Molecular Identification of Sweet potato virus C on Sweetpotato in Bali, Indonesia

Abstract

A survey was conducted in several sweet potato cultivations in Bali Province. Survey found that many plants exhibited potyvirus symptom, such as chlorosis blotches. This study was to determine disease incidence, detection and identification of the virus causing these symptoms on sweet potato plants in Bali. Samples were collected by purposive sampling of 10 plants from each location in Bali (Denpasar, Gianyar, Badung, Buleleng, Tabanan, Klungkung, Karangasem, Jembrana, Bangli). Disease insidence was observed based on viral symptoms in the field. Identification of nucleic acids was done using Potyvirus universal primer and DNA sequencing. Disease incidence in Bangli, Buleleng, and Denpasar Regencies was > 50%. RT-PCR and CiFor/CiRev Potyvirus universal primers successfully amplified ± 700 bp of CI genes from all samples from Bangli, while samples from 8 other districts were not amplified using the same primers. The SPVC isolate of sweet potato showed nucleotide and amino acid homology similarities with the sweet potato isolate from East Timor (MF572066), 96.8% and 97.4%, respectively and these were referred to the "Asian" strain. This indicates that SPVC has spread in East Java and Bali.

The antiviral potential of macroalgae in suppressing Sweet potato leaf curl virus (SPLCV) infection in sweet potatoes

“…A recovery period occurs when plants infected with the virus show very severe symptoms, but over a period of time the symptoms disappear or change into mild symptoms, especially on freshly grown plant parts (Listihani et al 2021;Selangga et al 2021;Selangga et al 2023). The inhibition level of SPLCV infection ranged between 5-71%, which was shown by macroalgae extract treatment (Table 2).…”

“…More than 20 viruses infect sweet potatoes from the genus Begomovirus, Carlavirus, Cavemovirus, Crinivirus, Cucumovirus, Enamovirus, Ipomovirus, Nepovirus, Potyvirus, Solendovirus, and Tospovirus (Cuellar et al 2015;Maina et al 2018). Several important viruses in sweet potato have been reported, such as sweet potato virus C (SPVC), sweet potato feathery mottle virus (SPFMV), sweet potato feathery mottle virus strain internal cork (SPFMV-IC), sweet potato feathery mottle virus strain russet crack (SPFMV-RC), sweet potato mild mottle virus (SPMMV), sweet potato chlorotic stunt virus (SPCSV), sweet potato virus G (SPVG), and sweet potato leaf curl virus (SPLCV) (Choi et al 2012;Clark et al 2012;Kim et al 2015;Maina et al 2018;Zhang et al 2020;Listihani and Selangga 2021;Listihani et al 2022a). SPLCV (Geminiviridae; Begomovirus) was first infect sweet potatoes in Kenya, U.S., China, Japan, Spain, Uganda, Brazil, Korea, and Tanzania (Albuquerque et al 2012;Choi et al 2012;Cho et al 2020;Wanjala et al 2020;Andreason et al 2021;Bachwenkizi et al 2022).…”