Aggressiveness of Cuban Papaya ringspot virus Isolates on Carica papaya L. cv. Maradol Roja under Greenhouse Conditions

Abstract

Carica papaya is a major fruit crop in tropical and subtropicalregions; however, its production has several constraints. Papayaringspot virus (PRSV) is the most important pathogen affectingpapaya plantations. Symptoms induced by a known PRSV isolateon papaya plants after mechanical inoculation were describedto elaborate an evaluation scale under greenhouse conditions.The aggressiveness of 24 Cuban PRSV isolates was determinedby assessing symptom severity induced on papaya plants cv.Maradol roja under greenhouse conditions. An evaluation scale of0 to 6 scores was elaborated based on the observations of PRSVsymptom progress. Symptoms induced by Cuban PRSV isolatesincluded vein clearing, mottling and swelling zones on the adaxialleaf surface, slight deformation of young leaves and distortion.PRSV isolates from Nueva Paz, Güines, and San José de Las Lajasin the west, Sancti Spíritus in the center, and Palma Soriano andPuerto Padre in the east of the country were the most aggressiveaccording to their area under the disease progress curve values.Knowledge about the aggressiveness of this virus is crucial forselecting PRSV isolates to implement management strategies andpapaya breeding programs in Cuba.