摘要
【目的】调查重庆柑橘轮斑病田间症状、发病规律,探究47个柑橘品种对3个省份来源致病菌株的抗性差异。【方法】调查重庆万州柑橘轮斑病田间症状变化和不同情况果园发病时间、发病率及病情指数,采用分离自陕西、湖北、重庆的3个菌株离体接种47个柑橘品种叶片,根据发病率和病斑平均直径评价不同柑橘品种的抗病性。【结果】柑橘轮斑病侵染叶片、枝梢、果实、叶(果)柄、花萼等部位。病斑由内而外为灰白色、棕褐色和深褐色,中央产生“轮纹状”排列的黑色子实体,外缘油渍状,不同柑橘品种和不同生育期叶片病斑有差异;此病1—2月为发病高峰,高海拔区、果园郁闭、树势弱、种植感病品种的果园发病早(12月3日),病情指数均大于其他果园;11—1月,平均高温、平均低温和极端低温越低,发病越重,而2—4月,以上3个气候因子值越高,发病加重;12—4月,雨日、空气湿度和降雨量值越大,发病越重;不同来源菌株对47个品种毒力差异显著(p<0.05),YLSDP80毒力最强,CGDS2毒力中等,WZSS1毒力相对较弱。24个柑橘品种表现为抗病,尤力克柠檬表现感病,其余22个品种对3个省份的菌株抗性表现不一。【结论】田间症状及其发病规律为其诊断和防控奠定了理论基础。避免连片集中种植感病品种;引进22个抗性表现不一的品种接穗时应加强检疫;抗病的24个品种可以与感病的尤力克柠檬间作或者替代严重发病的尤力克柠檬。
【Objective】Citrus target spot has been discovered on Citrus unshiu and Fortunella margarita in Shaanxi Province,C.unshiu in Hubei Province,C.reticulata var.ponkan in Hunan Province,as well as C.reticulata var.ponkan,C.limon var.eureka,C.meyerii var.meyer and C.sinensis var.newhall in Chongqing,which has seriously threatened the citrus production in China.Thus,the symptomatic change and occurrence regularity of the target spot in Chongqing were investigated,and the resistance difference of the 47 varieties to 3 strains from C.unshiu in Shanxi,Hubei and C.limon var.eureka in Chongqing were evaluated in this study.【Methods】The symptomatic changes of the target spot on C.limon var.eureka in Wanzhou,Chongqing were investigated by photography.The time of appearance of the typical target spot symptoms,and the incidence and disease index in various orchards under different conditions were also investigated when the disease condition was stable.The leaves of the 47 varieties were inoculated in vitro with the 3 strains.And the virulence of the 3 strains and the resistance of the 47 varieties were analyzed and evaluated based on the incidence and average diameter of disease spots.【Results】After the Citrus trees were infected by Pseudofabraea citricarpar,the symptoms could appeared on the leaves,branches,shoots,fruits,petioles,fruit stalk,and calyx,etc.At the early stage of the disease,the reddish brown spots formed on the leaves,and then they gradually expanded to dark brown round lesions.The disease spots were scattered,and the multiple disease spots would connect to one large spot.The leaf spot was slightly concave,round,oval,fusiform or irregular,and the concave and water stain were more obvious on the young tissues.One side or multiple sides of the lesion could produce tail along the vein.The diameter of the disease spot was mostly 0.2-2.2 cm.The outer edge of the spot on the front of the leaf was oil stained,and then it became dark brown and reddish brown inward,and light white in the center.Most of the black dots(acervuli) were arranged in concentric circles,and there was no any conidiamata on some diseased leaves.Later,the black dots(acervuli) on the diseased leaves could falled off with the leaf abscission,which could be the main source of infection in the next year.The disease spots on some perennial leaves were relatively small,and they could remain on the leaf surface without perforation or expansion until conditions were suitable for infecting the other leaves.There were also symptom differences on the leaves of the different Citrus varieties and different growth stages.The incidence of the citrus target spot peaked from January to February,and the time of appearance of the typical target spot symptoms was as early as December 3 in the high-altitude areas,the orchards in canopy,the weak trees and the orchards of susceptible varieties,of which the disease index was higher than that of other orchards.From November to January,the lower of the average maximum temperature,the average low temperature,and the extreme low temperature were,the higher of the disease index was,while from February to April,the higher of the above three climate factors were,the higher of the disease index was.From December to April,with more rain days,high relative humidity and rainfall the disease index was higher.The different strains from the different sources had certain virulence to the 47 varieties with significant difference.Overall,the virulence of YLSDP80 was the strongest(the average diameter of the lesion was 6.40 mm),and that of CGDS2 was medium(the average diameter of the lesion was 5.03 mm),but the incidence was the highest(85.75%).WZSS1 was relatively weak(the average diameter of the lesion was 4.52 mm),and the incidence was the lowest(66.94%).Among the 47 varieties,24 varieties were resistant to the 3 strains,including Tarocco Blood Orange No.9,Liduo Blood Orange,Fengwan Navel Orange,Cara cara Navel Orange,Jinxiang Orange,Fukumoto Navel Orange,Tarocco Blood Orange No.8,98-1 Long Leaf Orange,Sanhongyou Pomelo,Huangjinyou Pomelo,Dianjiang Laohongyou Pomelo,Liangpingyou Pomelo,Shatianyou Pomelo,Longduzaoxiangyou Pomelo,Chandler Pummelo,Daya mandarin,Orah,Aiyuan No.30,Satsuma mandarin No.1,Nankou,Shiranui,Kouzhumi,Hongjü and Poncirus trifoliata Eureka lemon was susceptible to the strains from three provinces at the same time,and the resistance of the other 22 varieties to the strains from three provinces was different.【Conclusion】Comparing with the black spot on citrus,the conidiomata on the diseased leaves of the citrus target spot were obviously arranged in concentric circles,and the citrus target spot usually developed in mid December to March of the next year.Comparing with the anthracnose,the diseased spots of the citrus target spot were smaller in size and more in number,and the conidiomata were still black rather than those of the anthracnose were orange when the relative humidity were very high,which was benificial for distinguishing the citrus black spot,the anthracnose and the target spot for the field worker of plant protection.The 24 varieties with resistance to the 3 strains could be inter-cropped with the other 25 varieties to retard the spread of the disease.
作者
陈泉
张文晶
何锦辉
徐嵩琳
郭建伟
CHEN Quan;ZHANG Wenjing;HE Jinhui;XU Songin;GUO Jianwei(Chongqing Three Gorges Academy of Agricultural Sciences,Wanzhou 404155,Chongqing,China;College of Biology and Food Engi-neering,Chongqing Three Gorges University,Wanzhou 400401,Chongqing,China;Plant Protection and Fruit Tree Technology Popu-larization Station in Wanzhou District of Chongqing City,Wanzhou 404020,Chongqing,China;Center for Mountain Futures/Kunming Institute of Botany,Chinese Academy of Sciences,Kunming 650201,Yunnan,China)
出处
《果树学报》
CAS
CSCD
北大核心
2023年第8期1675-1691,共17页
Journal of Fruit Science
基金
重庆市教委会科学技术研究项目(KJ202301289858551)资助
重庆市万州区科技计划项目(wzstc-20210211)
国家自然科学基金(31860026)
重庆三峡农业科学院青年人才项目(Sxnykxy2019001)。
关键词
柑橘轮斑病
田间症状
发病规律
抗性测定
Citrus target spot
Field symptoms
Occurrence regularity
Resistance determination
