42 research outputs found
Production characteristics of clones of Italian riesling varieties SK-13, SK-54 and SK-61 on Kober 5BB rootstock under meteorological conditions in 2021 : [abstract]
Chemical analysis of blueberry fruits (Vaccinium corymbosum L.) for pesticide residues in the MaÄva district : [abstract]
Antifungalna aktivnost hitosana prema Alternaria alternata i Colletotrichum gloeosporoides
Chitosan and its derivatives have been reported as a promising alternative for control of postharvest fungal pathogens. The objective of this study was to evaluate in vitro and in situ antifungal activity of chitosan against Alternaria alternata and Colletotrichum gloeosporioides isolated from decayed apple fruits. The fungi were tested in vitro using PDA medium with three concentrations of chitosan (1, 2 and 3 mg/ml). Fungal growth of the test pathogens was significantly affected by all chitosan doses (P lt 0.05) after 7 days of incubation at 25Ā°C. Water solution of 3 mg/ml of chitosan inhibited completely the conidial germination of A. alternata and C. gloeosporioides after 18 h incubation at 25Ā°C. The results obtained from biocontrol assay indicate that the inhibition of postharvest decay of A. alternata and C. gloeosporioides was significantly influenced by chitosan concentrations. Disease incidence in chitosan-treated fruit after 7 days incubation at 25Ā°C was significantly lower than in the positive control for both fungi tested (P lt 0.05). A. alternata and C. gloeosporioides used in this study were progressively inhibited in vitro and in situ with increasing concentrations of chitosan from 1 to 3 mg/ml.Istraživanja pokazuju da su hitosan i njegovi derivati dobra alternativa u kontroli skladiÅ”nih fitopatogenih gljiva. Cilj ovog rada bio je da ispita antifungalnu aktivnost hitosana prema Alternaria alternata i Colletotrichum gloeosporoides, izolovanih sa inficiranih plodova jabuke, u in vitro i in situ uslovima. Rast gljiva je testiran in vitro koristeÄi PDA podlogu sa razliÄitim koncentracijama hitosana (1, 2 i 3 mg/ml). Porast oba patogena je bio znaÄajno smanjen (P lt 0.05) u svim koncentracijama hitosana nakon 7 dana inkubacije na 25Ā°C. Vodeni rastvor hitosana koncentracije 3 mg/ml je u potpunosti inhibirao klijanje konidija A. alternata i C. gloeosporoides nakon inkubacije od 18 sati na temperaturi od 25Ā°C. Rezultati ogleda in situ ukazuju da inhibicija propadanja plodova inficiranih sa A. alternata i C. gloeosporoides zavisi od koncentracije rastvora hitosana. Pojava bolesti na plodovima jabuka tretiranih rastvorom hitosana nakon 7 dana inkubacije na 25Ā°C bila je znaÄajno smanjena za obe vrste gljiva (P lt 0.05) u odnosu na pozitivnu kontrolu. Rast A. alternata i C. gloeosporoides je bio progresivno inhibiran in vitro i in situ sa poveÄanjem koncentracije rastvora hitosana, od 1 do 3 mg/ml
In vitro efekat kalcijumovih soli na gljiviÄne skladiÅ”ne patogene
In the recent years, several studies have shown that calcium salts may have potential as environmentally compatible, nontoxic fungicides for controlling postharvest fungal pathoĀgens. Therefore, the objective of this study was to evaluate and compare the effects of calcium chloride and calcium hydroxide on in vitro mycelial growth, spore germination and germ tube growth of Colletotrichum acutatum, C. gloeosporioides, Alternaria alternata, and Penicillium expansum. The obtained results showed that the fungal isolates grew simĀilarly or stimulated in the presence of 1 and 1.5% calcium salts compared to the control. After seven days of incubation, reduction of mycelial growth was observed only on PDA supplemented with 2% calcium salts. Calcium chloride and calcium hydroxide at 1.5% and 2.0% concentrations significantly decreased spore germination and germ tube growth of all fungal isolates. The results of this study show that the tested calcium salts can be used as a alternative treatment against postharvest fungal pathogens C. acutatum, C. gloeosporioides, A. alternata and P. expansum.Tokom poslednjih nekoliko godina, viÅ”e studija je pokazalo da u kontroli gljiviÄnih skladiÅ”nih patogena soli kalcijuma mogu imati potencijal kao ekoloÅ”ki kompatibilni, netoksiÄni fungicidi. Stoga je cilj ovog istraživanja bio da se u in vitro uslovima procene i uporede efekti kalcijum hlorida i kalcijum hidroksida na porast micelije, klijavost konidija i rast klicine cevi gljiva C. acutatum, C. gloeosporioides, A. alternata, i P. expansum. Dobijeni rezultati su pokazali da je u prisustvu 1 i 1,5% kalcijumovih soli porast izolata gljiva u tretmanima sliÄan ili poveÄan u odnosu na kontrolu. Nakon 7 dana inkubacije, redukcija porasta micelije je utvÄena samo na PDA podlozi sa 2% soli kalcijuma. Kalcijum hlorid i kalcijum hidroksid u koncentracijama od 1,5 i 2,0% znaÄajno smanjuju klijavost konidija i rast klicinih cevi svih ispitivanih izolata gljiva. Rezultati ove studije pokazuju da se testirane soli kalcijuma mogu primeniti kao alternativni tretman u kontroli gljiviÄnih skladiÅ”nih patogena, C. acutatum, C. gloeosporioides, A. alternata i P. expansum
Colletotrichum fioriniae prouzrokovaÄ antraknoze plodova kruÅ”ke
KruÅ”ka (Pyrus communis L.) je jedna od najstarijih i najrasprostranjenijih voÄarskih
kultura. Plodovi kruŔke su izrazito bogati nutrijentima i niskog glikemijskog indeksa, pa se
preporuÄuju u ishrani svih kategorija stanovniÅ”tva. U periodu vegetacije i nakon berbe
propadanje plodova kruÅ”ke mogu izazvati brojni biljni patogeni, meÄu kojima su i gljive roda
Colletotricum.
Tokom jeseni 2021. godine iz skladiŔta u okolini Smedereva sakupljeni su plodovi
kruŔke (cv. Santa Maria) sa simptomima antraknoze. Na povrŔini svih inficiranih plodova bile
su prisutne tamne, kružne, udubljene nekrotiÄne lezije sa koncentriÄno rasporeÄenim
acervulima i narandžastom konidijalnom masom. Izolacija patogena je obavljena standarnim
fitopatoloŔkim metodama na podlozi od krompir-dekstroznog agara (KDA). Svi dobijeni izolati
su nakon 7 dana na KDA i temperaturi od 25ā°C ispoljili uniformne morfoloÅ”ke osobine.
Formirane kolonije su bile svetlosive do svetloružiÄaste, sa naliÄja tamnoružiÄaste do
vinastocrvene boje. ProseÄan porast kolonija je iznosio 64Ā±2 mm. Konidije su bile hijalinske,
fuziformne, neseptirane, glatkih zidova, sa oba zaoÅ”trena kraja, veliÄine 12,8 - 16,6 Ć 3,5 ā 4,4
Āµm (n=100); a apresorije pojedinaÄne, tamnobraon boje, okrugle do nepravilnog oblika,
glatkih zidova, veliÄine 5,5 ā 9,6 Ć 4,8 ā 7,2 Āµm (n=20). MorfoloÅ”ke karakteristike izolata su
odgovarale literaturnom opisu C. acutatum species complex.
Molekularna identifikacija reprezentativnog izolata SZ-21-36 je obavljena na osnovu
ITS regiona rDNA koriÅ”Äenjem prajmera ITS1/ITS4; dela gena za beta tubulin (Ben A)
primenom prajmera Bt2a/Bt2b; gliceraldehid 3 - fosfat dehidrogenaze (GAPDH) sa
prajmerima GDF1/GDR1, i dela aktin gena (ACT) upotrebom prajmera ACT512F/ACT783R.
Dobijeni PCR produkti su sekvencirani, a nukleotidne sekvence deponovane u GenBank bazi
podataka. BLAST analizom je utvrÄeno da su sekvence ON171625 (ITS) i ON186698 (ACT)
99% sliÄne, a sekvence ON186696 (BenA) i ON186697 (GAPDH) identiÄne sa sekvencama
istih regiona izolata vrste C. fioriniae deponovanih u GenBank bazi. Multilokus filogenetska
analiza zasnovana na navedenim molekularnim markerima je potvrdila rezultate BLAST-a, i
svrstala izolat SZ-21-36 sa ostalim izolatima C. fioriniae iz GenBank baze podataka (100%
bootstrap podrŔka).
Provera patogenosti izolata obavljena je inokulacijom sa 50 Ī¼l suspenzije spora (1 Ć
106 konidija/ml) u prethodno napravljene povrede na zdravim plodovima kruŔke (cv. Santa
Maria). Kontrolni plodovi su inokulisani sterilnom destilovanom vodom. Nakon 10 dana
inkubacije u vlažnoj komori na 25Ā°C na svim inokulisanim plodovima kruÅ”ke razvili su se
tipiÄni simptomi antraknoze, dok su kontrolni plodovi bili bez simptoma. Kulture dobijene reizolacijom bile su istih morfoloÅ”kih karakteristika Äime je potvrÄena patogenost testiranih
izolata.
U ovom istraživanju je konvencionalnim i molekularnim metodama prvi put u Srbiji
identifikovana vrsta C. fioriniae - prouzrokovaÄ antraknoze plodova kruÅ”ke
Pseudomonas syringae - prouzrokovaÄ nekroze plodova treÅ”nje
Severe symptoms of necrosis sweet cherry fruits was recorded during 2014. in region of Å abac. 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 prouÄavanja sojeva bakterija izolovanih iz nekrotiÄnih plodova treÅ”nje sorte Samit (podruÄje Å apca). Nekroza zahvata u proseku oko 1/3 ploda koji potpuno gubi tržiÅ”nu vrednost. BoleÅ”Äu biva zahvaÄeno oko 30% plodova. Primenom standardnih bakterioloÅ”kih metoda (izolacijom na hranljivim podlogama), proverom patogenosti i prouÄavanjem bakterioloÅ”kih karakteristika, zakljuÄeno je da pomenute simptome prouzrokuje fitopatogena bakterija Pseudomonas syringae, Å”iroko rasprostranjen patogen naroÄito koÅ”tiÄavih voÄaka
Polyphasic identification of decay agents of lemon fruits in Serbia
Lemon fruits are an important source of vitamin C, potassium, folate, carotenoids, polyphenols, coumarins and terpenes. These lemon compounds have antioxidant and anti-inflammatory properties which have beneficial effects on human health. This re- search aimed to elucidate the etiology of blue and green molds detected on lemon fruits in Serbia. Using integrative identification approach, the obtained isolates were characterized from morphological, physiological, molecular, phylogenetic and pathological aspects. Col- ony growth and morphology were examined on Czapek yeast autolysate agar (CYA), Malt extract agar (MEA) and Creatine sucrose agar (CREA), and on CYA at two additional incu- bation temperatures (5 and 37 Ā°C). For molecular identification, ITS and partial Ī²-tubulin (BenA) genes were sequenced. Phylogenetic relationships were investigated using maximumlikelihood method. A pathogenicity test was carried out and the possible difference in pathogenicity among isolates was assessed with analysis of variance (ANOVA) and subsequent Tukeyās test. Four species were identified: Penicillium expansum, Penicillium digitatum, Penicillium polonicum and Talaromyces rugulosus. All four species proved to be pathogenic on lemon fruits, producing symptoms similar to those observed on naturally infected fruits. The results of this study are the first records of the beforementioned Penicillium/ Talaromyces species as postharvest pathogens on lemon fruits in Serbia and the first world report of T. rugulosus as phytopathogenic on the same host