Vesna Krnjaja

Dr. Vesna Krnjaja

orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 January 2019 in Toxins
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Aleksandar Ž. KostićAleksandar Ž. Kostić
Aleksandar Ž. Kostić
DMDanijel D. Milinčić
Danijel D. Milinčić
TPTanja Petrović
Tanja Petrović
VKVesna Krnjaja
Vesna Krnjaja
SSSladjana P. Stanojevic
Sladjana P. Stanojevic
Mirjana B. PešićMirjana B. Pešić
Mirjana B. Pešić
Due to its divergent chemical composition and good nutritional properties, pollen is not only important as a potential food supplement but also as a good substrate for the development of different microorganisms. Among such microorganisms, toxigenic fungi are extremely dangerous as they can synthesize mycotoxins as a part of their metabolic pathways. Furthermore, favorable conditions that enable the synthesis of mycotoxins (adequate temperature, relative humidity, pH, and aw values) are found frequently during pollen collection and/or production process. Internationally, several different mycotoxins have been identified in pollen samples, with a noted predominance of aflatoxins, ochratoxins, fumonisins, zearalenone, deoxynivalenol, and T-2 toxin. Mycotoxins are, generally speaking, extremely harmful for humans and other mammals. Current EU legislation contains guidelines on the permissible content of this group of compounds, but without information pertaining to the content of mycotoxins in pollen. Currently only aflatoxins have been researched and discussed in the literature in regard to proposed limits. Therefore, the aim of this review is to give information about the presence of different mycotoxins in pollen samples collected all around the world, to propose possible aflatoxin contamination pathways, and to emphasize the importance of a regular mycotoxicological analysis of pollen. Furthermore, a suggestion is made regarding the legal regulation of pollen as a food supplement and the proposed tolerable limits for other mycotoxins.

27 October 2020 in Agriculture
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VMVioleta Mandić
Violeta Mandić
SĐSnežana Đorđević
Snežana Đorđević
NDNikola Djordjevic
Nikola Djordjevic
ZBZorica Bijelić
Zorica Bijelić
VKVesna Krnjaja
Vesna Krnjaja
MBMilan Brankov
Milan Brankov
The successful production of soybeans is largely dependent on the sowing time, because every sowing outside the optimal time contributes significantly to yield losses. This field study aimed to evaluate the effects of sowing time (optimal—April 5; late—April 27) on the quantitative and quality traits of three soybean genotypes (Galina—0 maturity group; Sava—I maturity group; and Rubin—II maturity group) under dryland conditions in Vojvodina Province (Serbia) during 2017 and 2018. The genotype Sava had higher yield in climatic-unfavorable 2017, while Rubin had a higher yield in climatic-favorable 2018. The yields significantly decreased when the soybeans were sown in late April due to reductions in the number of pods per plant, seed weight per plant, and 1000-seed weight. The reduction in yield components was likely due to the accelerated senescence of plants and the negative effect of high temperature and low precipitation during the seed filling stage. Accordingly, the various sowing times and properly chosen genotypes provide a better utilization of soil and water resources. A proper genotype selection and sowing time can contribute to a high yield. At the same time, the protein and oil contents can be altered by the sowing time, especially under water stress during the reproductive stage.

1 January 2013 in Biotechnology in Animal Husbandry
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VKVesna Krnjaja
Vesna Krnjaja
JLJ. Levic
J. Levic
SSS. Stankovic
S. Stankovic
TPT. Petrovic
T. Petrovic
ZTZ. Tomic
Z. Tomic
ZBZ. Bijelic
Z. Bijelic
In this study the presence of moulds and mycotoxins in samples of stored maize grains in the period from October 2011 to September 2012 was investigated. Mycological analyses of whole and broken grains showed the presence of species from the genera Alternaria, Aspergillus, Fusarium, Penicillium, Rhizopus and others. Among the Aspergillus and Fusarium genera as potentially toxigenic fungi, Aspergillus flavus was identified with the highest percentage on broken grains (20.38%) whereas F. verticilioides was the predominant species in the whole maize grains (34.04%). In addition, it was obtained that tested samples of stored maize grains were 100% positive with aflatoxin B1 (AFB1), zearalenone (ZON), deoxynivalenol (DON) and fumonisin B1 (FB1) with an average concentration of 1.39 ?g kg-1, 71.79 ?g kg-1, 128.17 ?g kg-1, and 1610.83 ?g kg-1, respectively. A significant positive correlation was found between the moisture content and the presence of Fusarium spp. on the broken grains (r = 0.44) and between the moisture content and the concentration of DON (r = 0.61). However, a significant negative correlation was found between moisture content and FB1 (r = -0.34), and between the concentration of ZON and DON mycotoxins (r = -0.58).

9 April 2020 in Agronomy
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VMVioleta Mandić
Violeta Mandić
SĐSnežana Đorđević
Snežana Đorđević
ZBZorica Bijelić
Zorica Bijelić
VKVesna Krnjaja
Vesna Krnjaja
VPVlada Pantelić
Vlada Pantelić
Vesna DragicevicVesna Dragicevic
Vesna Dragicevic
The main nitrogen (N) sources in soybean production originate from soil fixing bacteria Bradyrhizobium spp. and from mineralization of soil organic N. These sources of N are often not sufficient to cover the N needs of the soybean. The present two-year field study aimed to evaluate the effects of soybean genotypes (Valjevka and Galina) and rates of starter fertilizer N (0, 30, 60, and 90 kg ha−1) on quantitative and qualitative parameters and on rain use efficiency (RUE) under contrasting weather conditions in the Pannonian region of Serbia. A field study conducted during two different growing seasons: first year with unfavorable weather conditions and second year with favorable weather conditions. As expected, the quantitative parameters, oil content, and RUE were higher in the year with favorable growing season, the second one. According to measured parameters, the genotype Valjevka performed higher yield potential as compared to the genotype Galina. The highest values of quantitative parameters and RUE were recorded at 60 kg N ha−1, protein content at 90 kg N ha−1 and oil content 0 kg N ha−1 (control). This study suggests that proper genotype selection and application of 60 kg N ha−1 as a starter dose with rhizobial inoculation could contribute to the high yield, while protein could be altered by N amount, independently on genotype.

8 November 2018 in Toxins
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VKVesna Krnjaja
Vesna Krnjaja
SSSlavica Stankovic
Slavica Stankovic
AOAna Obradovic
Ana Obradovic
TPTanja Petrović
Tanja Petrović
VMVioleta Mandić
Violeta Mandić
MBManja Božić
Manja Božić
Fusarium graminearum as the main causal agent of Fusarium head blight (FHB) and its ability to produce trichothecenes was investigated by molecular techniques. A total of 37 strains isolated from the wheat, harvested in Serbia in 2005, 2008 and 2015, and previously designated by morphological observation as F. graminearum, were used for trichothecene genotypes characterization. The strains were identified using the species-specific primer set FG16R/FG16F while genotypic characterization was done using specific TRI13 and TRI3 sequences of the trichothecene gene clusters. The PCR assays identified all strains as species of F. graminearum sensu stricto with the DON/15-ADON genotype. The quantification of the mycotoxin (DON) was performed using the biochemical assay. The high levels of DON (>20,000 µg kg−1) were recorded in all of the strains from 2005, four strains from 2008 and two strains from 2015. Weather data of the investigated seasons, showed that the optimal temperature, frequent rains and high relative humidity (RH) was very favourable for the development of F. graminearum, affecting the DON biosynthesis.

17 July 2022 in Agriculture
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VKVesna Krnjaja
Vesna Krnjaja
VMVioleta Mandić
Violeta Mandić
ZBZorica Bijelić
Zorica Bijelić
SSSlavica Stankovic
Slavica Stankovic
AOAna Obradovic
Ana Obradovic
MGMarija Predrag Gogić
Marija Predrag Gogić
The main aim of this research was to study the effect of two sowing times (early and late) on Fusarium and fumonisin contamination and some yield component traits of two maize hybrids from the FAO maturity groups 500 (ZP 560) and 600 (ZP 666) within a two-year growing season (2016–2017). F. verticillioides and F. subglutinans have been identified as Fusarium ear rot (FER) pathogens and potential producers of B-type fumonisins (FBs), with F. verticillioides as the predominant Fusarium species in both years. The incidence of F. verticillioides and FB levels were affected by sowing time and maize hybridity. With early sowing and the mid-maturity hybrid ZP 560, F. verticillioides and FB contamination were lower than with late sowing and the late-maturity hybrid ZP 666. Yield parameters also differed significantly between sowing time and maize hybrid treatments. Early sowing increased ear length (EL), number of grains per ear (NGE), grain weight per ear (GWE), and grain yield per hectare (GY). The late-maturity hybrid ZP 666 had higher yield component traits and GY than the mid-maturity hybrid ZP 560. EL, GWE, thousand-grain weight (TGW), and GY were affected by year. Interactions between sowing times and maize hybrids were highly significant (p ≤ 0.01) for FB level, GWE, and GY. The obtained results indicate the importance of applying early sowing to achieve high maize grain yields with lower contamination by F. verticillioides and FBs. Although mid-maturity hybrid ZP 560 and late-maturity hybrid ZP 666 showed significant differences in terms of levels of F. verticillioides and FB contamination, both were susceptible to F. verticillioides, with high FB levels. These results should be useful to breeders of maize hybrids to create genotypes more resistant to these fungal contaminants.