Uticaj etarskih ulja timijana, cimeta i karanfilića na porast micelije Colletotrichum acutatum

Effects of the volatile phase of thyme, cinnamon and clove essential oils on Colletotrichum acutatum were investigated. Mycelial disc was placed in the center of the Petri dish (V=66 ml) containing PDA. Different volumes of either non- or ethanol-diluted essential oils were placed on the inner side of the dish cover to obtain final concentrations of 153, 107, 76, 46, 15, 14, 12, 11, 7.6, 3.82, 1.53, 0.153 and 0.0153 μl/L of air. The dishes were sealed with Parafilm and incubated in up-side-down position. After 7 days of incubation, mycelial growth was recorded by measuring the colony diameter. If no mycelial growth was recorded, the disc was transferred to a new PDA plate in order to evaluate whether the activity was either fungistatic or fungicidal. Mean growth values were obtained and then converted to inhibition percentage of mycelial growth compared with the control treatment. All the tested essential oils inhibited mycelial growth of C. acutatum in the dose dependent manner. Mycelial growth was totally inhibited by thyme oil in the concentration of 76 μl/L of air. The same results were obtained by cinnamon and clove oil in the concentration of 107 μl/L of air. Thyme and cinnamon oil had fungicidal effect in concentrations of 107 and 153 μl/L respectively. The results obtained provide evidence on the antifungal in vitro effect of the tested essential oils as potential means for the control of C. acutatum.Proučavan je efekat isparljive faze etarskih ulja timijana, cimeta i karanfilića na prouzrokovača antraknoze jagode Colletotrichum acutatum u uslovima in vitro. Fragmenti micelije gljive, prečnika 1 cm, zasejani su na KDA podlogu u petri-kutije (V = 66 ml). Različite koncentracije etarskih ulja (153, 107, 76, 46, 15, 14, 12, 11, 7,6, 3,82, 1,53, 0,153 i 0,0153 μl/l vazduha) dobijene su nanošenjem određene količine ulja, koncentrovanih ili razblaženih u etanolu, na središnji deo unutrašnje strane poklopca. Petri-kutije su zatvorene parafilmom i postavljene u obrnuti položaj, a porast micelije je meren posle 7 dana inkubacije. U kulturama u kojima nije došlo do porasta micelije fungicidno ili fungitoksično dejstvo određeno je prebacivanjem fragmenata na KDA podloge bez prisustva ulja. Efekat etarskih ulja predstavljen je procentom inhibicije porasta micelije, poređenjem sa kontrolom. Proučavana etarska ulja timijana, cimeta i karanfilića su svojom gasovitom fazom inhibirala porast micelije C. acutatum. Stepen inhibicije zavisio je od primenjene koncentracije. Etarsko ulje timijana je potpuno inhibiralo porast micelije pri koncentraciji 76 μl/l vazduha, a cimeta i karanfilića pri koncentraciji 107 μl/l vazduha. Fungicidno dejstvo ispoljilo je etarsko ulje timijana u koncentraciji 107 μl/l vazduha i cimeta u koncentraciji 153 μl/l vazduha. Rezultati istraživanja in vitro pokazali su antifungalno dejstvo testiranih etarskih ulja, što govori o potencijalu korišćenja etarskih ulja u kontroli C. acutatum

Utvrđivanje prisustva Colletotrichum acutatum u latentno zaraženom lišću i lisnim drškama jagode

Colletotrichum acutatum is the most significant agent of anthracnose strawberry fruit rot. Besides being a necrotrophic pest, it can spend a part of its life cycle as an epiphyte, in a form of latent infection. The presence of the fungi on symptomless plant tissue is considered one of the main ways of distribution of this economically harmful pathogen in the world. Investigation of latent C. acutatum infection was carried out on artificially inoculated strawberries. The initiation of fungi sporulation on symptomless petioles and leaves was carried out by exposing them to the herbicide paraquat (0.25%) and low temperatures, which caused plant tissue decay in different ways. Surface sterilization with 0.5% NaOCl precedes the exposure of plant material to paraquat. The freezing procedure was carried out by exposure of plant material to the temperature of -20°C for 2h. After the freezing, one group was rinsed in Tween 20 (18 μl/l), and another group underwent surface sterilization in 0.0525% NaOCl with an addition of Tween 20 (18 μl/l). After 6 days of incubation, the appearance of acervuli and conidia was detected in 93.33 to 100% plant parts exposed to paraquat treatment and freezing procedure. In inoculated parts which were not exposed to herbicides or low temperatures, the presence of acervuli was detected in 3.33% tested petioles and 6.67% leaves.Colletotrichum acutatum je najznačajniji prouzrokovač antraknoznog propadanja plodova jagode. Pored nekrotrofnog načina parazitiranja, deo svog životnog ciklusa može da provede kao epifit i to u vidu latentnih zaraza. Prisustvo gljive na asimptomatičnom biljnom tkivu smatra se jednim od glavnih načina širenja ovog ekonomski štetnog patogena u svetu. Ispitivanja latentne zaraze C. acutatum urađena su na veštački inokulisanim jagodama. Iniciranje sporulacije gljive na asimptomatičnim lisnim drškama i lišću urađeno je izlaganjem biljnog tkiva delovanju herbicida parakvata, kao i niskim temperaturama, koji na različite načine izazivaju propadanje biljnog tkiva. Izlaganju asimptomatičnih biljnih delova delovanju parakvata (0,25%), prethodila je površinska sterilizacija 0,5% NaOCl. Postupak smrzavanja urađen je izlaganjem biljnih delova temperaturi od -20oC u trajanju od 2 h. Posle smrzavanja jedna grupa je isprana Tween 20 (18 μl/l), a druga grupa je površinski sterilisana 0,0525% NaOCl uz dodatak Tween 20 (18 μl/l). Posle šest dana inkubacije, pojava acervula i konidija detektovana je u 93,33% do 100% lisnih delova izloženih delovanju parakvata ili postupcima smrzavanja. U inokulisanim biljnim delovima koji nisu izlagani delovanju herbicida ili niskih temperatura, sporulacija je detektovana kod 3,33% testiranih lisnih drški, odnosno 6,67% lišća

Morfološke, serološke i molekularne analize prouzrokovača antraknoze ploda banane

Two species of the genus Colletotrichum, C. musae and C. gloeosporoides, occur as infecting species of banana. The study focused on examining the etiology of anthracnose on banana fruits sold on the domestic market. An isolate was obtained from a deseased banana fruit on PDA medium, forming a white colony with intensive and uniformed growth. It was not possible to identify the isolated fungus based on its morphological characteristics. Positive serological reaction in an ELISA test with monoclonal antibodies for C. acutatum indicated an antigen site for the used monoclonal antibodies. Positive reaction when C. gloeosporioides-specific primers were applied indicated a similarity in the ITS sequence of the fungus and the examined isolate from banana fruit. Although there are no available data in literature that C. gloeosporioides-specific CgInt primer can be used for amplification of the phylogenetically related C. musae, our results do not exclude that the isolate could be C. musae. The host plant, symptoms observed and colony characteristics of the fungus isolated from the banana fruit mostly correspond to C. musae. Based on morphological, antigen and gentic characteristics, the isolate from banana was determined as Colletotrichum sp., while species identification of the anthracnose-causing agent on banana requires additional analysis.Na banani se javljaju dve vrste iz roda Colletotrichum, C. musae i C. gloeosporoides. Cilj ovog rada bio je ispitivanje etiologije antraknoznog propadanja plodova banane koje se u našoj zemlji nalaze u prometu. Iz obolelog ploda banane dobijen je izolat koji na PDA podlozi formira koloniju bele boje sa intenzivnim uniformnim rastom. Na osnovu dobijenih morfoloških osobina izolovane gljive nije se mogla definitivno uraditi identifikacija. Pozitivna serološka reakcija u ELISA testu sa monoklonalnim antitelima za C. acutatum govori o postojanju antigenog mesta za korišćena monoklonalna antitela. Pozitivna reakcija korišćenjem prajmera specifičnih za C. gloeosporioides ukazuje na sličnost u sekvenci ITS regiona ove gljive i ispitivanog izolata iz banane. Mada u literaturi nije zabeleženo da se korišćenjem CgInt prajmera specifičnog za C. gloeosporioides može amplifikovati i njemu filogenetski bliska C. musae, ovi rezultati ne isključuju mogućnost da je izolat iz banane C. musae. Biljka domaćin, zabeleženi simptomi i osobine kolonije izolata iz banane najviše odgovaraju C. musae. Na osnovu dobijenih rezultata morfoloških, antigenih i genetskih osobina izolat iz banane označen je kao Colletotrichum sp., a za tačnu identifikaciju prouzrokovača antraknoze ploda banane do nivoa vrste neophodno je sprovesti dalje analize

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

Karakteristike sojeva bakterija roda Pseudomonas izolovanih iz obolelih grana šljive

Characteristics of Pseudomonas syringae strains isolated from diseased plum trees are presented is this paper. Based on pathogenic, biochemical and physiological characteristics, isolated starins were divided into two groups: First group of strains, isolated from diseased plum branches with symptoms of suden decay, was simillar to Pseudomonas syringae pv. syringae; second group of strains, isolated from necrotic flower buds on plum trees, exhibited characteristics simillar to Pseudomonas syringae pv. morsprunorum. In addition, phytopathogenic fungi belonging to genera Phomopsis, Botryosphaeria and Leucostoma, were also isolated from diseased plum trees. Further study of these pathogens and their role in the epidemiology of suden plum trees decay is in progress.U radu su prikazane karakteristike sojeva bakterije Pseudomonas syringae izolovanih iz nekrozom zahvaćenih tkiva šljive. Na osnovu patogenih i biohemijsko-fizioloških odlika proučavane izolate smo svrstali u dve grupe: I grupa sojeva izolovana je iz obolelih grana šljive sa simptomima sušenja i oni su prema svojim odlikama slični Pseudomonas syringae pv. syringae; II grupa sojeva izolovana je iz nekrotičnih cvetnih pupoljaka šljive i oni ispoljavaju karakteristike tipične za Pseudomonas syringae pv. morsprunorum. Iz obolelih grana šljive, pored ovih bakterija, izolovane su i gljive rodova Phomopsis, Botryosphaeria i Leucostoma. Dalja proučavanja ovih patogena i njihova uloga u pojavi iznenadnog sušenja mladih stabala šljive su u toku

Energy Efficiency and Sustainability of Biofibres-Based Thermal Insulation

Energy efficiency of residential and commercial buildings is acutely important as this sector is responsible for approximately 40% of overall energy consumption and around 35% of CO2 emissions (in the European Union). The construction sector has intense environmental footprint due to exploitation of non-renewable material and energy resources, land use and generation of waste materials during construction and demolition. It is therefore important to develop sustainable building structures, practices and materials with minimal resources and energy use. Utilization of energy efficient, sustainable and resource-saving building materials is of particular importance. The study is carried out to investigate possibilities and evaluate effects of application of biofibres-based structures as non-constructive and/or insulating materials in current building practice. Focus is on natural, dominantly cellulose, fibres, traditionally used in the past (hemp, reed, straw, flax, rice hulls, cotton stalks, sunflower, cattail, bagasse, etc) as well as on some promising grass/reed cultures, such as Miscanthus x Giganteus. The experimental examinations of thermal and mechanical properties decisive for the performance of thermal insulation have been undertaken. Expectedly, the thermal conductivity, as the material characteristic primarily responsible for Operational Energy Consumption, has been found mostly worse than in commonly used, mass produced, thermal insulation materials such as expanded or extruded polystyrene, glass or mineral wool, etc. On the other hand, conclusions of Life Cycle Analysis and examination of Embodied Energy advocates the utilization of designated natural biofibres-based thermal insulation as more sustainable and in the long run (Cradle to Grave) energy efficient alternative to the conventional insulation materials

Morphological, serological and molecular analyses of anthracnose-causing agent on banana fruit

Two species of the genus Colletotrichum, C. musae and C. gloeosporoides, occur as infecting species of banana. The study focused on examining the etiology of anthracnose on banana fruits sold on the domestic market. An isolate was obtained from a deseased banana fruit on PDA medium, forming a white colony with intensive and uniformed growth. It was not possible to identify the isolated fungus based on its morphological characteristics. Positive serological reaction in an ELISA test with monoclonal antibodies for C. acutatum indicated an antigen site for the used monoclonal antibodies. Positive reaction when C. gloeosporioides-specific primers were applied indicated a similarity in the ITS sequence ofthe fungus and the examined isolate from banana fruit. Although there are no available data in literature that C. gloeosporioides-specific CgInt primer can be used for amplification of the phylogenetically related C. musae, our results do not exclude that the isolate could be C. musae. The host plant, symptoms observed and colony characteristics of the fungus isolated from the banana fruit mostly correspond to C. musae. Based on morphological, antigenand gentic characteristics, the isolate from banana was determined as Colletotrichum sp., while species identification of the anthracnose-causing agent on banana requires additional analysis

Fuzariotoksini u zrnu pšenice u Srbiji

Samples of wheat grain (41), collected during the 2010 harvest from seven localities in Serbia, were analysed for the presence of zearalenone (ZEA), T-2 toxin, deoxynivalenol (DON) and fumonisine B1 (FB1). Results of Enzyme-Linked Immunosorbent Assay (ELISA) showed that all analysed samples were positive for the presence of at least one of four observed fusariotoxins. The most distributed mycotoxins were ZEA (90.2%, with the average concentration of 442.6μg kg–1) and T-2 (90.2%, with the average concentration of 24.2 μg kg–1). DON (73.2%) and FB1 (84.4%) were detected in a somewhat smaller number of samples, but their average concentrations were higher (1988.1 μg DON kg–1 and 882.7 μg FB1 kg–1). The established correlations between concentrations of DON and FB1 (r = 0.32) or DON and ZEA (r = 0.22) were not statistically significant. A negative correlation was established between concentrations of T-2 and FB1 (r= -0.24), as well as, between T-2 and DON (r = -0.36). Detected concentrations of ZEA and T-2 were bellow the level prescribed by the World Health Organisation (WHO), while concentrations of FB1 and DON detected in five that is, 17 samples, respectively, were above the permissible limit for human consumption.Uzorci zrna pšenice (41), sakupljeni tokom žetve 2010. godine iz 7 različitih lokaliteta na teritoriji Srbije, analizirani su na prisustvo ZEA, T-2 toksina, deoksinivalenola (DON) i FB1. Primenom ELISA metode utvrđeno je da su svi analizirani uzorci bili pozitivni na prisustvo bar jednog od četiri ispitivana fuzariotoksina. Najzastupljeniji mikotoksini su bili ZEA (90,2%, prosečne koncentracije 442,6 μg kg–1) i T-2 (90,2%, prosečna koncentracija 24,2 kg–1). U nešto manjem broju uzoraka utvrđeni su DON (73,2%) i FB1 (84,4%), ali u većoj prosečnoj koncentraciji (1988,1 μg DON kg–1 i 882,7 μg FB1 kg–1). Nije utvrđena statistički značajna korelacija između koncentracije DON i FB1 (r = 0,32) ili DON i ZEA (r = 0,22). Negativna korelacija je utvrđena između koncentracije T-2 i FB1 (r = -0,24), kao i između T-2 i DON (r = -0,36). Detektovane koncentracije ZEA i T-2 bile su niže od nivoa koji propisuje Svetska zdravstvena organizacija, dok su FB1 i DON detektovani kod 5, odnosno 17 uzoraka u koncentraciji većoj od dozvoljenih u ljudskoj hrani

Molekularna detekcija Monilinia fructigena prouzrokovača truleži ploda dunje

Species of the genus Monilinia are important causal agents of fruit rot on pome and stone fruits in Serbia. The pathogen is very harmful, especially on small properties and cottage plantations where intensive control measures are not applied. Quince is important host for the pathogens of this genus. During spring 2010, intensive occurrence of mummified fruits overwintering on branches of the quince was observed. The pathogen was isolated using standard phytopathological methods. Pathogenicity of eight obtained isolates was tested by artificial inoculation of injured apple fruits. Identification was performed according to pathogenic, morphological and ecological properties, and was confirmed by Multiplex polimeraze chain reaction, PCR. All the isolates studied caused brown rot on inoculated apple fruits. The isolates form light yellow colonies with lobate margins, with single-celled, transparent, elliptical or oval conidia in chains, regardless temperature or light presence. Sclerotia are observed in 14 days old cultures. The highest growth rate of most of the isolates is at 27°C and in dark. Based on studied pathogenic, morphological and ecological characteristics, it was found that the Monilinia fructigena is causal agent of brown rot of quince. Using specific primers (MO368-5, MO368-8R, MO368-10R, Laxa-R2) for detection of Monilinia species in Multiplex PCR reaction, the expected fragment 402 bp in size was amplified, which confirmed that the studied isolates belonged to the species M. fructigena.Vrste roda Monilinia su značajni prouzrokovači truleži ploda jabučastog i koštičavog voća u našoj zemlji. Parazit nanosi velike štete, posebno na malim posedima i u vikend zasadima u kojima se ne primenjuje redovna zaštita. Dunja je značajan domaćin patogena ovog roda. Tokom proleća 2010. godine ustanovljena je intenzivnija pojava mumificiranih plodova prezimelih na granama. Cilj ovog rada bio je da se identifikuje prouzrokovač mumifikacije plodova dunje, prikupljenih sa različitih lokaliteta. Patogen je izolovan primenom standardnih fitopatoloških metoda. Patogenost osam dobijenih izolata proverena je veštačkom inokulacijom povređenih plodova jabuke. Identifikacija je obavljena na osnovu patogenih, morfoloških i ekoloških osobina, a potvrđena je primenom Multiplex PCR. Svi proučavani izolati su na inokulisanim plodovima jabuke prouzrokovali trulež smeđe boje. Proučavani izolati na KDA podlozi formiraju svetlo-žute kolonije režnjevitog oboda. U kulturi gljiva, nezavisno od uticaja temperature i prisustva ili odsustva svetlosti, formira jednoćelijske, providne, eliptične ili ovalne konidije u nizovima. Sklerocije se uočavaju u kulturama starosti 14 dana. Većina izolata ostvaruje najbolji porast na temperaturi od 27°C i u odsustvu svetlosti. Na osnovu proučenih patogenih, morfoloških i odgajivačkih odlika, utvrđeno je da izolati pripadaju vrsti Monilinia fructigena. Korišćenjem specifičnih prajmera (MO368-5, MO368-8R, MO368-10R, Laxa-R2) za detekciju vrsta roda Monilinia u Multiplex PCR reakciji, amplifikovan je očekivani fragment veličine oko 402 bp čime je potvrđeno da proučavani izolati pripadaju vrsti M. fructigena