Jović Jelena, Marinković Slavica, Jakovljević Miljana, Krstić Oliver, Cvrković Tatjana, Mitrović Milana, Toševski Ivo
Department of Plant Pests, Institute for Plant Protection and Environment, 11080 Zemun, Serbia.
CABI, 2800 Delémont, Switzerland.
Pathogens. 2021 Feb 3;10(2):160. doi: 10.3390/pathogens10020160.
Field bindweed () is one of the major natural plant hosts and reservoirs of ' Phytoplasma solani' (' P. solani'), the causal agent of plant diseases in diverse agricultural crops, including Bois noir (BN) disease of grapevine. Phylogenetically, the most closely related phytoplasma to ' P. solani', the ' P. convolvuli', induces disease in field bindweed that is known by its symptoms as bindweed yellows (BY). The occurrence, coinfection and symptoms association of the two phytoplasmas in shared host plants were the subject of this study. Specific primers for the amplification of the elongation factor Tu gene () were developed for the identification of ' P. convolvuli' (by conventional nested PCR), as well as primers for simultaneous detection of ' P. solani' and ' P. convolvuli' by duplex SYBR Green real-time PCR. Among symptomatic bindweed plants, 25 and 41% were infected with a single phytoplasma species, ' P. solani' and ' P. convolvuli', respectively, while 34% were infected with both phytoplasmas. None of the non-symptomatic control plants carried phytoplasma, while non-symptomatic plants from our previous epidemiological studies in BN-affected vineyards were confirmed to be infected solely with ' P. solani'. gene typing revealed Rqg50 and Rqg31 ' P. solani' genotypes in plants coinfected with ' P. convolvuli', while three diverse genotypes (Rqg50, GGY and Rpm35) were identified in a single locality with symptomatic bindweeds infected solely with ' P. solani'. Variations in symptoms and their association with each of the phytoplasmas are described and documented. The symptom of bushy appearance could be single out as specific for ' P. convolvuli' infection, while occurrence of ' P. solani' could not be unequivocally associated with specific alterations in infected bindweeds. The results are discussed in the context of the epidemiological and ecological complexity of ' P. solani'-induced diseases and the relationship between the two phytoplasma relatives in shared host plant.
田旋花（）是“茄科植原体”（“P. solani”）的主要天然植物寄主和储存库之一，“茄科植原体”是多种农作物植物病害的病原体，包括葡萄藤的黑木杆病（BN）。在系统发育上，与“茄科植原体”关系最密切的植原体是“旋花科植原体”（“P. convolvuli”），它会在田旋花中引发疾病，其症状表现为田旋花黄化病（BY）。本研究的主题是这两种植原体在共享寄主植物中的发生情况、混合感染及症状关联。开发了用于扩增延伸因子Tu基因（）的特异性引物，用于鉴定“旋花科植原体”（通过常规巢式PCR），以及用于通过双重SYBR Green实时PCR同时检测“茄科植原体”和“旋花科植原体”的引物。在有症状的田旋花植株中，分别有25%和41%感染了单一的植原体物种，即“茄科植原体”和“旋花科植原体”，而34%的植株同时感染了这两种植原体。无症状的对照植株均未携带植原体，而我们之前在受BN影响的葡萄园进行的流行病学研究中的无症状植株被证实仅感染了“茄科植原体”。基因分型显示，在与“旋花科植原体”混合感染的植株中存在Rqg50和Rqg31“茄科植原体”基因型，而在一个单一地点，仅感染“茄科植原体”的有症状田旋花中鉴定出三种不同的基因型（Rqg50、GGY和Rpm35）。描述并记录了症状的变化及其与每种植原体的关联。丛生外观症状可能是“旋花科植原体”感染所特有的，而“茄科植原体”的出现与受感染田旋花的特定变化并无明确关联。结合“茄科植原体”引发疾病的流行病学和生态复杂性以及这两种植原体在共享寄主植物中的亲缘关系对结果进行了讨论。
