桃果实缝合线软化的生理原因探讨

为了明确桃果实缝合线软化的原因,采用气相色谱法对大久保桃果实缝合线软化过程中乙烯释放、果胶酶含量、种胚呼吸、矿质元素含量等指标进行了测定。结果表明,在果实症状出现初期,乙烯主要存在于种仁中,并开始向果肉释放,此时缝合线处果胶酶活性最高;种仁的呼吸高峰是在果实缝合线软化后,此时病果果肉、种仁和种壳含水量明显高于正常果;N素含量病果明显高于正常果,干物质含量则相反;种仁充水、呼吸加强,使种仁提早释放乙烯是缝合线软化的主要原因。建议采收前减少灌水和氮肥的施用。

Study on the physiological reasons caused the suture softening of peach fruit

In order to making clear the reasons caused the peach fruit suture softening, fruit of Okube cultivar were used as material. During the fruit suture softening, ethylene releasing was measured by GC. The pectic enzyme activity, intension of seed respiration and content of mineral elements were determined. The results showed that ethylene mainly located in embryo when symptom emerged and gradually released into peach flesh with symptom aggravation. At the same time ,pectic enzyme activity was in peak, but seed respiration peak appeared after fruit suture softening; meanwhile the content of water in flesh, seed and shell was higher in diseased fruits than in normal ones, and dry matter was opposite. Nitrogen content in diseased fruit was much higher than in normal fruit. So it might be speculated that the reason of fruit suture softening might be caused by too much water in seed which induced respiration increasing and released ethylene from seed to flesh. So we suggest that reducing irrigation and application of nitrogen before harvest would be important for retarding the fruit suture softening.