Pyramiding pepy-1 and Pepy-2 in Pepper ( Capsicum annuum ) Confers Improved Resistance Against Mixed Infection with Begomoviruses

Significant yield losses of peppers (Capsicum spp.) are caused by infection with begomoviruses (genus Begomovirus, family Geminiviridae). Breeding for host resistance to begomovirus is the most effective, sustainable method to mitigate losses, so pepper germplasm has been screened for resistance sources. Although host resistance against specific begomovirus species has been found, breeding for broad resistance to multiple species and mixed infections remains a challenge. We previously cloned two begomovirus resistance genes: recessive pepy-1, encoding Pelota, and dominant Pepy-2, encoding RNA-dependent RNA polymerase. Here, we inoculated pepper plants with a single species or with two Old World or two New World begomoviruses to evaluate the resistance conferred by single or multiple resistance genes. Our results demonstrated that introgression of pepy-1 and Pepy-2 in the homozygous state conferred durable resistance even to coinfections with two highly virulent begomoviruses. The findings provide a theoretical basis for accelerating DNA marker-assisted breeding for begomovirus resistance in pepper.