Estimation of uncertainty of trypsin inhibitor activity measurement in legume crops

Irradiation of legume seeds has emerged as an attractive alternative compared to conventional chemical treatments in seed production. Irradiation is also used for the decontamination of food and feed in order to increase the shelf-life of fresh and dry food materials. The effects of irradiation on nutritive and anti-nutritive factors such as trypsin inhibitors are usually reported together with the measurements obtained by using the quantitative analytical methods. The objective of this study was to measure trypsin inhibitor activity (TIA) of common bean cultivar Oplenac using the microtiter plate method and to identify factors that contribute to the uncertainty of TIA measurement according to the current Guide to the Expression of uncertainty in measurement (GUM). Dominant sources of uncertainty of TIA measurement were: absorbance measurements of sample and positive control reaction mixtures and preparation of the final sample solution using a graduated cylinder (V4). Absorbance measurement of sample reaction mixtures took 37.8% of the overall measurement uncertainty. Preparation of the final sample solution using a graduated cylinder (V4) and absorbance measurement of positive control reaction mixture contributed to the overall uncertainty with 35.1% and 15.8%, respectively. Acquired insight into factors that contribute to the uncertainty of TIA measurement gives directions for the improvement of TIA testing methods and TIA results management

Sampling Error in Relation to Cyst Nematode Population Density Estimation in Small Field Plots

Cyst nematodes are serious plant-parasitic pests which could cause severe yield losses and extensive damage. Since there is still very little information about error of population density estimation in small field plots, this study contributes to the broad issue of population density assessment. It was shown that there was no significant difference between cyst counts of five or seven bulk samples taken per each 1-m(2) plot, if average cyst count per examined plot exceeds 75 cysts per 100 g of soil. Goodness of fit of data to probability distribution tested with chi(2) test confirmed a negative binomial distribution of cyst counts for 21 out of 23 plots. The recommended measure of sampling precision of 17% expressed through coefficient of variation (cv) was achieved if the plots of 1 m(2) contaminated with more than 90 cysts per 100 g of soil were sampled with 10-core bulk samples taken in five repetitions. If plots were contaminated with less than 75 cysts per 100 g of soil, 10-core bulk samples taken in seven repetitions gave cv higher than 23%. This study indicates that more attention should be paid on estimation of sampling error in experimental field plots to ensure more reliable estimation of population density of cyst nematodes

The challenge of managing yellow rust (Puccinia striiformis f.sp. tritici) in winter wheat: how combined climate and pathogen stressors impact variability in genotype reactions

Despite the ongoing evolution of wheat pathogens due to the selection pressures of agro-ecological conditions, many studies have often overlooked the combined impact of both biotic and abiotic factors on disease occurrence. From 2016 to 2023, a comprehensive screening of obligate pathogens, including B. graminis f. sp. tritici, P. graminis f. sp. tritici, P. triticina, and P. striiformis f. sp. tritici, was carried out. This screening was conducted on a phenotyping platform encompassing 2715 winter wheat genotypes and their wild relatives, both with and without resistant genes (Lr, Yr, and Sr) for rust diseases. The data were analyzed using PCAmix, best subsets regression, and linear regression modeling. The findings from this study reveal that the plant reactions to leaf and yellow rust infections is far from straightforward. It is heavily influenced not only by prevalent rust races and climatic factors that impact pathogen life cycles but also by variations in the susceptibility reactions of wheat genotypes to the broader agro-ecological conditions. We also observed a tendency for leaf rust and yellow rust to coexist within the same host plant, even though yellow rust is typically considered more aggressive. We reported for the first time genes related to yellow rust resistance breakdown in Serbia in 2023. Lastly, we underscored the importance of investigating resistance responses to rust diseases not exclusively through the interrelation between resistance genes and pathogen virulence, but also by considering how plants respond to the combined stresses of abiotic and biotic factors. Consequently, our study sets the groundwork for further research into how plants respond to multiple stressors and contributes for further investigations related with effective integrated rust management

Occurrence of grass bunt in Vojvodina and its influence on wheat seed quality control

Causal agents of grass bunt, which infect wild grass hosts in Bromus, Festuca, Ventenata and Vulpia, are Tilletia species whose teliospores could be found in wheat seed samples too. Among them, T. bromi is morphologically similar to those of quarantined T. contraversa, and misidentification of this species could lead to commodity rejection. As a result, monitoring the presence of teliospores of quarantined species in seed samples, and identification of Tilletia species on the basis of morphological characteristics is difficult and in some cases impossible. In order to investigate the presence of grass bunt in seed samples of wheat in Vojvodina, teliospore extraction was carried out by using the size-selective sieving wash method and the OEPP/EPPO diagnostic protocol for Tilletia indica (2007). The analysis of 151 samples of basic, certified and commercial non-processed seed of wheat revealed that 127 samples were contaminated with T. caries, while 12 samples were contaminated with teliospores of Tilletia species which had morphological characteristics that correspond to T. bromi complex or quarantined T. contraversa. These teliospores displayed prominent gelatinous sheath with conspicuous depth of reticulations. Molecular identification of grass bunt teliospores was not possible in this study, because contamination level was too low (1 teliospore per 10 seeds). However, knowing that teliospores of T. bromi often occur in wheat seed samples in very low numbers there is a need for standardization of molecular techniques for the identification of a single teliospore of Tillletia species in order to make plant protection more efficient and reliabl

Variability of Stem-Base Infestation and Coexistence of Fusarium spp. Causing Crown Rot of Winter Wheat in Serbia

Investigations related with factors influencing root and crown rot are rare and mainly related to farming practice and soil management. The main objective of this study was to examine broader range of factors influencing stem-base infestation of winter wheat in the field conditions. The effect of spatial distribution of infected plants on disease index (DIs) assessments was also investigated. Analysis of factors influencing DIs of crown rot of wheat demonstrated significant influence of the growing seasons (P lt 0.001) and extreme fluctuations in winter temperatures (P lt 0.001). In addition to that, localities together with their interaction with the growing season also significantly influenced DIs (P lt 0.001). Aggregation of infected plants influenced variability of DI estimations, and it was pointed out that more extensive investigation should be conducted on broad range of DI in order to establish sampling method giving uniform sampling precision. Fusarium graminearum was shown to be predominant Fusarium species in Serbia (72.6%) using sequence-characterized amplified region analysis. Interestingly F. oxysporum was isolated in higher frequencies (27.4%) than it was reported in the literature. Given that there were no reports on the diversity of Fusarium species causing crown rot of wheat in Serbia, this study presents first report on this important subject. It also indicated that more attention should be focused on combined effects of abiotic and biotic factors influencing stem-base infestation of winter wheat. This knowledge will contribute to better understanding of factors influencing root and crown rot of wheat which would ensure sustainable disease management in the future

Specificity in reaction of winter wheat varieties Simonida and Zvezdana to fusarium head blight caused by Fusarium graminearum species complex

Important tool for the integrated control of Fusarium head blight (FHB) is monitoring changes in the prevalence of Fusarium species and toxin production. The knowledge of factors influencing FHB infection is usually related to climatic factors, tillage practice and the level of resistance/susceptibility of wheat varieties. However, little is known on differences in reactions of varieties on members of Fusarium species complexes. In this study, F. graminearum species complex (FGSC) was monitored on two winter wheat varieties Simonida and Zvezdana, created in Institute of Field and Vegetable Crops, Novi Sad. We analyzed 83 FGSC isolates collected from 21 locations in 2019. The study included four regions in Serbia (Vojvodina, Belgrade, Southern and Eastern Serbia and Šumadija and Western Serbia). Monitoring of FGSC populations were made using species- and trichothecene-specific primers. Species specific primers were Fg16F/R and Fgr-F/Fgc-R. Trichothecene genotyping was performed using the primer sets (Tri303F/R, Tri315F/R, and Tri5F/R) for the sequences of the Tri3, and Tri5 genes. Tri-5-specific PCR assay was used to assess the genetic potential of F. graminearum isolates for mycotoxin production. We used multiple correspondence analysis (MCA), to investigate associations between Fusarium damaged kernels (FDK), location, variety, members of the FGSC, and their predisposition for mycotoxin production. On average, the FDK of Simonida was 11.8% while it was 22.1% in Zvezdana

Diversity in susceptibility reactions of winter wheat genotypes to obligate pathogens under fluctuating climatic conditions

To date, studies have usually focused on the impact of abiotic factors on the distribution of plant pathogens and have built forecast models for the prediction of pathogen outbreaks. However, the impact of the combined effects of biotic and abiotic factors on the prevalence of economically important pathogens has usually been neglected. The objective of this study was to determine the relationship between powdery mildew and rusts of wheat and to examine how the combined effects of abiotic and biotic factors influence their prevalence. The study was conducted in the period 2016-2019 using the collection of 2158 genotypes of winter wheat. The most influential factors on disease indices and relationships among obligate pathogens were determined using multiple regression models and principal component analysis. The possibility of the coexistence of different rust species in the same growing season and in the same field was shown. The significant influence of fluctuations in winter temperatures on changes in the prevalence of obligate pathogens was determined. The strong impact of genotypes and their reaction on climatic elements in certain phenological stages were shown to be significant factors influencing the interactions among obligate pathogens and the predominance of one pathogen over another

Fuzarioza klasa - izazov u proizvodnji pšenice

Fusarium head blight belongs to the group of economically important diseases which negative effect is related not only to reduction of yield and quality of wheat but also with the production of mycotoxins that adversely affect the health of humans and animals. The screening of wheat varieties on resistance to fusariosis of wheat were carried out at the locality Rimski Šancevi. Significant impact of varieties (P = 0.000), disease index (P = 0.002) and climatic elements in May and June (P = 0.000) was confirmed using the General Linear Model. In addition, by using the Spearman’s correlation coefficient it was found that 44 wheat varieties were significantly moderatly correlated (r = - 0.574, P = 0.000) with yield and significantly low correlation (r = - 0.130, P = 0.035) with 1000-kernel weight was recorded. There was no correlation between disease index and test weight (r = - 0.009). Finally, fusarium damaged kernels (FDK) can be used in determining Type III resistance, but it should be pointed out that the year, variety and the interaction of the year and variety significantly affect FDK (P = 0.000). These results show the complexity of the causes and consequences related with occurrence of Fusarium head blight which indicate that only integrated plant protection measures can provide sustanable wheat production.Fuzarioza klasa pšenice pripada grupi ekonomski značajnih oboljenja čija se štetnost ogleda ne samo u smanjenju prinosa i kvaliteta zrna pšenice, već i u produkciji mikotoksina koji nepovoljno utiču na zdravlje ljudi i životinja. Proučavanja pojave i razvoja fuzarioze klasa pšenice vršena su na sortama u proizvodnji i selekcionerskom materijalu na Rimskim Šančevima. Primenom General Linear Modela potvrđen je značajan uticaj sorti (P=0,000), indeksa oboljenja (P=0,002) i klimatskih elemenata u maju i junu (P=0,000) na visinu prinosa. Analizom odnosa indeksa oboljenja 44 sorte u 2014. i 2015. godini i komponenata prinosa primenom Spearman-ovog koeficijenta korelacije utvrđeno je da je indeks oboljenja statistički značajno srednje negativno korelisan sa prinosom (r= - 0.574; P=0,000), statistički značajno nisko negativno korelisan (r= - 0.130; P=0,035) sa masom 1000 zrna, dok nije bilo linerne korelacije sa hektolitarskom masom (r= - 0.009). Parametar procentualnog prisustva fuzarioznih zrna može se koristiti pri određivanju Tipa III otpornosti, pri čemu treba imati u vidu da je uticaj godine, sorte i interakcije godine i sorte na ovo svojstvo statistički značajno (P=0,000). Rezultati istraživanja ukazuju na kompleksnost uzroka i posledica od pojave ovih patogena što upućuje da se jedino višestrukim merama zaštite može kontrolisati ovo oboljenje

Rde pšenice - prošlost, sadašnjost i budućnost

Historically, rusts have periodically been a threat to cereal production. The most economically important rusts occur on wheat, such as: leaf rust, yellow or stripe rust and stem rust. During the twentieth century the wheat-rust interaction has suffered significant changes, starting with the epidemics of stem rust at the beginning of this century, then establishing a system of control of given pathogens through major research programs, to the recurrence of epidemics of stem, as well as yellow rust at the end of the twentieth century. In our country a significant epidemic of leaf rust was reported in 1994, while in 2014 great yield losses in wheat were caused due to the large outbreak of yellow rust. Multi-year trials that were conducted on the experimental fields of Rimski Šancevi indicated significant effect of environment/year, and the variety on disease index of wheat rusts. Climatic elements which have significantly influenced the development of leaf rust in the period 1998-2013 were as follows: temperature and relative humidity in April, and temperature in May. Climatic conditions which were favorable to yellow rust in 2014, related primarily to mean temperature in January and February, which exceeded the ten-year averages, as well as the heavy rainfall in March and April, which were also higher than average. Furthermore, in these studies we found statistically significant effect of the leaf and yellow rust on wheat yield loss. Given the epidemics of stem rust which in 2016 affected thousands of hectares in the Italian island of Sicily, as well as the data on the occurrence of new aggressive races of yellow rust on the territory of Europe, regular monitoring of climate change and approach that includes integrated crop protection measures represents a necessity in order to keep pace with these pathogens.Tokom istorije rde su periodično bile pretnja proizvodnji ratarskih kultura. Ekonomski najznačajnije su rde koje se javljaju na pšenici: lisna, žuta i stabljična rda. Odnos pšenica-rde tokom XX veka je pretrpeo značajne promene, počevši od epidemija stabljične rde početkom ovog veka, zatim uspostavljanja sistema kontrole datih patogena kroz značajne istraživačke programe, pa do ponovne pojave epidemije stabljične, ali i žute rde na kraju XX veka. Na našim prostorima značajna epidemija lisne rde utvrđena je 1994. godine, dok su 2014. godine veliki gubici u prinosu pšenice uzrokovani jačom pojavom žute rde. Višegodišnja ispitivanja na oglednim poljima na Rimskim Šančevima ukazala su na statistički značajan uticaj sredine/godine i sorte na visinu indeksa oboljenja rda pšenice. Klimatski elementi koji su značajno uticali na razvoj lisne rde u periodu 1998-2013. godine bili su: temperatura u aprilu; relativna vlažnost vazduha u aprilu i temperatura u maju. Klimatski uslovi koji su pogodovali pojavi žute rde 2014. godine, odnose se pre svega na srednje temperature u januaru i februaru koje su nadmašile desetogodišnje proseke, kao i na obilne padavine u martu i aprilu koje su takođe bile iznad prosečnih vrednosti. Takođe, u ovim istraživanjima utvrđen je statistički značajan uticaj prouzrokovača lisne, kao i žute rde na gubitak prinosa pšenice. S obzirom na epidemiju stabljične rde koja je prošle, 2016. godine, zahvatila hiljade hektara na području Sicilije, kao i na podatke o pojavi novih, agresivnijih rasa žute rde na području Evrope, redovno praćenje klimatskih promena i pristup koji podrazumeva integralne mere zaštite useva predstavlja neophodnost kako bi se držao korak sa ovim patogenima

Zaštita pšenice od prouzrokovača oboljenja

Controlling wheat diseases with fungicides should be based on the principles of integrated pest management (IPM). The decision which strategies and models of fungicide applications to use is in direct correlation with the specificity of the pathogen, weather conditions for their development and growth stages of plant. Since the spike, flag leaf and the leaf below flag leaf are bearers of the yield, it is necessary to preserve their viability as long as possible. The loss of green leaf area after the flag leaf emergence, influences the development of the crop and results in the reduction of grain weight, which is directly reflected in the yield and quality. In order to avoid the appearance of fungal resistance to individual active ingredients, applying the fungicides on wheat should be in accordance with the principles of the FRAC.Zaštita pšenice od prouzrokovača oboljenja treba da se temelji na principima Integralne zaštite bilja. Izbor strategije i modela primene preparata u direktnoj je korelaciji sa specifičnošću patogena, vremenskim uslovima za njihov razvoj i fenofazama razvoja biljke. S obzirom da su klas, list zastavičar i list ispod zastavičara glavni nosioci prinosa, potrebno je sačuvati što duže njihovu vitalnost. Gubitak zelene lisne površine posle izbijanja lista zastavičara, utiče na razvoj zrna pšenice i ima za posledicu smanjenje njegove težine, što se direktno odražava na prinos i kvalitet. Pri primeni fungicida treba poštovati principe FRAC-a, kako bi se izbegla pojava rezistentnosti na pojedine aktivne supstance