Interaction between potyviruses and a crinivirus in sweet potato. (Interação entre potyvírus e crinivírus em batata-doce).

PEÑA MALAVERA, A.; FLAMARIQUE, S.; MARTINO J.; VILANOVA PEREZ A.; DI FEO L.

Pesquisa Agropecuária Tropical (Agricultural Research in the Tropics)

UFG (Universidad Federal de Goiania

Lugar: goiania; Año: 2020 vol. 50 p. 1 - 9

Sweet potato, in Argentina, is affected by the ?encrespamientoamarillo?, a viral disease in which seven viruses are involved, amongthem two potyvirus (sweet potato feathery mottle virus - SPFMVand sweet potato virus G - SPVG) and a crinivirus (sweet potatochlorotic stunt virus - SPCSV). This research aimed to study theinteraction between SPFMV and SPVG with SPCSV in sweetpotato. Two sweet potato cultivars (Gem and Arapey INIA) andIpomoea setosa as an indicator susceptible plant were tested assingle (SPFMV or SPVG), double (SPFMV + SPVG, SPFMV +SPCSV or SPVG + SPCSV) or triple (SPFMV + SPVG + SPCSV)grafts. Both potyviruses were purified and the viral concentrationsin the plant tissues were quantified by the DAS-Elisa method. Theviruses and their severities were evaluated at 7, 15, 21, 30 and 35days post-inoculation. A synergistic effect was observed with thethree viruses in the indicator plant. The viral concentration increasewas 50 times for SPFMV (day 35) and two times for SPVG (day 21)in the Gem cultivar, and 1.89 times for SPFMV (day 35) and threetimes for SPVG (day 7) in the Arapey INIA. For multiple infections,the indicator plant and the Gem cultivar exhibited synergisticsymptoms and increase in the viral titers, with a higher severity andvariability of the symptoms. Co-infections such as SPFMV + SPVGshowed characteristic potyvirus symptoms, without increasing theviral concentrations; triple co-infections exhibited viral complexsymptoms, with increase in the potyvirus titers; and the symptomswere mild or imperceptible in the simple infections.