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The effects of copper citrate on defoliation of one year old fruit stocks in a nursery are presented in this paper. The investigation aimed to evaluate the defoliation efficacy of copper citrate as a new formulation, compared with other compounds recommended for that purpose. Field trials were conducted in the region of Trstenik, a center of nursery production in Serbia in 2016 and 2017. Two years of investigation showed that copper citrate could be used as an efficient compound for defoliation in nursery production. A stronger defoliation effect was observed on plum stocks, compared to apple stocks. Better results were achieved with the highest concentration of copper citrate (2%), while the effectiveness decreased with lower concentrations (0.5%, 1.0% and 1.5%). Defoliation degree on nursery apple stocks after treatment with 2.0% concentration of copper citrate varied from 80.6% to 95.6%, while it reached 100% on plum stocks., U radu su prikazani efekti defolijacije sadnica jabuke i šljive, primenom različitih koncentarcija bakar citrata, kao nove formulacije, i standardnih preparata koji se koriste u ove svrhe (bordovska čorba, urea). Ogledi su sprovedeni u regionu Trstenika (Ljubava i Milutovac), koji je centar rasadničke proizvodnje u Srbiji. Tretiranja su obavljena tokom 2016. i 2017. godine. Na osnovu dobijenih rezultata zaključeno je da bakar citrat pokazuje visok potencijal za upotrebu u svrhu defolijacije sadnica jabuke i šljive. Korišćene koncentracije ovog jedinjenja su pokazale veću efikasnost u primeni na sadnicama šljive nego na sadnicama jabuke. Najbolji rezultati u oba ogleda su zabeleženi sa maksimalno primenjenom koncentracijom (2%), dok efekat defolijacije na sadnicama jabuke opada sa smanjenjem koncentracije. Stepen defolijacije jabuke primenom bakar citrata u koncentraciji od 2% kretao se od 80,6% do 95,6%, a kod šljive čak 100%. Potvrđeno je i da uspešna defolijacija sadnica jabuke i šljive značajno zavisi od vremena aplikacije kao i meteoroloških uslova.

The diversity of 30 Erwinia amylovora strains, isolated from quince, pear and apple trees on 14 localities in Serbia, was studied using bacteriological and molecular methods. In pathogenicity tests, all strains caused necrosis and oozing of bacterial exudate on inoculated immature pear, cherry and plum fruits, and induced hypersensitive reaction in tobacco leaves. The studied strains were Gram and oxidase negative, non-fluorescent, levan and catalase positive and facultatively anaerobic. The strains did not reduce nitrates, but utilized citrate and produced acid from sorbitol, hydrolyzed gelatine, produced reducing substances from sucrose and grew in the presence of 5% NaCl, but not at 36oC. Identity of the strains was confirmed by conventional and nested PCR methods. Rep-PCR with REP, ERIC and BOX primers resulted in amplification of several DNA fragments respectively, but showed no variation within the strains. However, different genetic profiles were obtained with RAPD-PCR by using six primers which enabled differentiation of the strains into four groups. Genetic differences between the studied strains did not correlate with the host plants, geographical origin or year of isolation., Primenom standardnih bakterioloških i molekularnih metoda proučen je diverzitet 30 sojeva Erwinia amylovora izolovanih iz dunje, kruške i jabuke, poreklom iz 14 lokaliteta u Srbiji. Svi proučavani sojevi izazvali su nekrozu i pojavu bakterijskog eksudata na nesazrelim plodovima kruške, trešnje i šljive, kao i hipersenzitivnu reakciju duvana. Proučavani sojevi bili su Gram i oksidaza negativni, fakultativno anaerobni, levan i katalaza pozitivni i nisu stvarali fluorescentni pigment na Kingovoj podlozi B. Svi sojevi hidrolizuju želatin, koriste citrate i stvaraju kiselinu iz sorbitola, proizvode redukujuće supstance iz saharoze, ne redukuju nitrate, razvijaju se u prisustvu 5% NaCl, ali ne i pri 36°C. Identitet sojeva potvrđen je konvencionalnim PCR i nested PCR metodama. Rep-PCR metodom korišćenjem REP, ERIC i BOX prajmera umnoženo je više fragmenata DNK čiji broj i veličina su se podudarali kod svih proučavanih sojeva. Za razliku od Rep-PCR, primenom RAPD-PCR metode uz korišćenje šest prajmera došlo je do izdvajanja različitih genetičkih profila i diferencijacije sojeva u četiri grupe. Genetičke razlike među proučavanim sojevima nisu bile u korelaciji sa domaćinima iz kojih su izolovani, niti sa njihovim geografskim poreklom i godinom izolacije.

Characteristics of pathogenic Pseudomonas bacterial strains isolated from cherry in Serbia are presented in the article. Two types of symptoms were observed on cherry trees at few localities with intensive production in Serbia (Belgrade, Čačak, Topola, Šabac, Novi Sad). The first symptom is bud necrosis and the second bacterial canker of cherry branch. Gram negative, fluorescent, oxidative bacterial strains were isolated from the margin of necrotic tissue. All investigated strains were levan and HR positive, while negative results were recorded for oxidase, pectinase and arginin dihydrolase tests (LOPAT+- - - +). Based on pathogenicity tests and differential GATT tests, investigated strains were divided in two distinct groups: the first group consisted of strains isolated from necrotic cherry branch which caused necrosis on artificially inoculated cherry, pear and lemon fruits, syringae leaves and bean pods, were gelatin and aesculin positive, and tyrosinase and tartrate negative (typical characteristics of P.s. pv. syringae). Contrary, second group strains were isolated from necrotic cherry buds, showed negative results in mentioned pathogenicity tests, gelatin and aesculin tests were negative, while tyrosinase and tartrate were positive (typical characteristics of P.s. pv. morsprunorum). REP PCR analyses showed that strains isolated from necrotic cherry buds belong to P. s pv. morsprunorum compared to referent strain. In contrast, isolates obtained from necrotic cherry branches had unique fingerprint profiles but different from all reference strains. According to the obtained results it was concluded that both pathovars of P. syringae (syringae and morsprunorum) cause necrosis of cherry trees in Serbia., U radu su prikazane patogene, bakteriološke odlike izolata bakterije Pseudomnas syringae poreklom iz trešnje, kao i njihova molekularna karakterizacija primenom REP-PCR metode. Dva tipa simptoma bolesti zapažena su u savremenim zasadima trešnje na području Beograda, Novog Sada, Topole i Šapca. Prvi tip simptoma se ispoljava u vidu nekroze cvetnih i lisnih pupoljaka trešnje, a drugi u vidu nekroze višegodišnjih grana. Iz nekrotičnog tkiva su izolovane Gram negativne bakterije , koje fluoresciraju na King podlozi B, a glukozu metabolišu isključivo u aerobnim uslovima; bakterija stvara levan i prouzrokuje HR duvana ali ne stvara oksidazu, pektinazu u arginin dehidrolazu (LOPAT +---+) što su odlike karakteristične za bakteriju P. syringae. U pogledu patogenosti izolovanih sojeva, kao i njihovih diferencijalnih biohemijskih testova (GATT) proučavani izolati su svrstani u dve jasno izdiferencirane grupe. Prvu čine sojevi izolovani iz nekrozom zahavćenih grana trešnje, koji prouzrokuju nekrozu inokulisanih plodova trešnje, kruške i limuna, listova jorgovana i mahuna boranije. Ova grupa izolata hidrolizuje želatin i eskulin, ali ne stvaraju tirozinazu i ne metabolišu tartarate. Pomenute patogene i diferencijalne biohemijske odlike su karakteristične za P.s. pv. syringae. Nasuprot njima, sojevi izolovani iz nekrotičnih pupoljaka trešnje negativno reaguju pri pomenutim testovima patogenosti, ne hidrolizuju želatin i eskulin, ali stvaraju tirozinazu i metabolišu tartarate, što su odlike P.s.pv. morsprunorum. REP-PCR analiza takođe ukazuje da sojevi iz nekrotičnih pupoljaka ispoljavaju identične karakteristike kao i referentni soj P.s. pv. morsprunorum. Primenom ovog metoda je takođe utvrđeno da su sojevi izolovani iz obolelih grana trešnje međusobno identični ali da se razlikuju od referentnih sojeva korišćenih u ovim istraživanjima. Na osnovu dobijenih rezultata, tokom ovih istraživanja zaključeno je da oba patogena varijeteta P. syringae patogena voćaka (pv. syrnigae i pv. m

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.

Recent studies of Erwinia amylovora in Montenegro, conducted from 2012 to 2014, indicated that the bacterium was widespread in the northern, continental part of the country, where the most important fruit-growing regions are situated. The presence of the bacterium was confirmed on quince, pear, apple, medlar and hawthorn. Pathogenic, cultural and biochemical characteristics of E. amylovora strains sampled from pome fruit species and indigenous flora in Montenegro had been studied previously. In the present study, serological tests were used for identification of E. amylovora strains originating from pome fruit trees and indigenous plants. Monitoring of E. amylovora and collection of samples with symptoms of bacterial fire blight from different hosts and locations were performed in Montenegro from 2012 to 2014. Isolation of the bacterium on nutrient medium produced a large number of isolates, whose pathogenicity was confirmed on immature pear fruits. Twenty-seven strains of the bacterium, originating from three pome fruit species (quince, pear and apple) and one indigenous species (hawthorn) were selected for serological analyses. Two applied serological methods, ELISA and IF test, enabled rapid detection of the bacterium and simultaneous examination of a large number of samples over a short period of time. Serological analyses showed high homogeneity in antigenic structure of the studied E. amylovora strains sampled from quince, pear, apple and hawthorn from nine locations in Montenegro., Novija proučavanja Erwinia amylovora u Crnoj Gori, sprovedena u periodu od 2012 do 2014. godine, pokazuju da je ova bakterija široko rasprostranjena u severnom, kontinentalnom delu zemlje, gde se nalaze i najznačajniji voćarski regioni. Prisustvo bakterije potvrđeno je na dunji, krušci, jabuci, mušmuli i glogu. U prethodnim istraživanjima proučene su patogene, odgajivačke i biohemijske odlike sojeva E. amylovora poreklom sa jabučastih voćnih vrsta i biljaka spontane flore u Crnoj Gori. U ovom radu primenjeni su serološki testovi u identifikaciji sojeva E. amylovora poreklom sa jabučastih voćaka i biljaka spontane flore. Monitoring E. amylovora i sakupljanje uzoraka sa simptomima bakteriozne plamenjače izvršeno je u periodu od 2012 do 2014. godine, sa različitih domaćina i lokaliteta u Crnoj Gori. Izolacijom bakterije na hranljive podloge dobijen je veći broj izolata, čija je patogenost potvrđena na zelenim plodovima kruške. Za serološke analize odabrano je 27 sojeva ove bakterije, poreklom sa tri jabučaste voćne vrste (dunja, kruška i jabuka) i jedne vrste iz spontane flore (glog). Primenjene su dve serološke metode: ELISA i IF test, koje su omogućile brzu detekciju bakterije i istovremeno ispitivanje velikog broja uzoraka za kratko vreme. Serološkim analizama utvrđena je visoka homogenost u antigenoj strukturi proučavanih sojeva E. amylovora poreklom sa dunje, kruške, jabuke i gloga, iz 9 lokaliteta u Crnoj Gori.

Soft rot symptoms were observed on broccoli plants in several commercial fields in the western part of Serbia. Six strains of bacteria were isolated from diseased tissues and identified as Pectobacterium carotovorum subsp. carotovorum using conventional bacteriological and molecular methods. All strains were non-fluorescent, gram-negative, facultative anaerobes, oxidase-negative and catalase-positive, causing soft rot on potato and carrot slices and did not induce hypersensitive reaction on tobacco leaves. They grew in 5% NaCl and at 37C, did not produce acid from α-methyl glucoside, sorbitol and maltose, nor reducing substances from sucrose, but utilized lactose and trehalose, and did not produce indole or lecithinase. The investigated strains showed characteristic growth on Logan's medium and did not produce blue pigmented indigoidine on GYCA medium nor 'fried egg' colonies on PDA. The identity of strains was confirmed by ITS-PCR and ITS-RFLP analyses and by sequence analysis of the 16S rRNA gene. In a pathogenicity assay, all strains caused tissue discoloration and soft rot development on inoculated broccoli head tissue fragments., Simptomi vlažne truleži brokolija uočeni su u nekoliko komercijalnih zasada u zapadnoj Srbiji. Sojevi bakterija izolovani su iz obolelog biljnog tkiva i identifikovani kao Pectobacterium carotovorum subsp. carotovorum korišćenjem konvencionalnih bakterioloških i novijih molekularnih metoda. Svi proučavani sojevi bili su nefluorescentni, Gram-negativni, fakultativno-anaerobni, oksidaza i lecitinaza negativni, katalaza pozitivni, prouzrokujući vlažnu trulež cvetnih drški brokolija, kriški krompira i kriški mrkve, ali nisu indukovali hipersenzitivnu reakciju duvana. Svi sojevi razvijaju se pri 37C i u prisustvu 5% NaCl, ne proizvode kiselinu iz α-metil glukozida, sorbitola i maloze, niti redukujuće supstance iz saharoze, ali razlažu laktozu i trehalozu, i ne stvaraju indol. Proučavani sojevi ispoljili su karakterističan razvoj na Loganovoj diferencijalnoj podlozi, i nisu proizvodili plavi pigment na GYCA podlozi niti 'fried egg' kolonije na PDA podlozi. Identifikacija sojeva potvrđena je korišćenjem ITS-PCR i ITS-RFLP, kao i analizom sekvenci 16S rRNA gena. Prilikom izvođenja testa patogenosti, svi sojevi prouzrokovali su obezbojavanje tkiva i vlažnu trulež cvetnih drški brokolija.

Venturia inaequalis is a common apple disease in Serbia and its intensity depends on weather conditions. The most successful method of combating apple scab is to use a lower dose of an active ingredient and increase its effectiveness by adding substances that do not cause environmental damage. The effectiveness of a fungicide mixture of captan and potassium phosphite against V. inaequalis was investigated in apple orchards in 2008 and 2009. A relevant EPPO standard method was used in all trials. Captan 50 WP was used as a standard fungicide. In order to determine the exact conditions marking the onset of apple infection, key meteorological conditions were monitored in the orchards using an automated iMetos weather station and a Lufft electronic instrument. The results showed high efficacy of the tested fungicides which remained similar in both years of investigation. The intensity of leaf infection after treatment with the mixture of captan and potassium phosphite was 0.7-2.4%, while fruit infection was 0.5-3.0%. The efficacy of this mixture ranged from 96.3-97.9% on leaves and 87.4-98.7% on fruits. The standard fungicide Captan 50 WP showed an efficacy ranging from 95.3-96.7% on leaves and from 87.8-99.3% on fruits. No statistically significant differences were found between the fungicide tested and the standard fungicide., Venturia inaequalis je široko rasprostranjena bolest jabuke u Srbiji, a njen intenzitet zavisi od vremenskih uslova. Najuspešniji metod borbe protiv čađave krastavosti jabuke je korišćenje manjih doza aktivnih materija uz istovremeno povećavanje efikasnosti dodavanjem supstanci koje ne prouzrokuju štetu u životnoj sredini. Tokom 2008 i 2009 godine, proučavana je efikasnost fungicidne mešavine kaptana i kalijum fosfita protiv V. inaequalis u jabučnjacima. U svim ogledima je korišćen standardni EPPO metod. Captan 50 WP je korišćen kao standardni fungicid. Kako bi se tačno odredili uslovi za početak zaraze na jabuci, praćeni su osnovni meteorološki parametri u voćnjacima pomoću iMetos stanice i elektronskog uređaja Lufft. Rezultati su pokazali visoku efikasnost testiranih fungicida koja je bila slična u obe godine istraživanja. Intenzitet zaraze lista nakon tretmana mešavinom kaptana i kalijum fosfita bio je 0.7-2.4%, dok je zaraženost plodova bila 0.5-3.0%. Efikasnost mešavine bila je 96.3-97.9% na listovima, a 87.4-98.7% na plodovima. Standardni fungicid Captan 50 WP pokazao je efikasnost u opsegu 95.3-96.7% na listovima i 87.8-99.3% na plodovima. Nisu konstatovane statistički značajne razlike između ispitivanog i standardnog fungicida.

Bacterial strains were isolated from above- and underground parts of diseased calla plants originating from different localities in Serbia and one locality in Montenegro. They were characterized by studying their pathogenic, cultural, biochemical and physiological characteristics. All investigated strains caused soft rot of calla leaf stalks, potato slices and aloe leaves, and induced hypersensitive reaction on tobacco. Bacteriological properties of the strains indicated that symptoms on calla plants were caused by Gram-negative, nonfluorescent, oxidase negative, catalase positive and facultatively anaerobic bacterium belonging to the genus Pectobacterium. The investigated strains grew at 37ºC and in 5% NaCl, utilised lactose and trechalose, and produced neither indol nor lecitinase. These results, as well as the characteristic growth on Logan's differential medium indicated that soft rot of tuber and stem base of calla plants was caused by Pectobacterium carotovorum subsp. carotovorum. This is the first report of this pathogen affecting calla plants in Serbia., Proučene su patogene, odgajivačke i biohemijsko-fiziološke odlike sojeva izolovanih iz nadzemnih i podzemnih delova obolelih biljaka kale gajene u različitim lokalitetima u Srbiji i jednom lokalitetu u Crnoj Gori. Svi proučavani sojevi ispoljili su izraženu pektolitičku aktivnost prouzrokujući vlažnu trulež lisnih drški kale, kriški krompira, liski aloje ili sanseverije, a prouzrokovali su i hipersenzitivnu reakciju duvana. Proučavanjem bakterioloških karakteristika utvrđeno je da promene na biljkama kale prouzrokuju Gram-negativni, nefluorescentni, oksidaza-negativni, katalaza-pozitivni i fakultativno-anaerobni sojevi bakterije, koja prema navedenim karakteristikama pripada rodu Pectobacterium. Proučavani sojevi se razvijaju pri 37ºC i u prisustvu 5% NaCl, razlažu laktozu i trehalozu, ne stvaraju indol i lecitinazu. Navedeni rezultati, kao i karakterističan razvoj na Loganovoj diferencijalnoj podlozi ukazuju da je vlažnu trulež korena i prizemnog dela biljaka kale prouzrokovala bakterija Pectobacterium carotovorum subsp. carotovorum. Ovo je prvo saopštenje o pojavi P. c. ssp. carotovorum kao patogena kale 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.