%。两个DNA序列与番木瓜曲叶广东病毒分离株（AJ558122、AY650283、FJ495184、FJ869907和JN703795）的核苷酸同一性最高（84.8%至87.6%）。据我们所知，这是首次报道与该物种黄脉病相关的一种此前未鉴定的菜豆金色花叶病毒。参考文献：（1）S. K. Green等人，《植物病害》85:1286，2001年。（2）W. S. Tsai等人，《植物病理学》60:787，2011年。
