Green Kelsie J, Chikh-Ali Mohamad, Hamasaki Randall T, Melzer Michael J, Karasev Alexander V
First, second, and fifth authors: Department of PSES, University of Idaho, Moscow; third and fourth authors: University of Hawaii at Manoa, Honolulu; and fifth author: and Bioinformatics and Computational Biology Program, University of Idaho, Moscow.
Phytopathology. 2017 Nov;107(11):1433-1439. doi: 10.1094/PHYTO-04-17-0147-R. Epub 2017 Aug 28.
Poha, or cape gooseberry (Physalis peruviana L.), is a plant species cultivated in Hawaii for fresh fruit production. In 2015, an outbreak of virus symptoms occurred on poha farms in the South Kohala District of the island of Hawaii. The plants displayed mosaic, stunting, and leaf deformation, and produced poor fruit. Initial testing found the problem associated with Potato virus Y (PVY) infection. Six individual PVY isolates, named Poha1 to Poha6, were collected from field-grown poha plants and subjected to biological and molecular characterization. All six isolates induced mosaic and vein clearing in tobacco, and three of them exhibited O-serotype while the other three reacted only with polyclonal antibodies and had no identifiable serotype. Until now, PVY isolates have been broadly divided into pepper or potato adapted; however, these six PVY isolates from poha were unable to establish systemic infection in pepper and in four tested potato cultivars. Whole-genome sequences for the six isolates were determined, and no evidence of recombination was found in any of them. Phylogenetic analysis placed poha PVY isolates in a distinct, monophyletic "Poha" clade within the PVY lineage, suggesting that they represented a novel, biologically and evolutionarily unique group. The genetic diversity within this poha PVY clade was unusually high, suggesting a long association of PVY with this solanaceous host or a prolonged geographical separation of PVY in poha in Hawaii.
酸浆，即灯笼果（酸浆属酸浆），是夏威夷种植用于生产新鲜水果的一种植物。2015年，夏威夷岛南科哈拉区的酸浆农场爆发了病毒症状。植株出现花叶病、发育不良和叶片变形，果实产量不佳。初步检测发现问题与马铃薯Y病毒（PVY）感染有关。从田间种植的酸浆植株中收集了6个单独的PVY分离株，分别命名为Poha1至Poha6，并对其进行了生物学和分子特征分析。所有6个分离株均在烟草中诱导出花叶病和叶脉黄化，其中3个表现为O血清型，另外3个仅与多克隆抗体反应，无可识别的血清型。到目前为止，PVY分离株大致分为适应辣椒或马铃薯的类型；然而，这6个来自酸浆的PVY分离株无法在辣椒和4个测试马铃薯品种中建立系统感染。测定了这6个分离株的全基因组序列，未发现任何重组迹象。系统发育分析将酸浆PVY分离株置于PVY谱系中一个独特的单系“酸浆”分支内，表明它们代表了一个新的、在生物学和进化上独特的群体。该酸浆PVY分支内的遗传多样性异常高，表明PVY与这种茄科宿主长期关联，或者PVY在夏威夷酸浆中经历了长期的地理隔离。
