The effectiveness of Methylobacterium symbioticum in maize and strawberry plants was measured under different doses of nitrogen fertilisation. The biostimulant effect of the bacteria was observed in maize and strawberry plants treated with the biological inoculant under different doses of nitrogen fertiliser compared to untreated plants (control). It was found that bacteria allowed a 50 and 25% decrease in the amount of nitrogen applied in maize and strawberry crops, respectively, and the photosynthetic capacity increased compared with the control plant under all nutritional conditions. A decrease in nitrate reductase activity in inoculated maize plants indicated that the bacteria affects the metabolism of the plant. In addition, inoculated strawberry plants grown with a 25% reduction in nitrogen had a higher concentration of nitrogen in leaves than control plants under optimal nutritional conditions. Again, this indicates that Methylobacterium symbioticum provide an additional supply of nitrogen.
Rate of photosynthesis and related plant carbohydrate status are crucial factors affecting plant vigor. Sugars providing carbon and energy sources serve also as important signaling molecules governing plant growth and development through a complex regulatory network. These facts are often neglected when mixotrophic cultivation of plants in vitro is used, where artificial exogenous sugar supply hinders studies of metabolism as well as sugar-driven developmental processes. We compared the growth, selected gas-exchange parameters and sugar metabolism characteristics in four model plants, potato (Solanum tuberosum 'Lada'), tobacco (Nicotiana tabacum 'Samsun'), rapeseed (Brassica napus 'Asgard') and strawberry (Fragaria vesca), under both photomixotrophic (PM) and photoautotrophic (PA) conditions. To ensure PA conditions, we used our improved sun caps that serve as gas and light permeable covers for cultivation vessels. We found bigger biomass accumulation, larger leaf areas, higher stomatal conductance and higher instantaneous water use efficiency and lower root sugar contents in PA plants compared to PM ones. However, for other characteristics (root biomass, root/shoot ratio, pigment contents, leaf sugar and starch levels and transpiration rates), a strong species-dependent reactions to the exogenous sugar supply was noted, which does not allow to create a general view on the overall impact of PM nutrition under in vitro conditions.
- MeSH
- Brassica napus genetika metabolismus fyziologie MeSH
- fotosyntéza genetika fyziologie MeSH
- jahodník genetika metabolismus fyziologie MeSH
- kořeny rostlin genetika metabolismus fyziologie MeSH
- listy rostlin genetika metabolismus fyziologie MeSH
- tabák genetika metabolismus fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
The dynamics of pesticide residues in strawberries that involved quantification of pesticide residues in ripe fruits after model treatment was evaluated in repeated field trials conducted over 3 years. Sixteen commercial pesticide formulations in various combinations were employed in applications from 7 to 44 days before harvest. Altogether 21 active ingredients and some of their metabolites were determined in treated strawberries using LC-MS and GC-MS methods. Except for propargite, the concentrations of all active ingredients declined below the respective MRLs (Regulation (EC) No. 396/2005); nevertheless, most of the tested fungicides often persisted above the 0.01 mg kg⁻¹ limit required by baby food producers to avoid the risk of exceeding the 'baby food limit' established in Commission Directive 2006/141/EC. On the other hand, residues of the majority of tested insecticides, namely spinosad, pymetrozine, deltamethrin, lambda-cyhalothrin and azadirachtin, declined below this limit.
- MeSH
- biotransformace MeSH
- chemické jevy MeSH
- cyklohexany škodlivé účinky analýza chemie metabolismus MeSH
- dodržování směrnic MeSH
- dospělí MeSH
- Evropská unie MeSH
- insekticidy škodlivé účinky analýza chemie metabolismus MeSH
- jahodník chemie růst a vývoj metabolismus MeSH
- kojenec MeSH
- kontaminace potravin zákonodárství a právo prevence a kontrola MeSH
- lidé MeSH
- ovoce chemie růst a vývoj metabolismus normy MeSH
- potrava pro kojence analýza normy MeSH
- průmyslové fungicidy škodlivé účinky analýza chemie metabolismus MeSH
- pyridaziny škodlivé účinky analýza chemie metabolismus MeSH
- rezidua pesticidů škodlivé účinky analýza chemie metabolismus MeSH
- spotřebitelská bezpečnost produktů * zákonodárství a právo MeSH
- veřejná politika MeSH
- zákonodárství potravinářské MeSH
- Check Tag
- dospělí MeSH
- kojenec MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Česká republika MeSH
