11 research outputs found
Pectobacterium carotovorum subsp. carotovorum – prouzrokovač vlažne truleži biljaka kale u Srbiji i Crnoj Gori
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
Impact of climatic conditions on outbreaks of bacterial spot on tomato and pepper caused by Xanthomonas vesicatoria and Xanthomonas euvesicatoria
Seed-borne bacterial pathogens of tomato and pepper are of major concern worldwide. Xanthomonas vesicatoria (Xv) and Xanthomonas euvesicatoria (Xe), the causal agents of bacterial leaf spot, and Clavibacter michiganensis subsp. michiganensis (Cmm), the causal agent of tomato bacterial canker, are worldwide distributed, but the occurrence of the latter is usually erratic. In order to evaluate the risk of seed transmission and the relationship between seed contamination and disease outbreak, an extensive field trial has been put in place in 2013 for each pathosystem. Three artificially contamination levels were considered, composed of 100 seedlings each. Disease outbreaks were weekly monitored during the growing season until harvesting and disease was quantified by means of AUDPC. Seeds were produced from each plot and analysed in order to assess their contamination level. Preliminary results of our studies showed that disease quantity caused by Xv, Cmm or Xe was directly correlated to the percentage of initial infection, according to AUDPC values obtained. Contamination rate of seed produced in diseased fields was not always correlated with disease quantity observed. A microbial consortium, a bacterial antagonist and a plant polyphenol were assayed to assess their potential efficacy in seed disinfection: naturally contaminated tomato and pepper seeds were treated and sown. Pepper and tomato seedlings were inspected and analysed for the presence of bacterial spot. Preliminary results obtained show that none of the above mentioned treatments was able to eradicate the pathogen from seeds
Diferencijacija fitopatogenih vrsta roda Agrobacterium
Due to the difficulties in differentiation of phytopathogenic Agrobacterium spp. and
lack of a standardized protocol, we carried out selection and evaluation of suitable methods
based on the bacterial physiological, genetic and pathogenic properties. Strains of
Agrobacterium tumefaciens, A. rhizogenes and A. vitis were differentiated using standard bacteriological
and molecular methods. The biochemical and physiological tests confirmed
authenticity of the strains. Two duplex PCR methods were conducted with four different
primer pairs. In all strains, presence of plasmid virD2 and virC pathogenicity genes was
detected. Chromosomal pehA gene was determined in A. vitis strain. Pathogenicity was
confirmed on carrot slices and young plants of tomato and sunflower. Strains of A. tumefaciens
and A. vitis were pathogenic on all test plants, while strain of A. rhizogenes induced
characteristic symptoms only on carrot slices. The tests used in this study provided reliable
discrimination between the three species and confirmed their identity as tumorigenic (Ti)
Agrobacterium tumefaciens and A. vitis, and rhizogenic (Ri) A. rhizogenes.Usled poteškoća u razlikovanju vrsta roda Agrobacterium i nedostatka standardizovanog
protokola izvršena je procena i odabir pogodnih metoda u cilju njihove diferencijacije
na osnovu fizioloških, genetskih i patogenih odlika. Diferencirani su sojevi Agrobacterium
tumefaciens, A. rhizogenes i A. vitis primenom standardnih bakterioloških i molekularnih metoda.
Primenom diferencijalnih testova sojevi su ispoljili očekivane biohemijsko-fiziološke
karakteristike. Izvedene su dve „duplex“ PCR metode sa 4 različita tipa prajmera. Kod proučavanih
sojeva detektovano je prisustvo virD2 i virC gena patogenosti, koji se nalaze na plazmidnoj
DNK bakterije. Prisustvo hromozomskog gena pehA, odgovornog za sintezu enzima
poligalakturonaze, utvrđeno je kod soja A. vitis. Patogenost je proverena na kriškama mrkve
i mladim biljkama paradajza i suncokreta. Sojevi A. tumefaciens i A. vitis bili su tumorogeni
na svim test biljkama, dok je soj A. rhizogenes ispoljio patogenost jedino na kriškama mrkve.
Na osnovu dobijenih rezultata, proučavani sojevi diferencirani su kao tumorogeni (Ti) Agrobacterium
tumefaciens i A. vitis, i kao rizogeni (Ri) A. rhizogenes
61 Analiza masnih kiselina sojeva Erwinia amylovora iz Srbije i Crne Gore
Automated method of fatty acid analysis was used to identify and study heterogeneity of
41 Erwinia amylovora strains, originating from 8 plant species grown in 13 locations in Serbia and
one in Montenegro. All strains contained 14:0 3OH fatty acid, characteristic for the “amylovora”
group. According to fatty acid composition 39 strains were identified as E. amylovora as the first
choice from the database. Due to their specific fatty acid composition, two strains were identified
as E. amylovora, but as a second choice. Fatty acid analysis also showed that E. amylovora
population from Serbia could be differentiated in three groups, designated in this study as
α, β and γ. All strains originating from central or south Serbia, as well as four strains from north
Serbia clustered into group α. Group β and γ contained only strains isolated in northern Serbia
(Vojvodina). The results show that E. amylovora population in this area is heterogeneous and
indicate pathogen introduction from different directions. Fatty acid analysis enabled identification
at species level, as well as new insights of heterogeneity of E. amylovora population.Automatizovana metoda analize masnih kiselina primenjena je za identifikaciju i proučavanje
heterogenosti Erwinia amylovora. Kao materijal za analizu prikupljen je 41 soj E.
amylovora izolovan iz 8 različitih vrsta domaćina gajenih u 13 lokaliteta u Srbiji i jednom lokalitetu
u Crnoj Gori. Rezultati ukazuju da svi proučavani sojevi poseduju 14:0 3OH masnu
kiselinu, koja je karakteristična za „amylovora“ grupu. Na osnovu sastava masnih kiselina 39
sojeva je identifikovano kao E. amylovora, kao prvi izbor iz baze podataka. Dva soja su identifikovana
kao E. amylovora, ali tek kao drugi izbor iz baze podataka, što je najverovatnije
posledica specifičnosti u sastavu njihovih masnih kiselina. Rezultati analize masnih kiselina
takođe pokazuju da populacija E. amylovora poreklom iz Srbije nije homogena i da među
sojevima postoje tri grupe ili profila, koji su u ovom radu obeleženi sa α, β i γ. Svi sojevi koji
su izolovani na prostoru centralne ili južne Srbije pripadaju grupi α, kao i četiri soja izolovana
na području Vojvodine. Grupama β i γ pripadaju samo sojevi izolovani na području Vojvodine.
Dobijeni rezultati predstavljaju dokaz heterogenosti populacije E. amylovora na ovim
prostorima i ukazuju na mogućnost prodora patogena u naše područje iz različitih pravaca.
Analiza masnih kiselina omogućila je ne samo identifikaciju do nivoa vrste, već i nova saznanja
o heterogenosti populacije E. amylovora na ovim prostorima
Karakterizacija sojeva Xanthomonas euvesicatoria, patogena paprike u Srbiji
During spring and summer of 2008, 101 bacterial strains was isolated from the diseased
pepper leaves collected from different pepper growing areas in the Republic of Serbia. The
aim of this research was to characterize the isolated strains and determine their taxonomic
position according to the most recent nomenclature.
Pathogenic, biochemical and physiological characteristics of isolated bacteria were
tested using standard bacteriological tests. The pathogen races were determined according
to the reaction of differential varieties of Early Calwonder (ECW), their isogenic lines
(ECW-10R, ECW-20R, ECW-30R) and Capsicum pubescens. The sensitivity of strains to bactericides
was studied in vitro by culturing bacteria on sucrose pepton agar (SPA) plates, amended
with filter-sterilized aqueous solution of streptomycin and kasugamycin (50, 100, 200
ppm) or copper-sulphate (100, 200 ppm).
Based on pathogenic, biochemical and physiological characteristics, the investigated
strains belonged to Xanthomonas euvesicatoria. The reaction of pepper differential varieties
indicated that these strains belonged to pepper races P1, P3, P7, P8. Streptomycin resistant
strains were not detected, but 6 strains were resistant to kasugamycin (50 ppm) and 13
strains to copper-sulphate (200 ppm), indicating bacterial resistance development.Tokom 2008. godine prikupljeni su uzorci obolelog lišća paprike sa simptomima bakteriozne
pegavosti iz različitih lokaliteta Republike Srbije. Izolacijom iz zaraženih listova dobijen
je 101 soj bakterija. Cilj ovog rada je proučavanje odlika i identifikacija izolovanih sojeva
bakterije u skladu sa najnovijom nomenklaturom. Patogene i biohemijsko-fiziološke karakteristike
sojeva proučene su korišćenjem standardnih bakterioloških testova. Određivanje fizioloških
rasa bakterijske populacije izvršeno je na osnovu reakcije diferencijalnih sorti paprike
Early Calwonder (ECW), njenih izogenih linija (ECW-10, ECW-20 ECW-30) i reakcijom
sorte Capsicum pubescens. Proučena je osetljivost sojeva u in vitro uslovima na streptomicin,
kasugamicin i bakar-sulfat. Rezultati proučavanja biohemijsko-fizioloških odlika sojeva ukazuju
da naši sojevi pripadaju genetičkoj grupi „A“, odnosno vrsti Xanthomonas euvesicatoria.
Proučavani sojevi, takođe, predstavljaju heterogenu populaciju u kojoj su zastupljene četiri
fiziološke rase bakterije X. euvesicatoria (P1, P3, P7, P8). Sojevi rezistentni na streptomicin nisu
detektovani ovim istraživanjima. Otpornost na 50 ppm kasugamicina utvrđena je kod 6
sojeva, a 13 sojeva je bilo otporno na 200 ppm bakar-sulfata. Prikazani rezultati ukazuju na
opasnost od razvoja rezistentnosti bakterija na ova jedinjenja
The impact of resistance training program on the muscle strength and bone density in adolescent athletes
© 2018 Saša Bubanj et al., published by Sciendo 2018. Strength training and other modes of physical activity may be beneficial in osteoporosis prevention by maximizing bone mineral accrual in childhood and adolescence. This study focuses on the impact of the nine-month long program of resistant exercises with different level of external loads (low, middle and high) on the lower limbs explosive strength and bone tissue density in athletes adolescents aged 17 to 18 years. Sixty healthy, male athletes and non-athletes, divided into experimental (ES, sprinters, N = 45) and control sub-sample (CS, non-athletes, N = 15), were included in study. ES examinees (EG1, EG2 and EG3) were subjected to the program of resistance exercises with low level (60% of the One Repetition Maximum-1RM), middle level (70% 1RM), and high level (85% 1RM) of external loads, respectively. Bone Density values were determined by the use of a clinical sonometer.,Sahara (Hologic, Inc., MA 02154, USA). Explosive strength values of hip extensors and flexors, knee extensors and flexors, and ankle plantar and dorsiflexors were determined by the use of accelerometer.,Myotest (Sion, Switzerland) and the means of Counter Movement Jump without arms swing (CMJ) and half squat. ANOVA method for repeated measures and ANCOVA method were used to determine significant differences and resistance program effects on the lower limbs explosive strength and bone tissue density. Resistance exercise does impact the explosive strength and bone parameters in a way to increase half squat 1RM values, but decreases CMJ values, and increases speed of sound (SOS), broadband ultrasound attenuation (BUA) and bone mineral density (BMD) values in athletes-adolescents, aged 17-18 years
Diferencijacija Pseudomonas syringae patogenih varijeteta poreklom iz koštičavih voćaka
Due to an overlapping host range, similar symptomatology and many common characteristics,
Pseudomonas syringae pathovars originating from stone fruits can easily be misidentified.
In order to select tests for rapid and efficient differentiation of P. s. pvs. syringae,
morsprunorum and persicae, we studied the suitability and differentiating potential of
some standard bacteriological and molecular methods. Differentiation of the strains was
performed using LOPAT, GATTa and ice nucleation tests, nutrient sucrose broth growth
and utilization of various carbon sources. PCR method enabled the detection of toxin-producing
genes: syrB and syrD in P. s. pv. syringae, and cfl gene in P. s. pv. morsprunorum race
1. Syringomycin production by pv. syringae was confirmed in bioassay using Geotrichum
candidum, Saccharomyces cerevisiae and Rhodotorula pilimanae as indicator organisms.
Pathogenicity test on lemon and immature nectarine fruits, as well as on string bean pods,
showed different intensity of reaction of the inoculated material which could separate pv.
syringae from the other two pathovars. PCR-based repetitive sequences, Rep-PCR with
REP, ERIC and BOX primers revealed different genetic profiles within P. syringae pathovars.Patogeni varijeteti Pseudomonas syringae poreklom sa koštičavih voćaka poseduju brojne
zajedničke karakteristike u pogledu kruga domaćina, simptomatologije i biohemijskofizioloških
osobina, što otežava njihovu identifikaciju. U cilju odabira testova pogodnih za
brzu i pouzdanu identifikaciju P. s. pv. syringae, morsprunorum i persicae, primenjeni su standardni
bakteriološki i molekularni testovi. Diferencijacija sojeva izvršena je LOPAT i GATTa
testovima, posmatranjem razvoja u hranljivom rastvoru sa saharozom, sposobnošću sojeva
da formiraju čestice leda, kao i mogućnošću korišćenja različitih ugljenikovih jedinjenja.
PCR metod korišćen je u detekciji gena odgovornih za proizvodnju toksina siringomicina
kod soja P. s. pv. syringae (syrB i syrD geni) i koronatina kod soja P. s. pv. morsprunorum rase 1
(cfl gen). Proizvodnja siringomicina potvrđena je i biotestom, korišćenjem gljiva Geotrichum
candidum, Saccharomyces cerevisiae i Rhodotorula pilimanae kao indikatora. Proverom patogenosti
sojeva na plodovima limuna, nesazrelim plodovima nektarine i mahunama boranije,
došlo je do ispoljavanja simptoma različitog intenziteta, na osnovu kojih se može izdvojiti
pv. syringae od ostala dva patovara. Primenom Rep-PCR metode, uz korišćenje REP, ERIC
i BOX prajmera, ustanovljene su razlike u genetskim profilima proučavanih P. syringae patogenih
varijeteta
Differentiation of Pseudomonas syringae Pathovars Originating from Stone Fruits
Due to an overlapping host range, similar symptomatology and many common characteristics,Pseudomonas syringae pathovars originating from stone fruits can easily be misidentified.In order to select tests for rapid and efficient differentiation of P. s. pvs. syringae,morsprunorum and persicae, we studied the suitability and differentiating potential ofsome standard bacteriological and molecular methods. Differentiation of the strains wasperformed using LOPAT, GATTa and ice nucleation tests, nutrient sucrose broth growthand utilization of various carbon sources. PCR method enabled the detection of toxin-producinggenes: syrB and syrD in P. s. pv. syringae, and cfl gene in P. s. pv. morsprunorum race1. Syringomycin production by pv. syringae was confirmed in bioassay using Geotrichumcandidum, Saccharomyces cerevisiae and Rhodotorula pilimanae as indicator organisms.Pathogenicity test on lemon and immature nectarine fruits, as well as on string bean pods,showed different intensity of reaction of the inoculated material which could separate pv.syringae from the other two pathovars. PCR-based repetitive sequences, Rep-PCR withREP, ERIC and BOX primers revealed different genetic profiles within P. syringae pathovars
Pectobacterium carotovorum subsp. carotovorum prouzrokovač vlažne truleži brokolija u Srbiji
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 37°C, did not produce acid from á-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 37ºC 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
Colletotrichum orbiculare on watermelon: Identification and in vitro inhibition by antagonistic fungi
Anthracnose caused by the fungus Colletotrichum orbiculare is one of the most significant diseases of Cucurbitaceae. In Serbia watermelon fruits with typical anthracnose lesions were collected during the year of 2015. Affected fruits showed sunken, dark brown to black lesions with orange conidial masses produced in black acervuli. In an attempt to identify the causal organism, small pieces of necrotic tissue were surface sterilized and placed on potato dextrose agar (PDA). Macroscopic and microscopic morphologicaly characteristics of three isolates were observed after growth on PDA for 7 days at 25 ºC under a 12 h light/dark cycle. Fungal colonies developed white, grey to black dense aerial mycelium. Conidia were hyaline, aseptate, straight and cylindrical to clavate, 9–12.5 μm × 4–5.5 μm. Fungal isolates were also characterized by sequencing of the internal transcribed spacer (ITS) rDNA region using ITS1F/ITS4 primers and β-tubuline 2 gene using T1/Bt2b primers. The nucleotide sequences were deposited in GenBank (ITS Acc. No. KT454386, KT454387 and KT454388; β-tubuline 2 gene Acc. No. KT581236, KT581237 and KT581238). BLAST analysis of ITS and β-tubuline 2 gene sequences showed that our isolates were 100% identical to other C. orbiculare in NCBI GenBank. Pathogenicity test was conducted on symptomless, detached watermelon fruits. All tested isolates caused anthracnose lesions on watermelon fruits after 10 days of incubation. Trichoderma harzianum (DSM 63059) and Gliocladium roseum (DSM 62726) were evaluated in vitro for their antagonistic potential against C. orbiculare. The results of this study identify T. harzianum and G. roseum as promising biological control agents (BCAs) for further testing against anthracnose disease on watermelon fruits