火龙果果实心腐病病原鉴定及初始侵染点研究  

Identification of pathogen causing heart rot of pitaya(Hylocereus polyrhizus)and studies on its initial infection point

作　　者：王信入 黄玉晴 范雪婷 秦永华[1] 孙清明[2] 张荣[1] WANG Xinru;HUANG Yuqing;FAN Xueting;QIN Yonghua;SUN Qingming;ZHANG Rong(College of Horticulture/Guangdong Province Key Laboratory of Microbial Signals&Disease Control,South China Agricultural University,Guangzhou 510642,China;Institute of Fruit Tree Research,Guangdong Academy of Agricultural Sciences/Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization,Ministry of Agriculture and Rural Affairs/Guangdong Provincial Key Laboratory of Tropical and Subtropical Fruit Tree Research,Guangzhou 510640,China)

机构地区：[1]华南农业大学园艺学院/广东省微生物信号与作物病害防控重点实验室,广州510642 [2]广东省农业科学院果树研究所/农业农村部南亚热带果树生物学与遗传资源利用重点实验室/广东省热带亚热带果树研究重点实验室,广州510640

出　　处：《华中农业大学学报》2024年第6期253-260,共8页Journal of Huazhong Agricultural University

基　　金：广东省大学生创新创业训练计划项目(S202210564151);广东省科技厅项目(粤科农字[2021]151号KTP20210078);阳江市科技专项(阳科通[2021]50号)。

摘　　要：为了有效防控火龙果心腐病,以田间果实心腐病分离菌株为材料,采用ITS基因序列分析以及室内、田间活体接种方法,对病原菌进行鉴定,并确定初始侵染点及病原菌生物学特性。结果显示,火龙果心腐病在田间导致部分幼果黄化脱落或幼果果皮提前转红,果实内部褐变腐烂。经分离、鉴定明确所获得的致病菌株为桃吉尔霉Gilbertella persicaria。病原菌的初始侵染点为雌花的柱头,孢囊孢子可直接或通过花粉带菌定殖在雌花柱头上,随着授粉授精、果实发育造成心腐。病原菌的最适生长温度为30℃,最适pH为5,光照不利于产孢。以上结果表明,桃吉尔霉可通过侵染柱头引起火龙果心腐病。建议在授粉后及时割除花瓣或进行药剂防治,减少初侵染源量从而减轻桃吉尔霉对火龙果果实的为害。Heart rot is a newly identified pitaya disease,which affects the yield and commercial value of the fruit,with an incidence rate of 10%in autumn and winter seasons.In order to effectively prevent and control heart rot in pitaya fruit,we used strains isolated from diseased fruit in the field as materials.We conducted ITS gene sequence analysis,as well as in vivo inoculation methods in both indoor and field settings,to identify the pathogen and determine the initial point of infestation and its biological properties.The results showed that the the symptoms of pitaya heart rot disease in the field include yellowing and dropping of some young fruits,premature reddening of young fruit skin,and brown rot of the fruit flesh.The pathogenic strain was identified as Gilbertella persicaria.The initial infection point of the pathogen is the stigma of the pistil,and the sporangiospores can colonize the stigmas of female either directly or indirectly through pollen,resulting in heart rot during pollination,fertilization and fruit development.The optimal growth temperature and pH value for G.persicaria were 30℃and pH 5,respectively,while light exposure could inhibit the sporulation of the fungus.These results indicate that G.persicaria could cause pitaya heart rot by infecting the stigmas of female.To mitigate the damage of G.persicaria to pitaya fruits,it is recommended to promptly remove petals after pollination or apply fungicide treatments,thus decreasing the initial inoculum load.

关 键 词：火龙果 心腐病 桃吉尔霉 侵染点 定殖 

分 类 号：S436.6[农业科学—农业昆虫与害虫防治]