Effects of Actinidia yellowing ringspot virus on the yield and quality of kiwifruit.

China is the origin and distribution center of kiwifruit, as well as the country with the largest cultivated area and output of kiwifruit. A previous study found that a new kiwifruit virus, Actinidia yellowing ringspot virus (AYRSpV), has been detected in kiwifruit samples with yellowed leaves. The incidence of this virus was high in kiwifruit plantings in Shaanxi Province. To determine the symptoms of this viral infection and the effects of this virus on the yield and quality of kiwifruits, we measured leaf chlorophyll levels and the fruit yield, total sugar, total acid and dry matter contents of 'Hayward' kiwifruits grafted with AYRSpV-infected scions. The results showed that after AYRSpV infection, symptoms including chlorotic ringspots were mainly observed in the spring and gradually recovered with high summer temperatures. A few of the leaves that did not recover showed symptoms of albinism, which lasted until the leaves fell. We found that AYRSpV infection could reduce the chlorophyll content of 'Hayward' kiwifruit by 74.61-76.64%, the fruit yield by 14.50-24.10%, the sugar to acid ratio by 50.09-50.57%, and the fruit dry matter content by 1.67-1.78%. Our results showed that AYRSpV infection could significantly affect the yield and quality of 'Hayward' kiwifruit.