诱导抗性在果蔬采后病害防治中的研究与应用

 近年来,有关果蔬产品采后诱导抗性的研究较多,生物和非生物因子(如微生物、化学物质、物理因素以及天然物质等)都能够诱导果蔬产品采后的抗性。生物因子研究较多的是拮抗菌,许多生物拮抗菌都具有自生和诱导果实产生抗病相关酶活性的作用,可以有效抑制病原菌的生长。物理诱导主要包括γ-射线、离子辐射、紫外光照和热水处理等,热水浸泡柑橘果实能有效控制贮藏期间的腐烂;低剂量紫外光照射桃、芒果、草莓、葡萄和甜椒等果蔬产品可明显减轻采后病害。用于果蔬产品的化学诱导剂主要有β-氨基丁酸(BABA),苯丙噻重氮(ASM),水杨酸(SA),茉莉酸(JA)和茉莉酸甲酯(MJ)等。将SA与生物拮抗菌配合,可诱导甜樱桃果实过氧化物酶(POD),苯丙氨酸裂解酶(PAL)和β-1,3-葡聚糖酶的活性,提高果实贮藏期间的抗病性;ASM在开花前处理哈密瓜也具有一定的抗病诱导效果;用BABA处理葡萄柚后,能刺激果实伤口附近PAL活性增加,增强了果实对绿霉病菌侵染的抵抗力;作为植物生长调节剂的JA及其酯化物MJ,对植物抗病性也具有明显的诱导作用,JA和MJ被认为是植物在病原菌侵染防御反应中细胞信号转导的一种关键物质;用MJ处理采后的苹果和桃果实能增强贮藏期间的抗病性,其诱导强度与果实的成熟度密切相关;将钙盐与生物拮抗菌配合使用,也显著提高拮抗菌的抑病效果。另外,在自然抗病物质中壳聚糖的使用较多,用它处理柑橘果实可提高贮藏期间绿霉病的防治效果。这些生物和非生物因子的诱导抗性机理主要涉及到寄主的细胞结构变化和生理生化反应。本文较详细地论述了诱导果蔬产品采后抗性的因子及其可能的诱导机理。

Potential of Induced Resistance in Postharvest Diseases Control of Fruits and Vegetables

The phenomenon of induced resistance to postharvest disease in fruits and vegetables has been studied intensively in recent years. Biotic and abiotic inducers, including microbial agents, chemical compounds, physical treatment and nature substance, have been used in fruits and vegetables. The mechanism of resistance has been studied on cell structure, physiological and biochemical changes of host. In this paper, some of the strategy and defense expressed in postharvest fruits and vegetables will be discussed in relation to how the induced plants may restrict disease development.