平腹小蜂滞育诱导研究

平腹小蜂是果树蝽类害虫的优势天敌,对重要果树蝽类害虫具有较强的控制作用,商品化生产的平腹小蜂已广泛应用于多种果树蝽类害虫的生物防治。为精确控制平腹小蜂的羽化时间和提高防控效果,本文对室内不同温度条件下不同龄期平腹小蜂的滞育诱导进行了初步研究。结果表明：平腹小蜂的滞育虫态为预蛹,从卵期开始至预蛹前期,对其进行低温和短光照刺激均可以诱导其进入滞育。短光照（6L：18D）,17℃条件下,处于卵期、1~2龄期和2~3龄期的平腹小蜂发育至预蛹期,滞育率分别为76.37%、81.51%和60.28%,其中卵期开始诱导和1~2龄开始诱导的处理之间,滞育率无显著性差异,且卵期处理组和1~2龄处理组的滞育率显著高于2~3龄处理组的滞育率;短光照条件下,当温度降低到11℃和14℃,对1~2龄和2~3龄期的平腹小蜂诱导滞育,滞育率显著下降到20%以下。综合而言,短光照条件下,温度在诱导平腹小蜂进入滞育中起着至关重要的作用。不同龄期平腹小蜂在17 ℃持续处理后,预蛹的滞育率不同。在本研究中,17℃结合短光照,对卵期和1~2龄期的平腹小蜂进行诱导,可获得较高的滞育率。     

温度和光周期对小黑瓢虫滞育的调节作用

在实验室条件下研究了温度（11℃、16℃、21℃、26℃和31℃）和光周期（16L：8D、14L：10D、12L：12D、10L：14D和8L：16D）对小黑瓢虫Delphastus catalinae（Horn）滞育的影响。结果表明,温度、光周期及二者的相互作用均对小黑瓢虫滞育有显著影响。低温和短光照诱导成虫进入滞育。26℃和31℃时,测定的5个光周期均不能诱导滞育;而11℃、16℃和21℃时,滞育率随温度降低或光照时长缩短均呈升高的趋势。11℃和光周期8L：16D是诱导滞育的最适条件。11℃和光周期8L：16D诱导40 d,成虫进入稳定的滞育状态,滞育率高达95.44%。同时发现,滞育成虫产卵前期随温度降低或光照时长缩短而延长。11℃和光周期8L：16D有利于维持滞育,延长成虫产卵前期。21℃和光周期14L：10D加速滞育的解除,缩短成虫产卵前期。     

光照和温度对螟卵啮小蜂滞育的影响

本研究表明,螟卵啮小蜂幼虫期的滞育主要由光照时间的长短所决定。造成幼虫滞育的临界光照时间在12小时到12小时30分之间。短日照控制滞育的温度上限为24℃左右。螟卵啮小蜂对光照的敏感虫态为早期幼虫,在短光照持续作用下,发育到老熟幼虫即进入滞育。短光照持续作用能较长时间地控制螟卵啮小蜂幼虫期的滞育。滞育一个月的老熟幼虫转入25℃长光照下,其羽化率为95.16％;滞育两个月的,羽化率仍达64.29％。     

伪钝绥螨滞育的研究

伪钝绥螨[Amblyseius fallacis(Garman)]是一种短光照滞育型的植绥螨。在温度为15.5℃、光照为16L:8D和8L:16D条件下饲育,滞育率分别为83.3%和0。诱导滞育的敏感虫期是个体发育的初期。卵、幼螨、前若螨、后若螨和刚羽化的雌成螨置于滞育诱导条件下饲养,其雌成螨滞育率分别为83.3%、81.3%、75%、44.6%和0。由不同虫态诱致的滞育个体和进入滞育经历不同时间的滞育个体,其解除滞育的难易差异均不显著。     

母代光照经历对菜蛾盘绒茧蜂滞育发生的影响

室内研究了在同一温度(25℃)3、种不同光照条件(8L∶16D、12L∶12D、16L∶8D)下饲养的菜蛾盘绒茧蜂,其后代在4种不同温度(13、15、17、20℃)和2种光周期(8L∶16D、11L∶13D)下饲养的滞育率变化情况。结果表明:母代的光照经历、子代饲养温度和光照周期这3个滞育诱导因素都会显著地影响滞育率。母代的光周期经历与子代诱导滞育的温度或光周期之间、子代诱导滞育的温度与光周期之间均存在交互作用,但3个因素间的交互作用不显著。母代在长日照条件下饲养可以降低子代诱导滞育的临界温度。子代在较低温度下饲养,母代经历的光周期对子代滞育的发生影响不大,甚至没有影响;但当子代在相对较高温度下饲养,母代经历的光周期对子代滞育发生的影响十分明显。     

日本平腹小蜂滞育幼虫的重要生化物质变化

日本平腹小蜂是多种果树蝽类害虫的优势寄生蜂, 能以老熟幼虫滞育越冬。本研究分别测定了日本平腹小蜂非滞育老熟幼虫、滞育25、35、45、55 d老熟幼虫和滞育解除老熟幼虫体内的总蛋白、脂类、糖类及醇类等生化物质的含量, 以及海藻糖酶和抗氧化酶(超氧化物歧化酶、过氧化物酶、过氧化氢酶)等关键酶的活性变化, 比较了日本平腹小蜂滞育、非滞育和滞育解除老熟幼虫体内重要生化物质的差异。结果表明:滞育老熟幼虫显著积累脂类、甘油三酯、糖原等能源物质以及山梨醇等低温保护物质, 且滞育个体的抗氧化能力显著增强, 这些变化有助于提高其抗逆性, 满足滞育维持期及滞育解除后恢复发育的能量需求, 保证滞育个体的发育和存活。结果为解析日本平腹小蜂的滞育机制奠定了基础。     

茶足柄瘤蚜茧蜂的滞育诱导及其寄生苜蓿蚜僵蚜的低温贮藏

为明确茶足柄瘤蚜茧蜂Lysiphlebus testaceipes人工诱导滞育的最佳条件,于室内条件下测定不同温度和光周期处理对该蜂滞育诱导的影响,并通过测定不同温度条件下的滞育率来确定滞育僵蚜的最佳贮藏时间。结果显示：25℃下培养茶足柄瘤蚜茧蜂120 h达高龄幼虫时,对其进行滞育诱导,此时该蜂滞育率最高;表明高龄幼虫期是其感受滞育信号的敏感时期,蛹是该蜂的滞育虫态。在温度为8~16℃、光照时间为8~14 h的范围内,随着温度的降低和光照时间的缩短,茶足柄瘤蚜茧蜂的滞育率呈增加趋势,其中在8℃、光周期8 L：16 D条件下其滞育率最高,为73.58%;当温度为16℃时,光照时间处于8~14 h范围内,该蜂不能进入滞育状态。在8℃下持续诱导30、40 d,茶足柄瘤蚜茧蜂的滞育率分别为72.38%和67.54%。在4℃下将滞育僵蚜贮藏90 d,与非滞育僵蚜相比,滞育僵蚜的羽化率和子代蜂的寄生率均无显著差异;冷藏120 d,滞育僵蚜的羽化率仍能达到69.64%。表明茶足柄瘤蚜茧蜂属低温短日照滞育型昆虫,最佳滞育诱导条件为25℃培育120 h后,转入8℃、8 L：16 D环境中连续诱导30 d;滞育僵蚜在4℃下可储存90~120 d。     

温度及光周期对日本食蚧蚜小蜂发育与繁殖的影响

为明确温度、光周期对日本食蚧蚜小蜂Coccophagus japonicus Compere发育与繁殖的影响,在不同温度、光周期条件下观察日本食蚧蚜小蜂的发育历期、出蜂数、雌蜂寿命以及寄生率。结果表明：温度和光周期显著影响日本食蚧蚜小蜂种群增长。在18~30℃之间,日本食蚧蚜小蜂的发育历期及雌蜂寿命均随温度的升高而缩短,18℃时发育历期与雌蜂寿命最长,分别为60.9 d和29.9 d,30℃时发育历期最短,为21.3 d,33℃时雌蜂寿命最短,为8.3 d;18~24℃之间,寄生率及出蜂数随温度的升高而增加,24℃时最高,分别为77.1%和38.7头;24~30℃之间,随温度升高日本食蚜小蜂的寄生率及出蜂数呈下降趋势。在光周期L 8 h∶D 16 h~L 16 h∶D 8 h范围内,当光周期为L 12 h∶D 12 h时,日本食蚧蚜小蜂的发育历期最短,为22.1 d,出蜂数最高,为39.0头;当光周期为L 14 h∶D 10 h时,雌蜂寿命最长,为22.6 d,寄生率最高,为71.1%。表明温度24~27℃、光周期L 12 h∶D 12 h为日本食蚧蚜小蜂种群增长的最适温度和光周期条件。     

光周期和温度对苹果蠹蛾滞育诱导的影响

为探讨光周期和温度对苹果蠹蛾Cydia pomonella滞育诱导的影响,通过人工诱导的方法对其滞育的光周期、温度诱导条件及滞育的敏感光照虫期进行了研究。结果表明:20℃时,光照时间短于12 h,苹果蠹蛾的滞育率可达到100%;25℃时,光周期为L 8∶D 16时滞育率最高,为98.3%;30℃时,光照时间少于10 h,苹果蠹蛾的滞育率可达85%以上。在20、25和30℃条件下,幼虫滞育的临界日长分别为14.21、13.68和13.73 h。苹果蠹蛾对光照反应有2个最敏感时期,即幼虫初孵化阶段和预蛹期阶段,卵期对光照反应不敏感。表明苹果蠹蛾是一种典型的短日照滞育型种类,光周期、温度及其交互作用均对其滞育诱导具有重要影响,其中光周期占主导作用,温度随着光周期起作用,低温对滞育诱导有很好的促进作用。     

光周期对异色瓢虫生殖滞育的影响

为明确光周期对异色瓢虫Harmonia axyridis（Pallas）生殖滞育的影响,于20 ℃条件下测定了13个光周期组合对异色瓢虫滞育率的影响和不同虫态对滞育诱导光周期的敏感性。结果表明：20 ℃条件下,异色瓢虫的滞育临界光周期为6.4 L：17.6 D和11.9 L：8.1 D,光周期10 L：14 D下异色瓢虫滞育率最高为94.2%。异色瓢虫的不同发育阶段对短光照10 L：14 D的敏感性测定表明,成虫阶段对光周期反应最敏感,且成虫羽化后1~4 d对短光照的敏感性较高。结果证实异色瓢虫属于典型的短日照滞育型,成虫羽化初期是感应光周期反应的敏感虫期。     

Differences in resistance in onion cultivars to pink root rot disease in Iran

Forty-five onion (Allium cepa) cultivars were evaluated for disease resistance to the fungal pathogen Pyrenochaeta terrestris (pink root disease). Forty-three Iranian cultivars and two commercially exotic resistant cultivars (Texas Early Grano and Yellow Sweet Spanish) were grown in a glasshouse for two successive years (2003 and 2004) in Isfahan, Iran. Susceptibility of the cultivars was determined using a scale of 0–3. Six cultivars had significantly lower susceptibility of pink root compared to the exotic ones. High susceptibility tended to be associated with high mean scores (2–3), and the highly resistant cultivars had the lowest scores (0–1). In addition, the 45 examined cultivars were ranked from 1 to 45 according to their markedly differing reactions to P. terrestris, which differed markedly. Of 32 cultivars that were less resistant, 30 with an intermediate status or tolerance (1–2) differed considerably in their rank order. No pink root symptoms were seen in the early stages, but on blotter paper or wheat-straw agar some roots turned pink with no pycnidia formation, whereas on potato dextrose agar medium (PDA) with a few fresh healthy and sterile onion roots on the surface, mycelia and pycnidia were recovered. Variance and cluster analysis showed similar results among the cultivars with various levels of resistance, tolerance and susceptibility as determined by scoring scales.     

Pathogenic fungi involved in root rot of peas in the Netherlands and their physiological specialization

Research on root rot pathogens of peas in the Netherlands has confirmed the prevalence ofFusarium solani, F. oxysporum, Pythium spp.,Mycosphaerella pinodes andPhoma medicaginis var.pinodella. Aphanomyces euteiches andThielaviopsis basicola were identified for the first time as pea pathogens in the Netherlands. Other pathogens such asRhizoctonia solani andCylindrocarpon destructans were also found on diseased parts of roots. F. solani existed in different degrees of pathogenicity, and was sometimes highly specific to pea, dwarf bean of field bean, depending on the cropping history of the field.A. euteiches was specific to peas, whereasT. basicola showed some degree of physiological specialization.     

Broad bean mottle virus in Morocco; curculionid vectors,and natural occurrence in food legumes other than faba bean (Vicia faba)

Broad bean mottle virus (BBMV) was transmitted from infected to healthy faba-bean plants by the curculionid weevilsApion radiolus Kirby,Hypera variabilis Herbst,Pachytychius strumarius Gyll,Smicronyx cyaneus Gyll, andSitona lineatus L. The latter appeared to be an efficient vector: acquisition and inoculation occurred at the first bite, the rate of transmission was c. 41%, and virus retention lasted for at least seven days.S. lineatus transmitted the virus from faba bean to lentil and pea, but not to the three genotypes of chickpea tested. This is the first report on the generaHypera, Pachytychius, andSmicronyx as virus vectors, and onA. radiolus, H. variabilis, P. strumarius, andS. cyaneus as vectors of BBMV.Out of 351 samples of food legumes with symptoms suggestive of virus infection, 16, 11, 19, and 17% of the samples of chickpea, lentil, pea, and common bean, respectively, were found infected when tested for BBMV in DAS-ELISA. This is the first report on the natural occurrence of BBMV in chickpea, lentil, pea, and common bean. The virus should be regarded as a food-legume virus rather than a faba-bean virus solely, and is considered an actual threat to food legume improvement programmes.     

Epidemiology and simulation of population development of Sitobion avenae in winter wheat

The epidemiology ofSitobion avenae and its natural enemies in winter wheat was studied in 1975, 1976 and 1977. Immigration was important until the end of flowering. The alate immigrants had apterous offspring. These became the driving force in population growth. Their offspring were mostly alatae which usually left the field. A model of the epidemic was developed. Quantitative relations between the aphids and their environment were obtained from literature or established in laboratory trials. The model simulated population development and population composition from the beginning of June till the population peak at the end of June or early in July. Because quantitative data on relations between aphids and their natural enemies and pathogens are scarce, and since the knowledge on wing formation is still limited, the population collapse could not be predicted. In the future, prognosis over a period of three weeks seems possible.Samenvatting De toenemende betekenis van graanbladluizen (vooralSitobion avenae) gepaard gaande met een sterke toename van het gebruik van insecticiden op granen maakte verbetering van de prognose over het schadelijk optreden wenselijk. Door gedetailleerde tellingen in het veld (Fig. 1–7) werden gegevens verkregen over het verloop van de epidemie en het optreden van natuurlijke vijanden in 1975, 1976 en 1977.Een immigratieperiode tot in de bloei kon worden vastgesteld. Daarna lijkt de aantrekkelijkheid van het gewas voor alate luizen te verminderen. De alate immigranten krijgen aptere nakomelingen. Deze vormen de stuwende kracht van de populatiegroei. De nakomelingen van apteren zijn merendeels alaat. Zij verlaten het gewas.Een model van de populatieontwikkeling gedurende de epidemie werd opgesteld. De relatiediagrammen Fig. 9 en 10 laten groei en ontwikkeling vanS. avenae en een predator (Syrphus corollae) zien. Kwantificering van de betrekkingen werd mogelijk door literatuurgegevens en laboratoriumexperimenten.Met het model kon de populatieontwikkeling vanS. avenae vanaf begin juni tot aan de populatiepiek in 1975, 1976 en 1977 vrij goed worden gesimuleerd (Fig. 12). Ook de populatieopbouw kon worden gesimuleerd (Fig. 14). De teruggang van de populatiedichtheid blijkt moeilijker te voorspellen door het ontbreken van gegevens over natuurlijke vijanden.Het lijkt waarschijnlijk dat in de toekomst met het model een prognose over de piek van de bladluispopulatie circa 3 weken tevoren mogelijk zal zijn.     

Recent observations on leafy gall in Liliaceae and some other families

Corynebacterium fascians, which causes leafy gall, has been shown to be responsible for the unusual symptoms recently found in lilies. The symptoms are described and the different bacterial isolates compared by biochemical, serological and pathogenicity experiments. No evidence could be found for the existence of specialized strains even though considerable variation in virulence could be demonstrated. Although the role of variation in susceptibility of the different lily cultivars should not be underestimated, it would appear that high inoculum levels ofC. fascians in the soil may be largely responsible for these outbreaks.Also included in this study are the results of biochemical, serological and pathogenicity experiments ofC. fascians which has been isolated fromKalanchoe, Euphorbia, Brodiaea, Hebe andVerbascum.Samenvatting Reeds een aantal jaren was in lelies een woekering in stengelbollen bekend, die echter sporadisch voorkwam en economisch van weinig betekenis was. Tijdens de zomer van 1977 echter trad de ziekte op één enkel perceel zo ernstig op dat zeer aanzienlijke oogstderving het gevolg was. Behalve de stengelbol kan ook de hoofdbol misvormd zijn. Bovendien kunnen misvormde stengelbollen lange spruiten vormen, zgn. sabeltandvorming. Soms is het wortelstelsel gereduceerd; in de kas zijn verdikte stengels waargenomen. De ziekte staat nu bekend onder de naam woekerziekte.Door de PD te Wageningen en het LBO te Lisse werd de bacterieCorynebacterium fascians (Tilford) Dows. uit het zieke materiaal geïsoleerd. In gezamenlijk onderzoek werd nagegaan of de bacterie de veroorzaker is van bovengenoemde symptomen en of hier sprake is van een op lelie gespecialiseerde stam.Biochemische en serologische vergelijkingen tussen isolaten vanC. fascians uit lelie,Kalanchoe, Euphorbia, Brodiaeea, Hebe enVerbascum laten zien dat er zeer weinig verschillen bestaan. Alle isolaten reageren op een standaard antiserum met titers variërend tussen 1: 640–1: 5120.Een oriënterende inoculatieproef werd uitgevoerd op het LBO in 1977. Daarna werden op de PD 10 van de 25 isolaten uit lelie en 8 uit andere waardplanten getoetst op lelie, chrysant en lathyrus. Uit de inoculatieproeven blijkt, dat de bacterie de veroorzaker is van de waargenomen symptomen. Tussen de isolaten blijkt een groot verschil in pathogeniteit te bestaan (12–100% aantasting), zonder dat dit aan herkomst gebonden is. Het voorkomen van op lelie of andere waardplanten gespecialiseerde stammen is daarom niet aan te nemen.In hoeverre de hevige aantasting een gevolg is van een opbouw van de bacterie-populatie door een te nauwe vruchtwisseling en mechanische rooimethoden moet worden nagegaan.     

Damage effects of cereal aphids in wheat

Laboratory and field studies on aphid damage in wheat are described. Both direct and indirect effects of aphids on the behaviour of the crop were studied. In the laboratory a clear effect of honeydew and yeasts on photosynthesis was found. This effect could not be demonstrated under field conditions, since even at yield loss levels of 700 kg ha^–1 the size of this effect may be undetectable with crop enclosures reaching an accuracy of 10%. The effect of honeydew on ageing, measured in the laboratory trials was also found in the field and may form a major cause of the yield losses found in the field. Yield losses under field conditions reached 700 kg ha^–1 and were for 72% due to direct sucking damage of the 35 aphids, found maximally per culm, and direct and indirect honeydew effects. Saprophytic and possibly also some necrotrophic fungi caused 28% of the yield losses. The exact contribution of each of the damage factors was not revealed but it was demonstrated that direct and indirect effects contribute to the final yield losses.Samenvatting Laboratorium- en veldproeven over de schade door bladluizen in tarwe worden beschreven. Een analyse van de directe en indirecte effecten van bladluizen op de groei van het gewas werd verricht. In het laboratorium werd een duidelijk effect van honingdauw en gisten op de fotosynthese gevonden. Dit effect kon niet worden gedemonstreerd in het veld, hetgeen waarschijnlijk wordt veroorzaakt door de orde van grootte van dit effect dat valt binnen de meetfout van de gewasfotosyntheseapparatuur.Het effect van honingdauw op veroudering, dat in het laboratorium werd vastgesteld, kon ook worden aangetoond in het veld en is waarschijnlijk een van de hoofdoorzaken van de oogstverliezen. Deze oogstverliezen in het veld bedroegen 700 kg ha^–1 bij een maximale dichtheid van 35 bladluizen per halm en werden voor 72% veroorzaakt door direct zuigsschade en honingdauweffecten. Van de totale schade werd 28% veroorzaakt door saprofytische en wellicht ook door enige necrotrofe schimmels. De precieze bijdrage van ieder van de schadefactoren tot de schade werd niet vastgesteld, maar de wijze waarop directe en indirecte effecten hun bijdrage leverden aan de uiteindelijke oogstverliezen werd zichtbaar gemaakt.     

Major gene resistance in Brassica napus (oilseed rape) is overcome by changes in virulence of populations of Leptosphaeria maculans in France and Australia

Resistance of Brassica napus (oilseed rape, canola) conferred by three different major resistance genes has been overcome by changes in virulence of Leptosphaeria maculans populations in France and Australia. In South Australia where B. napus cultivars with major gene resistance derived from Brassica rapa ssp. sylvestris were grown extensively, resistance was rendered ineffective within 3 years of commercial release of the cultivar. Disease severity was higher on cultivars with sylvestris-derived resistance than cultivars with polygenic resistance. This Australian situation is compared to that in France, where resistance conferred by the Rlm1 gene was overcome nation-wide in 5 years under commercial cropping practices, and also where a source of resistance introgressed into B. napus from B. juncea was rendered inefficient in 3 years in experimental field plots near Rennes.     

Identification and Characterisation of Bacteria Causing Soft-rot in Agave tequilana

Agave tequilana is the raw material for the production of the alcoholic beverage tequila. A bacterial disease has affected the A. tequilana crop in recent years. Previous reports based on colony and cell morphology, Gram stain and potato rot indicated that Erwinia sp. is the main pathogen. We isolated a several bacterial isolates capable of producing soft-rot symptoms in greenhouse pathogenicity assays. An extensive characterisation involving pathogenicity tests, fatty acid profile, metabolic and physiological properties, ribosomal DNA sequence and intergenic transcribed spacer amplification (ITS-PCR) and restriction banding pattern (ITS-RFLP) was made of each isolate. Three different species: Erwinia cacticida, Pantoea agglomerans and Pseudomonas sp. were identified. Fatty acid and metabolic profiles gave low similarity values of identification but 16S rDNA sequence, ITS-PCR and ITS-RFLP confirmed the identification of E. cacticida. In the phylogenetic tree, E. cacticida from blue agave was grouped neither with E. cacticida type strains nor with Erwinia carotovora. This is the first report that associates E. cacticida with A. tequilana soft-rot symptoms.     

Benomyl-resistant Fusarium-isolates in ecological studies on the biological control of fusarium wilt in carnation

Ecological properties and stability of benomyl resistance of three benomyl-resistant mutants of nonpathogenicFusarium-isolates antagonistic to fusarium wilt in carnation, and three benomyl-resistant mutants of a pathogenic isolate ofFusarium oxysporum f.sp.dianthi were evaluatedin vitro and in glasshouse experiments. The benomyl resistance of the nonpathogenic mutants was stable under all conditions tested, also after a 1000-fold increase of the population in sterilized soil. Mutants of the pathogen were stable during allin vitro tests, but after proliferation in carnation stems only part of the population was benomyl resistant.Compared to the wild type, mutants of the pathogen were less pathogenic, also if thein vitro propeties were similar. Colonization of carnation by benomyl-resistant nonpathogenicFusarium in the presence of the pathogen showed that the antagonistic effect correlated with the presence of the nonpathogenic isolates within the carnation stem. The wild types and two of the mutant nonpathogenicFusarium-isolates controlled fusarium wilt in the susceptible cultivar Lena for 50% or more.UV-induced benomyl resistance appeared to be a valuable marker to distinguish between differentFusarium isolates and to study the population dynamics, but intensive screening of the mutants is a prerequisite since alterations in antagonism and pathogenicity can occur.     

Detection of the phytotoxin coronatine by ELISA and localization in infected plant tissue

Several pathovars of Pseudomonas syringae produce the phytotoxin coronatine (COR)in vitro, and the availability of purified toxin has facilitated development of immunological detection methods. A modified, indirect competitive ELISA using the COR-specific monoclonal antibody 11B8 was developed to detect COR in various host plants infected by P. syringae. The estimated detection limit for COR was 50 pg per well, and COR could be reliably quantified from 5 to 40 ng ml⁻¹. The subcellular localization of COR within infected tomato tissue was investigated using the COR-specific antibody MAb 8H3G2. Immunofluorescence microscopy and immunogold labelling showed that COR was present inside tomato cells and was associated with chloroplasts and particles of proteinase inhibitor I. Localization studies indicated that COR is mobile in infected plant tissue and can be detected in healthy tissue adjacent to the bacterial lesions.