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具防病并提高植物耐旱功能的小链霉菌HS57的筛选 总被引：1，自引：0，他引：1
本研究旨在寻找防治黄瓜枯萎病并提高植物抗逆能力的多功能菌株。从连作田健康黄瓜根际土中分离筛选到1株放线菌HS57。平板对峙法测定菌株HS57对尖孢镰刀菌、茄病镰刀菌和立枯丝核菌的抑制作用,平皿对扣共培养法测定其挥发性物质对尖孢镰刀菌的抑制作用,温室盆栽法测定其对黄瓜枯萎病的防病效果及对小麦耐旱能力的影响,结合菌株形态特征和16S rRNA基因序列分析对其进行鉴定。结果表明,菌株HS57可抑制3种病原菌生长,其中对尖孢镰刀菌的抑制率为52.4%;其挥发性物质对尖孢镰刀菌的抑制率为32.1%。浓度为10^7个/mL的HS57孢子悬浮液浸种对黄瓜枯萎病的防效最好,为51.0%;小麦种子经浓度为10^7、10^8个/mL的HS57孢子悬浮液浸种,麦苗经连续7 d缺水处理后再浇水,比对照恢复得更好。初步鉴定HS57菌株为小链霉菌Streptomyces parvus,是一株非常有潜力的多功能菌株。 相似文献
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合欢枯萎病是导致多年生合欢衰弱和死亡的主要因素之一,目前尚无有效的防治手段。本研究通过平板对峙法和含毒培养基法分离筛选健康合欢植株根际土壤中的潜在拮抗菌,结合形态学特征和双基因系统发育分析对拮抗菌进行鉴定,并通过盆栽试验验证拮抗菌株对合欢枯萎病的防治效果。结果表明,经过初筛得到11株对合欢枯萎病具有潜在拮抗作用的菌株,其中菌株5-2的抑制作用最为显著。对峙培养6d,菌株5-2对尖孢镰刀菌Fusariumoxysporum和腐皮镰刀菌Fusariumsolani的抑制率分别为76.88%和84.08%,两种病原菌在含6.67%拮抗菌孢悬液(孢子浓度1.0×107个/mL)的平板上生长均受到显著抑制。显微观察发现菌株5-2可缠绕病原菌菌丝体并寄生生长,盆栽试验表明菌株5-2对尖孢镰刀菌和腐皮镰刀菌具有优良的拮抗作用,防治效果达78.26%和57.89%。通过形态学和ITS-TEF1双基因系统发育分析,菌株5-2鉴定为康宁木霉Trichodermakoningii。综上所述,菌株5-2对合欢枯萎病具有良好的防治效果,可作为合欢枯萎病生防菌剂的候选菌株资源。 相似文献
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太阳能消毒技术在世界范围内广泛使用, 由于其经常受到气候差异的影响导致效果不稳定, 通常与其他措施结合以加强防治效果。种植前采用土壤熏蒸是土传病害的有效预防策略, 本研究通过监测土壤温度、理化性质、土传病原菌、草莓植株长势、产量和分析经济效益, 评价了不同浓度的土壤熏蒸剂棉隆和太阳能消毒联合处理对草莓土传病害的防治效果及经济效益分析。种植前棉隆熏蒸和太阳能消毒处理不仅能很好地控制土传病害, 其对镰刀菌属、疫霉属的抑制率分别为64.41%~84.75%、51.59%~86.94%, 而且显著提高了草莓的产量, 增产率为79.9%~99.4%;联合处理的成本较单独太阳能消毒处理仅增加约3.29%~13.17%, 但净收入增长率高达49.77%~66.28%。因此, 在草莓土传病害管理中, 土壤熏蒸与太阳能消毒处理相结合, 可以降低作物感染土传病害的风险, 保证作物稳定高产。 相似文献
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为研究植物根际细菌HQ1-2在黄瓜根际定殖能力及对根际土壤微生态和枯萎病的影响,本研究采用稀释涂布平板法测定HQ1-2在黄瓜根际定殖密度,采用对峙试验和孢子萌发试验测定其对尖孢镰刀菌的抑制活性,通过盆栽试验评价其对黄瓜枯萎病的防治效果和对黄瓜根际土壤微生态的影响,并对其进行鉴定。结果表明,HQ1-2在黄瓜根系和根际土壤具有稳定的定殖能力,处理12 d时在黄瓜根系和根际土壤分别能保持104和106 cfu/g的定殖密度;HQ1-2处理显著增加黄瓜根际土壤细菌和放线菌数量,减少真菌数量,提高根际土壤脲酶、磷酸酶、蔗糖酶和过氧化氢酶的活性,增加根际土壤速效氮、磷、钾的含量。在室内试验,HQ1-2对尖孢镰刀菌的菌丝生长、分生孢子形成和孢子萌发均具有显著的抑制作用,在盆栽试验,HQ1-2显著防治黄瓜枯萎病,其防效达到84.62%。另外,根据形态特征、生理生化特性和16S rRNA序列同源性分析,将HQ1-2菌株鉴定为多粘类芽胞杆菌Paenibacillus polymyxa。 相似文献
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为探究大蓟总黄酮对尖孢镰刀菌甜瓜专化型Fusarium oxysporum f. sp. melonis的抑制效果,采用微波超声法提取大蓟种子中的总黄酮,并测定其对其尖孢镰刀菌甜瓜专化型生长、生理指标的影响及其田间防治效果。结果显示,大蓟总黄酮浓度为10 mg/mL时,对尖孢镰刀菌甜瓜专化型的菌丝生长抑制率和孢子萌发抑制率达到100.0%,菌丝畸变、断裂;尖孢镰刀菌甜瓜专化型OD650 nm和pH最小,分别为0.3和5.5;其电导率是对照组1.2倍。不同浓度大蓟总黄酮处理下尖孢镰刀菌甜瓜专化型呼吸强度、超氧化物歧化酶(superoxide dismutase,SOD)和过氧化氢酶(catalase,CAT)活性均呈现先上升后下降的趋势,羧甲基纤维素酶和β-葡萄糖苷酶活性降低,浓度为10 mg/mL大蓟总黄酮处理尖孢镰刀菌甜瓜专化型60 h后,呼吸强度、SOD和CAT活性均降至最低,分别为7.8 mgCO2·cm-2·h-1、22.9 U/mL和20.8 U/mL。田间防治结果表明,浓度为10 mg/mL大蓟总黄酮处理下,甜瓜枯萎株数最少,防治效果最佳,为93.5%。表明大蓟总黄酮能够有效地抑制尖孢镰刀菌甜瓜专化型生长,具有进一步发展为绿色新型植物源尖孢镰刀菌甜瓜专化型防治剂的能力。 相似文献
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棉隆与粉红螺旋聚孢霉67-1协同防治黄瓜枯萎病的研究 总被引：1，自引：0，他引：1
本文通过温室大棚试验,开展了设施栽培条件下土壤熏蒸剂棉隆与生防真菌粉红螺旋聚孢霉Clonostachys rosea 67-1协同防治黄瓜枯萎病Fusarium oxysporum f.sp.cucumerinu(FOC)的研究。结果表明,采用棉隆熏蒸土壤(1‰,W:W)结合生防菌剂拌土(106孢子/g土),可以有效降低土壤中枯萎病菌对直播黄瓜种子和幼苗的侵染,30 d黄瓜死苗率为0,而单一使用棉隆或菌株67-1菌剂,死苗率分别为13.3%和44.5%。田间大棚试验表明,采用25 g/m2剂量的棉隆熏蒸土壤,并在移苗时穴施107孢子/穴生防菌液,对黄瓜枯萎病防效达到98.5%,显著高于单独使用棉隆(88.8%)和菌株67-1菌剂(62.2%),黄瓜产量增加48.5%。布里斯模型分析表明,棉隆与菌株67-1菌剂结合使用具有增效作用。对土壤中微生物数量监测表明,二者联合处理可有效降低土壤中尖孢镰刀菌种群数量,提高生防菌在根际的定殖水平,并且有利于被病原菌污染土壤的生态修复。本研究为土传病害的有效防治和生防菌剂的高效利用提供了理论依据。 相似文献
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土壤强还原消毒过程中产生气体对土传病原菌的抑制作用 总被引：1，自引：0，他引：1
土壤强还原(reductive soil disinfestation,RSD)是一种高效、环保的土壤消毒方法,为明确RSD杀菌机理,采用气相色谱和荧光定量PCR等技术研究RSD过程中产生的气体对土传病原菌的杀菌作用。结果表明:RSD过程中土壤能够产生H_2S和NH_3;当在装有25 g病土的三角瓶中分别加入25 m L的H_2S和NH_3时,土壤中尖孢镰刀菌的数量均显著下降,其杀菌效果分别为90.3%和100.0%;当在病土中加入0.125%(w/w)氨水时,尖孢镰刀菌、茄劳尔氏菌、辣椒疫霉和立枯丝核菌的数量分别下降至对照土壤的1.0%、0.3%、0.1%和0.9%;此外,加入10μL氨水即可显著抑制尖孢镰刀菌菌丝生长和孢子萌发,抑制率分别为52.8%和100.0%。表明RSD过程中产生的H_2S和NH_3对RSD过程的杀菌效果起着一定的作用。 相似文献
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为明确棘孢木霉Trichoderma asperellum菌肥在防治黄瓜枯萎病的同时对连作黄瓜根际土壤微生物种群的影响,采用实时荧光定量PCR(real-time fluorescence quantitative PCR,RT-qPCR)和磷脂脂肪酸(phospholipid fatty acid,PLFA)分析方法分别测定了棘孢木霉菌肥对连作4年的黄瓜根际棘孢木霉菌和尖孢镰孢菌Fusarium oxysporum DNA拷贝数变化和黄瓜根际微生物种群的影响。结果表明:棘孢木霉菌肥对黄瓜幼苗期和速长期黄瓜枯萎病的防治效果分别为70.24%和76.81%,均与药剂对照的防效差异不显著。棘孢木霉菌的DNA拷贝数出现2个高峰期,即黄瓜苗期和盛果期,其DNA拷贝数分别为235 000.00 ng/μL和80 500.00 ng/μL。黄瓜速长期、盛果期、生长末期的尖孢镰孢菌DNA拷贝数分别为15.41、54.87和18.36 ng/μL,且显著低于同一时期药剂对照和清水对照。黄瓜幼苗期、速长期、开花期和盛果期根际土壤微生物丰度分别为2.24、1.98、2.52和2.12,均高于药剂对照。由此可见,棘孢木霉菌肥在防治黄瓜枯萎病的同时,还可以改善黄瓜连作土壤微生物种群结构。 相似文献
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H. A. Van Hoof H. Huttinga A. Knaap H. P. Maas Geesteranus W. H. M. Mosch D. G. J. De Raay-Wieringa 《European journal of plant pathology / European Foundation for Plant Pathology》1979,85(3):87-98
In 1975 many tumours were observed in plants ofBegonia Schwabenland grown in Aalsmeer. Submersion of the roots ofNicotiana megalosiphon seedlings in a homogenate of tumorous tissue, induced tumours after two weeks. Short periods of submergence yielded results similar to those obtained after longer periods. Tumour homogenates lost their infectivity after ten min at 50°C. Aphids transmitted the infectious agent.Treatment with propylene oxide did not inhibit infectivity completely. Filtration through a 450 nm filter removed the infectious agent.Tobacco tumor virus or a viroid could not be isolated. Cultures ofCorynebacterium fascians, isolated from tumours ofN. megalosiphon were highly infectious and induced tumours in healthyN. megalosiphon andBegonia. Tumorous tissue homogenates ofPelargonium zonale, Dahlia sp.,Gladiolus sp., andLilium sp. also caused tumours inN. megalosiphon, from whichC. fascians was isolated. It was not possible to produce tumours inN. megalosiphon with homogenates from roses with symptoms of bud proliferation.Samenvatting In 1975 werden vele tumoren waargenomen inBegonia Schwabenland op Aalsmeerse bedrijven (Fig. 1). De infectiositeit van tumorweefsel kon goed en snel worden vastgesteld door de wortels van zaailingen vanNicotiana megalosiphon in een homogenaat van tumorweefsel te dompelen. Tumoren ontstonden na twee weken, de eindbeoordeling geschiedde na een maand (Fig. 2). Ook verschillende andereNicotiana spp.,Melilotus officinalis (Fig. 3) enPisum odoratum (Fig. 4) werden aangetast.Bij de infectiositeitstoets gaven zeer korte dompeltijden even goede resultaten als langere (Tabel 1). Infectieus sap verloor zijn infectievermogen na 10 min verhitting bij 50°C. Bladluizen brachten de smetstof over. Propyleenoxide verminderde de infectiositeit wel, doch onderdrukte deze niet totaal. Bij filtratie door een 450 nm filter bleef het infectieuse agens op het filter achter. Het tumor-inducerende agens was ook aanwezig in die delen van planten met tumoren welke gezond leken en het ging voor een gering deel over met zaad (Tabel 2).Uit tumoren konden wij geen tabakstumorvirus of een viroïde isoleren. Culturen vanCorynebacterium fascians, geïsoleerd uit tumoren vanN. megalosiphon bleken zeer infectieus en veroorzaakten tumoren inN. megalosiphon enBegonia. Homogenaten van tumorweefsel vanPelargonium zonale, dahlia (Fig. 5), gladiool (Fig. 6) enLilium Mid Century Hybrid Enchantment (Fig. 7) veroorzaakten ook tumoren opN. megalosiphon, waaruitC. fascians werd geïsoleerd. Met sap van kroeskopzieke rozen konden wijN. megalosiphon niet besmetten. 相似文献
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Plant Viruses Transmitted by Whiteflies 总被引：18，自引：0，他引：18
David R. Jones 《European journal of plant pathology / European Foundation for Plant Pathology》2003,109(3):195-219
One-hundred and fourteen virus species are transmitted by whiteflies (family Aleyrodidae). Bemisia tabaci transmits 111 of these species while Trialeurodes vaporariorum and T. abutilonia transmit three species each. B. tabaci and T. vaporariorum are present in the European–Mediterranean region, though the former is restricted in its distribution. Of the whitefly-transmitted virus species, 90% belong to the Begomovirus genus, 6% to the Crinivirus genus and the remaining 4% are in the Closterovirus, Ipomovirus or Carlavirus genera. Other named, whitefly-transmitted viruses that have not yet been ranked as species are also documented. The names, abbreviations and synonyms of the whitefly-transmitted viruses are presented in tabulated form together with details of their whitefly vectors, natural hosts and distribution. Entries are also annotated with references. Whitefly-transmitted viruses affecting plants in the European–Mediterranean region have been highlighted in the text. 相似文献
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During a survey conducted from 1998 to 2002, Fusarium proliferatum was found associated with young and adult palms belonging to the genera Chamaerops, Phoenix, Trachycarpus and Washingtonia showing symptoms of wilt and dieback. The fertility and toxicological profile of 36 strains representing different locations and hosts were studied. All of them except two, which were infertile, belonged to mating population D. Both mating types (MATD-1 and MATD-2) were isolated from the same host species, showing a high potential of genetic recombination in the field. Additionally, eight strains were fertile once crossed as female. Toxin analysis showed differences in the ability of strains to produce fumonisin B1, moniliformin, beauvericin, fusaric acid and fusaproliferin. Only 17 of them produced all the toxins analyzed. Pathogenicity tests were conducted on Phoenix dactylifera and P. canariensis using nine F. proliferatum Spanish strains and two reference strains from Saudi Arabia. Eight months after inoculation all strains caused disease, with palms showing lesions on the bases of leaves and development of wilt symptoms similar to those originally observed in affected plants. This is the first report on the occurrence of F. proliferatum on P. dactylifera in Spain and also the first report of this pathogen on C. humilis, P. canariensis, P. reclinata, T. fortunei, W. filifera and W. robusta. 相似文献
14.
R. Rabbinge G. W. Ankersmit G. A. Pak 《European journal of plant pathology / European Foundation for Plant Pathology》1979,85(5):197-220
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. 相似文献
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Barley yellow dwarf disease is one of the most important problems confronting cereal production in Iran. Barley yellow dwarf virus-PAV (BYDV-PAV) and Cereal yellow dwarf virus-RPV (CYDV-RPV) are the predominant viruses associated with the disease. One isolate of BYDV-PAV from wheat (PAV-IR) and one
isolate of CYDV-RPV from barley (RPV-IR) were selected for molecular characterisations. A genome segment of each isolate was
amplified by PCR. The PAV-IR fragment (1264 nt) covered a region containing partial genes for coat protein (CP), read through
protein (RTP) and movement protein (MP). PAV-IR showed a high sequence identity to PAV isolates from USA, France and Japan
(96–97%). In a phylogenetic analysis it was placed into PAV group I together with PAV isolates from barley and oats. The fragment
of RPV-IR (719 nt) contained partial genes for CP, RTP and MP. The sequence information confirmed its identity as CYDV. However,
RPV-IR showed 90–91% identity with both RPV and Cereal yellow dwarf virus-RPS (CYDV-RPS). Phylogenetic analyses suggested that it was more closely related to RPS. These data comprise the first attempt
to characterise BYD-causing viruses in Iran and southwest Asia.
The nucleotide sequence data reported appear in the EMBL, GenBank and DDBJ Nucleotide Sequence Databases under the accession
numbers AY450425 and AY450454 相似文献
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M. Fortass S. Diallo 《European journal of plant pathology / European Foundation for Plant Pathology》1993,99(4):219-226
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. 相似文献
17.
H. Ishihara G. Ponciano J. E. Leach S. Tsuyumu 《Physiological and Molecular Plant Pathology》2003,63(6):329-338
The phytopathogens Xanthomonas oryzae pathovar (pv.) oryzae and Xanthomonas axonopodis pv. citri each contain several avrBs3/pthA family genes. Structural features of these genes important for avirulence and/or virulence functions include a central region of multiple direct repeats and three nuclear localization signals (NLSs) and an acidic activation domain (AAD) at the 3′ end. To identify other regions critical to function in the 3′ ends of these genes, we constructed several chimeras using apl1 and apl2 from X. axonopodis pv. citri and avrXa10 and avrXa7 from X. oryzae pv. oryzae and evaluated their functions by inoculation to citrus and rice. The apl1 and avrXa7 genes are major virulence determinants in citrus and rice, respectively, while the contributions of apl2 and avrXa10 to virulence are negligible or not measurable. Constructs that contained a 417 bp HincII-SphI fragment from the 3′ end of apl1 in combination with the repeats from avrXa7, avrXa10, and apl1 caused a canker phenotype on citrus. Interchange of the HincII-SphI fragment between avrXa7 and avrXa10 abolishes avrXa7 avirulence function and reduces its virulence but it does not affect avrXa10 avirulence function in rice. avrXa7 caused a hypersensitive response (HR) in citrus and replacement of it's 3′ end with that of apl1 resulted in loss of canker and induction of HR. Thus, the HincII-SphI fragment of the avrBs3/pthA gene family is important for avirulence and virulence functions in two different plant species, Oryza sativa and Citrus natsudaidai HAYATA. 相似文献
18.
Takeshi Toda Toshihiro Hayakawa Joseph Mwafaida Mghalu Shigeharu Yaguchi Mitsuro Hyakumachi 《Journal of General Plant Pathology》2007,73(6):379-387
Isolates of an unidentified Rhizoctonia sp. (UR isolates) were obtained from creeping bentgrass and Kentucky bluegrass with reddish brown sheath and foliar rots.
Because the UR isolates anastomosed with isolates of three varieties of Waitea circinata (var. oryzae, var. zeae, and var. circinata), colony morphology, hyphal growth rate at different temperatures, pathogenicity, sequence analysis of the internal transcribed
spacers (ITS) region of ribosomal RNA genes (rDNA) were compared. The colony color of mature UR isolates was distinct from
isolates of the other three varieties of W. circinata. In pathogenicity tests on creeping bentgrass, the severity of the disease caused by UR isolates was significantly higher
than that caused by the three varieties of W. circinata. Sequence similarities of the rDNA-ITS region between UR isolates and between isolates within each variety were high (97–100%),
but they were lower among isolates from UR and the varieties of W. circinata (88–94%). In a phylogenetic tree based on the rDNA-ITS sequences, UR isolates formed a cluster separate from each of the
clusters formed by the three varieties of W. circinata. These results indicate that the UR isolates clearly differ from the three varieties of W. circinata. We therefore propose that the UR isolates be classified as new Rhizoctonia sp. that are closely related to W.
circinata and that the disease on creeping bentgrass should be called Waitea reddish-brown patch disease (Sekikasshoku-hagusare-byo
in Japanese). 相似文献
19.
G. J. Bollen D. Volker A. P. Wijnen 《European journal of plant pathology / European Foundation for Plant Pathology》1989,95(Z1):19-30
Samples of heavily infested crop residues were incorporated in static compost heaps (2.5–4.6 m3) of the Indore type. Temperature increased to 50–70°C within 6 days depending on the type of crop residues used and the location within the heap. The heat phase (>40 °C) lasted 2–3 weeks and was followed by a c. 5-months maturation phase (<40 °c).=" among=" the=" 17=" pathogens=" tested,=">Olpidium brassicae and one of the four formae speciales ofFusarium oxysporum that were tested survived composting, but also their inoculum was greatly reduced.Survival during specific phases of composting was studied by incorporation and retrieval of samples at various stages of the process.F. oxysporum f. sp.melonis was completely inactivated andO. brassicae andPlasmodiophora brassicae were almost completely inactivated during the short heat phase. The three pathogens survived the long-lasting maturation phase without loss of viability. Heat evolved during composting was found to be the most important factor involved with sanitation of crop residues. The possible involvement of fungitoxic conversion products and microbial antagonism is discussed. 相似文献
20.
H. J. Miller J. D. Janse W. Kamerman P. J. Muller 《European journal of plant pathology / European Foundation for Plant Pathology》1980,86(2):55-68
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. 相似文献