摘要
【目的】利用实时荧光定量PCR检测土壤中梨火疫病菌(Erwinia amylovora)浓度,明确梨火疫病菌在土壤中的动态变化规律。【方法】2021年3—11月采集库尔勒市发病香梨园810份土壤样品,应用所建立的实时荧光定量PCR检测体系,测定土壤中的梨火疫病菌浓度,同时对梨园发病率及病情指数进行调查。【结果】土壤中梨火疫病菌浓度值变化趋势与梨园病情指数变化趋势一致,4—5月梨园病情指数快速升高至最高值,随着果树生长期延长,病情指数逐渐降低。土壤中梨火疫病菌浓度值从4月逐渐升高,6月平均浓度值为914 CFU·g^(-1),7月平均浓度值最高为965 CFU·g^(-1),随后逐渐降低;6月土壤带菌率为42.2%,浓度值≥10^(3)CFU·g^(-1)的土样13份;7月土壤带菌率为44.4%,浓度值≥10^(3)CFU·g^(-1)的土样26份;6月、7月土壤中梨火疫病菌浓度显著高于4月、10月、11月,致病风险较高。【结论】6月和7月土壤中梨火疫病菌浓度值最高,主要与4月、5月大量病花病果掉落造成病原菌积累有关。加强花期病害防治和梨园病残体清理可有效降低土壤中梨火疫病菌浓度,是降低梨火疫病菌在梨树根部侵染风险的关键点。
【Objective】The pear fire blight is induced by Erwinia amylovora(E.amylovora).It first appeared in May,2016 in Huocheng County,Xinjiang Yili,China.It has spread to 14 Xinjiang regions,posing danger to pears,apples,hawthorns,quince,and other fruit trees,particularly in Korla.The disease has been considered an enormous risk to the Xinjiang fruit industry.Since 2019,we have discovered that the main stem of the pear tree exhibits noticeable lesions and bacterial fluids that spread from the root to the stem and ultimately induce the tree to die.Thus,we assessed the E.amylovora concentrations in the soils of the pear orchards and monitor the dynamic variation trend of E.amylovora by realtime fluorescence quantitative PCR in order to get insight into the occurence and control of the pear fire blight.【Methods】Six samples were collected from the each point following the random diagonal fivepoint sampling method.From March to November 2021,we collected 810 soil samples from the diseased pear orchards in Korla,with a sampling depth of 0-20 cm and a sampling volume of around 100 g at every point.The soil was sieved in order to obtain a 2.0 mm fraction,air-dried at room temperature for 2 days and stored in paper bags.The total DNA was extracted from the each soil sample at a dry weight of 0.25 g using the MOBIO Soil Genomic DNA Extraction Kit.0.25 g dry soil was taken out,and a standard bacterial suspension of 2.0×10^(9)CFU·mL^(-1)was used for serial dilution of quantitative soil DNA using sterile water.The standard curve was generated using different amounts of standard DNA dilutions,and the concentration of E.amylovora in soil samples was detected by the real-time fluorescence quantitative PCR established by our lab.【Results】The real time fluorescence quantitative PCR reaction was conducted under conditions of initial 5 min denaturation at 95℃,45 cycles of 95℃for 10 s,60℃for 30 s.The equation of standard curve was y=-3.458x+46.033,there was a good linear relationship between the CT value and the logarithm
作者
乾义柯
韩丽丽
陈珊珊
罗亮
魏霜
李晓妹
牛蒙亮
陈卫民
QIAN Yike;HAN Lili;CHEN Shanshan;LUO Liang;WEI Shuang;LI Xiaomei;NIU Mengliang;CHEN Weimin(Jianghan University,Wuhan 430056,Hubei,China;Yili Vocational and Technical College,Yining 835000,Xinjiang,China;Guangzhou Customs Technology Center,Guangzhou 510000,Guangdong,China;General Biology(Anhui)Co.,Ltd.,Hefei 230000,Anhui,China)
出处
《果树学报》
CAS
CSCD
北大核心
2023年第9期1839-1847,共9页
Journal of Fruit Science
基金
国家重点研发计划(2022YFC2601500)。
关键词
梨火疫病菌
土壤
荧光定量PCR
动态分析
Erwinia amylovora
Soil
Real-time fluorescence quantitative PCR
Dynamic analysis
