Effect of Exogenous Abscisic Acid (ABA), a Potential Growth Regulator on Physiological Response to Chilling Stress of Adzuki Bean (Vigna angularis) at Flowering Stage

Background: Low temperatures during flowering severely affect crop growth and yield. Methods: This experiment was conducted under potted conditions with LXD 4 and TJH as test materials and pre-sprayed with exogenous ABA at a concentration of 20 mg center dot L-1 at flowering stage, respectively and then with an average of 15.C condition for 5 days. Result: The results showed that foliar spraying exogenous ABA effectively inhibited the increase of MDA content and relatively significantly improved the photosynthetic parameters such as Gs and Tr and alleviated the loss of yield factors caused by chilling stress. Compared with spraying water, spraying exogenous ABA can significantly increase the yield per pot of LXD 4 by 6.72.17.77% and TJH by 6.41(+/-)37.04% under low temperature conditions. In summary, foliar spraying exogenous ABA ameliorated the effects of chilling stress on the physiological characteristics of adzuki bean leaves and improved yield as a result of improved antioxidant defense mechanisms which impeded lipid peroxidation. Thus, we conclude that foliar spraying exogenous ABA could decelerate the damages caused by chilling stress to some extent.