Action of ethylene on postharvest of summer squash ‘Menina Brasileira’

ABSTRACT The purpose of this study was to evaluate the sensitivity and the physiological responses of summer squash ‘Menina Brasileira’ to ethylene. Immature fruits were harvested and placed in 20 L sealed buckets, in which ethylene was applied at concentrations of 0.1, 1.0, 10, 100, and 1000 μL L-1 for 24 h. Fruits were placed in buckets with no ethylene as a control treatment. Thereafter, the fruits were taken out of the buckets and maintained on bench, wherein on days 0, 2, 4, 6, and 8, they were evaluated regarding the accumulated fresh weight loss, soluble sugars, reducing and non-reducing sugars, starch, total chlorophyll, content of malondialdehyde, and electrolyte leakage. Fruits of summer squash ‘Menina Brasileira’ showed sensitivity to exogenous ethylene with no weight loss stimulation. Additionally, the fruits exhibited small changes in nutritional quality attributes and changes in the external fruit appearance, including decreased chlorophyll content as well as damage to cell membrane characterized by increase in malondialdehyde content and electrolyte leakage. These changes were stimulated by increasing exogenous ethylene concentration.

摘要 本研究旨在评估西葫芦（summer squash）‘Menina Brasileira’对乙烯（ethylene）的敏感性及其生理响应。采收未成熟果实，置于20升密封桶中，分别以0.1、1.0、10、100和1000 μL·L⁻¹的浓度施加乙烯，处理时长为24小时；设置不加乙烯的桶作为对照处理。随后将果实取出置于实验台存放，分别在第0、2、4、6、8天对其累积鲜重损失、可溶性糖、还原糖与非还原糖、淀粉、总叶绿素含量、丙二醛含量以及电解质渗漏率进行测定。西葫芦‘Menina Brasileira’果实对外源乙烯表现出敏感性，但未出现重量损失的诱导效应。此外，该品种果实的营养品质指标仅出现小幅变化，而果实外观性状发生改变，包括叶绿素含量下降，以及以丙二醛含量升高和电解质渗漏率上升为特征的细胞膜损伤；上述变化随外源乙烯浓度升高而加剧。