Isolation and Identification of Hibiscus Chlorotic Ringspot Virus (HCRSV) infecting Gumamela (Hibiscus rosasinensis) in the Philippines
By: Lolita M. Dolores, Maricel C. Gonzales, Yron M. Retuta, Pablito M. Magdalita
Key Words: Hibiscus chlorotic ringspot, HCRSV, Gumamela, ELISA, RT-PCR.
Int. J. Biosci. 8(2), 149-158, February 2016.
Gumamela (Hibiscus rosa-sinensis L.) is a malvaceous ornamental plant commonly grown in the Philippines. Virus-like symptoms such as chlorotic spots, mottling, vein banding and clearing, vein enation, chlorosis, rosetting, leaf distortion, flower abortion and distortion and stunting were observed on gumamela plants growing in the hibiscus breeding blocks at the Institute of Plant Breeding (IPB).. A new virus, Hibiscus chlorotic ringspot virus (HCRSV), a member of the genus Carmovirus was isolated and identified to be infecting gumamela plants by mechanical inoculation using the sap from symptomatic leaves. The virus isolate caused chlorotic lesions to Chenopodium quinoa, C. amaranticolor, C. murale and Abelmoschus esculentus. However, it did not induce any symptoms in Gomphrena globosa, Nicotiana glutinosa, Physalis floridana, Datura stramonium, Lycopersicon esculentum and Capsicum annuum. Gumamela plants (IPB Accessions No. 95 and 97 and the variety “Superstar”) showing chlorotic ringspots and the symptomatic indicator plants tested positive for HCRSV by Enzyme-linked immunosorbent assay (ELISA). The Reverse Transcriptase Polymerase Chain Reaction (RT-PCR ) using primers that amplify a conserved region in the coat protein (CP) gene of HCRSV giving an amplification with a size of 557bp further confirmed the results. Nucleotide sequence analysis of the CP gene of the HCRSV Philippines showed 97.5 to 97.9% similarity to the HCRSV isolates of Iran, New Zealand and Singapore. It is most related to the Israel isolate with 98.1% identity and less similar with HCRSV-Taiwan with only 93% sequence identity. To our knowledge, this is the first report of HCRSV in gumamela in the Philippines.