采后硅酸钠处理对苹果梨青霉病的抑制

离体条件下,硅酸钠可抑制Penicillium expansum的菌丝生长,当浓度达到50 mmol/L时菌丝生长可被完全抑制.采用不同浓度的硅酸钠浸泡果实,可显著降低苹果梨损伤接种P.expansum的病斑面积,其中以200mmol/L的处理效果最好.硅酸钠处理可有效提高果实体内的过氧化物酶(POD)和多酚氧化酶(PPO)活性,促进过氧化氢(H2O2)和超氧化物阴离子(O2-)的产生,但对过氧化氢酶(CAT)和超氧化物岐化酶(SOD)活性的影响不大.由此表明,硅酸钠对梨果实青霉病的抑制与其的直接抑菌作用和诱导体内的抗性有关.

Inhibiting effect of postharvest sodium silicate treatment on blue mold of pear (cv.Pingguoli)

In vitro test indicated that sodium silicate reduced the mycelium growth of Penicillium expansum.The growth was completely inhibited with the treatment at 50 mmol/L.Lesion area of fruit inoculated with P.expansum was significantly decreased by sodium silicate at different concentrations.The treatment at 200 mmol/L showed the best control effect.The activity of polyphenoloxidase(PPO) and peroxidase(POD) was increased in treated fruit.A promoted production of hydrogen peroxide(H 2O 2) and superoxide radical(O-2) was also observed.However,no significant difference was found in the activity of catalase(CAT) and superoxide dismutase(SOD) between treated and control fruit.It is suggested that sodium silicate reduces blue mold in pears by inhibiting growth of pathogen and inducing resistance in fruit.