枸杞果实采后白霉病菌生物学特性及反式-2-己烯醛对其防控研究

Study on biological characterization of Fusarium incarnatum causing white mold in Lycium barbarum L. fruits and its the prevention and control by trans-2-hexenal

中文关键词:  枸杞  白霉病  变红镰刀菌  生物学特性  反式-2-己烯醛

英文关键词:Lycium barbarum L.  white mold  Fusarium incarnatum  biological characteristics  trans-2-hexenal

中文摘要:

      目的 探究枸杞采后白霉病菌生物学特性以及反式-2-己烯醛对白霉病的控制和预防效果。方法 以前期分离鉴定的引起枸杞鲜果采后白霉腐烂的变红镰刀菌(Fusarium incarnatum)为研究对象, 采用皿内测定方法研究其在不同营养基质和培养条件下的生物学特性, 并通过体外菌丝扩展抑制法和体内损伤接种后药物熏蒸病害防控法筛选有效控制枸杞白霉病的反式-2己烯醛浓度, 最后通过药物熏蒸后损伤接种处理考查反式-2-己烯醛对该病的预防效果。结果 枸杞采后白霉病菌菌丝最适生长条件为马铃薯葡萄糖琼脂培养基(potato dextrose agar, PDA)或马铃薯蔗糖琼脂培养基(potato sugar agar, PSA)培养基、28℃、全光照; 最佳产孢条件为PDA培养基(pH 5)、28℃、全黑暗; 最佳孢子萌发条件为pH 7~8、28℃、全光照, 51℃ (10 min)为菌丝致死温度, 最适生长碳源、氮源分别为果胶和酵母粉。反式-2-己烯醛可抑制枸杞白霉菌菌丝扩展且呈浓度依赖性, 其半数效应浓度(median effect concentration, EC50)和最小抑菌浓度(minimal inhibit concentration, MIC)分别为0.0184和0.0322 μL/mL; 反式-2-己烯醛对枸杞白霉菌既有控制又有预防效果, 且40.0 μL/L是反式-2-己烯醛的最有效熏蒸浓度。结论 PDA或PSA培养基、28℃、酵母粉为氮源、全光照有利于枸杞果实白霉病菌的繁殖, 为生产上选择氮肥、贮藏上低温避光条件的选择提供依据, 40.0 μL/L的反式-2-己烯醛具有预防和控制枸杞白霉病的潜力, 为枸杞果实采后白霉病的综合防控和绿色药物开发奠定了基础。

英文摘要:

      Objective To explore the biological characterization of the pathogen of white mold in Lycium barbarum L. fruits and to study on the prevention and control of the mold by trans-2-hexenal. Methods The Fusarium incarnatum isolated and identified from the white mold after Lycium barbarum L. fruits harvest was chosen as the research material. The dish assay method was used to study the biological characteristics of Fusarium incarnatum under varying nutrient substrates and culture conditions. The concentration of trans-2-hexenal was required as an effective treatment to the white mold of goji berries, which was determined by the method of the inhibit to the mycelial expansion in vitro, and the damage of inoculation by the pathogen, with the control of the disease by drug fumigation in vivo. Finally, the prevention effect of trans-2-hexenal on the disease was investigated through damage inoculation treatment after drug fumigation. Results The results showed that the ideal conditions for the mycelium growth of Fusarium incarnatum were potato dextrose agar (PDA) or potato sugar agar (PSA) medium, a temperature of 28℃, and total exposure to light. To achieve optimal spore production, the following conditions should be maintained: Use a PDA medium with a pH of 5, keep the temperature at 28℃, and ensure complete darkness. To promote spore germination, maintain a pH between 7 to 8, keep the temperature at 28℃, expose the sample to light, and subject it to a temperature of 51℃ for 10 minutes, which was lethal for hyphae. For the best growth about the sources of carbon and nitrogen, the pectin and yeast powder were the most suitable, respectively. Trans-2-hexenal, used in varying concentrations, which could inhibit the mycelium growth of Fusarium incarnatum. The concentration for 50% of the maximal effect (EC50) and minimum inhibitory concentration (MIC) for this pathogen were 0.0184 and 0.0322 μL/mL, respectively. Meanwhile, trans-2-hexenal was both control and prevent effects on the white mold of goji berries. The most effective concentration of trans-2-hexenal to fumigating was 40.0 μL/L. Conclusion It can be concluded that PDA or PSA medium, yeast powder as a nitrogen source, total light, and 28℃ temperature are enjoyed by the growth of the white mold pathogen in goji berries. This information can be used to choose an appropriate nitrogen fertilizer during production and a condition of low temperature and avoid light during storage. Additionally, trans-2-hexenal at 40.0 μL/L has been identified as a potential treatment to white mold disease of goji berry. These findings provide a foundation of effectively preventing, controlling the disease, and developing eco-friendly drugs.