Erwinia amylovora – prouzrokovač nekroze korenovog vrata stabla jabuke

A large-scale outbreak of fire blight symptoms caused by Erwinia amylovora was recorded in pome fruit trees during 2007. In addition to fruit necrosis and shoot blight as the typical disease symptoms, dark purple necrosis was observed in the root collar area girdling the trunk just above the ground and thus withering the whole apple tree. Since similar symptoms on apple trees could be caused by E. amylovora or one of several phytopathogenic fungi of the genera Phomopsis and Phytophthora, an investigation was conducted to identify the causal agent of this disease. Levan-producing, nonfluorescent bacteria were isolated from diseased samples. The isolated strains produced HR in tobacco leaves and necrosis of artificially inoculated, immature pear fruits, followed by oozing of bacterial exudate, a characterisitic of E. amylovora. Based on the results of pathogenicity tests, biochemical characteristics, ELISA test and PCR analysis, it was confirmed that the investigated strains belonged to E. amylovora, causing the root collar necrosis of apple trees as an atypical symptom of this bacterium in Serbia. The explanation of this symptom may be that the vegetative rootstocks were infected with E. amylovora. Therefore, the development of diagnostic protocols for detection of E. amylovora in apple rootstock is very important for health inspections of planting materials.Tokom 2007. godine zabeležena je masovna pojava bakteriozne plamenjače jabučastih voćaka prouzrokovana bakterijom Erwinia amylovora. Pored nekroze plodova i plamenjače mladara, tipičnih simptoma bolesti, našu pažnju je privukla pojava nekroze mrkoljubičaste boje u zoni korenovog vrata, koja prstenasto zahvata prizemni deo i prouzrokuje izumiranje stabala jabuke. S obzirom na to da uzrok ovakvih patoloških promena može da bude E. amylovora, ali i fitopatogene gljive iz rodova Phomopsis i Phytophthora, preduzeta su istraživanja sa ciljem da se utvrdi etiologija ovog oboljenja jabuke. Iz obolelih uzoraka izolovane su bakterije koje stvaraju levan, ali ne i fluorescentni pigment. Proučavani sojevi prouzrokovali su HR na listovima duvana i nekrozu inokulisanih, nesazrelih plodova kruške, uz obilno stvaranje bakterijskog eksudata, što je karakterističan znak E. amylovora. Na osnovu rezultata dobijenih pri testovima provere patogenosti, ali i rezultata biohemijskih odlika, ELISA testa i molekularnih metoda (PCR), potvrđeno je da proučavani izolati pripadaju bakteriji E. amylovora, koja je uzročnik simptoma nekroze korenovog vrata stabala jabuke, prvi put zabeleženih u Srbiji. Moguće objašnjenje ove pojave je da su vegetativne podloge za kalemljenje bile inficirane ovom bakterijom. Zbog toga je veoma bitno razvijati dijagnostičke protokole za utvrđivanje prisustva E. amylovora u podlogama za kalemljenje jabuke, tokom procesa kontrole zdravstvene ispravnosti sadnog materijala

Efikasnost bakarnih preparata u suzbijanju Xanthomonas campestris pv. vesicatoria, prouzrokovača bakteriozne pegavosti lišća paprika

The efficacy of several new formulations of copper compounds in controlling Xanthomonas campestris pv. vesicatoria in pepper was estimated in field conditions using artificial inoculation. The efficacies of Cuprozin 35 WP (copper-oxychloride) and Blauvit (copper-hydroxide) were tested in the localities Dobanovci and Kupinovo in 2005. Another two formulations, Cuproxat (copper-sulfate) and Fungohem SC (copper-hydroxide), were tested along with the previous two in the localities Zemun and Smederevska Palanka in 2006. Both bactericides tested in 2005 exhibited high efficacy in controlling X. c. pv. vesicatoria in both localities. However, there were no significant differences in the efficacy of Cuprozin 35 WP at higher concentration (74.3%-78.7%) and Blauvit (74.6%-78.9%) in the two trials. Cuprozin 35 WP decreased efficacy, but a satisfactory effectiveness was still achieved at lower concentration (66.5%-66.5%). In the experiments conducted in 2006, higher concentration of Fungohem SC showed the highest efficacy (86.1%-89.1%) in controlling bacterial spot of pepper. Blauvit, Cuprozin 35 WP and Cuproxat also exhibited high efficacy. However, there were no significant differences in the efficacy of these bactericides between the two localities. Fungohem SC applied at lower concentration was less effective (77.2%-80.0%) but its efficacy was still good enough. Our experiments showed that copper bactericides based on copper-sulfate, copper-oxychloride and copper-hydroxide exhibited satisfactory efficacy in controlling the causal agent of bacterial spot of pepper in our climatic conditions.Ispitivana je efikasnost novijih formulacija bakarnih preparata u suzbijanju Xanthomonas campestris pv. vesicatoria na paprici u uslovima veštačke inokulacije u polju. U 2005-oj godini, na lokalitetima Dobanovci i Kupinovo, ispitivana je efikasnost preparata Cuprozin 35 WP (bakar- oksihlorid) i Blauvit (bakar- hidroksid). Tokom 2006. godine osim ovih preparata primenjeni su i Cuproxat (bakar-sulfat trobazni) i Fungohem SC (bakar-hidroksid), na lokalitetima Zemun i Smederevska Palanka. Preparati ispitivani u 2005-oj godini ispoljili su zadovoljavajuć u efikasnost u suzbijanju X. c. pv. vesicatoria na oba lokaliteta. Između efikasnosti preparata Cuprozin 35 WP pri višoj koncentraciji primene (74,3%-78,7%) i preparata Blauvit (74,6%-78,9%) nije zabeležena statistički značajna razlika u oba ogleda. Nešto nižu, ali zadovoljavajuć u efikasnost ispoljio je Cuprozin 35 WP pri nižoj koncentraciji primene (66,5%-66,5%). U ogledima izvedenim tokom 2006. godine, najveću efikasnost u suzbijanju prouzrokovača bakteriozne pegavosti paprike ispoljio je preparat Fungohem SC (86,1%-89,1%) pri višoj koncentraciji primene. Preparati Blauvit, Cuprozin 35 WP i Cuproxat pokazali su takođe visoku efikasnost tako da statistički značajne razlike nisu zabeležene između tretmana ovim preparatima na oba lokaliteta. Nešto nižu, mada zadovoljavajuću efikasnost imao je preparat Fungohem SC primenjen u nižoj koncentraciji (77,2%-80,0%). Naši ogledi pokazali su da preparati na bazi bakarsulfata trobaznog, bakar- oksihlorida i bakar- hidroksida u našim klimatskim uslovima ispoljavaju zadovoljavajuć­u efikasnost u suzbijanju prouzrokovača bakteriozne pegavosti paprike

Mogućnost zaštite pasulja od Xanthomonas campestris pv. phaseoli primenom bakarnih preparata i aktivatora otpornosti

The efficacy of several new formulations of copper compounds, namely Cuprozin 35 WP (copper-oxychloride), Cuproxat (copper-sulphate), Funguran OH (copper-hydroxide) and the plant activator Bion (acibenzolar-S-methyl), and their combinations with dithiocarbamates (Dithane M-70) was estimated in controlling Xanthomonas campestris pv. phaseoli (artificial inoculation) in field conditions in two localities during 2006. In the locality Zemun, the efficacy of copper compounds ranged from 92.7% to 98.5%. The plant activator Bion 50 WG exhibited similar efficacy (94.4-97.1%). Combinations of Funguran OH and Dithane M-70, applied at different concentrations, also showed high efficacy (98.3-99.3%), as well as the combinations of Bion 50 WG and the other bactericides (95.5-96.8%). There was no significant difference between the efficacies achieved by the compounds applied individually and their combinations, except Cuproxat, which exhibited decreased efficacy at lower concentration. In the locality Smederevska Palanka, the efficacy of copper compounds was 95.0-98.2%, while Bion achieved 96.8-97.7% efficacy. Combinations of copper-hydroxide (Funguran OH) and dithiocarbamates (Dithane M-70) also showed high efficacy (98.1- 99.4%) but without a significant difference. The efficacy of combinations of Bion and copper- hydroxide, and Bion and mancozeb was 97.9-98.9%. There was no significant difference in the efficacies of the bactericides tested or the efficacies of their combinations in that locality. Our investigation confirmed high efficacy of acibenzolar-S-methyl, which was equal to the efficacy of standard bactericide treatment. This compound therefore offers a very good alternative to conventional chemicals used for controlling bacterial diseases in beans.U radu je ispitivana efikasnost novijih formulacija bakarnih jedinjenja; Cuprozin 35 WP (bakar-oksihlorid), Cuproxat (bakar-sulfat), Funguran OH (bakar-hidroksid) i aktivatora otpornosti Bion-a (acibenzolar-S-metil), i njihovih kombinacija sa ditiokarbamatima (Dithane M-70), u suzbijanju Xanthomonas campestris pv. phaseoli (veštačka inokulacija). Ispitivanja su obavljena tokom 2006. godine u poljskim uslovima na dva lokaliteta. Na lokalitetu Zemun, efikasnost bakarnih preparata kretala se 92.7-98.5%. Sličnu efikasnost ispoljio je i activator otpornosti Bion 50 WG (94.4-97.1%). Zadovoljavajuću efikasnost (98.3-99.3%) imale su I kombinacije preparata Funguran OH i Dithane M-70 pri različitim koncentracijama primene, kao i kombinacije Bion-a sa drugim preparatima (95.5-96.8%). Statistički značajne razlike u efikasnosti primenjenih preparata i njihovih mešavina nisu zabeležene, izuzev kod preparata Cuproxat, koji je ispoljio slabiju efikasnost pri nižoj koncentraciji primene. Na lokalitetu Smederevska Palanka efikasnost bakarnih jedinjenja iznosila je 95.0-98.2%, a za Bion 96.8-97.7%. Kombinacije bakar-hidroksida (Funguran OH) i ditiokarbamata (Dithane M-70) ispoljile su nešto veću efikasnost (98.1-99.4%), ali razlike nisu bile statistički značajne. Efikasnost Bion-a u mešavini sa bakar-hidroksidom i mankozebom iznosila je 97.9-98.9%. Na ovom lokalitetu nisu konstatovane statistički značajne razlike između samostalno primenjenih preparata i njihovih kombinacija. U ovim ispitivanjima potvrđena je i visoka efikasnost acibenzolar-S-metil-a (preparat Bion), koja je bila na nivou efikasnosti standardnih baktericida. Zbog toga ovo jedinjenje predstavlja dobru alternativu konvencionalnom hemijskom suzbijanju bakterioza pasulja

Clavibacter michiganensis subsp. michiganensis, bakteriozni rak paradajza: 1. Konvencionalna i molekularna identifikacija

In May 2006, tomato leaves with watersoaked areas between leaf veins were detected in glasshouses in Padinska Skela. The early-stage symptoms were followed by rapid desiccation to white and pale brown necrosis and subsequently by wilting of entire tomato plants. In June 2006, symptoms of bacterial canker and wilt were also recorded in many greenhouses in the Jablanica County in southern Serbia. Samples of diseased tomato plants were collected from several tomato-growing regions in Serbia in order to identify the causal agent using conventional identification methods (isolation, pathogenicity and bacteriological determinative tests). Another objective of this study was to confirm the identity of isolated bacterial strains by polymerase chain reaction (PCR method). According to the morphological characteristics observed on NA and NBY media, biochemical characteristics, hypersensitive response in four-o’clock plant leaves and pathogenicity test on tomato seedlings, the investigated strains were identified as C. michiganensis subsp. michiganensis. To confirm the identity of isolated strains two PCR protocols were used. Amplification of expected length DNA fragments, 614 bp and 270 bp, respectively, confirmed that the investigated strains belonged to C. michiganensis subsp. michiganensis.Tokom maja 2006. godine zapažene su vlažne pege na lišću paradajza gajenom u staklenicima u Padinskoj Skeli. Ovi početni simptomi praćeni su brzim sušenjem lisnog tkiva, pojavom bele i svetlomrke nekroze i uvenućem celih biljaka. U junu 2006. godine, simptomi bakterioznog raka i uvenuća paradajza takođe su zapaženi i u mnogim plastenicima u Jablaničkom okrugu. Uzorci obolelih biljaka paradajza sakupljeni su sa nekoliko lokaliteta u Srbiji, u cilju identifikacije prouzrokovača bolesti korišćenjem konvencionalnih metoda za identifikaciju (izolacija, patogenost i bakteriološki testovi). Drugi cilj istraživanja bio je da potvrdimo identitet izolovanih sojeva bakterija primenom lančane reakcije polimeraze (PCR metod). Prema morfološkim karakteristikama na mesopeptonskoj (MPA) i NBY podlozi, biohemijsko-fiziološkim odlikama, hipersenzitivnoj reakciji na noćurku (Mirabilis jalapa) i patogenim odlikama na rasadu paradajza, izolovani sojevi su identifikovani kao C. michiganensis subsp. michiganensis. Identifikacija izolovanih sojeva bakterija potvrđena je korišćenjem dva PCR protokola. Amplifikovani su DNA fragmenti očekivane dužine, 614 bp i 270 bp, čime je po tvrđeno da testirani sojevi pripadaju bakteriji C. michiganen sis subsp. michiganensis

Prvi nalaz tumorogenih sojeva Agrobacterium radiobacter na malini u Srbiji

During the spring of 2003, gall symptoms on the roots and crowns of young raspberry plants cv. Vilamette were observed near Valjevo. Phytopathogenic bacteria were isolated from diseased plant samples. Based on the pathogenic, morphological, differential biochemical and physiological characteristics, the isolated strains were identified as tumorigenic Agrobacterium radiobacter (biovar 1 Agrobacterium). In order to confirm the identity of isolated strains by polymerase chain reaction (PCR) primers complementary to tms2 gene located on the Ti plasmid were used. In the first PCR protocol using a tms2F1 + tms2R2 primer pair, 617 bp products specific for tumorigenic Agrobacterium strains were amplified. The second PCR protocol, using a tms2F1 + tms2B primer pair, amplified the expected 458 bp products. On the basis of multiplex PCR with primers complementary to chromosomal gene coding for 23S rRNA, the isolated strains were classified as biovar 1 Agrobacterium (A. radiobacter). This is the first report of tumorigenic A. radiobacter on raspberry in Serbia.Tokom proleća 2003. godine, zapaženi su tumori na korenu i korenovom vratu mladih biljaka maline sorte Vilamette u okolini Valjeva. Iz obolelih uzoraka izolovane su fitopatogene bakterije. Proučavanjem patogenih, morfoloških i diferencijalnih biohemijsko-fizioloških karakteristika izolovanih sojeva, utvrđeno je da proučavani sojevi pripadaju bakteriji Agrobacterium radiobacter (biovar 1). U cilju potvrde identiteta izolovanih sojeva lančanom reakcijom polimeraze (PCR), korišćeni su prajmeri komplementarni tms2 genu lociranom na Ti plazmidu. U prvoj PCR reakciji izvedenoj korišćenjem tms2F1 + tms2R2 para prajmera, detektovani su fragmenti nukleinske kiseline veličine 617 baznih parova (bp), specifični za tumorogene sojeve A. tumefaciens. U drugoj PCR reakciji korišćenjem para prajmera tms2F1 i tms2B su amplifikovani PCR produkti očekivane veličine 458 bp, karakteristični za ovu bakteriju. Na osnovu multiplex PCR reakcije korišćenjem prajmera komplementarnih na hromozomalni gen koji kodira 23S rRNA sojevi izolovani iz tumora na korenu maline svrstani su u biovar 1 Agrobacterium (A. radiobacter). Ovo je prvi nalaz ove bakterije na malini u Srbiji

Prvi nalaz tumorogenih sojeva Agrobacterium radiobacter na malini u Srbiji

During the spring of 2003, gall symptoms on the roots and crowns of young raspberry plants cv. Vilamette were observed near Valjevo. Phytopathogenic bacteria were isolated from diseased plant samples. Based on the pathogenic, morphological, differential biochemical and physiological characteristics, the isolated strains were identified as tumorigenic Agrobacterium radiobacter (biovar 1 Agrobacterium). In order to confirm the identity of isolated strains by polymerase chain reaction (PCR) primers complementary to tms2 gene located on the Ti plasmid were used. In the first PCR protocol using a tms2F1 + tms2R2 primer pair, 617 bp products specific for tumorigenic Agrobacterium strains were amplified. The second PCR protocol, using a tms2F1 + tms2B primer pair, amplified the expected 458 bp products. On the basis of multiplex PCR with primers complementary to chromosomal gene coding for 23S rRNA, the isolated strains were classified as biovar 1 Agrobacterium (A. radiobacter). This is the first report of tumorigenic A. radiobacter on raspberry in Serbia.Tokom proleća 2003. godine, zapaženi su tumori na korenu i korenovom vratu mladih biljaka maline sorte Vilamette u okolini Valjeva. Iz obolelih uzoraka izolovane su fitopatogene bakterije. Proučavanjem patogenih, morfoloških i diferencijalnih biohemijsko-fizioloških karakteristika izolovanih sojeva, utvrđeno je da proučavani sojevi pripadaju bakteriji Agrobacterium radiobacter (biovar 1). U cilju potvrde identiteta izolovanih sojeva lančanom reakcijom polimeraze (PCR), korišćeni su prajmeri komplementarni tms2 genu lociranom na Ti plazmidu. U prvoj PCR reakciji izvedenoj korišćenjem tms2F1 + tms2R2 para prajmera, detektovani su fragmenti nukleinske kiseline veličine 617 baznih parova (bp), specifièni za tumorogene sojeve A. tumefaciens. U drugoj PCR reakciji korišćenjem para prajmera tms2F1 i tms2B su amplifikovani PCR produkti očekivane veličine 458 bp, karakteristièni za ovu bakteriju. Na osnovu multiplex PCR reakcije korišćenjem prajmera komplementarnih na hromozomalni gen koji kodira 23S rRNA sojevi izolovani iz tumora na korenu maline svrstani su u biovar 1 Agrobacterium (A. radiobacter). Ovo je prvi nalaz ove bakterije na malini u Srbiji

Osetljivost Cladobotryum spp., patogena šampinjona (Agaricus bisporus), na neke fungicide

Thirteen isolates of Cladobotryum spp., isolated from diseased fruiting bodies of Agaricus bisporus, sampled from mushroom farms in Serbia during 2003-2006, were studied. Sensitivity to several selected fungicides was tested and all isolates were found to be highly sensitive to iprodione (EC50 = 0.35-2.30 mg L-1), benomyl (EC50 = 0.14-0.97 mg L-1) and especially to prochloraz-Mn (EC50 = 0.02-0.09 mg L-1). The minimum inhibitory concentration (MIC) of benomyl was 4 mg L-1, while those of prochloraz-Mn and iprodione exceeded 1000 mg L-1. The minimum fungicide concentration (MFC) of benomyl was 4 mg L-1, and none of the tested concentrations of prochloraz-Mn and iprodione were lethal to any of the investigated Cladobotryum spp. isolates.Trinaest izolata Cladobotryum spp., dobijeno je iz obolelih plodonosnih tela Agaricus bisporus iz gajilišta šampinjona u Srbiji tokom 2003-2006. godine. Ispitivanje osetljivosti izolata na fungicide je pokazalo da su svi izolati visoko osetljivi na benomil (EC50 = 0.14-0.97 mg L-1), iprodion (EC50 = 0.35-2.30 mg L-1) i naročito na prohloraz (EC50 = 0.02-0.09 mg L-1). Minimalna inhibitorna koncentracija (MIC) benomila je bila 4 mg L-1, a prohloraza i iprodiona veća od 1000 mg L-1. Minimalna fungicidna koncentracija (MFC) benomila je takođe bila 4 mg L-1, a nijedna od testiranih koncentracija prohloraza i iprodiona nije bila letalna za Cladobotryum spp. izolate

Efikasnost kombinacija nespecifičnih i fungicida iz grupe strobilurina u suzbijanju čađave pegavosti jabuke

The efficacy of several fungicide mixtures in controlling Venturia inaequalis in apple was evaluated in field trials. The efficacies of Flint Plus (trifloxystrobin + captan) and Tercel (pyraclostrobin + dithianon) in comparison with standard fungicides Zato 50-WG (trifloxystrobin) and Stroby + Delan (kresoxim-methyl + dithianon) were tested in the localities Mihajlovac, Radmilovac and Landol in 2004 and 2005. Both tested fungicides exhibited high efficacy in controlling apple scab. There were significant differencies in the efficacies of Flint Plus (91.3-98.5%) and Zato 50-WG (68.2% and 78.4%); and Tercel (88.7-93.5%) and Stroby + Delan (77.9% and 82.1%). Our experiments showed that the investigated fungicide mixtures are highly effective against V. inaqeulais, even under high disease pressure.Ispitivana je efikasnost nekoliko kombinacija fungicida u suzbijanju Venturia inaequalis na jabuci u poljskim uslovima. U 2005-oj i 2006-oj godini ispitivana je efikasnost Flint Plus (trifloksistrobin + kaptan) i Tercel (piraklostrobin + ditianon) u odnosu na standardne fungicide Zato 50-WG (trifloksistrobin) i Stroby + Delan (kresoksim-methil + ditianon) na lokalitetima Mihajlovac, Radmilovac i Landol. Oba ispitivana fungicida ispoljila su visoku efikasnost u suzbijanju čađave pagavosti jabuke. Između efikasnosti Flint Plus (91.3-98.5%) i Zato 50-WG (68.2% i 78.4%), i Tercel (88.7-93.5%) i kombinacije fungicida Stroby + Delan (77.9% i 82.1%) zabeležena je statistički značajna razlika. Naši ogledi su pokazali da su ispitivane kombinacije fungicida visoko efikasne protiv V. inaequalis čak i u uslovima jake zaraze

In vitro toksičnost fungicida različitih mehanizama delovanja za Agaricus bisporus (Lange) Imbach

Isolates of Agaricus bisporus strains F56 and U3 were tested for sensitivity to several selected fungicides in vitro. The analysis showed that flusilasole + carbendazim and cyproconazole + carbendazim were the most toxic fungicides to A. bisporus strain F56 with respective EC50 values of 0.04 and 0.23 mg/l. The least toxic fungicides were carbendazim (EC50 = 16.58 mg/l) and trifloxystrobin (EC50 = 20.69 mg/l) to A. bisporus F56 and benomyl (EC50 = 14.99 mg/l) to A. bisporus U3.Ispitana je in vitro toksičnost odabranih fungicida za sojeve F56 i U3 Agaricus bisporus (Lange) Imbach. Analiza je pokazala da su fungicidi fluzilazol + karbendazim i ciprokonazol + karbendazim pokazali najveću toksičnost za soj F56 A. bisporus sa EC50 vrednostima 0.04 i 0.23 mg/l. Karbendazim (EC50 = 16.58 mg/l) i trifloksistrobin (EC50 = 20.69 mg/l) su bili najmanje toksični fungicidi za A. bisporus F56 i benomil (EC50 = 14.99 mg/l) za A. bisporus U3