Preharvest treatment with 1-aminoethoxyvinylglycine and gibberellin on the quality and physiology of cashew peduncles

Abstract: The objective of this work was to evaluate the effects of the preharvest treatment with gibberellic acid (GA3) and aminoethoxyvinylglycine (AVG) on the quality and physiological attributes of ripe 'CCP 76' cashew (Anacardium occidentale) peduncles at different developmental stages. Sprays of 180 mg L-1 GA3 and 180 mg L-1 AVG were applied, combined and isolated, at 34, 40, and 44 days after anthesis (DAA), and peduncles were harvested ripe at 46 DAA and evaluated for physical and physiological variables. The treatment with GA3 resulted in firmer peduncles with a greater apical diameter, but did not affect the physiological variables activity of the pectin methylesterase and polygalacturonase cell wall enzymes and degree of lipid peroxidation of the biological membranes, nor the physical attributes total mass (peduncles and nut) and nut size. At early developmental stages (34 DAA), GA3 increased the activity of the antioxidant enzymes superoxide dismutase and catalase, and, at later stages (40 DAA), promoted polyphenol and carotenoid accumulation. The application of AVG at the final stages (44 DAA) provided greater total antioxidant activity, despite the lower ascorbate peroxidase activity. The application of GA3 pre-harvest increases the firmness and diameter of the cashew peduncles, and the treatment with AVG increases the total antioxidant activity of the peduncles.

摘要：本研究旨在评估采前施用赤霉素（gibberellic acid, GA3）与氨基乙氧基乙烯甘氨酸（aminoethoxyvinylglycine, AVG）对不同发育阶段成熟'CCP 76'腰果（Anacardium occidentale）果梗的品质及生理特性的影响。试验于开花后天数（days after anthesis, DAA）34、40、44天分别喷施180 mg·L⁻¹ GA3、180 mg·L⁻¹ AVG，设置单施与混施处理；于开花后46天采收成熟果梗，对其物理及生理指标进行测定。结果显示，GA3处理可提升果梗硬度与顶端直径，但未影响果胶甲酯酶（pectin methylesterase）、多聚半乳糖醛酸酶（polygalacturonase）等细胞壁酶活性，生物膜脂质过氧化程度，以及总质量（果梗与坚果）、坚果大小等物理属性。在发育早期（开花后34天）施用GA3可增强抗氧化酶超氧化物歧化酶（superoxide dismutase）与过氧化氢酶（catalase）活性；在发育后期（开花后40天）施用GA3则可促进多酚与类胡萝卜素积累。于发育末期（开花后44天）施用AVG虽会降低抗坏血酸过氧化物酶（ascorbate peroxidase）活性，但可提升总抗氧化能力。综上，采前喷施GA3可提升腰果果梗的硬度与直径，而施用AVG可增强果梗的总抗氧化能力。