采后硅酸钠处理对杏果粉霉病的抑制及机理

Inhibiting Effect of Postharvest Sodium Silicate Treatment on Pink Rot of Apricot Fruits and Its Mechanism

为探讨采后硅酸钠处理对杏果粉霉病的抑制效果及机理,作者观察了体外条件下硅酸钠对杏果粉霉病病原物粉红单端孢(Trichothecium roseum)的抑制效果,并以"李杏"为试材,采用不同浓度的硅酸钠溶液(0、25、50、75 mmol/L)浸泡果实10 min,测定常温贮藏期间处理对T.roseum损伤接种果实病斑直径的抑制,以及对果实两种防御性酶过氧化物酶(POD)和多酚氧化酶(PPO)活性及抗性物质总酚和类黄酮含量的影响。结果表明,体外条件下硅酸钠可抑制粉红单端孢(Trichotethium roseum)的生长,其中以25 mmol/L处理效果最好,抑菌率可达85%。不同浓度硅酸钠浸泡可明显降低杏果损伤接种T.roseum的病斑直径,其中以50 mmol/L效果最好,且抑制效果可持续72 h。50 mmol/L硅酸钠处理还有效提高了果实体内过氧化物酶(POD)和多酚氧化酶(PPO)活性,促进了总酚的积累,但对类黄酮含量影响不大。由此表明,采后硅酸钠处理可通过直接抑菌和诱导果实抗性来抑制杏的粉霉病。

Effect of sodium silicate treatment on pink rot of apricot fruit(cv.Lixing) and its partial mechanism were studied in this manuscript.Inhibitory effect of sodium silicate on Trichothecium roseum was evaluated by in vitro.Apricot fruits were dipped with sodium silicate at different concentration(0,25,50 and 75 mmol/L) for 10 min,the inhibition effect of treatment on the lesion diameter of fruit inoculated with T.roseum were investigated during storage at room temperature.Two defense enzyme peroxidase(POD) and polyphenol oxidase(PPO) activities and disease resistance substances total phenolic and flavanoids accumulation in fruits were also detected.The results showed that sodium silicate significantly inhibited mycelial growth of T.roseum in vitro,with the inhibition rate of 85% when 25 mmol/L sodium slicacate was used.Moreover,application of sodium silicate reduced pink rot development on artificially inoculated apricot fruit.It was found that 50 mmol/L sodium slicacate showed the highest inhibitory effect on pink rot for 72 h.Furthermore,Sodium silicate treatment increased the activities of peroxidase(POD) and polyphenol oxidase(PPO) in apricot fruit,enhanced accumulation of total phenolic.However,no significant difference was found in flavanoids between treated and control fruit.Therefore,it is suggested that postharvest sodium silicate treatment can reduce pink rot in apricot fruits by inhibiting the growth of pathogen and inducing resistance in fruit.