贵州火龙果采后病害主要病原菌分离鉴定及抑菌植物精油筛选

Isolation and Identification of Major Pathogens of Postharvest Pitaya Fruit Disease and Screening of Bacteriostasis of Plant Essential Oil in Guizhou Province

为贵州火龙果采后病害发生规律研究及采后病害综合防治提供参考,对采摘于贵州罗甸、关岭、镇宁的火龙果进行了病原菌分离、纯化及致病性检测,根据形态学特征和rDNA-ITS序列分析鉴定病原菌;选择7种植物精油(肉桂精油、生姜精油、桔子精油、丁香叶精油、丁蕾精油、罗勒精油和香根精油)对病原菌进行抑菌试验。结果表明:贵州火龙果采后主要致病菌为仙人掌平脐蠕孢〔Bipolaris cactivora (Petrak)Alcorn〕、链格孢〔Alternaria alternata(Fr.)Keissl.〕、桃吉尔霉(Gilbertella persicaria)、层生镰刀菌(Fusarium proliferatum)和尖镰刀菌(Fusarium oxysporum);7种植物精油中,肉桂精油对各病原菌有较好的抑制效果,添加量为4μL时对链格孢和尖镰刀菌的抑制率为100%,添加6μL时对仙人掌平脐蠕孢和层生镰刀菌的抑制率为100%,对桃吉尔霉的抑制率为96.71%;肉桂精油熏蒸处理能有效降低无伤接种火龙果的腐烂率,减缓有伤接种病斑的扩大速度。

In order to provide reference for the research on the occurrence rule of postharrow-harvested diseases and the comprehensive control measures of postharrow-harvested diseases of pitaya in Guizhou Province,the isolation,purification and pathogenicity detection of the pathogens were carried out on the fruit collected in Luodian,Guanling and Zhenning of Guizhou Province,and the pathogens were identified according to morphological characteristics and rDNA-ITS sequence analysis.7 plant essential oils(cinnamon essential oil,ginger essential oil,orange essential oil,clove leaf essential oil,dinglei essential oil,basil essential oil and vetiver essential oil)were selected to conduct bacteriostasis test against pathogens.Results:The main pathogenic bacteria of post-harvest pitaya in Guizhou were Bipolaris cactivora(Petrak) Alcorn,Alternaria alternata(Fr.) Keissl.,Gilbertella persicaria,Fusarium proliferatum and F.oxysporum.Among the 7 plant essential oils,cinnamon essential oil had a good inhibitory effect on various pathogens.When the addition amount was 4 μL,the inhibitory rate on A.alternata(Fr.)Keissl.and F.oxysporum was 100%;when the addition amount was 6μL,the inhibitory rate on B.cactivora(Petrak)Alcorn and F.proliferatum was 100%;and the inhibitory rate on G.persicaria was 96.71%.Fumigation of cinnamon essential oil can effectively reduce the rotting rate of pitaya fruit inoculated with no injury and slow down the expansion rate of diseased spots inoculated with injury.