Quaglino Fabio, Maghradze David, Casati Paola, Chkhaidze Nona, Lobjanidze Mzagho, Ravasio Adriano, Passera Alessandro, Venturini Giovanni, Failla Osvaldo, Bianco Piero Attilio
Department of Agricultural and Environmental Sciences-Production, Landscape, Agroenergy (DISAA), University of Milan, Milano, Italy.
Institute of Horticulture, Viticulture and Oenology, Agricultural University of Georgia, Tbilisi, Georgia.
Plant Dis. 2016 May;100(5):904-915. doi: 10.1094/PDIS-09-15-0978-RE. Epub 2016 Feb 29.
Evidence from a preliminary survey highlighted that 'Candidatus Phytoplasma solani', the etiological agent of bois noir (BN) disease of grapevine, infects grapevine varieties in Georgia, a country of the South Caucasus. In this study, field surveys were carried out to investigate the BN symptom severity in international and Georgian native varieties. 'Ca. P. solani' was detected and identified by polymerase chain reaction-based amplification and restriction fragment length polymorphism analysis of 16S ribosomal DNA, and further characterized by multiple gene typing analysis (vmp1 and stamp genes). Obtained data highlighted that the majority of Georgian grapevine varieties showed moderate and mild symptoms, whereas international cultivars exhibited severe symptoms. Molecular characterization of 'Ca. P. solani' from grapevine revealed the presence of 11 distinct phytoplasma types. Only one type (VmGe12/StGe7) was identical to a strain previously reported in periwinkle from Lebanon; the other 'Ca. P. solani' types are described here for the first time. Phylogenetic analyses of vmp1 and stamp gene concatenated nucleotide sequences showed that 'Ca. P. solani' strains in Georgia are associated mainly with the bindweed-related BN host system. Moreover, the fact that 'Ca. P. solani' strains are distributed in grapevine cultivars showing a range of symptom intensity suggests a different susceptibility of such local cultivars to BN.
一项初步调查的证据突出表明，葡萄黑痘病（BN）的病原体“Ca. Phytoplasma solani”感染了南高加索国家格鲁吉亚的葡萄品种。在本研究中，开展了田间调查以研究国际品种和格鲁吉亚本土品种中BN症状的严重程度。通过基于聚合酶链反应的16S核糖体DNA扩增和限制性片段长度多态性分析检测并鉴定了“Ca. P. solani”，并通过多基因分型分析（vmp1和stamp基因）进一步进行了特征描述。获得的数据突出表明，大多数格鲁吉亚葡萄品种表现出中度和轻度症状，而国际品种则表现出严重症状。对葡萄中“Ca. P. solani”的分子特征分析揭示了11种不同的植原体类型的存在。只有一种类型（VmGe12/StGe7）与先前在黎巴嫩长春花中报道的一个菌株相同；其他“Ca. P. solani”类型在此首次描述。对vmp1和stamp基因串联核苷酸序列的系统发育分析表明，格鲁吉亚的“Ca. P. solani”菌株主要与旋花科相关的BN宿主系统有关。此外，“Ca. P. solani”菌株分布在表现出一系列症状强度的葡萄品种中的这一事实表明，这些当地品种对BN的易感性不同。
