乙烯对采后菠萝蜜果实碳水化合物代谢及其酶活性的影响

摘要

以'海大2号'菠萝蜜为试材,研究了果实采后乙烯利和1-MCP处理对果实碳水化合物代谢及相关酶活性的影响.结果表明,在果实成熟过程中,随着淀粉含量的下降,可溶性糖(主要为蔗糖)含量增加,淀粉酶和SPS酶活性呈先增后减的单峰型变化.相关性分析发现,可溶性糖含量的增加与淀粉含量的下降呈极显著负相关,与SPS酶活性呈极显著正相关,淀粉含量的变化与淀粉酶活性没有显著的相关关系.乙烯利处理在极显著加速淀粉降解的同时也极显著加快蔗糖、葡萄糖和果糖积累.乙烯利处理后,淀粉酶和SPS酶活性峰的出现分别提前了2 d和4 d,并极显著地增加了淀粉酶和SPS酶活性(P<0.01).1-MCP处理在极显著减慢淀粉降解的同时也极显著延缓了可溶性糖的积累.1-MCP处理降低了前期总淀粉酶和SPS酶的活性,并将二者的活性峰推迟了8 d,但却极显著地增加了总淀粉酶活性峰值(P<0.01),对SPS活性峰无显著影响.乙烯利和1-MCP处理极显著增加了成熟果中果糖和葡萄糖的含量,但对蔗糖和可溶性总糖含量无显著影响.综合分析认为,淀粉和蔗糖是菠萝蜜果实中碳水化合物代谢的枢纽,乙烯对菠萝蜜果实采后成熟过程中碳水化合物的代谢及总淀粉酶和蔗糖磷酸合酶的活性有重要影响.%The effects of ethephon and 1-MCP ( 1-Methylcyclopropene ) on carbohydrate metabolism and activities of the related enzymes were studied in the fruit of 'Haida 2 ' Jackfruit during the ripening period were studied.The results showed that the soluble sugars (mainly sucrose) content increased with the decrease of the starch content in the fruit ripening process.A single peak of the total amylase and SPS activity of jack-fruit was observed during storage.Correlation analysis showed that the decrease of soluble sugar content had a significantly negative correlation with the increase of starch content,and a significantly positive correlation withSPS activity.The change of starch content had no significant correlation with the total amylase activity.Ethephon significantly increased the activity of total amylase and SPS (P<0.01),and shifted the peak of amylase and SPS activity 2 and 4 days earlier,respectively.1-MCP significantly slowed the degradation of starch but also de-layed the accumulation of soluble sugars.1-MCP treatment reduced the early total amylase enzyme and SPS ac-tivity,and delayed the time of its activity peak for 8 days,but significantly increased the total amylase activity peak (P<0.01),and had no significant effect on the SPS activity peak.Ethephon and 1-MCP treatment signifi-cantly increased the fructose and glucose levels,but had no significant effect on the sucrose and total soluble sugar content in the ripe fruit.It is suggested that starch and sucrose may be a key in carbohydrate metabolism of jackfruit,and ethylene has an important effect on carbohydrate metabolism,total amylase and sucrose phos-phate synthase activities in the postharvest maturity of jackfruit fruit.