Identifikacija i suzbijanje Cladobotryum spp., prouzrokovača paučinaste plesni šampinjona

Cladobotryum spp. are causal agents of cobweb disease, one of the most serious diseases of cultivated mushroom (Agaricus bisporus (Lange) Imbach) in Serbia and worldwide, which affects product quality and yield. The disease symptoms are: cottony fluffy white or yellowish to pink colonies on mushroom casing, rapid colonization of casing surface, covering of host basidiomata by mycelia, and their decay. Prochloraz-Mn has been officially recommended for mushroom cultivation in EU countries. However, inefficiency of prochloraz- Mn has been noted at a level of spotting symptoms of cobweb disease. With regard to cases of resistance evolution and a general threat to the environment and human health, special attention should be focused on good programmes of hygiene, and inventing and developing alternative methods of disease control.Cladobotryum spp., prouzrokovač paučinaste plesni šampinjona (Agaricus bisporus (Lange) Imbach), nanosi značajne štete u gajilištima ove gljive širom sveta, pa i u Srbiji. Simptomi bolesti su: pojava sivo-belih kolonija nalik paučini na površini pokrivke i pojava smeđih mrlja na površini plodonosnih tela šampinjona. Kolonije gljive su kružnog oblika. Micelija se brzo razvija i pokriva plodonosna tela A. bisporus koja se smežuravaju i trule. Od mnogobrojnih fungicida, zvaničnu preporuku za primenu u gajilištima šampinjona u zemljama EU ima samo fungicid prohloraz. U poslednje vreme uočena je smanjena efikasnost ovog fungicida u oglednim gajilištima u Velikoj Britaniji, koja se manifestovala u nemogućnosti sprečavanja pojave smeđih mrlja, ranih simptoma bolesti. Zbog toga se velika pažnja posvećuje merama primene strogih higijenskih zahteva u gajilištima, kao i razvoju alternativnih metoda zaštite

Morfološke i patogene karakteristike prouzrokovača suve i mokre truleži šampinjona (Agaricus bisporus (Lange) Imbach) u Srbiji

Diseased fruit bodies of Agaricus bisporus, bearing symptoms similar to those caused by Verticillium fungicola and Mycogone perniciosa, were observed during the screening of eight mushroom farms in Serbia in 2002 and 2003. Nine isolates, forming either appressed white or pale brown colonies on PDA medium, were recovered. The isolates were identified on the basis of their morphological, physiological and pathogenic characteristics, and by comparing them to V. fungicola var. fungicola and M. perniciosa isolates originating from United Kingdom, and V. fungicola var. aleophilum from the USA. Pathogenicity of these isolates was confirmed by casing inoculation, on which occasion symptoms of both dry and wet bubble disease were recorded. Five isolates were identified as Verticillium fungicola (Preuss) Hassebrauk var. fungicola (W. Gams & Van Zaayen), and four as Mycogone perniciosa (Magnus) Delacroix.Plodonosna tela Agaricus bisporus sa simptomima nalik onima koje izazivaju Verticillium fungicola i Mycogone perniciosa primećena su u osam gajilišta u Srbiji tokom 2002. i 2003. godine. Dobijeno je 9 izolata patogena koji obrazuju supstratne bele ili svetlo smeđe kolonije na PDA podlozi. Izolati su identifikovani na osnovu morfo-fizioloških karakteristika i patogenih osobina a determinacija potvrđena poređenjem sa kontrolnim izolatima V. fungicola var. fungicola i M. perniciosa iz Velike Britanije i V. fungicola var. aleophilum iz SAD. Veštačkim inokulacijama pokrivke za gajenje A. bisporus, dobijenim izolatima, pojavili su se simptomi suve i mokre truleži. Pet izolata je identifikovano kao Verticillium fungicola (Preuss) Hassebrauk var. fun­gi­co­la (W. Gams & Van Zaayen), a četiri kao Mycogone perniciosa (Magnus) Delacroix

In vitro osetljivost Fusarium graminearum (Schwabe) na difenokonazol, protiokonazol i tiofanat-metil

A survey of in vitro sensitivity of eight isolates of the Fusarium graminearum to the fungicides difenoconazole, prothioconazole and thiophanate-methyl, was undertaken. The isolates were isolated from infected wheat heads collected from 8 different localities in Serbia over the period 2005-2006. Among the tested isolates ZE (RF=11.34), RU (RF=5.98) and AR (RF=5.08) isolates showed moderate resistance to difenoconazole. The EC50 values of this isolates were 19.16, 10.09, and 8.59 mg l-1, respectively. The isolates ZE (RF=5.38) and RU (RF=4.43) also showed the moderate resistance to prothoconazole. The EC50 values were 9.69 and 7.97 mg l-1, respectively. All the isolates tested were the least sensitive to thiophanate- methyl. The EC50 values were in range of 12.1 to 64.03 mg l-1. The highest resistance factor was found for the isolates ZE (RF=5.29).Ispitivana je osetljivost osam izolata Fusarium graminearum na difenokonazol, protiokonazol i tiofanat-metil. Izolati su dobijeni iz zaraženih klasova pšenica sakupljenih tokom 2005. i 2006. godine sa osam različitih lokaliteta iz Srbije. Izolati ZE (RF=11,34), RU (RF=5,98) i AR (RF=5,08) su ispoljili umerenu rezistentnost na difenokonazol. Dobijene EC50 vrednosti ovih izolata bile su 19,16, 10,09, i 8,59 mg l-1. Izolati ZE (RF=5,38) i RU (RF=4,43) su ispoljili umerenu rezistentnost na protiokonazol. Dobijene EC50 vrednosti iznosile su 9,69 i 7,97 mg l-1. Svi ispitivani izolati ispoljili su najmanju osetljivost na tiofanat-metil. Dobijene EC50 vrednosti su bile u opsegu od 12,1 do 64,03 mg l-1. Najveći faktor rezistentnosti je utvrđen kod izolata ZE (RF=5,29)

Morfološke i patogene karakteristike gljive Cladobotryum dendroides, prouzrokovača paučinaste plesni šampinjona Agaricus bisporus u Srbiji

Twenty isolates were isolated from diseased fruiting bodies of Agaricus bisporus collected from Serbian mushroom farms during 2003-2007. The isolates formed white, cottony, aerial colonies on agar media. With age, conidia and colonies turned yellow and redish. Pathogenicity of these isolates was confirmed by inoculation of harvested basidiomes of A. bisporus and by casing inoculation. Symptoms similar to natural infection were recorded. Based on pathogenicity tests and morphological characteristics, the isolates were identified as Cladobotryum dendroides (Bulliard : Fries) W. Gams & Hoozemans.Dvadeset mikrofungalnih izolata je dobijeno iz obolelih plodonosnih tela Agaricus bisporus prikupljenih iz gajilišta u Srbiji u periodu od 2003. do 2007. godine. Izolati su obrazovali bele, vazdušne kolonije na krompir-dekstroznoj podlozi. Nakon nekoliko dana kolonije su poprimile žutu i ružičastu boju. Veštačkim inokulacijama ubranih plodonosnih tela A. bisporus i pokrivke za gajenje šampinjona, pojavili su se simptomi paučinaste plesni. Izolati su identifikovani na osnovu morfoloških i patogenih osobina kao Cladobotryum dendroides (Bulliard : Fries) W. Gams & Hoozemans

Osetljivost genotipova pasulja na Xanthomonas campestris pv. phaseoli u zaštićenom prostoru

Plants of 17 bean genotypes were evaluated under greenhouse conditions for their reaction to X. campestris pv. phaseoli, the causal agent of common blight of beans, following leaf-spray inoculation with bacterial suspension (108 cfu/ml). The plants were evaluated based on the number of leaf lesions, and the disease severity index (DSI) was calculated. The evaluated genotypes showed various levels of susceptibility to X. campestris pv. phaseoli strain VS-1. The results of both experiments showed that the cultivar Oreol was the most resistant. The genotypes: KB 142, HR-45, Tisa and Panonski tetovac also showed low susceptibility with DSI values in the first trial ranging from 2.27 to 3.60. The same genotypes, with the exception of Panonski tetovac, were also categorized as low-susceptible to the bacterium in the second experiment, having the DSI values between 2.27 and 3.60. Most genotypes (Slavonski žutozeleni, Zlatko, Biser, Sremac, Naya Nayahit) were categorized as susceptible in the first experiment, including Panonski tetovac in the second one, while the genotypes Dvadesetica, Prelom and Oplenac displayed the highest susceptibility in both trials.Ispitivana je reakcija 17 genotipova pasulja i boranije na X. campestris. pv. phaseoli, prouzrokovača obične bakteriozne plamenjače pasulja u uslovima staklenika nakon inokulacije biljaka prskanjem bakterijskom suspenzijom (108 ćel/ml). Reakcija biljaka ocenjivana je na osnovu broja pega na lišću i izračunat je indeks oboljenja (IO). Proučavani genotipovi su ispoljili različit nivo osetljivosti na soj bakterije VS-1. U oba ogleda najveću otpornost je ispoljila sorta oreol. Slabo osetljivim genotipovima u prvom ogledu pripadali su genotipovi KB 142, HR-45, tisa i panonski tetovac sa IO 2,73-3,93. Isti genotipovi, osim panonskog tetovca, i u drugom ogledu su svrstani u kategoriju slabo osetljivih (IO 2,27 do 3,60). Najveći broj genotipova pripadao je kategoriji osetljivih (slavonski žutozeleni, zlatko, biser, sremac, Naya Nayahit) u prvom ogledu, a u drugom, pored navedenih genotipova, spada i panonski tetovac. Najveću osetljivost u oba ogleda ispoljile su sorte dvadesetica, prelom i oplenac

Osetljivost patogena šampinjona Verticillium fungicola var. fungicola, Mycogone perniciosa i Cladob otry um sp. na neka etarska ulja

Antifungal activity of 18 essential oils was evaluated against Verticillium fungicola var. fungicola, Mycogone perniciosa and Cladobotryum sp., the causal agents of button mushroom diseases. Essential oils including: turpentine, basil, lemon, mint, fenchel, rose geranium, anise, cinnamon, scots pine, clove, thyme, juniper, lavender, orange, eucalyptus, rosemary, bergamot orange and tea tree, were screened for their effectiveness against the pathogens in vitro. In order to investigate fungicidal activity, isolates were exposed to the volatile phase of the oils for seven days. Of the 18 essential oils analyzed, cinnamon, clove, thyme, and tea tree showed the highest antifungal activity against all investigated mycopathogens, with Minimum Fungicidal Concentration (MFC) being 0.02 μl/ml of air. Turpentine essential oil expressed the lowest antifungal effect to all isolates tested.U radu je ispitivano delovanje 18 etarskih ulja na Verticillium fungicola var. fungicola, Mycogone perniciosa i Cladobotryum sp., prouzrokovače bolesti šampinjona. Ispitano je antifungalno dejstvo etarskih ulja: terpentina, bosiljka, limuna, pitome nane, mora.a, geraniola, anisa, cimeta, bora, karanfili.a, timijana, kleke, lavande, pomorand.e, eukaliptusa, ruzmarina, bergamota i čajnog drveta na porast izolata in vitro. Fungicidni efekat gasovite faze etarskih ulja na izolate je određen nakon ekspozicije od sedam dana. Među 18 proučenih etarskih ulja, cimet, karanfili., timijan i čajno drvo su najtoksičniji za sve izolate mikopatogenih gljiva sa minimalnom fungicidnom koncentracijom od 0.02 μl/ml vazduha. Najslabije inhibitorno dejstvo ispoljila su ulja terpentina na sve testirane izolate

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

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

Clavibacter michiganensis subsp. michiganensis, bakteriozni rak paradajza: 2. Poređenje efikasnosti procedura za ekstrakciju i osetljivosti metoda za detekciju na semenu paradajza

Two seed extraction procedures, used for detection of Clavibacter michiganensis subsp. michiganensis (Cmm) in artifficially infested tomato seed lots, were evaluated. A comparison of the efficiency of pathogen detection by using different extraction methods showed that a grinding procedure was more effective than soaking seed samples. The extraction by grinding resulted in a higher number of samples with Cmm colonies than did the method that included soaking. The detection threshold of Cmm in relation to seed sample size was evaluated by adding different numbers of artificially infested seeds to uninfected samples of 2000 or 5000 seeds. Four detection methods were simultaneously compared for their sensitivity in Cmm detection in seeds: isolation on semiselective media (mSCM, D2ANX, mCNS), direct PCR from seed material, Bio-PCR with initial culturing of bacteria on NBY agar prior to PCR, and Enrichment PCR. The pathogen was detected in samples of 2000 seeds containing one, five and ten infested seeds, in at least two out of three replicates by three detection methods (selective plating, direct PCR and Bio-PCR), using the grinding extraction method with an addition of centrifugation step. In samples of 5000 seeds, five infested seeds were detected in all replicates by the same detection methods. Similar results were obtained by the soaking extraction method. In Enrichment PCR, positive results were obtained only in samples of 2000 seeds containing five and ten infested seeds regardless of the extraction method.Ocenjivane su dve procedure ekstrakcije koje se primenjuju u detekciji Clavibacter michiganensis subsp. michiganensis (Cmm) u uslovima veštačke inokulacije uzoraka semena paradajza. Poređenje efikasnosti detekcije patogena korišćenjem metoda mlevenja i potapanja semena pokazalo je da je metod mlevenja bio efikasniji. Ekstrakcija mlevenjem semena rezultirala je neznatno veæim brojem uzoraka sa kolonijama Cmm nego procedura potapanja semena. Prag detekcije Cmm u zavisnosti od velièine uzorka ocenjivan je dodavanjem različitog broja veštački inokulisanih semena u nezaražene uzorke semena veličine 2000 i 5000 semena. Istovremeno je poređena osetljivost četiri metode za detekciju Cmm na semenu: izolacija na poluselektivne podloge (mSCM, D2ANX, mCNS), direktni PCR iz uzoraka semena, Bio-PCR koji uključuje gajenje bakterija na NBY podlozi pre PCR reakcije i Enrichment PCR. Patogen je detektovan u uzorcima veličine 2000 semena u koje su dodati jedno, pet i deset veštački zaraženih semena, u najmanje dva od tri ponavljanja korišćenjem tri metode za detekciju (izolacija na poluselektivne podloge, direktni PCR i Bio-PCR), nakon ekstrakcije mlevenjem uzoraka. Istim metodama, u uzorcima velièine 5000 semena, pet zaraženih semena je detektovano u svim ponavljanjima. Slični rezultati su dobijeni i nakon ekstrakcije potapanjem semena. U Enrichment PCR reakciji, pozitivni rezultati su dobijeni samo u uzorcima veličine 2000 semena u koje je dodato pet i deset zaraženih semena nezavisno od toga koja je procedura ekstrakcije korišćena