番石榴叶挥发油的抗菌性及优化提取研究

分别由酸疮痂链霉菌（Streptomyces acidiscabies, SA）、茄科雷尔氏菌（Ralstonia solanacearum, RS）和胡萝卜软腐欧文氏菌（Erwinia carotovora subsp. carotovora Borgey, ECCB）引起的植物疮痂病、青枯病、软腐病是农作物生产中常见多发的细菌病害。番石榴叶挥发油由多种活性物质组成，具有广谱抗微生物活性。本研究旨在提取并配置番石榴叶挥发油抗菌液，针对酸疮痂链霉菌、茄科雷尔氏菌、胡萝卜软腐欧文氏菌等3种病原菌进行挥发油的抗性研究，为农作物病害生物防治储备资源。采用添加锂盐结合微波辅助水蒸馏法提取番石榴叶挥发油，通过滤纸片扩散法和最小抑制浓度（MIC）评价了番石榴叶挥发油对3种供试菌株的抗菌效果，单因素结合响应面试验优化提取工艺，采用气相色谱-质谱联用技术（GC-MS）测定番石榴叶挥发油的化学成分。结果表明：番石榴叶挥发油对酸疮痂链霉菌、茄科雷尔氏菌、胡萝卜软腐欧文氏菌均表现出良好的抑制效果，抑菌圈直径范围为20.57～23.24 mm，抑菌率均达到60%以上，MIC值分别为3.13、1.56、3.13...     

评价马铃薯黑胫病感病性的简化薯片法

在作者先前(1984)的报告中曾描述过一种薯块切片法,用来测定不同马铃薯品种在15℃下对由马铃薯黑胫病欧氏杆菌(Frwinia carotovora subspp.atroseplica)和胡萝卜软腐病欧氏杆菌(E.carotovora)引起黑胫病的感病程度。每一重复的薯片切成三片,每片接种上述两种病原体,使之部分愈合或造成新伤痕。病     

11种植物提取物对4种病原细菌的抑菌活性筛选

采用琼脂扩散法初步测试11种植物提取物对魔芋软腐病菌(Erwinia carotovora pv. carotovora)、猕猴桃溃疡病菌(Pseudomonas syringae pv. actinidiae)、白菜软腐病菌(Erwinia carotorora)、核桃细菌性黑斑病菌(Xanthomonas campestris pv.juglandis)4种病原细菌的抑制活性，进一步采用二倍稀释法测定高抑菌活性物质的最低抑菌浓度(MIC)，旨在为植物源杀细菌剂的研发提供线索。测定结果表明，1 000 μg/mL剂量下，大黄、博落回和狼毒提取物对魔芋软腐病菌具有较强抑制活性，对猕猴桃溃疡病菌抑制作用最好的是博落回和大黄提取物，对核桃黑斑抑菌效果最好的是蛇床提取物，均优于或相当于农用链霉素200 μg/mL的效果；二倍稀释法测试表明，大黄和博落回提取物对魔芋软腐病菌的MIC值分别为7.8、15.6 μg/mL；大黄和博落回提取物对猕猴桃溃疡病菌的MIC值分别为3.9、15.6 μg/mL。说明大黄、博落回和狼毒提取物均具有显著抑制植物病原细菌的活性，有开发为新型植物源杀细菌剂的潜力。     

彩色马蹄莲品种对果胶软腐杆菌Pcc抗性的评价方法及鉴定

为探索彩色马蹄莲（Zantedeschia spp.）接种胡萝卜软腐果胶杆菌（Pectobacterium carotovora subsp. Carotovora, Pcc）的适宜方法,鉴定彩色马蹄莲组内品种对软腐病菌Pcc的抗性情况,本研究先以10个彩色马蹄莲品种为试验材料,进行以完整叶片、叶片圆片（叶盘）为接种材料的室内离体接种,以及以主脉、侧脉为接种部位的温室活体植株接种,接种后分别于12、24、36 h 3个时间点,以发病率、病情指数为指标,统计马蹄莲软腐病发病情况;在明确适宜的接种方法和发病时间后,选取包括第1步试验品种在内的34个彩色马蹄莲品种进行Pcc抗性鉴定。结果表明：离体接种的最佳材料为完整叶片,最佳发病观察时间是24 h;活体接种的最佳接种部位为叶片主脉,最佳发病观察时间是36 h;离体鉴定的中抗品种为5个,感病品种为11个,高感品种为18个;而活体鉴定的中抗、感病和高感品种分别为2、17、15个。离体方法鉴定的中抗品种多于活体鉴定,离体方法鉴定的抗性情况更接近田间大规模生产,其原因可能是离体方法鉴定时接种材料的均一性、环境条件的一致性好,更能反应品种本身的抗性情况。     

马铃薯软腐病菌的16SrDNA PCR检测

马铃薯软腐病是威胁马铃薯块茎的细菌性病害之一,为了提高马铃薯的品质与产量,减少贮藏期马铃薯块茎的腐烂,对马铃薯进行软腐病检测与鉴定是十分必要的。利用16SrDNA PCR对马铃薯软腐病原菌的进行检测,证实16SrDNA PCR检测技术是可行可靠的。在对PCR引物的筛选中,要根据所检测的对象进行有效、合理的设计,才能达到快速有效的目的。以马铃薯软腐病菌为代表,利用16SrDNA PCR进行鉴定,达到了预期的目的,为病原菌的快速鉴定方法提供了依据。     

不同马铃薯软腐病菌的致病力分析

为了明确马铃薯软腐病菌的致病力,本研究分别使用BL-1、BL-2和KF-1 3个马铃薯软腐病菌接种了‘尤金’和‘夏波蒂’2个马铃薯品种,对出苗率进行了调查,分析、鉴定不同菌种的致病力。结果显示:2个供试品种接种3个马铃薯软腐病菌后的出苗率均有不同程度的下降,平均出苗率为27.5%,与对照(CK)相比,出苗率降低67.5个百分点,其中KF-1是3个病原菌中致病力最强的,平均降低92.5个百分点。     

香草兰生防细菌的筛选、分子鉴定及其抑菌机制的初步研究

通过平板对峙法从香草兰根际微生物中筛选出对香草兰根(茎)腐病菌(Fusarium oxysporum)、香草兰疫病菌(Phytophthora nicotianae)和香草兰细菌性软腐病菌(Erwinia carotovora)均有良好抑制效果的生防菌10株。通过16S rDNA序列比对及系统发育树分析,其中7株为解淀粉芽孢杆菌(Bacillus. amyloliquefaciens),2株为枯草芽孢杆菌(B. subtils),1株为甲基营养型芽孢杆菌(B. methylotrophicus)。提取脂肽类化合物进行抑菌分析,发现10株生防菌脂肽类提取物对香草兰根(茎)腐病菌和香草兰疫病菌均有良好的抑制效果,有4株的脂肽类粗提物对香草兰细菌性软腐病菌有强烈的抑制活性。对其中2个菌株脂肽类粗提物进行MALDI-TOF/TOF-MS检测,发现菌株 VX2R11 产生表面活性素(Surfactin)和伊枯草素A(IturinA)2种脂肽类化合物,菌株 VX2S02 仅产生伊枯草素A,推测产生伊枯草素A是菌株VX2R11和VX2S02拮抗香草兰根(茎)腐病菌和疫病菌重要机制;产生表面活性素是菌株VX2R11拮抗香草兰细菌性软腐病菌的重要机制。     

中国桉树焦枯病病原菌物种多样性及致病力初步分析

为了明确中国桉树焦枯病病原菌的物种多样性、生物学特性和致病力强弱,本试验对在中国报道的桉树焦枯病病原菌进行了形态学比较,β-tubulin、Histone H3、TEF-1α三段基因系统发育学分析,并测定各病原菌在7个温度下的菌落生长速度,以及对4个桉树无性系(DH32-29、广州1号、广林4号、OC14)离体叶片的致病力大小。结果表明,到目前为止我国桉树焦枯病病原菌分属6个不同的物种,分别是Ca.cerciana、Ca.crousiana、Ca.pauciramosa、Ca.pseudocolhounii、Ca.pseudoreteaudii和Ca.fujianensis。不同病原菌的形态存在一定差异,病原菌分属于不同的系统发育树分枝。被测试病原菌的最适生长温度为20~30℃,在5℃和35℃下均停止生长。被测试的5种桉树焦枯病病原菌在4个桉树无性系上的致病力差异显著,总体致病力强弱顺序为:Ca.cercianaCa.pauciramosaCa.pseudoreteaudiiCa.crousianaCa.fujianensis。桉树无性系对不同种桉树焦枯病病原菌的抗性存在显著差异。研究结果显示桉树焦枯病病原菌物种存在多样性,各病原菌的致病性差异显著,有针对性地选择抗特定病原物种的桉树无性系是解决桉树焦枯病危害的一条有效途径。     

种薯热处理防治马铃薯黑胫病

马铃薯黑胫病是一种世界性的病害。它主要是被细菌Erwinia carotovora的亚种atroseptica(Van Hall)Dye(缩写为Eca)引起的,然而在温暖的土壤中,另一个亚种carotovara(Jones)Dye(缩写Ecc)也可能引起发病。病菌通常存在于块茎表面、皮孔或伤口内,维管束组织中很少,皮层中未发现。     

玉米苗期病害的发生与防治

铁岭市玉米面积达26.7万ｈｍ2,是全国重要的商品粮产区,又是重点玉米制种基地之一。1988～1992年该市昌图县、铁岭县个别乡(镇)发生大面积玉米黄枯苗、死苗现象,制种田尤为严重,重者减产七成。近几年发病减轻,但也时有发生。玉米苗病原因较复杂,有生理性的,也有侵染性的。经沈阳农业大学植保系室内分离鉴定,引起苗病发生的主要病原菌有:镰刀菌、蠕虫菌、木霉菌、青霉菌,其中以镰刀菌为主。该病主要发生于玉米3～5叶期。发病时病根部变褐、温腐、根毛少、茎部软腐易断裂、叶片褪绿发黄、干尖扭曲、植株逐渐萎蔫死亡。发病严重的缺苗断垄,对玉…     

应用间接酶联免疫吸附试验检测马铃薯环腐病

用马铃薯环腐菌菌株NCPPB2140和HEC_1免疫家兔得到效价1:2048的抗血清。通过硫酸铵沉淀法和DE52柱层析提取免疫球蛋白(IgG)。应用间接ELISA检测了马铃薯环腐菌及其供试样品。结果表明:免疫球蛋白最适浓度为5～10μg/ml,酶标记羊抗兔结合物的最适稀释度为1:75～100,检测环腐菌的灵敏度为2×10~5CFμ/ml,用NCPPB2140和HEC_1的IgG同马铃薯黑胫病菌、软腐病菌和青枯病菌等不发生反应,用间接ELISA可以检出轻度感病或受其它细菌二次感染腐烂的环腐病薯块。     

欧文氏杆菌CXJZ95-198基因组文库的构建

采用改良鸟枪法构建了草本纤维精制高效菌种Erwinia carotovora CXJZ95-198的基因组文库，结合透明圈法，筛选到了8个甘露聚糖酶基因阳性克隆，并采用PCR方法对它们进行了分析鉴定，结果表明它们含有同一个甘露聚糖酶基因。     

Evaluation of potato varieties and selections for resistance to bacterial soft rot

Potato varieties and selections were evaluated for resistance to bacterial soft rot caused byErwinia carotovora subsp. carotovora and Erwinia carotovora subsp. atroseptica in mist chamber. A randomized complete block design with a single treatment and 3 replications was used in this study. Potato lines were inoculated with bacterial suspension (10 tubers / line) using the puncture inoculation method and incubated for 4 days in a mist chamber at 21 C and 100 % relative humidity in the dark. Although there were differences in incidence of soft rot and in amount of weight reduction, most of the potato lines were susceptible to tuber soft rot. Mean incidence (%) of soft rot ranged from 10 to 100%. Mean reduction of tuber weight (%) ranged from 0.13 to 16.43 %. Among the varieties and selections tested, AF 522-5 was the most resistant to tuber weight loss, while AF 1424-7 was most susceptible. There were also significant differences between years, and a variety by year interaction. Testing over a period of years is recommended. A significant correlation coefficient of soft rot incidence (%) and reduction of tuber weight (%) was obtained (r=0.65; P=0.05), indicating that incidence was a fair measure of soft rot potential. However, the greater variability in results for incidence make weight loss a better measure of soft rot reaction. There was a significant difference among varieties in the reduction of tuber weight when potato lines were inoculated either 1 month or 2 months after harvest, but the interaction of time by year prohibits a conclusion as to which time gives a better test reaction. Late maturing varieties had slightly less weight loss than earlier maturing varieties.     

实时定量荧光PCR法检测马铃薯黑胫病菌

马铃薯黑胫病是国内外马铃薯产区发生比较普遍的一种细菌性病害,严重地影响了马铃薯的产量和质量。本研究根据Potato Black Leg序列,设计出马铃薯黑胫病菌特异性的引物,对10种供试菌株进行了实时荧光PCR检测。结果表明,该方法的特异性好,可以将马铃薯黑胫病菌和其它马铃薯常见病害相区分;灵敏度较高,可检测出最低的黑胫病菌浓度为3.6~3.9 cfu.mL-1;而且检测时间仅用4 h,大大缩短了检测周期。该方法可有效地应用于马铃薯黑胫病菌的检测和监控。     

Screening tuber-bearingSolanum spp. for resistance to soft rot caused byErwinia carotovora ssp.atroseptica (van Hall) Dye

Summary Soft rot caused by Erwinia carotovora ssp. atroseptica is a major disease of stored potatoes. Since varietal resistance can contribute to control, the work reported was designed to find new sources of resistance among related tuber-bearing Solanum spp. True seeds were imported from two international collections and families were screened for resistance to tuber soft rot. Forty-eight resistant clones were found in 21 out of 100 accessions. These clones will be used in breeding programmes at the diploid or tetraploid level.     

利用体细胞杂交获取马铃薯软腐病的抗性

对马铃薯四倍体栽培种和二倍体野生种Solanumbrevidens的体细胞杂种通过叶片离体培养获得的四倍体植株,以及用四倍体栽培种进行回交获得的五倍体植株的块茎对软腐病的抗性进行了测定。结果表明,由体细胞杂种通过叶片组织离体培养再生植株中,有一个株系SC107对软腐病菌Erwiniacarotovora具有较强的抗性。在用不抗软腐病的马铃薯栽培种对体细胞杂种进行回交获得的杂种后代中,大部分株系对软腐病菌具有高水平的抗性,从而说明Solanumbrevidens对软腐病的抗性基因已转移到马铃薯栽培种。     

The role ofErwinia carotovora in the epidemiology of potato blackleg I. Relationship ofE. carotorora var.carotovora andE. carotovora var.atroseptica to potato blackleg in Colorado

Isolations from 315 blackleg infected potato stems collected over a two year period in Colorado, demonstrated that both varieties ofErwinia carotovora, E. carotovora var.carotovora andE. carotovora var.atroseptica, are involved in stem infections under field conditions.E. carotovora var.atroseptica was the predominant organism associated with stem infections in all areas sampled.E. carotovora var.carotovora was isolated, with few exceptions, only from plants collected from the warmer areas of the state. The epidemiological implications of the effect of soil temperature on the distribution of these two organisms are discussed.     

Transgenic potato plants expressing oxalate oxidase have increased resistance to oomycete and bacterial pathogens

Summary Potato (cv. Bintje) was transformed with a gene encoding an oxalate oxidase from wheat under the control of the CaMV35S promoter. Transgenic potato plants produced high constitutive levels of H₂O₂ as visualized by 4-chloro-l-naphtol staining. The resistance of these plants was tested againstPhytophthora infestans. An increased level of resistance to the disease was marked by a reduced number of lesions as well as by a decreased number of sporangia formed per lesion. In addition, oxalate oxidase overexpressing plants also exhibited improved resistance toStreptomyces reticuliscabiei, the causal agent of netted scab. Increased expression of oxalate oxidase had no effect on the interaction withErwinia carotovora. These experiments show that overexpression of oxalate oxidase represents a potentially interesting approach for protection of potato to pathogens.     

甜菜四种细菌性病害的鉴定

吉林省甜菜发现有四种细菌病害,其中两种为叶斑病、两种为根病。经对其症状观察和病原细菌的分离、致病性测定,细菌的形态、培养性状、生理生化等系统鉴定,确认两种叶部病害为甜菜细菌性斑点病Pseudomonassyringae pv.apiata(Brown and Jamieson)Young et al和甜菜细菌性叶斑病Curtobacterium flaccumfaciens pv.betae(Keyworth Howell andBowson)Collins and Jones.两种根病为甜菜根癌病Agrobacterium tume-faciens(Smith and Townsend)Conn.和甜菜根软腐病Erwinia Caroto-vora subsp.Carotovora(Jones)Bergey et al.