Effects of physalis rugose mosaic and groundnut ringspot viruses, in single and double infections, on the development, yield and postharvest fruit characteristics of Physalis peruviana plants

Physalis peruviana (Solanaceae), originating from the Andean region of South America, is an exotic plant cultivated in Brazil that produces edible fruit. Five viruses have been reported to naturally infect the Physalis plants in Brazil, of which, two have been drawing attention for the severity of their infections: sobemovirus, physalis rugose mosaic virus (PhyRMV) and orthotospovirus, groundnut ringspot virus (GRSV). This study aimed to evaluate the effects of single and double infections of PhyRMV and GRSV on the development, yield and postharvest fruit characteristics of P. peruviana plants. We found that both viruses caused severe systemic symptoms in infected plants, and double infection even led to plant death. Plant height and aerial dry weight were significantly affected by PhyRMV and GRSV infections. Double-infected plants were the most affected, exhibiting average height and aerial dry weight reductions of 70.9% and 89.7%, respectively. Moreover, PhyRMV- and GRSV-infected plants showed average fruit yield reductions of 66.4% and 85.2%, respectively, compared to healthy plants. Notably, double-infected plants did not produce any fruit. The fruits produced by infected plants were smaller than those produced by healthy plants. Viral infections also affected postharvest characteristics, such as titratable acidity, total soluble solids (degrees Brix), phenolic compound concentration and antioxidant activity. Both viruses affected the pulp firmness and palatability, but not the colour of the fruits. Therefore, effective disease management strategies against these viruses are necessary to prevent economic losses.