赤霉素复合壳聚糖处理后火龙果贮藏品质及内源激素的变化

Changes in Storage Quality and Endogenous Hormones of Pitaya after the Treatment with Gibberellin-chitosan Combination

摘要:

该研究探讨了赤霉素复合壳聚糖处理对采后火龙果的保鲜效果及内源激素的变化，以‘ 金都一号’火龙果为试材，经复合处理后，定期测定采后火龙果的贮藏品质及内源激素含量。结果表明：50 mg/L赤霉素+ 壳聚糖处理的保鲜效果最佳，贮藏12 d后，火龙果的腐烂指数、鳞片黄化率和失重率分别比对照降低了55.56%、15.91%、20.75%，而可溶性固形物（TSS）、甜菜素、维生素C（Vc）分别比对照提高了17.76%、24.70%、17.85%，复合处理还提高了火龙果总抗氧化能力（T-AOC）和总酚的含量；贮藏9 d时，处理组的火龙果内源激素含量变化最大，脱落酸（ABA）比对照降低了1 436.1 ng/g，赤霉素（GA4）和生长素（IAA）的含量分别提高了0.29 ng/g和192.3 ng/g。可见，50 mg/L赤霉素+壳聚糖处理可维持火龙果内源激素代谢平衡，提高火龙果的抗氧化性，延缓火龙果贮藏品质的下降及成熟衰老，该复合处理可作为一种绿色环保的方法应用于火龙果采后贮藏保鲜。

Abstract:

The preservation effect of the treatment with gibberellin-chitosan combination on postharvest pitaya and the changes in endogenous hormones were investigated in this study. 'Jindu No.1' pitaya was used as the test material, and the storage quality and endogenous hormone content of postharvest pitaya were regularly measured after the treatment with the combination. The results showed that the preservation effect of the treatment with 50 mg/L gibberellin+chitosan was the best. After 12 days of storage, compared with the control, the decay index, bract yellowing rate, and weight loss rate of the treated pitaya were reduced by 55.56%, 15.91%, and 20.75%, respectively, the contents of its total soluble solids (TSS), betaine and vitamin C (Vc) increased by 17.76%, 24.70%, and 17.85%, respectively, and its total antioxidant capacity (T-AOC) and total phenolic content also increased. After 9 days of storage, compared with the control, the endogenous hormone content of the treated pitaya changed the most, with its abscisic acid (ABA) content decreasing by 1 436.1 ng/g, and its contents of gibberellin (GA4) and auxin (IAA) increasing by 0.29 ng/g and 192.3 ng/g, respectively. It can be seen that the treatment with 50 mg/L gibberellin+chitosan can maintain the metabolic balance of endogenous hormones in pitaya, improve the antioxidant capacity of pitaya and delay the decline of storage quality, ripening and senescence of pitaya. Thus, the treatment with the combination can be used as a green and environmentally friendly approach for postharvest storage and preservation of pitaya.