茉莉酸甲酯对鲜食槟榔冷害调控研究

Effect of Methyl Jasmonate on Chilling Injury Regulation in Fresh Betel Nut

为探索控制采后鲜食槟榔贮藏冷害的保鲜技术,本研究以海南省万宁县万城镇鲜食槟榔为实验材料,研究了不同浓度茉莉酸甲酯(Methyl jasmonate,MeJA)处理对鲜食槟榔冷害的影响。于15℃条件下,将鲜食槟榔置于密闭环境中分别用0、10和100μmol/L MeJA熏蒸24 h,处理结束后将槟榔果实放置于11℃条件下贮藏30 d,每隔一周测定果实的相关冷害指标。结果表明,未经MeJA预处理的槟榔果实在贮藏1周后即发生明显冷害症状,主要表现为表皮出现水渍状斑点和黑斑,果核褐变,木质化加重。相比之下,MeJA处理组显著抑制了槟榔果实表皮冷害症状和果核褐变,抑制了细胞膜透性和丙二醛(malondialdehyde,MDA)含量的增加,同时抑制与木质化合成相关的多酚氧化酶(polyphenol oxidase,PPO)、苯丙氨酸解氨酶(phenylalanine ammonia lyase,PAL)、肉桂醇脱氢酶(cinnamic alcohol dehydrogenase,CAD)和过氧化物酶(peroxidase,POD)等几种酶活性,从而抑制了木质素的增加,减少了酚类物质的减少,其中100μmol/L的处理效果较优于10μmol/L MeJA处理。

Fresh betel nuts from Wancheng Town, Wanning County, Hainan Province were used to evaluate the effect of different concentrations of methyl jasmonate（MeJA） on chilling injury in fresh betel nuts. In a sealed environment at 15 ℃, fresh betel nuts were fumigated with 0, 10, or 100 μmol/L MeJA for 24 h. After the treatment was completed, betel nut fruits were stored at 11 ℃ for 30 d and sampled every other week for measurement of chilling indicators. The results showed that betel nuts not treated with MeJA exhibited clear symptoms of chilling injury after one week of storage, which primarily presented as water stain-like spots and dark spots on the surface, core browning, and increased lignification. In contrast, symptoms of chilling injury and core browning were significantly inhibited in the MeJA-treated group of betel nuts, and increases in cell membrane permeability and malondialdehyde（MDA） content were inhibited. The activity of several enzymes related to lignification were inhibited, including polyphenol oxidase（PPO）, phenylalanine ammonia lyase（PAL）, cinnamic alcohol dehydrogenase（CAD）, and peroxidase（POD）, thereby inhibiting the increase of lignification and slowing the loss of phenolic substances. The effect of 100 μmol/L MeJA treatment were superior to those of 10 μmol/L MeJA treatment.