菠萝黑钉病病原菌分离鉴定及防控药剂筛选OA

[Objective]To isolate and identify the pathogen responsible for Pineapple(Ananas comosu)fruitlet core rot(FCR),and screen control agents and field-based combination treatments,thereby providing a basis for studying the disease pattern and mechanism as well as green prevention and control.[Method]Pathogens were isolated and purified,and the pathogenicity was verified using Koch's law.The species of pathogens were determined according to the morphological characteristics of the strains and multi-gene sequence analysis.The inhibitory effects of the pathogen on five single agents and eight compound agents were determined using the mycelial growth rate method.[Result]Nine genera of fungal strains were obtained by isolation and purification,among which two strains could infect pineapple fruitlets and cause brown spots.Combining morphological characterization with multi-gene sequence analysis,the pathogenic fungi that caused FCR were identified as Fusarium verticillioides LDL-3 and Talaromyces funiculosus LL-3,with LDL-3 being more pathogenic than LL-3.The results of fungicide virulence tests showed that flucytosine,feniconazole,pyraclostrobin,imidacloprid manganese salts and compound formulations had effects on the growth of the pathogens.Among these agents,imidacloprid manganese salts had a better inhibitory effect on LDL-3 with an EC50 of 0.009 μg/mL,while pyraclostrobin showed a better inhibitory effect on LL-3 with an EC50 of 0.134 μg/mL.Among eight compound formulations,benzyl·pyraclostrobin(volume ratio of difenoconazole and pyraclostrobin was 3∶1)inhibited both pathogens effectively with EC50 less than 0.2 μg/mL.The combined use of insecticide,fungicide and growth regulator could effectively inhibit the pathogen growth with EC50 less than 0.2 μg/mL.[Conclusion]The FCR is mainly caused by Fusarium sp.and Talaromyces sp..Benzyl·pyraclostrobin(3∶1,v/v)effectively inhibits these pathogens and offers a simplified and efficient solution for field control during flower induction and fruit expansion.