Citrus plants presenting the typical huanglongbing (HLB) symptoms have been associated to 16SrIX phytoplasma in the States of São Paulo (SP), Minas Gerais (MG), Bahia (BA) and, more recently, Distrito Federal (DF), Brazil. Although in SP and MG states ‘ Candidatus Liberibacter asiaticus’ is more commonly associated with HLB, single infection by phytoplasmas also occurs. To date, only 16SrIX phytoplasma induces HLB symptoms in BA and DF, a region free of ‘ Ca . Liberibacter spp.’. The objective of this work was to survey for alternative hosts and potential vectors of the 16SrIX phytoplasma in citrus orchards from DF using quantitative real-time PCR (qPCR) detection. Fifty-three specimens encompassing fifteen species of weeds were collected from three Tahiti lime ( Citrus latifolia Tanaka) and Ponkan mandarin ( Citrus reticulata Blanco) orchards. Only five plants, one Euphorbia s p., one Sida sp., and three Bidens pilosa were positive for the presence of the 16SrIX phytoplasma. Regarding the leafhoppers, 16SrIX phytoplasma was detected in 11/ 38 specimens of Scaphytopiu s sp. and not detected in 32 specimens of Planicephalus flavicosta. These results suggest that spontaneous vegetation and the leafhoppers Scaphytopius may harbor 16SrIX phytoplasma that can further infect citrus orchards. The capacity of Scaphytopius insects to vector the phytoplasma to citrus plant should be better investigated.

中文翻译：

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柑橘园杂草和叶蝉与HLB症状相关的16SrIX植原体调查

在圣保罗州 (SP)、米纳斯吉拉斯州 (MG)、巴伊亚州 (BA) 和最近的巴西联邦区 (DF)，呈现典型黄龙病 (HLB) 症状的柑橘植物与 16SrIX 植原体有关。尽管在 SP 和 MG 状态中，'Candidatus Liberibacter asiaticus' 更常与 HLB 相关，但也会发生植原体的单一感染。迄今为止，只有 16SrIX 植原体在 BA 和 DF 中诱导 HLB 症状，这是一个不含 'Ca 的区域。Liberibacter spp.'。这项工作的目的是使用定量实时 PCR (qPCR) 检测调查 DF 柑橘园中 16SrIX 植原体的替代宿主和潜在载体。从三个大溪地酸橙 (Citrus latifolia Tanaka) 和椪柑 (Citrus reticulata Blanco) 果园收集了包含 15 种杂草的 53 个标本。只有 5 株植物、1 株大戟属、1 株 Sida sp. 和 3 株 Bidens pilosa 对 16SrIX 植原体呈阳性。关于叶蝉，在 11/ 38 个 Scapphytopiu s sp. 标本中检测到 16SrIX 植原体。并且在 32 个 Planicephalus flavicosta 标本中未检测到。这些结果表明自发植被和叶蝉 Scaphytopius 可能含有 16SrIX 植原体，可进一步感染柑橘园。应该更好地研究 Scaphytopius 昆虫将植原体带入柑橘植物的能力。这些结果表明自发植被和叶蝉 Scaphytopius 可能含有 16SrIX 植原体，可进一步感染柑橘园。应该更好地研究 Scaphytopius 昆虫将植原体带入柑橘植物的能力。这些结果表明自发植被和叶蝉 Scaphytopius 可能含有 16SrIX 植原体，可进一步感染柑橘园。应该更好地研究 Scaphytopius 昆虫将植原体带入柑橘植物的能力。