Biodiversity-friendly designs for gravel pit lakes along the Drina River floodplain (the Middle Danube Basin, Serbia)

Massive gravel excavation is one of the most destructive forces affecting riverine habitats in Europe. However, gravel pit lakes are also recognized as valuable wildlife refuge areas. Different hydromorphological characteristics of gravel pits may influence aquatic biota differently. Optimal selection of gravel excavation procedures may create favorable conditions for ecosystem diversity. The aim of this study was to correlate hydromorphological variables against macrophyte composition and metrics in gravel pit lakes along the lower course of the Drina River. Field research was carried out at 18 gravel pit lakes (60 survey sectors) and four fluvial lakes (13 survey sectors), during the summer months of 2015, 2016 and 2018. The role of hydromorphological variables in structuring macrophyte assemblages was tested using the partial Canonical Correspondence Analysis, while the Generalized Linear Model was performed to test the ability of selected hydromorphological attributes to predict macrophyte quantitative metrics. The results demonstrated high habitat quality and conservation value of the gravel pit lakes compared to natural sites. Hydromorphological predictors for different macrophyte assemblages were defined. General recommendation is that two pit types should be excavated within a single extraction field, with the minimal impact to the riparian and shore zones. The first type should be located up to 100m from river main channel, having area lt 1000m(2) and a relative depth ratio gt 5%. The second type should be optimally located 300m form river main channel, with maximum depth of 3-4m, surface area of 10,000-20,000m(2), and a relative depth ratio lt 5%

Supplementary description of five species from the genus Cecidophyopsis (Eriophyoidea: Eriophyidae: Cecidophyinae)

Supplementary morphological descriptions of five Cecidophyopsis species collected in Europe (Serbia, Austria, Italy and Montenegro) are given: Cecidophyopsis vermiformis from Corylus avellana L. (Betulaceae), C. hendersoni from Yucca gigantea Lem. (Asparagaceae), C. verilicis from Ilex aquifolium L. (Aquifoliaceae), C. psilaspis from Taxus baccata L. (Taxaceae) and C. malpighianus from Laurus nobilis L. (Lauraceae). Males of C. vermiformis, C. verilicis, C. hendersoni and C. malpighianus, and immatures of C. hendersoni and C. verilicis, are described for the first time. C. verilicis is recorded for the first time in the fauna of Serbia and the European region. Female cuticle-lined internal genitalia of five Cecidophyopsis species are studied under confocal laser scanning microscopy. A several steps of oviposition in cecidophyines is proposed based on CLSM observations on their internal genitalia. Sequences of the barcoding region of the mitochondrial cytochrome oxidase subunit I (mtCOI) gene are given for the following species: C. hendersoni, C. verilicis, C. psilaspis and C. malpighianus

First pentasetacid mite from Australasian Araucariaceae: morphological description and molecular phylogenetic position of Pentasetacus novozelandicus n. sp. (Eriophyoidea, Pentasetacidae) and remarks on anal lobes in eriophyoid mites

A new vagrant eriophyoid mite species of the archaic genus Pentasetacus (Schliesske 1985), P. novozelandicus n. sp., is described with the aid of conventional microscopy, confocal laser scanning microscopy and scanning electron microscopy. It was found on Araucaria heterophylla, which is an araucarian that is endemic to Norfolk Island and introduced to New Zealand. Partial sequences of mitochondrial barcode COI gene and D1–D2 domains of nuclear rDNA of two pentasetacid mites, P. araucariae (MK903025 and MK898944) and P. novozelandicus n. sp. (MK903024 and MK898943) are provided. Molecular phylogenetic analyses of full-length D1–D2 eriophyoid sequences, including GenBank sequences and newly generated sequences of pentasetacids, confirmed the monophyly of Pentasetacidae but failed to resolve the basal phylogeny of Eriophyoidea. This may be because the D1–D2 domains of 28S are hypervariable in Eriophyoidea. Moreover, in pentasetacids D1–D2 sequences are about 20% shorter than in other eriophyoids, and thus harder to align. Two types of anal lobes are described in Eriophyoidea: (1) Eriophyidae s.l. and Phytoptidae s.l. have bilaterally symmetric lobes; (2) pentasetacids have non-divided lobes. The presence of an anal secretory apparatus, comprising internal structures that have previously been described in Eriophyidae s.l. and Phytoptidae s.l., is confirmed in pentasetacid genera. The phylogeny of pentasetacids is also discussed in the context of the paleobiography of Araucariaceae

Enhancement of antioxidant activity and bioactive compound contents in yellow soybean by plant-extract-based products

Abstract: Polyphenols present in different plant cell organelles increase the resistance of plants to various types of environmental stresses. We investigated the possibility of increasing the content of bioactive compounds in the seed of yellow soybean variety Laura. The soybean was treated during vegetation with five products based on plant extracts, on the assumption of enrichment of plants with various nutrients. Soybean flour extracts were screened spectrophotometrically for total phenolic content and antioxidant activity. The antioxidant activity was evaluated using three methods. The content of phenolic acids was determined by HPLC, and the raw protein content was estimated by the Kjeldahl method. Depending on the treatment, variations in the quantity of individual phenolic acids with up to 90% higher concentration as compared to the control were observed. Controlled usage of certain plant extracts can increase the concentration of the target group of bioactive compounds in the samples. The synergistic effect of proteins and phenolic compounds on the antioxidant activity of extracts was detected. The results of this study are not only important from the aspect of plant resistance to various types of stress, but also when considering soybean as a functional food

Patogeni lista trešnje i višnje u Srbiji

In recent years, sweet and sour cherry production in Serbia has increased. Under Serbian agroecological conditions, pathogens causing leaf diseases threaten the success of sweet and sour cherry production. In the period 2012-2019, the health status of cherries was monitored in more than 30 locations. Depending on the production system, the following leaf pathogens were identified: Blumeriella jaapii, Wilsonomyces carpophilus, Mycosphaerella cerasella, Phoma prunicola, Podosphaera clandestina and Pseudomonas syringae pv. syringae and morsprunorum race 1. Leaf pathogens caused premature defoliation, which adversely affected bud formation for the next growing season and increased susceptibility to freezing. Therefore, attention should be focused on correct leaf pathogen identification, and proper selection, application and rotation of fungicides.Poslednjih godina proizvodnja trešnje i višnje u Srbiji je povećana. U našim agroekološkim uslovima, patogeni lista ugrožavaju proizvodnju ovih perspektivnih voćnih vrsta. U periodu 2012-2019. godine praćeno je zdravstveno stanje trešnje i višnje, na više od 30 lokaliteta. avisno od sistema proizvodnje identifikovani su sledeći patogeni lista: Blumeriella jaapii, Wilsonomyces carpophilus, Mycosphaerella cerasella, Phoma prunicola, Podosphaera clandestina, Pseudomonas siringae pv. syringae i morsprunorum rasa 1. Patogeni lista izazivaju prevremenu defolijaciju, što negativno utiče na formiranje pupoljaka za narednu vegetaciju i povećanu osetljivost na izmrzavanje. Stoga pažnju treba usmeriti na ispravnu identifikaciju patogena, pravilan izbor i rotaciju fungicida različitog mehanizma delovanja, kao i optimalno vreme za njihovu primenu

Integration of biological and conventional treatments in control of pepper bacterial spot

Bacterial spot caused by Xanthomonas euvesicatoria is one of the most devastating pepper diseases in Serbia. Questionable seed quality, climatic conditions, and frequent irrigation during summer favour the disease occurrence and spread. The available management practices do not provide adequate disease control. Therefore, development of alternative and more sustainable disease management strategies is needed. Integration of classical and biological treatments could be an effective, environmentally safe option for reducing pepper bacterial spot severity. In order to develop an efficient integrated disease management program, we studied efficacy of biocontrol agents (bacteriophage strain KФ1 and two strains of Bacillus subtilis AAac and QST 713), systemic acquired resistance (SAR) inducer (acibenzolar-S-methyl - ASM), a commercial microbial fertilizer (Slavol), copper based compounds (copper hydroxide and copper oxychloride) in combination with or without mancozeb, and antibiotics (streptomycin sulphate and kasugamycin). They were applied as single treatments in two separate field experiments. Based on the single treatment efficacy, various combinations of the treatments were chosen for further testing in three separate field experiments. Additionally, we evaluated potential negative effect of ASM on pepper growth and yield in the growth chamber experiment. All the tested single treatments significantly reduced disease severity compared to the inoculated control (IC), except microbiological fertilizer and the antagonistic strain AAac. Integration of copper hydroxide, ASM and bacteriophages was the most efficient treatment, reducing the disease intensity by 96–98%. The results indicated that this combination may be an adequate alternative program for control of pepper bacterial spot

Biological control of Pseudomonas syringae pv. aptata on sugar beet with Bacillus pumilus SS-10.7 and Bacillus amyloliquefaciens (SS-12.6 and SS-38.4) strains

Aim Assessment of biological control of Pseudomonas syringae pv. aptata using crude lipopeptide extracts (CLEs) of two Bacillus amyloliquefaciens strains (SS-12.6 and SS-38.4) and one Bacillus pumilus strain (SS-10.7). Methods and Results The minimum inhibitory concentration (MIC) of CLEs and their combinations against the pathogen and potential interaction between the extracts were determined in vitro. The most effective antibacterial activity was achieved with the CLE from B. amyloliquefaciens SS-12.6, with an MIC value of 0 center dot 63 mg ml(-1). Interactions between CLE combinations were mostly indifferent. The biocontrol potential of CLEs, mixtures of CLEs, and cell culture of B. amyloliquefaciens SS-12.6 was tested on sugar beet plants inoculated with P. syringae pv. aptata P53. The best result in inhibiting the appearance of tissue necrosis (up to 92%) was achieved with B. amyloliquefaciens SS-12.6 cell culture. Conclusion This work demonstrated significant biocontrol potential of the CLE and cell culture of B. amyloliquefaciens SS-12.6 which successfully suppress leaf spot disease severity on sugar beet plants. Significance and Impact of the Study The findings of biocontrol of sugar beet emerging pathogen will contribute to growers in terms of alternative disease control management. This study represents first assessment of biological control of P. syringae pv. aptata

In vitro biodegradation potential of airborne Aspergilli and Penicillia

The study addresses in vitro degradation potential of airborne Aspergillus and Penicillium/Talarmyces species originating from cultural heritage conservation premises. A series of rapid, cost effective biodegradation assays were performed to assess production of extracellular pigments, acids, and enzymes. Most of the isolates have demonstrated positive growth in at least one of the preformed tests. Strongest overall degradation potential was demonstrated for Penicillium brevicompactum, P. glabrum, and Talaromyces sayulitensis while Aspergillus domesticus, A. penicillioides, A. pseudoglaucus, and A. ruber did not exhibit positive reaction in any of the employed assays. Majority of isolates exhibited proteolytic and cellulolytic activity while carbonate dissolution was observed for only five tested fungi. Highest alteration of pH value in liquid media was documented for T. sayulitensis while A. niger and P. expansum exhibited strongest acid production on CREA. Certain isolates, mostly Penicillium species, displayed production of extracellular pigments. The results imply that many of the tested fungi have significant biodegradation capacity, indicating their potential to inflict structural and esthetic alterations on cultural heritage objects

Specificity and sensitivity of three pcr-based methods for detection of erwinia amylovora in pure culture and plant material

Three PCR methods, referred in this study as,conventional" "nested" and,chromosomal" PCR and suggested for routine detection of Erwinia amylovora in pure culture and plant material, were evaluated according to their specificity and sensitivity. Specificity of PCR methods was analyzed by using 42 strains of E. amylovora, originating from different locations and plant species, with diverse PFGE profiles, representing distant populations of the pathogen. Sensitivity of PCR protocols in pure culture was studied by using nine different concentrations of E. amylovora in sterile ultrapure water as a template in PCR reactions. In order to study inhibitory effect of plant DNA and other inhibitors on sensitivity of the three PCR methods bacterial dilutions were mixed with plant macerate of pear, apple and quince prior to the PCR reaction. In specificity assays, tested PCR protocols were able to detect all E. amylovora strains regardless of the host of the strain, its origin or PFGE group, indicating primer specificity. On the other hand, sensitivity among tested methods varied, depending on bacterial concentration and selected plant material used in the PCR. When working with pure cultures nested PCR showed the greatest sensitivity by detecting 1.9 bacterial cells per PCR reaction, followed by detection limit of 9.5 cells per PCR reaction with conventional PCR and 1.9.105 cells/PCR reaction with chromosomal PCR. In spiked samples plant inhibitors either did not affect or they decreased the sensitivity of the PCR reaction, depending on the protocol and/or type of plant macerate. In our experiments, inhibitors from pear and quince macerates did not affect sensitivity of nested PCR, while apple macerate reduced its sensitivity by a factor of 10. Conventional PCR protocol was able to detect 95 cells/PCR reaction in pear and apple macerate, but only 9.5.103 cells/PCR in quince macerate. Greatest decrease in sensitivity of the PCR method was observed in spiked samples with chromosomal PCR since bacterial DNA was not detected in each of the spiked samples. Our research shows that all three PCR protocols are specific for detection of E. amylovora, but nested PCR proved to be most sensitive when working with pure cultures and plant material

The negative influence of Ambrosia artemisiifolia and A. Trifida on agriculture production

Ambrosia artemisiifolia is considered a serious and problematic weed in crops and other crops, but also on non-agricultural land in Serbia. Due to the early rapid growth in spring and the large vegetative and generative production, as well as the seeds that maintain germination in the soil for many years (up to 40 years) it is very difficult to control the spread. Also, its related species Ambrosia trifida, currently only locally present in the territory of Serbia, is in the focus of interest of many researchers dealing with invasive biology. It does great damage to crops, reducing yield and product quality. Also, both weed species have a negative impact on human and animal health with their allergens, so it is necessary to continuously monitor and implement adequate suppression measures, as well as to continuously promote the topic and inform the public about problems and damages that they cause.Ambrosia artemisiifolia smatra se ozbiljnim i problematičnim korovom u okopavinama i drugim usevima ali i na nepoljoprivrednim zemljištima na području Srbije. Zbog ranog brzog porasta tokom proleća i velike vegetativne i generativne produkcije, kao i semena koje održava klijavost u zemljištu dugi niz godina (i do 40 godina), veoma je teško kontrolisati njeno širenje. Takođe, njoj srodna vrsta Ambrosia trifida, za sada samo lokalno prisutna na području Srbije, nalazi se u žiži interesovanja mnogih istraživača koji se bave invazionom biologijom. U usevima pravi velike štete, redukujući prinos i kvalitet proizvoda. Takođe, obe korovske vrste svojim alergenima negativno utiču na zdravlje ljudi i životinja, pa je neophodno kontinuirano vršiti monitoring i sprovoditi adekvatne mere suzbijanja, kao i neprekidno sprovoditi popularizaciju ove tematike i javnost informisati o problemima i štetama koje prouzrokuju