Wang Ruoxing, Zhang Hui, Zhang Qingru, Xi Jihui, Jiang Kunhao, Li Jinzhu, Xue Huali, Bi Yang
College of Science, Gansu Agricultural University, Lanzhou 730070, China.
College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China.
J Fungi (Basel). 2024 Nov 14;10(11):789. doi: 10.3390/jof10110789.
This study was conducted in order to explore the pathogens that cause stem rot of fresh onions during postharvest storage, identify the incidence of stem rot, investigate the influence of pathogen infection on the active components of onion, and provide a theoretical basis for disease control during the postharvest storage of fresh onions. The pathogens were isolated and purified from the junction between the rotten and healthy tissues of onion stem rot that occurred naturally during storage at room temperature by tissue separation; then, the pathogens were identified by morphological and molecular biological techniques, the biological characteristics of the pathogens were analyzed, and finally, the influence of pathogen infection on the active ingredients of onion was studied. The results suggested that the main pathogens causing stem rot of fresh onions during postharvest storage were , and . The optimum colony growth conditions for were as follows: a temperature of 30 °C, a pH of 7, light for 24 h, maltose as a carbon source, and peptone as a nitrogen source; the lethal temperature was 65 °C for 15 min. For , the lethal temperature was 60 °C for 15 min, and the optimum sporulation conditions were a temperature of 25 °C, a pH of 5-7, light for 24 h, a carbon source of sucrose, and a nitrogen source of yeast powder. For , the lethal condition was 65 °C for 15 min; the optimum colony growth conditions were a temperature of 25 °C, a pH of 8-9, 24 h of darkness, a carbon source of maltose, and a nitrogen source of peptone. The relative content of sulfur compounds, as the active components of onions, was much lower in the infected onions than in the healthy onions due to infection by the pathogens , and . This study will provide a theoretical basis for further effective control of the occurrence of postharvest stem rot diseases of onions.
本研究旨在探究鲜洋葱采后贮藏期间引起茎腐病的病原菌，明确茎腐病的发病率，研究病原菌侵染对洋葱活性成分的影响，为鲜洋葱采后贮藏期病害防治提供理论依据。通过组织分离法从室温贮藏期间自然发生的洋葱茎腐病腐烂与健康组织交界处分离纯化病原菌；然后采用形态学和分子生物学技术对病原菌进行鉴定，分析病原菌的生物学特性，最后研究病原菌侵染对洋葱活性成分的影响。结果表明，鲜洋葱采后贮藏期间引起茎腐病的主要病原菌为 、 和 。 的最适菌落生长条件如下：温度30℃、pH值7、光照24小时、以麦芽糖为碳源、蛋白胨为氮源；致死温度为65℃处理15分钟。对于 ，致死温度为60℃处理15分钟，最适产孢条件为温度25℃、pH值5 - 7、光照24小时、以蔗糖为碳源、酵母粉为氮源。对于 ，致死条件为65℃处理15分钟；最适菌落生长条件为温度25℃、pH值8 - 9、黑暗24小时、以麦芽糖为碳源、蛋白胨为氮源。由于 、 和 的侵染，作为洋葱活性成分的含硫化合物在染病洋葱中的相对含量远低于健康洋葱。本研究将为进一步有效防控洋葱采后茎腐病的发生提供理论依据。
