Asociación de un Potexvirus como Agente Causal de Manchas Cloróticas en Opuntia ficus-indica Association of a Potexvirus as a Causal Agent of Chlorotic Spots on Opuntia ficus-indica

The cactus pear (Opuntia ficus-indica ) was recently introduced in Cuautepec de Hinojosa, Hidalgo. In this region, a virus was detected causing chlorotic halos and irregular spots on the cladodes. In severe infections, postharvest cladodes lose turgidity, which causes significant commercial losses. The virus was mechanically transmitted to six out of eleven indicator plants. In Chenopodium quinoa, it caused systemic infection showed as chlorotic veins and intervenal yellow spots. The virus was transmitted in 43 % of the inoculated cladodes, inducing chlorotic halos and irregular chlorotic spots at 7 and 25 days after inoculation, respectively. The electrophoretic analysis showed that the virus is an RNA single stranded genome, and flexible rod particles were observed using a transmission electron microscope. The RT-PCR diagnostic test indicated that the virus is a species of Potexvirus. In the cactus pear production units that were evaluated, the virus caused a 47-60 % and 51-79 % of incidence and severity, respectively, with an aggregated spatial pattern with strong row directionality, suggesting virus dispersion through pruning and harvesting.