膜醭毕赤酵母结合杀菌剂对柑橘果实采后病害的控制效果

Combination of Pichia membranaefaciens with Fungicides for Control of Postharvest Diseases of Citrus Fruit

探究膜醭毕赤酵母与低剂量杀菌剂(多菌灵、甲基硫菌灵)结合使用对柑橘采后病害的防治效果。通过筛选能与膜醭毕赤酵母结合使用的杀菌剂,考察柑橘常见病原菌对杀菌剂的敏感性,继而在果实上验证结合处理对柑橘采后病害的防治效果。离体实验的结果表明,多菌灵和甲基硫菌灵对酵母生长无抑制作用;柑橘青霉菌、绿霉菌和炭疽菌对两种杀菌剂敏感性不同,但半数抑制浓度(EC50值)均小于建议剂量的1%。果实活体实验的研究结果表明,膜醭毕赤酵母结合低剂量的多菌灵或甲基硫菌灵对柑橘果实青霉病、绿霉病的防治效果均好于膜醭毕赤酵母和低剂量杀菌剂单独处理;但膜醭毕赤酵母结合低剂量的甲基硫菌灵对夏橙果实接种炭疽病的防治效果不佳。同时,膜醭毕赤酵母结合低剂量的多菌灵或甲基硫菌灵对夏橙果实自然发病率的控制呈增效作用,对锦橙果实自然发病率的控制呈叠加作用,两种结合处理均能保证夏橙和锦橙的好果率。

In order to reduce the dosage of fungicides and find an effective control method for postharvest diseases of citrus, the effect of Pichia membranefaciens in combination with low-dose fungicides(carbendazim and thiophanate-methyl) on the control of postharvest citrus diseases was studied. Fungicides which could be well combined with P. membranaefaciens were selected and the sensitivity of common citrus pathogens to the selected fungicides was verified. The postharvest fruits were then used to validate the controlling effect of P. membranefaciens combined with fungicides on their diseases. The in vitro experiments showed that neither carbendazim nor thiophanate-methyl inhibited the growth of P. membranaefaciens. However, Penicillium italicum, Penicillium digitatum and Colletotrichum gloeosporioides showed different sensitivities to the two fungicides, but the EC50 values were all lower than 1% of the recommended dosage. The in vivo experiments showed that the treatment with P. membranefaciens in combination with either carbendazim or thiophanate-methyl had a better control efficacy on blue mold and green mold than the individual treatments. However, the anthracnose rot in Valencia orange was not well controlled by Pichia membranefaciens combined with thiophanate-methyl. The combined treatments had a synergistic control effect on the incidence of Valencia orange diseases and an additive effect on that of Jincheng, which could be an effective strategy to maintain good commercial rates of Valencia orange and Jincheng.