Identification and subgrouping of cucumber mosaic virus isolate infecting New Guinea impatiens (Impatiens hawkeri) in Serbia

Abstract

New Guinea impatiens (Impatiens hawkeri) is a species of flowering plant in the family Balsaminaceae that is popular as a bedding and pot plant. In May 2020, impatiens plants showing chlorotic and necrotic concentric rings, mosaic, leaf malformation and filiformism were noticed in a greenhouse in Rača Kragujevačka, Šumadija District, Serbia. Collected leaves were serologically tested against impatiens necrotic spot orthotospovirus (INSV, Orthotospovirus impatiensnecromaculae), tomato spotted wilt orthotospovirus (TSWV, Orthotospovirus tomatomaculae), cucumber mosaic virus (CMV), turnip mosaic virus (TuMV), and tobacco mosaic virus (TMV). Most of tested samples with chlorotic and necrotic concentric rings (81.81%) were positive for TSWV, while CMV was detected in four samples with mosaic, leaf malformation and filiformism. CMV ELISA-positive sample (106-20) was mechanically inoculated to five plants of Chenopodium quinoa, Nicotiana debneyii, and N. glutinosa. Local chlorotic lesions on C. quinoa and severe mosaic and leaf malformation on N. debneyii and N. glutinosa were observed 5 and 13 days post-inoculation, respectively. PCR fragments of all five genes were digested by following restriction enzymes: HindIII, SacII (1a gene), MluI (2a gene), StuI, SalI (2b gene), BaeI (MP gene), SfcI and HaeIII (CP gene). Differentiation of CMV subgroups were conducted based on the restriction patterns obtained by in situ RT-PCR-RFLP analyses and isolate 106-20 was classified into subgroup IA with haplotype IA; IA, IA; IA, IA. This study reports for the first time the presence of CMV on impatiens in Serbia and its occurrence on this widely cultivated ornamental in our country may have a destructive impact on its production.

Keywords

• new guinea impatiens
• cmv
• bioassay
• serology
• rt-pcr-rflp