Potential of New PrunusRootstocks for Managing ArmillariaRoot Rot Disease in Peach Production

Abstract

Armillariaroot rot (ARR) pathogen is currently one of the most important diseases affecting peach [ Prunus persica(L.) Batsch] production in the southeastern United States causing high plant mortality. This soil-borne disease affects the roots of the plant, producing subsequent symptoms in the canopy, and finally killing the host. No chemical control is currently available for ARR. To overcome this disease, rootstock use is an option; however, resistant rootstocks are fairly new and their availability is limited. The objective of this review is to describe the sources of resistance against the pathogen, the rootstock breeding procedures for peaches, and the management tools for fighting the infection and reducing symptoms. Multiple peach and plum accessions have been evaluated for ARR resistance over the last few decades. The main sources of resistance were identified in plum hybrids of native North American plum species. These resistance sources were used as the foundation for breeding peach rootstocks with resistance to ARR. Resistant plum lines were hybridized with peach germplasm to develop rootstocks resistant to ARR. Two rootstock cultivars were developed and released: ‘Sharpe’ and ‘MP-29’. Although some ARR disease management practices have been examined, rootstocks are still a good option to reduce losses induced by ARR in peaches.