1-MCP诱导苹果采后灰霉病抗性的作用机理

Mechanism of 1-MCP-induced Resistance to Grey Mold in Postharvest Apples

为了探讨1-MCP对苹果采后灰霉病的影响及其抗性诱导机理,该文以"红富士"苹果为试材,采后用1μL/L 1-甲基环丙烯(1-MCP)熏蒸处理,以不经1-MCP处理的作为对照,常温(20±1)℃下放置24 h后,分别接种灰葡萄孢菌。结果显示:采后1-MCP处理较对照可显著降低苹果灰霉病的发病率,抑制病斑的扩张(p<0.05)。经过5 d贮藏,1-MCP处理的苹果发病率仅为58.24%,显著低于对照(90.73%);贮藏结束时,处理组发病率不足70%,病斑直径为37.19 mm,而对照组几乎全部发病且病斑扩展至50.80 mm,1-MCP明显抑制了苹果灰霉病的发展。1-MCP处理能够诱导果实中苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、过氧化物酶(POD)、β-1,3-葡聚糖酶(GLU)、几丁质酶(CHI)活性的提高,增加总酚、类黄酮和木质素的合成与积累,进而增强果实的抗病性。研究结果为1-MCP应用于苹果采后病害的防治研究提供理论依据和技术参考。

The effect of 1-methylcyclopropene （1-MCP） treatment on postharvest gray mold in apples and its mechanism were investigated. ＂Red Fuji＂ apples were used as the test materials and treated with 1 μL/L 1-MCP; apples without 1-MCP treatment were used as controls. After being allowed to stand at room temperature for 24 h, the samples were inoculated with a conidial suspension of Botrytis cinerea. The results showed that 1-MCP treatment effectively limited the lesion diameter of gray mold rot and significantly reduced the incidence of Botrytis cinerea compared to the control,. After five days of storage, the disease incidence of 1-MCP-treated apples was only 58.24%, which was significantly lower than that of the controls （90.73%）. At the end of storage, the disease incidence in the treatment group was less than 70% and the lesion diameter of gray mold rot was 37.19 ram, while Botrytis cinerea occurred in nearly all apples in the control group and the lesion diameter expanded to 50.80 mm. Therefore, 1-MCP effectively inhibited the development of apple gray mold. Moreover, the activities of phenylalanine ammonia-lyase （PAL）, polyphenol oxidase （PPO）, peroxidase （POD）, β-1,3-glucanase, and chitinase of apple fruits were increased remarkably by 1-MCP, and the synthesis and accumulation of total phenolic compounds, ftavonoids, and lignin were also increased, thus enhancing the disease resistance in fruits. These findings provide a theoretical basis and technical reference for studies of the application of 1-MCP in control ofpostharvest diseases of apples.