Insect pollination as a key factor for strawberry physiology and marketable fruit quality

Abstract

About 35% of global crop production arises from crop species that benefit from animal pollination, especially by insects. Animal pollination can enhance yields and increase fruit quality, but the effects of insect pollination on pre- and post-harvest fruit physiology and quality are largely unknown. For the first time, we analysed in much detail the physiological responses of fruit development and marketable quality improvements to different pollination treatments such as self-pollination, open-pollination and hand-pollination. In strawberries, self-pollination led to reduced seed set (fertilized achenes), reduced concentration of the phytohormone auxin, highest share of deformed fruits (> 90%), smallest and lightest fruits, considerably lower commercial value (8% of the value of open- or hand-pollinated fruits), and reduced shelf life of fruits. Overall, insect pollination increased the average commercial value of marketable fruits by 92%. The commercial value of hand-pollinated and open-pollinated strawberries did not differ. We conclude that pollination services are not merely important for yield, but also vital for physiological processes that result in better marketable quality (e.g. fruit appearance, flavour-enhancing constituents, prolonged shelf life) and commercial value of many pollinator-dependent crops.