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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.

Erwinia amylovora (Burrill) Winslow, uzročnik je bakteriozne plamenjače, jedne od najdestruktivnijih bolesti voćaka i ukrasnih biljaka i jedne od najštetnijih bakterijskih bolesti gajenih biljaka. U Crnoj Gori prisustvo ove bakterije prvi put je uočeno 1993. godine, na stablima kruške, u opštinama Berane i Andrijevica, u severnom delu zemlje, a eksperimentalno potvrđeno 2003. godine u uzorcima jabuke iz okoline Nikšića. U okviru ovog istraživanja izvršena su proučavanja bakterije E. amylovora u Crnoj Gori. Istraživanje je obuhvatilo terenski i laboratorijski rad, u periodu 2012‒2015. godine. Na terenu je posmatrana pojava simptoma bakteriozne plamenjače na osetljivim vrstama, utvrđen krug domaćina i rasprostranjenost bakterije po opštinama. Prilikom terenskih obilazaka sakupljeno je preko 200 biljnih uzoraka sa simptomima bolesti, iz kojih je uspešno izolovana bakterija. Potvrđeno je da je ova bakterija široko rasprostranjena na čitavoj teritoriji države, posebno u voćarskim regionima u severoistočnim i zapadnim, kontinentalnim delovima zemlje. Prisustvo E. amylovora utvrđeno je na pet domaćina, među kojima su četiri voćne vrste: dunja (Cydonia oblonga), kruška (Pyrus communis), jabuka (Malus domestica) i mušmula (Mespilus germanica), kao i jedna vrsta iz 4 spontane flore‒ glog (Crataegus sp.). Praćenjem uticaja meteoroloških faktora na pojavu simptoma bakteriozne plamenjače u klimatski različitim regionima Crne Gore, uočena je njihova tesna korelacija. Utvrđeno je da zasadi dunje, kruške i jabuke, kao i pojedinačna jako zaražena stabla ovih voćnih vrsta u u severoistočnim (lokaliteti Bijelo Polje i Berane) i zapadnim (lokalitet Nikšić) delovima zemlje predstavljaju žarišta iz kojih se bakterija širi na nova područja i nove biljke domaćine. Navedeni podaci ukazuju na činjenicu da je poslednjih godina došlo do širenja E. amylovora u kontinentalnom delu zemlje, gde je prouzrokovala značajnije štete. Zbog toga ova bakterija danas predstavlja ozbiljnu pretnju uspešnom g, Erwinia amylovora (Burrill) Winslow is the causal agent of fireblight, one of the most destructive diseases of fruits and ornamental plants and one of the most damaging diseases of cultivated plants. In Montenegro, fireblight symptoms were observed for the first time in 1993 on pear trees in the municipalities of Berane and Andrijevica, in northern part of the country. The occurrence this bacterium was experimentally confirmed in 2003 on apple samples from vicinity of Nikšić. Studies of bacterium E. amylovora in Montenegro were carried out in this research. The study comprised of field and laboratory work, conducted in the period 2012‒2015. During fieldwork, the fireblight simptoms were observed on susceptible species, host range and distribution of bacterium in the municipalities was determined. More than 200 plant samples with fireblight symptoms were collected, from which the bacterium was successfully isolated. Widespread of the bacterium was confirmed in whole country, particularly in fruit growing regions in northeastern and western continental part. Presence of E. amylovora was confirmed on five hosts, including four fruit species: quince (Cydonia oblonga), pear 8 (Pyrus communis), apple (Malus domestica), medlar (Mespilus germanica) and one species from spontaneous flora ‒ hawthorn (Crataegus sp.). Monitoring effects of meteorological factors on fireblight symptom occurrence in different climatic regions of Montenegro revealed their high correlation. Quince, pear and apple orchards, as well as single heavily infected trees in northeastern (localities Bijelo Polje and Berane) and western (locality Nikšić) parts of the country, have been confirmed as hotspots from which the bacterium spreads to other areas and new hosts. Presented data points to the fact that in the last few years E. amylovora spread in continental part of the country where it caused significant damages. Therefore, this bacterium presents is a serious threat to successful cultivation of pome f

Severe symptoms of necrosis sweet cherry fruits was recorded during 2014. in region of Šabac. About 30 % of fruits (cv. Summit) were affected and necrosis cover 1/3 of fruit surface in average. Gram negative, fluorescent, oxidative bacterial strains were isolated from diseased tissues. Symptoms similar to those, observed in natural infection were recorded on artificial inoculated cherry fruits (cv. Summit and cv. Summbarst). Isolated strains were HR positive, oxidase, pectinase, arginin dehidrolase negative and levan positive (LOPAT +---+). Same characteristics also own check strains Pseudomonas syringae (CFBP 11). According obtained results it was concluded that necrosis of sweet cherry fruits is caused by Pseudomonas syringae. Further characteristic in order proper detection of pathogens, including molecular methods are underway., U radu su prikazani rezultati proučavanja sojeva bakterija izolovanih iz nekrotičnih plodova trešnje sorte Samit (područje Šapca). Nekroza zahvata u proseku oko 1/3 ploda koji potpuno gubi tržišnu vrednost. Bolešću biva zahvaćeno oko 30% plodova. Primenom standardnih bakterioloških metoda (izolacijom na hranljivim podlogama), proverom patogenosti i proučavanjem bakterioloških karakteristika, zaključeno je da pomenute simptome prouzrokuje fitopatogena bakterija Pseudomonas syringae, široko rasprostranjen patogen naročito koštičavih voćaka.

Characteristics of Erwinia amylovora strains isolated from quince trees (Cydonia oblonga) in different localities in Serbia are presented in this paper. In the period 2010-2012, severe occurrence of fire blight on quince was recorded in almost all localities in Serbia. First symptoms appeared after blooming period, but most expressed symptoms were recorded during intensive growth of shoots. Isolated strains elicted HR in tobacco, necrosis of pear seedlings and immature pear fruits ('Williams'). Strains were non-fluorescent, produce levan; oxidase negative, catalase positive; hydrolysis of gelatine positive; esculin and starch tests were negative; strains metabolise sucrose, sucrose, fructose and galactose. After amplification of total DNA with REP-PCR followed by agarose gel electrophoresis, the tested isolates originating from quince showed indistinguishable PCR patterns for all investigated native strains that were identical to European reference strains.

Susceptibility of different pear cultivars to Erwinia amaylovora by artificial inoculated immature pear fruits are shown in this article. According obtained results significant differences among cultivars are confirmed and they could be divided in four groups. Most susceptibly cultivars were Santa Marija. Second group includes Williams, Morettini, Carmen, Hardenpont. As most resistant shown to be Magness, Turandot and two local varietyies Karamanka, as well as another unknown local cultivar. This results are compatible with literature data, but also confirmed observations about susceptibility of various pear cultivars to E. amylovora under natural infections. Artificial inoculation immature pear fruit could be considered as relativelu relible method for estimation of pear fruit trees resistance to this bacteria., U radu je prikazana reakcija plodova različitih sorata kruške prema Erwinia amylovora metodom inokulacije nesazrelih plodova. Utvrđeno je da postoje značajne razlike u osetljivosti raznih sorata kruške prema patogenu i one se mogu podeliti u četiri grupe prema korišćenoj skali. Najosetljivijom se pokazala sorta Santa Marija. Nešto manju osetljivost ispoljile su sorte Vilijamova, Moretini, Karmen i Hardenpont; najotpornijim su se pokazale Magnes, Turandot, Junska Lepotica, Karamanka i nepoznata autohtona sorta. Prema dosadašnjim saznanjima ovi rezultati su u saglasnosti sa podacima iz literature i zapažanjima o otpornosti sorti kruške prema E. amylovora, primenom metode inokulacije plodova. Istraživanja su pokazala da se ovakav metod utvrđivanja otpornosti kruške prema E. amylovora sa relativnom pouzdanošću može koristiti u ove svrhe.

Мискантус (Miscanthus x giganteus Greef et Deu.) представља енергетски усев из групе ратарских биљака која годишњом продукцијом биомасе може да обезбеди задовољавајуће количине сировине за добијање биогорива. Истраживања о утицају густине садње на закоровљеност и принос биомасе мискантуса су изведена постављањем пољских микроогледа у периоду од 2011-2014. године, на земљишту типа бескарбонатни чернозем у Земуну и ритској црници у Грабовцу. Резултати истраживања показали су да је густина садње имала статистички значајан утицај на закоровљеност засада мискантуса. На оба локалитета већа закоровљеност засада била је при мањој густини садње (2 ризома m-2). Већа закоровљеност усева утврђена је на земљишту типа чернозем (локалитет Земун), док је већи број коровских врста детерминисан на земљишту типа ритска црница (локалитет Грабовца). Сува маса корова расла је од прве до треће оцене закоровљености у првој и другој години, док је мискантус у трећој години у фази метличења порастом висине стабла и бројем листова испољио одређену компетицију у односу на корове. Коровске врсте нису показале исти интезитет компетитивости у односу на мискантус. У Земуну су током трогодишњег периода у коровској заједници биле присутне Lolium multiflorum Lam., Convolvulus arvensis L. и Sonchus oleraceus (L.) Gou., док је изузетно конкурентна према мискантусу била Lolium multiflorum Lam. На локалитету Грабовац у све три године биле су присутне врсте Convolvulus arvensis L., Polygonum aviculare L., Cirsium arvense L., Setaria glauca L., Ambrosia artemisifolia L. и Chenopodium album L., али су најконкурентније за усев мискантуса биле Setaria glauca L. и Ambrosia artemisifolia L..., Miscanthus (Miscanthus x giganteus Greef et Deu.) is an energy crop from the group of arable crops which can provide sufficient quantity of raw material for biofuel. The study was carried out by setting up field microtrials at two growing sites Zemun and Grabovac (chernozem and humogley soil type, respectively). The results of the study showed that the planting density had a significant effect on the weed infestation of miscanthus plantation. At both sites, the weed infestation of the plantation was increased at a lower planting density (2 rhizomes m-2). More intensive weed infestation was recorded in Zemun, while a larger number of weed species was determined in Grabovac. Weed dry weight was increasing from the first to third measurement of weed growth in the first and the second season, whilst miscanthus at tasseling growth stage became more competitive againts weeds in the third year due to increased stem height and number of leaves per stem. There was a differential intensity of competition between weed species and miscanthus. In Zemun, during the three-year period, in the floristic composition there were Lolium multiflorum Lam., Convolvulus arvensis L. and Sonchus oleraceus (L.) Gou., while Lolium multiflorum Lam. was extremely competitive towards miscanthus. Weed species Convolvulus arvensis L., Polygonum aviculare L., Cirsium arvense L., Setaria glauca L., Ambrosia artemisifolia L. and Chenopodium album L. were determined in Grabovac in three years, but the most competitive ones for miscanthus crop were Setaria glauca L. and Ambrosia artemisifolia L...

Alfalfa is the most important forage plant species. There are numerous alfalfa varieties in the world with improved yield potential and forage quality. Many of them have also been created in the region of Southeast Europe, using various breeding techniques. This investigation was carried out in central Serbia and it included 15 alfalfa varieties of different origin (nine from USA and six from Europe). The objective was to determine their yield in each cut and total dry matter yield (TDMY) in the second (A1) and third (A2) year of exploitation, as well as forage quality: the content of mineral matter (MM), crude protein (CP), crude fiber (CF), crude fat matter (CFM) and nitrogen-free extract (NFE). Investigated varieties exhibited high total variability in dry matter yield (DMY) (A1: CV= 13.19%; A2: CV= 9.33%). DMY variability was higher with the varieties from USA (A1: CV= 13.65%; A2: CV= 9.92%) than with those from Europe (A1: CV= 6.67%; A2: CV= 8.01%). Varieties from USA also proved more variable in crude protein (CP) content than European varieties (CV= 6.27% and CV= 2.68%, respectively). Differences between the investigated varieties (genotypes) also influenced total variability of forage quality parameters, with total CV ranging from 5.07% for CP to 10.48% for CF. Dry matter yield (DMY) had significant positive correlation with CP (r= 0.344), CF (r= 0.342) and CFM (r= 0.306), and the strongest correlation, although negative, was between CF and NFE (r= -0.917).

During past few years a symptoms of plum and cherry bud necrosis were observed in some regions with significant cherry production in Serbia. Gram negative, fluorescent, oxidative bacterial strains were isolated from the margin of necrotic tissue. All investigated strains are levan and HR positive, while negative results are recorded in oxidase, pectinase and arginin dihydrolase tests (LOPAT+---+). Symptoms similar to those observed in natural infection were obtained after artificial inoculation of cherry leaf scares and dormant one year old cherry shoots. Investigated strains as well as reference strain of P. syringae pv. morsprunorum cause the superficial necrosis on artificially inoculated immature cherry fruits, but negative results were recorded in immature pear and lemon fruit tests as well as syringae leaves and bean pods. Gelatin and aesculin tests were negative and tyrosinase and tartrate were positive. Investigated strains isolated from necrotic cherry buds had identical REP-PCR pattern with reference strain of P. syringae pv. morsprunorum. On the basis of obtained results, it was concluded that this bacterium is causal agent of cherry trees bud necrosis in Serbia., Tokom nekoliko poslednjih godina u nekim regionima Srbije, značajnim za proizvodnju trešanja, uočeni su simptomi nekroze pupoljaka ovog voća. Sa margina nekrotičnog tkiva izolovani su sojevi gram negativnih, fluorescentnih, oksidativnih bakterija. Svi ispitivani sojevi su bili levan i HR pozitivni dok su negativni rezultati zabeleženi u oksidaza, pektinaza i dihidrolaza testovima (LOPAT +---+). Simptomi slični onima zabeleženim u prirodnim infekcijama dobijeni su nakon veštačke inokulacije lisnih ožiljaka i dormantnih jednogodišnjih sadnica trešnje. Ispitivani sojevi, kao i referentni soj Pseudomonas syringae pv. morsprunorum izazivaju površinsku nekrozu na veštačkim nezrelim plodovima trešnje, ali negativni rezultati su zabeleženi na nezrelim plodovima kruške i limuna kao i na lišću jorgovana i mahunama pasulja. Ispitivani sojevi izolovani sa nekrotičnih pupoljaka trešnje i šljive imali su identičan REP-PCR profil traka kao i referentni soj P. syringae pv. morsprunorum. Dobijeni rezultati ukazuju na to da je uzročnik nekroze pupoljaka trešnje bakterijska infekcija sojem P. syringae pv. morsprunorum.

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

Characteristics of pathogenic Pseudomonas bacterial strains isolated from necrotic sour cherry fruits (Kelleris 14) in region of south Banat. First symptoms of disease appeared as dark green wet spot. Later on it turns to brown or black sunken necrosis. During rainy spring percent of affected fruits reached up 60-80. Gram negative, fluorescent, oxidative bacterial strains were isolated from the margin of necrotic tissue. All investigated strains are levan and HR positive, while negative results are recorded in oxidase, pectinase and arginin dihydrolase tests (LOPAT+- - - +). Investigated strains cause severe necrosis of artificially sour cherry fruits (Kelleris 14) as well as necroses on artificially inoculated cherry, pear and lemon fruits, lilac leaves and bean pods. Positive results were recorded in gelatin and aesculin hydrolysis tests while, tyrosinase and tartrate tests were negative (typical characteristics of P.s. pv.syringae). According the obtained results it was concluded that severe necrosis of sour cherry fruits (Kelleris 14) in South Banat is caused by Pseudomonas syringae pv syringae., U radu su saopštene karakteristike izolata bakterije Pseudomonas syringae izolovane iz nekrozom zahvaćenih plodova višnje (Kelleris 14) na području Južnog Banata. Simptomi sa karakterističnim crnomrkim ulegnutim nekrozama prikupljani su u periodu 2008-2010 godine. Iz obolelog tkiva izolavani su gramnegativni, fluorescentni sojevi bakterija, koji glukozu metabolišu isključivo u aerobnim uslovima (oksidativno); prouzrokuju HR duvana i stvaraju levan, ali ne proizvode oksidazu, pektinazu i arginindehidrolazu (LOPAT I). Proučeni izolati prouzrokuju nekrozu plodova višnje, trešnje, kruške i limuna, listova jorgovana i mahuna boranije. U pogledu diferencijalnih testova za patogene varijetete P. syringae, rezultati ukazuju da dobijeni sojevi hidrolizuju želatin i eskulin, ali ne stvaraju tirozinazu i ne metabolišu tartarate. Na osnovu dobijenih rezultata i odlika izolovanih sojeva zaključeno je, da nekrozu plodova višnje veoma visokog intenziteta, zapaženu poslednjih godina u Južnom Banatu, prouzrokuje bakterija Pseudomonas syringae pv. syringae.

Pseudomonas syringae is economically important plant pathogen, found on a number of hosts including fruit trees, field crops, vegetables and decorative plants. This phytopathogenic bacteria is becoming a quite widespread pathogen on the fruit trees in Serbia, causing significant economic loses. Up to now it was experimentally confirmed as a pathogen on the pear, apple, apricot, cherry, sour cherry, plum trees as well as raspberries. In this study Pseudomonas syringae was identificated as pathogen on peach tree in Serbia. Detection of syrB gene was used for identification phytotoxins tipical for P. syringae pv. syringae. Our experiment showed that detection of syrB genes can be used as a diagnostic tool in determining pathovars of Pseudomonas syringae parasites on peach trees., Pseudomonas syringae ekonomski značajan biljni patogen širokog kruga domaćina koji uključuje voćke, ratarske, povrtarske i ukrasne biljke. Ova fitopatogena bakterija naročitu pažnju privlači kao patogen voćaka prouzrokujući sve veće štete. Do sada je eksperimentalno potvrđen kao parazit kruške, jabuke, kajsije, trešnje, višnje, šljive i maline. Pseudomonas syringae je identifikovan kao patogen breskve u Srbiji. Detekcija syrB gen je korišćena za identifikaciju fitotoksina karakterističnog za P. syringae pv. syringae. Naš je eksperiment pokazao da se detekcijom SyrB gena kao dijagnostičkog alata može identifikovati patogeni varijetet patogen breskve.

The test results of Pseudomonas syringae strains, isolated by a pear trees are as given. The symptoms of disesease, caused by this bacterium, appeared in two types: a blossom blast, a trunk necrosis and a branch followed by canker formation. All strains are Gram negative, fluorescent on a King medium B and oxydative (O/F test). The tested strains are HR positive, producing a levan, but don't oxydase, arginindehydrolase and pectinase (LOPAT +---+). Strains originated from a pear trees caused necrosis on an artificial inoculated pear, cherry and lemon fruits, as well as a syringae leaves and bean pods. The results of differential tests for P. syringae pv. syringae and P. syringae pv. morsprunorum (GATT) revealed that the tested strains hydrolise gelatin and esculin, but the negative results are recorded in tyrosinase production and tartrate utilization tests. The PCR analysis, by using a BOX primer, shows the high level of symilarity among the Serbian P. syringae strains, isolated from a pear fruit trees, but also within a slice differencies, compared with a check strain CFBP 1582. These results confirm a previous data about genetic diversity among P. syringae strains originated from a different areas all around the world. Based on the obtained results, it's concluded that the tested strains belong to P. syringae pv. syringae. Further characterization of P. syringae strains, isolated from pear in Serbia use the ERIC and REP PCR and it's still underway., U radu su prikazani rezultati proučavanja fitopatogene bakterije Pseudomonas syringae, kao patogena kruške u Srbiji. Bolest se ispoljava u dva vida simptoma: palež cvasti i nekroza grana i debla mladih stabala kruške praćena obrazovanjem rak rana. Izolovani sojevi bakterije su Gramnegativni, fluorescentni, glukozu metabolišu isključivo u aerobnim uslovima (oksidativno). Stvaraju levan i prouzrokuju HR duvana ali ne stvaraju oksidazu, arginin dehidrolazu i pektinazu (LOPAT + - - - +). Prouzrokuju nekrozu inokulisanih plodova kruške, trešnje, limuna, listova jorgovana i mahuna boranije. Proučavani izolati hidrolizuju želatin i eskulin ali negativno reaguju pri testovima stvaranja tirozinaze i metabolizma tartarata (GATT). Na osnovu patogenih i biohemijskih odlika zaključeno je da proučavani izolati ispoljavaju izrazitu sličnost sa Psudomonas syringae pv. syringae, široko rasprostranjenim i ekonomski štetnim patogenom kruške. Primenom PCR analize korišćenjem BOX prajmera potvrđena je izrazita homogenost sojeva poreklom sa kruške, izolovanih u Srbiji, ali izvesne razlike u odnosu na kontrolne sojeve, što potvrđuje ranije dokazanu raznolikost sojeva ove bakterije u zavisnosti od lokaliteta i područja iz kog su izolovani. Na osnovu rezultata istraživanja dat je i predlog za uspostavljanje standardne procedure na bazi patogenih, biohemijskih i molekularnih metoda (primenom PCR) u cilju što brže i pouzdanije detekcije ove bakterije u biljnom materijalu, što je od velikog značaja pri proizvodnji sadnog materijala, proučavanja epidemiologije patogena i razrade mera njegovog suzbijanja.

Soft rot bacterial strains were isolated from diseased fennel bulbs. They were characterised on the basis of its pathogenicity morphological, cultural and biochemical properties. All investigated strains caused the soft rot of inoculated fenel bulbs, pepper fruits as well as clices of potato and carrot. Results of bacteriological properties show that soft rot of fennel bulbs were caused by Gram negative, nonfluorescent, facultative anaerobic, levan and oxidase negative bacteria belonging to the genus Pectobacterium. The investigared strains utilised lactose, grew at 5% NaCl and weak growth was recorded on 37oC; they are resistent to erytromicin. Negative results were recorded in indol, phospathase, lecithinase and reducing compounds pf sucrose tests. These results as well as the characteristics growth on Logan differential medium indicated that sof rot of fenel bulbs was caused by Pectobacterium carotovorum subsp. carotovorum. This is the first report of this bacterium affecting fennel bulbs in Serbia., U radu su proučene patogene i biohemijske odlike fitopatogenih bakterija izolovanih iz glavica komorača sa simptomima truleži. Proučavani sojevi prouzrokuju trulež glavica komorača, veštački inokulisanih, plodova paprike, kao i kriški mrkve i krompira i pri tome ispoljavaju izraženu pektolitičku aktivnost. Proučavanjem bakterioloških odlika utvrđeno je da su izolovani sojevi Gramnegativni, ne fluoresciraju na Kingovoj podlozi B, glukozu metabolišu i u aerobnim i anaerobnim uslovima, ne stvaraju levan i oksidazu. Na osnovu navedenih karakteristika zaključeno je da ispitivani sojevi pripadaju rodu Pectobacterium. Proučavani sojevi ne stvaraju fosfatazu, lecitinazu, indol, redukujuće supstance iz saharoze, a na Loganovoj podlozi formiraju karakteristične kolonije ružičaste boje sa tamnim centrom. Na osnovu ovih, ali i rezultata ostalih diferencijalnih testova za vrste roda Pectobacterium (metabolizam ugljenih hidrata, razvoj pri 5% NaCl, osetljivost prema eritromicinu), zaključeno je da vlažnu trulež komorača prouzrokuje bakterija Pectobacterium carotovorum subsp. carotovorum. Ovo je prvo saopštenje o nalazu ove bakterije kao patogena komorača u Srbiji.

Owing to its characteristics, alfalfa (Medicago sativa L.) is the most important forage plant in our country. The great importance of alfalfa is reflected in the production of high-quality fodder and alfalfa seeds, which are a valuable and competitive commodity on domestic and foreign markets. In this study, the presence of plant pathogenic genera of fungi on the seeds of five different alfalfa cultivars was investigated (Kruševačka 28, NS-Mediana, Zaječarska 83, Banjalučanka i Osječka-66) from three different lots (sites) of each cultivar. The detected phytopathogenic fungi on the alfalfa seeds caused a decrease in the overall germination, but the present research results indicate a satisfactory health status of all alfalfa cultivars and seed lots., Plava lucerka (Medicago sativa L.) je zbog svih svojih osobina najvažnija krmna biljka u našoj zemlji. Veliki značaj lucerke se ogleda u proizvodnji kvalitetne kabaste hrane, ali je i seme lucerke vredna i tražena roba na domaćem i inostranom tržištu. Areal gajenja lucerke je na svim kontinentima u više od 80 zemalja, od umereno hladnog do tropskog pojasa. Široka geografska rasprostranjenost lucerke uslovljena je njenom velikom adaptabilnošću na različite klimatske i zemljišne uslove. U ovom radu je ispitivano prisustvo fitopatogenih rodova gljiva na semenu pet različite sorata lucerke (Kruševačka 28, NS-Mediana, Zaječarska 83, Banjalučanka i Osječka-66) sa po tri različite partije (lokaliteta) od svake sorte. Kod ispitivanih sorti identifkovani su sledeći rodovi gljiva: Alternaria spp.,Fusarium spp., Penicillium spp. i Mucor spp. Prisustvo identifikovanih rodova gljiva bilo je u rasponu od 0 % do 15,5%. Rod Mucor spp. najmanju prosečnu vrednost imao je kod sorte lucerke K-28 (0,08%), dok je najveću prosečnu vrednost imao kod sorte Zaječarska 83 (8,67%), a takođe kod iste sorte konstatovano je najveće prisustvo od (15,5%) na lokalitetu Veliki Izvor. Najveće prosečno prisustvo roda Fusarium spp. zabeleženo je kod sorte Zaječarska 83 (0,25%). Na proučavanim sortama lucerke ispitani su korelacioni odnosi između parametara kvaliteta semena i prisustva patogena na semenu različitih sorata i partija lucerke. Negativna korelaciona međuzavisnost zabeležena je između ukupne klijavosti i prisustva gljive iz roda Fusarium spp. (r= - 0,415*). Detektovane fitopatogene gljive na semenu lucerke su uticale na smanjenje ukupne klijavosti, ali ipak rezultati ovih ispitivanja ukazuju na zadovoljavajuće zdravstveno stanje svih sorata i partija semena lucerke.

In 1989 Erwinia amylovora was confirmed to be a pathogen of pear and quince in Serbia. Subsequently, apple, firethorn, hawthorn, Mespilus spp., Cotoneaster horisontalis and Cheanomeles spp. were confirmed as hosts of the pathogen. During the summer 2005, fire blight symptoms were observed on Sorbus spp. for the first time in the south-eastern Serbia, near Nis. Disease symptoms included leaf and shoot blight and cankers with purple-brown colouration of necrotic tissue on mature branches. The diseased tissue was macerated and the suspension was streaked on nutrient sucrose agar (NAS) and King's medium B. Typical light grey, levan-positive colonies developed on NAS medium after two day incubation at 25°C. Colonies on King's medium B were white and nonfluorescent. The results of physiological and biochemical tests of the bacterium were as follows: gram negative, oxidative and fermentative metabolism of glucose; oxidase negative, gelatin hydrolysis positive, aesculin hydrolysis negative and acid produced from most carbon sources. In pathogenicity tests, all isolates induced HR in tobacco leaves and necrosis on artificially inoculated pear fruits followed by appearence of bacterial ooze. After inoculation of petioles and shoots of the host plant (Sorbus spp.) initial symptoms were dark green, watersoaked, eliptical spots on inoculated tissues. Leaf and shoot blight resembling the natural infection appeared five to six days after inoculation. The investigated strains reacted positively with antisera specific to E. amylovora in DASI ELISA test. Identity of isolated strains also was confirmed by polymerase chain reaction (PCR). According to the biochemical and physiological characteristics, pathogenicity tests, results of PCR analyses and ELISA test, strains isolated from Sorbus spp. plants were identified as E. amylovora. This is the first report of E. amylovora on Sorbus spp. plants in Serbia.

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.

Poslednjih godina na pijacama je uočena učestala pojava truleži korena celera i paštrnaka. Laboratorijskom analizom obolelih biljka prikupljenih iz različitih lokalitata, ispostavilo se da su navedene promene, ispoljene u vidu truleži posledica dejstva fitopatogenih bakterija. U cilju identifikacije izolovanih bakterija proučene su njihove patogene i biohemijsko-fiziološke odlike. Dobijeni rezultati ukazuju da trulež korena celera i paštrnaka prikupljenih sa pijaca u Beogradu, Zemunu i Šapcu prouzrokuje bakterija Pseudomonas marginalis, patogen širokog kruga domaćina koji parazitira brojne zeljaste biljke različitih familija i rodova., The results about pathogenic, and bacteriological properties of bacterial strains isolated from roted celery and parsnips root are given in this paper. Investigated strains showed high level of pathogenicity to artificially inoculated slices of celery, parsnip, parsley, carrot and potato and inoculated immature pepper and tomato fruits. Negative results were recorded in pathogenicity test on artificially inoculated radish slices, onion bulbs as well as sunflower stems. Bacterial strains are Gram negative, aerobe and produce green fluorescent pigment on King medium B. According to LOPAT tests they form levan on nutrient media containing 5% sucrose (NAS), produce oxidase, arginine dihydrolase and pectinase. They do not induce HR in tobacco. Positive results also recorded in following tests: gelatine and Tween 80 hydrolysis, catalase activity, nitrate reduction. They utilize glucose, fructose, sucrose, mannitol, sorbitole but not lactose. Negative results were recorded in following tests: starch hydrolysis, indole and hydrogen sulphide production. According the results obtained it is concluded that investigated strains belong to the same bacterium identified as Pseudomonas marginalis (Brown) Stevens 1925.

Olender (Olender nerii L.) is wide spread ornamental plant on the coast in Montenegro. Symptoms of knots appears on leaves and shoots noticed on oleander plants in Herceg Novi and Bečići during 2005-2007.A number of non levan bacterial strains were islolated on nutrinent sucrose agar (SNA), from the knots on olender leaves and shoots. Investigated strains are Gram negative, oxidative and fluorescent on King, s medium B. They ere negative in oxidase, pectinse and arginin dehidrolase test, while induct HR in tobacco after 24 hours of inoculation. Small pale white knots appear on inoculated oleander leaves three weeks after inoculation, and they are very similar to those recorded in natural infection. Investigated strains do not produced a necrosis on artificially pear and lemon fruits as well as on bean pods. Invstigated strains not hydrolised gelatine and esculine and don't utilized lactose, xilose and DL- lactate; they utilize sucrose and sorbitole. According obtained results and their comparing with literature data we concluded that olenaneder knots in Montengro is caused by Pseudomonas savastanoi pv. nerii. It is the first record of these pathogen in Montenegro., U radu su proučene bakteriološke odlike izolata bakterije izolovane iz tumora formiranih na listovima i mladarima oleandera (Nerium oleander L.). Na osnovu rezultata testova patogenosti, odgajivačkih i biohemijskih karakteristika i njihovim poređenjem sa podacima iz literature zaključeno je da pomenute simptome bolesti na oleanderu prouzrokuje fitopatogena bakterija Pseudomonas savastanoi pv. nerii, ekonomski značajan pathogen ove ukrasne biljke na području Mediterana.

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.