猕猴桃溃疡病流行的生态因子及药剂对病菌的抑菌作用

经5年系统研究得出,影响猕猴桃溃疡病发生流行的特点是,海拔750m以上的果园发病重,向阳坡发病重于背阳坡,不同品种发病差异显著,金丰品种易感病,金魁品种高度抗病;树龄越大,病株率越高;不同枝龄比较,一年生枝条病枝死亡率和枝条死亡率最高.6种药剂以加瑞农和硫酸链霉素抑菌效果最好.     

猕猴桃细菌性溃疡病流行预测初探

对猕猴桃溃疡病流行分析表明,影响该病发生严重程度y的生态因子是3月中下旬降水x1和1月份均温x2,其模型是y=2.1359 0.0107x1-0.6061x2;猕猴桃溃疡病发生流行的主导因子为冬季及初春旬均温和降水量的相对变差,并且由此得到病害流行的回归方程为：y=-8.127 22.739x-13.254x^2,经检验,该方程达极显著水平。     

噬菌体鸡尾酒对猕猴桃溃疡病的田间防治效果及叶际细菌群落结构的影响

【背景】噬菌体鸡尾酒可作为一种杀灭猕猴桃溃疡病病原菌(Pseudomonassyringaepv.actinidiae, Psa)的生物制剂,但关于噬菌体鸡尾酒在田间的防治效果和对猕猴桃植株叶际内生细菌群落结构影响的研究依然较少。【目的】探究噬菌体鸡尾酒在田间防控猕猴桃溃疡病的效果,以及噬菌体鸡尾酒对猕猴桃茎内叶际细菌微生态的影响。【方法】使用猕猴桃溃疡病病原菌感染健康植株,对比施用噬菌体鸡尾酒和传统铜制剂后溃疡病的发病情况,利用高通量测序技术分析猕猴桃叶际内生细菌群落结构的变化。【结果】与铜制剂相比,噬菌体鸡尾酒可更有效地控制猕猴桃溃疡病,改变叶际细菌群落的丰富度与多样性,增强群落结构的稳定性,改善群落物种功能基因丰度情况,一定程度使叶际细菌群落恢复至健康状态。【结论】噬菌体鸡尾酒在杀灭病原菌的同时具有良好的微生态调节功能,在猕猴桃溃疡病的生物防治中具有巨大的应用潜力。     

陕西省猕猴桃溃疡病病原菌分离鉴定及分型研究

明确陕西省猕猴桃主产区丁香假单胞菌猕猴桃致病变种（Pseudomonas syringae pv. actinidiae,Psa）的变型,从而有针对性地制定猕猴桃溃疡病的综合防治策略,采集陕西省猕猴桃主产区周至、眉县、灞桥、渭南、长安和鄠邑不同年份发病样本进行病原菌的分离,对病原菌进行初步鉴定后再应用特异性PCR进行分子鉴定,并进行回接实验。从鉴定出的Psa菌株中选出16株不同年份不同地区的代表性菌株应用7个管家基因进行MLSA分型分析。共分离鉴定出86株不同地区不同年份的Psa菌株,并通过回接实验验证了其致病性。MLSA分型结果表明16株代表性Psa菌株均属于Psa3,且Psa3与Psa6的遗传距离最近。陕西省猕猴主产区的Psa变型为Psa3,近十年未发生变异。研究结果为今后Psa的检测鉴定及防治研究提供参考。     

几种同工酶与猕猴桃品种对溃疡病抗性关系的研究

应用聚丙烯酰胺凝胶电泳、同工酶分析技术分别研究了猕猴桃植株体内过氧化物酶(POD)、多酚氧化酶(PPO)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、酯酶(EST)同工酶谱带的变化,结果表明:自然感染溃疡病前后,此6种同工酶谱带特征在不同抗感品种中表现出一定的差异.未感染溃疡病菌前,抗(感)品系枝条、叶片POD同工酶均有2条酶带,PPO同工酶有3条酶带,但感病品种酶带颜色深且粗,而抗病品种酶带颜色浅且细,叶片酶带颜色深于枝条;SOD、CAT同工酶谱带均为1条,Rf值分别为0.38、0.28,感性品种较抗耐品种谱带亮度高活性强;自然发病后,抗(感)品系POD、PPO同工酶谱带数都增加,分别为4、3条和5、4条,且抗病品种新酶带出现较感病品种早且酶带粗颜色深活性强,感病品系虽也有新酶带出现,但酶带少活性弱,抗病品系枝条、叶片POD、PPO同工酶新谱带的Rf值分别为0.63、0.67和0.85、0.87;抗感病品种SOD、CAT同工酶都被诱导产生了1条新的同工酶谱带,Rf分别为0.32和0.27,新酶带现色时间迟,且酶带颜色浅活性弱,但抗耐品种较感性品种谱带亮且活性强;EST同工酶于自然发病前后变化不大,与抗病性关系不很明显.     

永泰县猕猴桃细菌性溃疡病发生的原因与防治策略

猕猴溃疡病属细菌性病害,可引起植株死亡,严重降低其产量,是福建省福州市永泰县猕猴桃生产上主要病害之一.本文结合永泰县品种选择、地理环境、水肥管理、栽培技术,适时用药,分析了引起溃疡病发生的原因,对其发生规律和防治策略进行分析与总结,为该县后期猕猴桃溃疡病防治提供科学依据.     

湘西地区猕猴桃溃疡病病原菌分离及其全基因组分析

通过了解湘西地区猕猴桃溃疡病致病菌分类地位和基因类型,初步探讨其致病的分子机理。采用纯培养法分离猕猴桃溃疡病菌;基于16S～23S rRNA基因内转录间隔序列进行病原菌的系统发育分析;通过基因组测序和生物信息学分析解析其致病的分子机理。从“米良1号”和“红阳”猕猴桃感病枝条中分离获得5株溃疡病菌,编号为L211、L212、L321、L322、L323;通过形态特征和16S～23S rRNA基因内转录间隔序列分析,鉴定5株细菌均为丁香假单胞菌猕猴桃致病变种(Pseudomonas syringae pv.actinidae,Psa)。以菌株L211为代表进行体外猕猴桃枝条接种实验表明能引起典型溃疡病症状。通过菌株L211的全基因组测序和生物信息学分析,获得5 741条基因数目,长5 412 072 bp;基因功能注释发现菌株L211携带121种毒力因子、71个植物互作因子和77个耐药基因;同时,基因组单核苷酸多态性分析发现病原菌L211为基因Ⅲ型Psa。引起湘西地区猕猴桃溃疡病的病原菌是丁香假单胞菌猕猴桃致病变种基因Ⅲ型,与国内外报道的引起猕猴桃溃疡病大流行的致病菌一致。猕猴桃溃疡病发病...     

中国野生猕猴桃资源的溃疡病抗性种质筛选

细菌性溃疡病严重威胁猕猴桃(Actinidia)产业发展,本研究对国家猕猴桃资源圃中29个种82份种质资源进行了离体枝条的溃疡病菌接种,以病斑长度评价其抗病能力,将种质划分为高抗至高感7个抗性等级。结果显示：不同种间材料抗性差异显著,大部分种内材料存在明显的抗性分化。82份种质中含高抗种质5份(6.09%)、中抗种质9份(10.98%)、低抗种质18份(21.95%)、耐病种质21份(25.61%)、低感种质11份(13.41%)、中感种质9份(10.98%)及高感种质9份(10.98%)。32份抗病种质包括软枣(A.arguta(Siebold&Zuccarini) Planchon ex Miquel)6份,异色(A.callosa var.discolor C. F. Liang)5份,黑蕊(A.melanandra Franchet)4份,京梨(A.callosa var.henryi Maximowicz)及毛花(A.eriantha Bentham)各3份,葡萄叶(A.vitifolia C. Y. Wu)、安息香(A.styracifolia C. F. Lian...     

猕猴桃套袋技术的生态效应

提出了猕猴桃套袋技术,并在田间系统研究了套袋对猕猴桃生长发育、温湿度效应及对病虫的控制效果,室内测定分析了套袋猕猴桃的营养物含量及农药残留量。结果表明,袋型不同,其生态效应差异明显,套膜袋能显著改变温湿度条件,袋内温度升高0．7～0．9℃,相对湿度增大10．8％～11．8％．果重增加25．7％～37．7％,商品果率提高20．4％～30．1％,病虫危害率降低87．5％～90．2％,贮藏性能好,化学农药使用量减少72．2％,果实中农药残留量仅为0．31mg·kg^-1,降低90．5％,减轻了化学农药对生态环境及猕猴桃果实的污染,为绿色果品的生产开辟了新途径,具有广阔的推广应用前景,套纸袋负效应明显,果色发黄,品质差,不宜推广应用。     

改造农田小生境,增加天敌,抑制病虫

湖北省郧阳地区位于东经109°50′—111°50′,北纬31°30′—33°25′之间,处在世界陆地动物古北界与东洋界混合地带的西沿中部,利于这两界的天敌昆虫交互来往和生息繁衍。该地区又是我国东部平原西部山区过渡阶梯的典型地段,西北和西南山岭高竣重叠,海拔2,500米以上的山峰有7座,最高的达3,054米,阻挡了北来的冷空气。全年大风日数在10天以内,大风强度一般为5—7级,是湖北省大风日数最少、强度最弱的地区之一。风小既便于南下北上的天敢昆虫落脚     

An ELISA method to identify the phytotoxic Pseudomonas syringae pv. actinidiae exopolysaccharides: A tool for rapid immunochemical detection of kiwifruit bacterial canker

The phytotoxic exopolysaccharides produced by Pseudomonas syringae pv. actinidiae, the causal agent of bacterial canker of kiwifruit, were isolated and partially identified. Their phytotoxic activity was evaluated on host and non-host plants and their role in the complex mechanisms of host-pathogen interaction was also discussed. The phytotoxic exopolysaccharides, which are natural antigens, were used to arise specific antibodies by rat immunization. The antibodies were used to develop a rapid and specific method to unambiguously detect P.s. pv. actinidiae exopolysaccharides isolated from bacterial culture and infected plant samples. Indeed, the antibodies recognized the exopolysaccharides produced by other two strains of P. s. pv. actinidiae but did not cross reacted with those isolated from P. s. pv. syringae and Pseudomonas viridiflava culture filtrates. Finally, the same antibodies significantly recognized the exopolysaccharides extracted from infected kiwi leaves.     

乳酸杆菌代谢产物对引起阴道炎常见细菌的抑制作用的初步探讨

目的探讨乳酸杆菌代谢产物对临床常见引起阴道炎的大肠埃希菌、铜绿假单胞菌、金黄色葡萄球菌、白色念珠菌、伤寒杆菌和肠球菌的抑菌作用。方法采用营养琼脂平板培养基定量涂菌,国际标准药敏杯给药的药敏试验法,检测乳酸杆菌代谢产物对大肠埃希菌、铜绿假单胞菌、金黄色葡萄球菌、白色念珠菌、伤寒杆菌和肠球菌的抑菌环的大小。结果乳酸杆菌代谢产物对大肠埃希菌、铜绿假单胞菌、金黄色葡萄球菌和伤寒杆菌有明显的抑菌作用,对肠球菌、白色念珠菌无抑菌作用。结论在临床上可应用乳酸杆菌及其制剂调节阴道微生态平衡,治疗细菌性阴道炎。     

短棒状杆菌体外抑菌作用的初步探讨

探讨短棒状杆菌体外用药的抑菌效果,为临床应用奠定基础。将短棒状杆菌稀释成6.0×109/mL的菌悬液,分别与已传代扩增的1.0×102/mL的供试菌菌悬液等量混合,再接种至培养皿中,计算菌落总数。同时设生理盐水、CP滤液和灭活CP的对照试验。大肠埃希菌、金黄色葡萄球菌、淋病奈瑟菌、铜绿假单胞菌、乙型溶血性链球菌较对照组同比长菌量明显减少,T检验与对照组均有显著性差异;白假丝酵母菌、黑曲霉与对照组长菌量均无显著性差异。短棒状杆菌外用给药对某些细菌具有一定的抑菌效果,对白假丝酵母菌及黑曲霉菌无抑菌作用。     

Integration of Pseudomonas fluorescens and salicylic acid improves citrus canker disease management caused by Xanthomonas citri subsp citri-A*

The individual and combined effects of Pseudomonas fluorescens (Pf) and salicylic acid (SA) were investigated for control of citrus bacterial canker (CBC). Both treated plants with copper hydroxide and untreated ones were used as controls. Mexican lime (Citrus aurantifolia) seedlings were treated with SA at 10 mM, Pf and distilled water. Plants were initially inoculated with Xanthomonas citri subsp citri 72 h post treatments. Results indicated that the Pf and SA treatment controlled CBC more effectively compared to separately applying Pf or SA. The application of Pf in combination with SA significantly reduced lesion number per leaf (72%) and disease severity (84%). Significant changes in the activities of peroxidase and catalase were found. In conclusion, the integration of Pf with SA complements each other and can be applied to manage citrus canker disease in conjunction with other control programmes.     

Epidemiology of Pseudomonas syringae Pathovars Associated with Decline of Plum Trees in the Southwest of Germany

Plum decline was associated with Pseudomonas syringae pathovars syringae and morsprunorum in Baden‐Württemberg. The trunks of affected plum trees (Prunus domestica) were girdled by bacterial cankers resulting in sudden death of infected trees. Copper compounds that were applied extensively during leaf fall and bud burst, were not effective. A minority of P. syringae strains isolated from cankers on plum trees were moderately resistant, while most strains were sensitive to cupric ions. Invasions through blossoms, leaves and wounds during the vegetation period were limited to the infection sites and plum trees coped effectively with both P. syringae pathovars eliminating them eventually. Infections after dormancy including very rare leaf scar infections did not induce cankers on the trunk. However, infections of dormant trees through frost injuries, (pruning) wounds or non‐injurious ingress by freezing and thawing were serious, because they led to cankers girdling the trunk. Control strategies to manage plum decline have to be adapted to the disease cycle. They should concentrate on the dormant period beginning with early frosts in autumn and ending with bud burst.