Physiological Response of Strawberry to Water Stress under Different Deficit Irrigations

Abstract

【Background】Strawberry is a cash crop, more than 40% of which is produced in China by facility cultivation. Since strawberry is a shallow-root crop characterized by large leaves and high water-demanding, its growth is sensitive to water deficit. Given that climate change is likely to make water shortage in agricultural production in China worsen, improving agronomic practices to increase water use efficiency is critical to sustaining agricultural production in China and worldwide. 【Objective】The objective of this paper is to investigate the response of physiological traits of strawberry (cv. Honeoye) to water stress under different deficit irrigations. 【Method】Field experiment designed using complete randomized block method was conducted consisting of three drip deficit irrigations: Partial root-zone irrigation (PRI), deficit irrigation (DI) and sufficient irrigation (FI). Three water stress levels were further set in PRI and DI modes: minor water stress (LS), moderate water stress (MS) and severe water stress (SS). In each treatment, we measured chlorophyll content in the leaves, as well as the transpiration and photosynthetic rate. 【Result】Compared to FI, PRI and DI reduced the contents of both chlorophyll a and b. In all treatments, both chlorophyll a and b decreased as the water stress severity increased. It was found that chlorophyll in PFI was higher than that in DI. With the increase in water stress, DI and PRI reduced transpiration by 35.2%~44.7% and 21.0%~47.0% respectively, compared to FI, although the net photosynthetic rates in them were comparable. Under moderate and severe water stress, the WUE of DI and PRI increased by 101.8%~117.9% and 68.8%~149.8% over FI, respectively. The proline accumulation in PRI was significantly higher than that in FI, varying from 19.0% to 26.0% with water stress, and it was also higher than that in DI when water stress was in minor and moderate level. Compared to FI, PRI increased malondialdehyde (MDA) accumulation by 30.2% at severe water stress, while DI increased MDA accumulation by 34.3% and 56.3%, respectively, under moderate and severe water stress. 【Conclusion】The osmotic adjustment and drought resistance of the strawberry in PRI were stronger than those in DI, and PRI+MS treatment was the most efficient irrigation strategy for strawberry production for the area we studied.

Keywords

• strawberry
• water stress
• partial root-zone irrigation
• deficit irrigation
• physiological response