利用葡萄籽油防治桃子采后褐腐病的研究

为探索桃采后褐腐病的新型非化学农药防治手段,研究了不同用量葡萄籽油处理(体积分数分别为0.5%、0.1%、0.05%、0.01%)对桃采后褐腐病的抑制效果。将褐腐病菌(Monilinia fruc-ticola)(终浓度:5×104 cfu/mL)和不同体积分数的葡萄籽油于PDB培养基中25℃下共培养24～96h,然后调查病原菌孢子萌发及芽管伸长情况。结果表明,当葡萄籽油体积分数≥0.05%时,其对病原菌孢子萌发的抑制率为100%。以打孔法人为模拟接种褐腐病菌(浓度:5×104 cfu/mL)至桃子上,随后接种不同体积分数的葡萄籽油,25℃下贮藏6d后调查褐腐病斑大小。结果表明,当葡萄籽油体积分数≥0.05%时,其在桃子体内对褐腐病斑的抑制率在50%以上,而且0.1%和0.5%的葡萄籽油用量对褐腐斑的抑制效果相当;当体积分数为0.01%时,葡萄籽油对病菌孢子萌发及桃褐腐斑的抑制效果大大降低。因此,将0.1%定为葡萄籽油抑制桃褐腐病菌的最佳用量。自然条件下,在1℃冷藏21d后,经0.1%葡萄籽油处理过的桃子发病率为20.0%,化学药剂戊唑醇处理过的桃子发病率为18.7%,而空白对照组发病率为45.5%,表明0.1%葡萄籽油的防治效果(56.0%)接近化学药剂防治效果(58.9%)。同时,对葡萄籽油处理过的果实进行了果实品质参数测定,包括果实硬度、可溶性固形物含量、维生素C含量、可滴定酸含量,结果表明,与空白对照组相比,葡萄籽油处理过的果实品质没有发生显著变化。说明葡萄籽油在防治桃采后褐腐病方面具有代替化学农药的潜力。

Application of Grape Seed Oil to Control Brown Rot of Postharvest Peaches

In this study,the efficacy of grape seed oil(GFO) at different concentrations(0.5%,0.1%,0.05%,0.01%) in controlling brown rot caused by Monilinia fructicola on postharvest peaches was evaluated in artificially-wounded peaches or under storage conditions,and moreover,the effects of GFO on fruit quality parameters including firmness,total soluble solids,ascorbic acid and titratable acidity were investigated.In vitro,when M.fructicola at 5×104 cfu/mL was cultured at the presence of GFO at the concentration of ≥0.05%,the pathogen spore germination was completely inhibited by GFO;In vivo,when M.fructicola at 5×104 cfu/mL was inoculated into artificially-wounded peaches followed by inoculating GFO,GFO at the concentration of≥0.05% reduced the brown rot diameter by more than 50%,but no significant difference was observed between 0.1% and 0.5%.However,when the concentration of GFO was 0.01%,the control efficacy in vivo was significantly decreased.Therefore,the optimal concentration of GFO in controlling brown rot on postharvest peaches was defined as 0.1%.When stored at 1 ℃ and 96% RH for 21 days,the disease incidence of 0.1% GFO-treated peaches was 20.0%,the disease incidence of the fungicide(tebuconazole)-treated peaches was 18.7%,and the disease incidence of the control group was 45.5%,showing that the efficacy of 0.1% GFO in controlling brown rot was 56.0%,which was very similar to that of fungicide(58.9%).Fruit quality parameter assessment indicated that GFO had no significant effects on the peach quality.As far as we know,this is the first report on application of non-harmful grape seed oil to control the brown rot on postharvest peaches as an alternative to fungicide.