The highbush blueberry (Vaccinium corymbosum L.) is a promising fruit species due to its high nutritional value and health benefits. This study, conducted between 2020 and 2024, monitored the phenological and pomological characteristics of 32 different blueberry cultivars grown in the Czech Republic. The evaluation was carried out according to Czech Republic standardized methodologies, BBCH (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie) and GRIN (Genetic Resources Information Network), and included parameters such as fruit size, flavor, aroma, firmness, color, and soluble solids content (SSC in °Brix). The correlation between individual traits was assessed, along with their phenotypic stability. The results showed that all cultivars exhibited high pomological values, making them suitable for breeding programs. The cultivars ‘Collins’ and ‘Patriot’ received the highest flavor ratings. Firmness, aroma, and color traits were found to be correlated with consumer preferences. The interannual coefficient of variation (CV) obtained for the evaluated blueberry cultivars differed for both pomological and phenological traits, allowing the identification of genotypes with high stability (CV ≤ 10%) and their potential use in targeted breeding programs and industrial production. The ‘Pink Lemonade’ blueberry cultivar, in particular, combines unique color characteristics with a strong aroma. Overall, this study provides valuable insights for future breeding efforts aimed at improving blueberry quality and cultivar adaptability under different cultivation conditions.
Triazole compounds are members of the demethylation inhibitor class of systemic agents used to combat the most widespread apple diseases worldwide, namely apple scab and powdery mildew. The dissipation kinetics of difenoconazole, mefentrifluconazole, myclobutanil, penconazole, tebuconazole and tetraconazole from commercial products in two apple cultivars (Rosana and Selena) were studied over four years. Pesticide residues in the apples were determined using the QuEChERS extraction procedure, followed by liquid chromatography–mass spectrometry analysis. Triazoles applied 84–100 days before harvest dissipated faster than those applied 44–55 days before harvest, with half-lives of 4.0–22.3 days and 7.1–43.9 days, respectively. Except for tebuconazole, all triazoles were found to be well below 30% of the maximum residue levels at the end of the pre-harvest interval, which is mandatory for products in use. The dissipation of five triazoles was evaluated during cold storage over two subsequent years. Residues of difenoconazole, myclobutanil and tebuconazole were detected at levels above 0.01 mg/kg after more than five months. The calculated risk intake values were lower than the established acceptable daily intake and acute reference dose values, indicating that the acute and chronic risks of pesticide exposure from consuming apples are not expected.
The European plum (Prunus domestica L.) is a hexaploid species that is grown worldwide for its tasty fruits. Many pomological forms and varieties exist, and thus it is important for genebank curators, breeders, growers, and/or control authorities to distinguish them with certainty. The purpose of this study was to select and verify a set of simple sequence repeat (SSR) markers for reliable genotyping, and to optimize their use in a one-reaction format for easy routine practice. After testing 78 SSR markers from different diploid Prunus species, 8 SSR markers were selected, multiplexed, and successfully verified as being able to distinguish all 242 unique genotypes tested. The selected markers were relatively easily scored and highly heterogenic, giving more than 35 alleles/genotype on average. The allele atlas was created to become a valuable tool for allele calling that should lead to standardized and reliable genotyping results between laboratories. The population analysis confirmed high diversity of the Czech germplasm collection used. The kit was also successfully tested for diploid “plums” of various origins and interspecies hybrids, as these are sometimes phenotypically indistinguishable from hexaploid European plums. The one-tube approach substantially simplified the plum genotyping laboratory workflow, minimizes errors, and saves labor, time, and money.
The aim of this study was to evaluate the occurrence of pesticide residues in apples from the Czech Republic in comparison to other countries (mainly Poland) and to answer the question of whether pesticide patterns are different. A set of 265 samples of apples harvested in the Czech Republic (48.7 % of the total number of samples) and grown in other countries (51.3 % of the total number of samples) were analysed for 460 pesticide residues using LC-MS/MS and GC-MS/MS methods between 2020 and 2023. Pesticide residues were found in 260 of them (98.1 % of all samples). A total of 74 different pesticides were found. Only diflubenzuron, folpet, prothioconazole-desthio and tebuconazole exceeded the maximum residue limits (MRLs). The percentage of samples containing pesticide residues of up to 10 % of the MRL is increasing. Six or more residues were detected in 50.1 % of all apple samples. The most frequently quantifiable pesticide residues in all sample sets were captan and its metabolites (in 74 % of samples). The data show different pesticide treatment strategies in the European countries. The largest difference in pesticide use between Czech and imported apple producers was found for difenoconazole (50 % of Czech samples and 19 % of imported samples).
Specimens of the plum seed wasp, Eurytoma schreineri Schreiner, 1908 (Hymenoptera: Eurytomidae), collected in the Czech Republic were found to be parasitized by an unidentified species of Pyemotes Amerling, 1861 (Acari: Pyemotidae) very close to or identical to P. herfsi. Out of 526 collected wasps, 24.14% were parasitized, primarily as larvae (21.48%). Infected larvae and pupae of the plum seed wasp were covered by spherical, physogastric females of the genus Pyemotes. Genus identification was based on sequence similarity analysis of the nuclear 18S rDNA region, amplified from DNA isolated from the mites. This is the first record of pyemotid mite parasitisim on the plum seed wasp, E. schreineri, and the first report of natural infection of an insect by these mites in the Czech Republic.
