Effects of selenium application on selenium content and fruit quality in Actinidia chinensis ‘Jinfeng’

Selenium is an essential trace element for humans and plays important roles in physiological processes, including antioxidant defense and immune regulation. Dietary supplementation is an effective approach to improve human selenium status. However, research on selenium-enriched cultivation techniques for kiwifruit and their effects on fruit quality remains limited. In this study, Actinidia chinensis ‘Jinfeng’ plants were foliar-sprayed with different types and concentrations of selenium fertilizers at various fruit developmental stages to investigate their effects on fruit selenium accumulation and quality and to identify the optimal selenium-enrichment treatment. Subsequently, the accumulation and distribution patterns of selenium, as well as its impacts on fruit developmental quality and storage characteristics, were examined. The results showed that the optimal selenium-enrichment strategies for ‘Jinfeng’ kiwifruit were foliar application of 50 mg/L nano-selenium at the young fruit stage or 75 mg/L selenium-yeast at the fruit expansion stage. Selenium treatment significantly increased fruit selenium content, improved single-fruit weight, and enhanced fruit quality. It also promoted the uptake of mineral elements in leaves and pulp but had no significant effect on flesh cadmium content. During ambient storage, selenium treatment did not significantly affect dry matter or soluble solids content; however, nano-selenium was more effective than selenium yeast in reducing decay rate and weight loss, thereby extending shelf life. These findings provide a theoretical basis and technical support for elucidating the effects of selenium on ‘Jinfeng’ kiwifruit quality, exploring scientific approaches for selenium biofortification in kiwifruit, and promoting efficient production of selenium-enriched kiwifruit.