Abstract Several virus diseases cause damage to Vitis vinifera L., but information on their incidence and impact on hybrid cultivars is scarce, particularly under cool-climate conditions. In Nova Scotia (NS), the wine industry is based predominantly on interspecific hybrid cultivars. To understand the occurrence of major grapevine viruses in NS, surveys were conducted in 2016, 2017 and 2018. A total of 965 composite five-vine samples, collected from 35 hybrids and 18 V. vinifera vineyard blocks, were tested for grapevine leafroll-associated virus 1 (GLRaV-1), GLRaV-2, GLRaV-3 and GLRaV-4, grapevine fanleaf virus (GFLV), grapevine red blotch virus (GRBV) and grapevine Pinot gris virus (GPGV) by PCR/RT-PCR. Overall, 3.4% of the samples were positive for GLRaV-1, 22.8% for GLRaV-3, 0.9% for GFLV, 4.6% for GRBV and 3.2% for GPGV. None of the 575 samples collected in 2016 and 2017 tested positive for GLRaV-2 or GLRaV-4. Mixed infections by more than one virus occurred in 3% of the composite samples. Of 671 hybrid and 294 V. vinifera samples tested, 38.3% and 27.6% were positive for at least one of the viruses (GLRaV-1, −3, GFLV, GRBV and GPGV), respectively. Phylogenetic analysis of GLRaV-1, −3, GFLV and GPGV revealed the presence of global variants. Complete genome characterization and phylogenetic analysis of nine GRBV isolates grouped three into clade I and six into clade II, indicating the presence of two variants. These findings, along with preliminary reports of insect vectors, establish the first epidemiological framework of the major viral diseases in NS, highlighting the need for long-term management strategies.

中文翻译：

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新斯科舍省重要经济葡萄病毒的发病率和遗传变异性

摘要 几种病毒病对 Vitis vinifera L. 造成损害，但关于它们的发病率和对杂交品种的影响的信息很少，特别是在凉爽气候条件下。在新斯科舍省 (NS)，葡萄酒行业主要基于种间杂交品种。为了解 NS 中主要葡萄藤病毒的发生情况，我们于 2016 年、2017 年和 2018 年进行了调查。从 35 个杂交品种和 18 个 V. vinifera 葡萄园块中收集了 965 个复合五葡萄藤样本，进行了葡萄叶卷相关检测病毒 1 (GLRaV-1)、GLRaV-2、GLRaV-3 和 GLRaV-4、葡萄扇叶病毒 (GFLV)、葡萄红斑病毒 (GRBV) 和葡萄树灰皮诺病毒 (GPGV) 通过 PCR/RT-PCR。总体而言，3.4% 的样本对 GLRaV-1、22.8% 对 GLRaV-3、0.9% 对 GFLV、4.6% 对 GRBV 和 GPGV 呈阳性。2016 年和 2017 年收集的 575 个样本均未检测出 GLRaV-2 或 GLRaV-4 呈阳性。超过一种病毒的混合感染发生在 3% 的复合样本中。在测试的 671 个杂交和 294 个 V. vinifera 样本中，38.3% 和 27.6% 分别对至少一种病毒（GLRaV-1、-3、GFLV、GRBV 和 GPGV）呈阳性。GLRaV-1、-3、GFLV 和 GPGV 的系统发育分析揭示了全局变异的存在。九个 GRBV 分离株的完整基因组特征和系统发育分析将三个分为进化枝 I，六个分为进化枝 II，表明存在两种变异。这些发现，连同昆虫载体的初步报告，建立了 NS 主要病毒性疾病的第一个流行病学框架，突出了长期管理策略的必要性。