Genotypic differentiation of Monilinia spp. populations in Serbia using a high-resolution melting (HRM) analysis

Monilinia laxa, Monilinia fructicola and Monilinia fructigena are the three main causal agents of brown rot, which is one of the most important diseases of stone fruits in pre-and postharvest conditions. Nowadays, the need for the precise genotyping of these Monilinia species in terms of the genetic diversity of their populations or differences in their pathogenicity and host range is a prerequisite for any efficient disease management. In our study, the genetic structure of Monilinia populations in Serbia from three geographically distinct regions was investigated employing a high-resolution melting (HRM) analysis which is a sensitive and rapid molecular approach in fungal genotyping and diagnostics. Using species-specific primer pairs genotype-specific HRM melting curve profiles were generated allowing to efficiently decipher the genetic diversity of the Monilinia populations. The Monilinia genotypes could be easily distin-guished according to their melting curves. The isolates from the northern region were assigned to distinct genotypes and grouped rather independently compared to the isolates of the other two regions among all three tested Monilinia spp. M. fructicola and M. fructigena showed a higher genetic diversity among their populations (44%) compared with the genetic diversity among the M. laxa populations (7%). In contrast, the genetic variance within the pathogen populations was higher in the case of M. laxa (93%). Our data revealed an absence of host specificity in the Monilinia spp. populations. © 2020, Czech Academy of Agricultural Sciences. All rights reserved

Determination of the Optimal Regression Model for the Measurement Quality Characteristics of the Micro Cutting Stone-Based Materials

Micro cutting represents one modern approach of processing the materials in order to achieve parts that feature high surface quality with low intensity of residual cracks. In the most cases, these parts are small sizes. Mechanisms that occur during micro cutting are not similar to those that occur during macro cutting. Even in the case of micro cutting brittle materials, the micro cutting mechanism becomes much more complex. The possibility of processing brittle materials in a ductile mode allows reduction of the intensity of the residual cracks within the material, since there is no initialization of the cracks within the material in this regime. However, although in this mode part is only plastically deformed, the intensity values of the components of the cutting force can vary considerably, especially if the processing is carried out on stone-based materials that are highly heterogeneous. In order to establish an adequate dependence of the cutting force components of the processing regimes, it is necessary to apply optimal regression model on the experimental results that will optimally cover all existing conditions, which is also the topic of this paper. The material over which micro-cutting experiments were carried out was marble Plavi tok. Experiments were carried out with two different tools whose tip radius value were R0.2 and R0.15 mm, and the value of the micro-cutting speed was vs = 25 m/s

Supplementary data: UV-C light irradiation enhances toxic effects of chlorpyrifos and its formulations

Supplementary data 1: Table 1S. The chromatographic gradient profile; Table 2S. CPF concentration decrease (corresponding initial CPF concentration decrease was set as 0%) for all three forms of CPF depending on irradiation time; Table 3S. CPF and CPO concentrations determined chromatographically for TCPF, EW and EC formulations, as the function of irradiation time; % of CPO comparing to initial CPF concentration in all three forms of CPF; Supplementary data 2: Material safety data sheet according to 1907/2006/EC, Article 31/version 1; Supplementary data 3: Material safety data sheet according to 1907/2006/EC, Article 31/version 4Supplementary data for the article: [http://dx.doi.org/10.1016/j.foodchem.2018.07.207]Related to: [http://vinar.vin.bg.ac.rs/123456789/7821

Toxicity of copper hydroxide, dithianon, fluazinam, tebuconazole and pyraclostrobin to Didymella applanata isolates from Serbia

A study of the in vitro sensitivity of 10 isolates of Didymella applanata to copper hydroxide, dithianon, fluazinam, tebuconazole and pyraclostrobin, was conducted. The isolates were derived from diseased raspberry canes sampled during 2013 at five localities in western part of Serbia, known as the main raspberry growing region of the country. Prior to sensitivity testing experimental conditions for radial growth assay were optimized. The results showed that the temperature of 22 degrees C, oatmeal agar medium and 12/12 hrs light/ darkness light regimen provided the best conditions for sensitivity tests. Most of D. applanata isolates were sensitive to the tested fungicides. The narrowest range of EC50 values was recorded for tebuconazole (1.42-2.66mg L-1). The widest range of EC50 values was obtained for pyraclostrobin, ranging from 0.17mg L-1 to 55.33mg L-1. The EC50 values for the studied isolates were 39.48-51.19mg L-1 for copper hydroxide, 12.12-18.73mg L-1 for dithianon and 5.72-42.56mg L-1 for fluazinam. According to resistance factor values, all D. applanata isolates were sensitive to copper hydroxide, dithianon and tebuconazole. Among tested isolates, six were highly resistant to pyraclostrobin (RFs in the range of 207.1-325.5) and two moderately resistant to fluazinam (RFs were 3 and 7.4), respectively