The effects of high temperature and water stress on fruit growth and anthocyanin content of pot-grown strawberry (Fragaria × ananassa Duch. cv. 'Sachinoka') plants

Abstract

We investigated the effects of high temperatiffe and water stress on fruit growth and levels of anthocyanins and their precursors in pot-grown strawberry (Fragaria × ananassa Duch.) plants. Nursery seedlings in pot were grown at a greenhouse. For simplicity, fruit set was fixed at one per plant. After pollination by honeybees, plants were transferred to growth chambers for high temperature (30/15°C day/night) or control (20/15°C) treatments, both with a 14L/10D photoperiod. Water stress was applied in both temperature regimes. After fruit weights were measured, the fruits were divided into three portions: inner (pith), middle (cortex), and outer parts. The anthocyanin, flavonoid, and cinnamic acid derivative contents were then analyzed. The harvest time (days after anthesis) was shorter at the high temperature. Anthocyanin content decreased in all three parts of the fruit at high temperature but was not affected by water stress. Cinnamic acid derivative content decreased (but not significantly) in all three parts of the fruit at high temperature but flavonoid content did not differ from the levels in the control. In the anthocyanin biosynthesis pathway, high temperature affected for anthocyanins and cinnamic acid derivatives inside the strawberry fruit.