摘要
【目的】筛选高效防治桃枝枯病的化学药剂,探究桃枝条韧皮部挥发性物质与抗病性的关联,为桃枝枯病的综合防控和抗病育种提供依据。【方法】采用菌丝生长速率法测定15种药剂对桃枝枯病病原菌(Diaporthe amygdali)的室内毒力。采集22份抗性不同的桃种质健康1年生枝条韧皮部,利用顶空固相微萃取-气质联用技术测定挥发性物质含量,并分析其含量与种质抗性的相关性。选取2种抗性不同的种质进行接种验证,测定接种后韧皮部关键挥发性物质含量的变化。【结果】在15种药剂中,咪鲜胺的抑制作用最强,其EC50值为0.0042 mg·L^(-1);苯醚甲环唑、吡唑醚菌酯、丙环唑、咯菌腈、氟硅唑、己唑醇和戊唑醇对桃枝枯病病原菌有较好的抑制作用;而啶酰菌胺对桃枝枯病病原菌的抑制作用最差。对桃枝枯病病原菌抗性不同的22份种质中,鉴定出121种挥发性物质,主要为萜烯类(30种)、酯类(22种)、醇类(17种)和酮类(16种),而酚类(3种)、呋喃类(3种)、酸类(2种)和内酯类(1种)较少。相关性分析表明,有16种挥发性物质含量与抗性呈显著负相关,负相关系数最高的为酯类物质油酸二十烷醇酯(Icosyl oleate),达到了-0.6765(P<0.01)。同时,有6种挥发性物质含量与抗性呈显著正相关,正相关系数最高的为醛类物质2-庚烯醛(2-Heptenal),达到了0.5704(P<0.01)。接种验证结果表明,抗性正相关物质2-庚烯醛含量在感病品种奉化蟠桃中快速上升,而在高感品种白凤中上升较少;抗性负相关物质苯甲酸(Benzoic acid)含量在感病品种中上升的幅度低于高感品种。【结论】咪鲜胺对桃枝枯病病原菌的抑制作用最强。16种挥发性物质含量与抗性呈显著负相关,负相关系数最高的为油酸二十烷醇酯。6种挥发性物质含量与抗性呈显著正相关,正相关系数最高的为2-庚烯醛。
【Objective】Prunus persica(L.)Batsch,a member of the Rosaceae family,is native to China and has a cultivation and evolutionary history spanning thousands of years.In recent years,peach shoot blight caused by Diaporthe amygdali has been one of the most prevalent fungal diseases in major peachproducing regions of southern China.This study aimed to screen out highly effective chemical fungicides for controlling peach shoot blight,and investigated the relationship between volatile compounds in the phloem of peach shoots and resistance to the disease,providing a scientific basis for integrated disease management strategies and resistance breeding programs.【Methods】The inhibitory effects of 15 fungicides against D.amygdali were evaluated in vitro using the mycelial growth rate method.The active ingredient information was as follows:difenoconazole,pyraclostrobin,propiconazole,boscalid,carbendazim,hymexazol,flusilazole,fludioxonil,hexaconazole,prochloraz,azoxystrobin,trifloxys trobin,tebuconazole,lprodione,and dithianon.A series of concentrations were prepared for each fungicide.The effective medium concentration(EC50)values were calculated based on the correlation between fungicide concentration and mycelial growth inhibition rate by DPS in this study.At the same time,healthy and disease-free one-year-old shoot phloem tissues were collected from 22 peach varieties,which exhibited varying levels of resistance to D.amygdali.After rapid freezing within the liquid nitrogen,the samples were transported to the laboratory for volatile compound analysis.Volatile compounds were extracted and analyzed using Headspace Solid-Phase Microextraction coupled with Gas Chromatography-Mass Spectrometry(HS-SPME-GC-MS).The correlation between the relative content of each identified volatile compound and the resistance level of the corresponding variety was examined.In addition,two typical peach cultivars(Fenghua Pantao,susceptible;and Hakuho,highly susceptible)were selected for inoculation with D.amygdali.Phloem tissue around necrotic spots was collected 7 days after inoculation,flash-frozen,and used for volatile compound analysis.Key volatile compounds significantly correlated with resistance(identified in the correlation analysis)were quantified in these tissues to observe pathogen-induced changes.【Results】The toxicity test of fungicides showed that prochloraz had the strongest inhibitory effect,with an EC50 value of 0.0042 mg·L^(-1).Difenoconazole,pyraclostrobin,propiconazole,fludioxonil,flusilazole,hexaconazole,and tebuconazole also showed strong activity.Boscalid showed the weakest inhibitory effect,with an EC50 value of 49.0252 mg·L^(-1).Analysis of volatile compounds content showed that volatile compounds were identified in 22 peach samples.A total of 121 volatile compounds were identified,falling into 12 distinct categories:30 terpenoids,22 esters,17 alcohols,16 ketones,13 aldehydes,5 alkanes,4 fatty acids,3 phenolics,3 furans,2 acids,1 lactone,and 5 other compounds.Among the samples,Richuan Baifeng and Reddomun had the highest number of volatile compounds,with 85 and 80,respectively.In contrast,the samples Baihua and Zhouxingshantao had the fewest,with 52 and 51 compounds,respectively.To identify volatile metabolites associated with resistance to D.amygdali,we conducted a correlation analysis between the volatile substance content and germplasm resistance to D.amygdali across 22 samples.Sixteen compounds were significantly and negatively correlated with resistance,and six were significantly and positively correlated.Negatively correlated compounds included one acid,one aldehyde,two alkanes,two esters,one fatty acid,four ketones,one phenolic compound,and four terpenoids.The ester compound icosyl oleate had the strongest negative correlation,with a coefficient of-0.6765(P<0.01).Positively correlated compounds included one alcohol,two aldehydes,one ester,one ketone,and one terpenoid.Among these,the aldehyde 2-heptenal had the highest positive correlation,with a coefficient of 0.5704(P<0.01).The distribution of two volatile compounds(a:n-Hexadecane;b:1-Nonanol)with different resistance level to D.amygdali of 22 peach varieties was revealed.To further validate the relationship between volatile compounds and shoot blight resistance,we selected two peach cultivars with different resistance levels and inoculated them with D.amygdali.After 7 days,lesion diameters reached 52.62 mm in Fenghua Pantao and 84.50 mm in Hakuho.Volatile compounds in the phloem tissue around the lesions were analyzed in both samples.After inoculation,the content of the volatile compound 2-heptenal,positively correlated with resistance,rapidly increased in the susceptible germplasm Fenghua Pantao,in comparison to the highly susceptible germplasm Hakuho,suggesting that higher 2-heptenal levels may enhance resistance.Benzoic acid,negatively correlated with resistance,was induced in both germplasms,but the increase was smaller in susceptible peaches,suggesting that lower accumulation may reduce resistance.【Conclusion】Among the 15 fungicides,prochloraz exhibited the strongest inhibitory effect,with an effective medium concentration value of 0.0042 mg·L^(-1).Correlation analysis identified 16 compounds that were significantly and negatively correlated with resistance,with the ester icosyl oleate showing the strongest correlation(r=-0.6765).Six compounds were significantly and positively correlated,with 2-heptenal showing the highest correlation(r=0.5704).This study layed an important theoretical foundation for achieving sustainable comprehensive control of peach shoot blight.
作者
胡祝
王丽
赵红月
HU Zhu;WANG Li;ZHAO Hongyue(School of International Education,Henan University of Technology,Zhengzhou 450001,Henan,China;Zhengzhou Fruit Research Institute CAAS,Zhengzhou 45009,Henan,China;Zhongyuan Research Center,CAAS,Xinxiang 453003,Henan,China)
出处
《果树学报》
北大核心
2025年第8期1811-1819,共9页
Journal of Fruit Science
关键词
桃枝枯病
桃拟茎点霉
药剂筛选
挥发性物质
Peach shoot blight
Diaporthe amygdali
Fungicide screening
Volatile compound
