Susaimuthu James, Tzanetakis Ioannis E, Gergerich Rose C, Kim Kyung S, Martin Robert R
Department of Plant Pathology, University of Arkansas, Fayetteville 72701.
Horticultural Crops Research Lab, USDA-ARS, Corvallis 97330.
Plant Dis. 2008 Sep;92(9):1288-1292. doi: 10.1094/PDIS-92-9-1288.
Blackberry yellow vein disease (BYVD) poses a new threat to the blackberry industry in the United States. Blackberry yellow vein associated virus (BYVaV) was originally thought to be the sole cause of this disease. However, BYVaV has been found in several asymptomatic blackberry cultivars. An unusual member of the family Potyviridae was identified recently from symptomatic plants and named Blackberry virus Y (BVY). BVY has been shown to spread in the field and cause BYVD when co-infected with BYVaV. Both viruses are asymptomatic in single infections but are readily detectable in asymptomatic plants by reverse transcription-polymerase chain reaction (RT-PCR). However, in mixed infections, the titer of BYVaV is repressed, sometimes to levels undetectable by RT-PCR, while the concentration of BVY is increased several fold. Electron microscopy revealed a variety of viral inclusions in symptomatic leaf samples, but none could be found in single infections with either BVY or BYVaV. Although BYVaV has been consistently associated with BYVD in different geographical regions, the detection of BVY has thus far been restricted to northwest Arkansas. It has been hypothesized that BYVaV is the synergistic determinant of BYVD that causes symptoms in different cultivars at various locations during co-infection with other viruses.
黑莓黄脉病（BYVD）对美国的黑莓产业构成了新的威胁。黑莓黄脉相关病毒（BYVaV）最初被认为是这种疾病的唯一病因。然而，在几个无症状的黑莓品种中发现了BYVaV。最近从有症状的植株中鉴定出一种弹状病毒科的不寻常成员，并将其命名为黑莓病毒Y（BVY）。已证明BVY在田间传播，当与BYVaV共同感染时会导致BYVD。两种病毒在单一感染时均无症状，但通过逆转录聚合酶链反应（RT-PCR）很容易在无症状植株中检测到。然而，在混合感染中，BYVaV的滴度受到抑制，有时会降至RT-PCR检测不到的水平，而BVY的浓度则增加了几倍。电子显微镜检查在有症状的叶片样本中发现了多种病毒内含物，但在BVY或BYVaV的单一感染中均未发现。尽管在不同地理区域BYVaV一直与BYVD相关，但迄今为止BVY的检测仅限于阿肯色州西北部。据推测，BYVaV是BYVD的协同决定因素，在与其他病毒共同感染期间，它会在不同地点的不同品种中引起症状。
