Application of polysaccharide peptide for the effective elimination of AYRSpV in kiwifruit

Actinidia yellowing ringspot virus (AYRSpV) is an economically important pathogen that significantly reduces kiwifruit yield and impairs fruit quality. Conventional virus eradication methods, such as thermotherapy and ribavirin-based chemotherapy, often cause phytotoxicity and involve complex procedures. In this study, we evaluated the efficacy of polysaccharide peptide (PSP), a natural antiviral compound, for eliminating AYRSpV from kiwifruit (Actinidia spp.) in combination with shoot tip culture. Our results show that PSP treatment not only achieved high virus eradication rates but also promoted the growth and rooting capacity of kiwifruit plantlets in tissue culture. Treatment with 1 mg/mL PSP followed by culture of 0.5–1.5 mm shoot tips resulted in 76.7% to 90% elimination of AYRSpV, along with significant improvements in plant height and leaf development. This study reports the first successful use of PSP for eradicating kiwifruit viruses, offering a cost-effective and phytobeneficial alternative to conventional antiviral agents.