Peach marafivirus

Peach marafivirus (Marafivirus nucipersicae) is a serious viral disease that primarily affects stone fruit crops. The pathogen belongs to the marafivirus group, characterized by a single-stranded RNA genome and a specific replication mechanism within host tissues. This pathogen causes systemic infection, which significantly disrupts the physiological development processes of the tree.

The main hosts for this virus are species within the Prunus genus, particularly the common peach. The virus can affect both young seedlings in nurseries and mature fruit-bearing trees, making it a major threat to intensive horticulture. The infection gradually spreads through all plant organs, including the root system, vascular tissues, and reproductive parts.

Key symptoms and signs of the disease include leaf blade deformation, chlorotic spots, mosaic patterns, and premature leaf drop. Fruits often show morphological changes, necrotic spots, and reduced market quality, making the harvest unsuitable for commercial sale. In severe cases, progressive dieback of individual branches and general stunted growth of the tree are observed.

The transmission of the virus occurs mainly through infected planting material, contaminated pruning or grafting tools, and specialized insect vectors such as aphids and leafhoppers. Conditions that promote the spread and development of the disease include high humidity, the presence of weed hosts that act as virus reservoirs, and a lack of rigorous phytosanitary monitoring within the orchard.

The economic impact of the disease is significant, resulting in sharp yield losses and poor fruit quality. Effective control measures focus on using only certified virus-free planting material, regular disinfection of orchard tools, strict management of insect vector populations, and the immediate rogueing of infected trees to prevent the spread of the virus throughout the orchard.