Mariana Popescu, Florin Oancea, Elena Radu, Mălina Deșliu-Avram and Călina Petruța Cornea
Natural by-products from vegetable oil industries and spent edible oils from domestic or public food spaces should be recycled to obtain new added value products. Present paper proposed a technical solution for complete valorisation of inedible oilseeds or spent edible oils into bioproducts for nutrition and protection of plants cultivated in conservative organic agrosystems. Pressed cakes resulted from mechanical cold extraction of mustard oil contain residual oil and bioactive compounds which were released using an enzymatic cocktail 1:1 cellulase with proteases coupled with azeotropic solvents into a single Soxhlet extractor. From mustard meal, a solid fraction with glycerol derivatives of fatty acids (56.23% oleate and 17.47% linoleate) decanted from syrup (41.78% xylopyranoside and 48.48% trilinolein) and from mustard cake (76.44% linoleate) in the supernatant, the same oligosaccharide (29.64%) and proteinates (30.18%) in the solid fraction. The total extract was simultaneously concentrated and converted into a bioactive potassium salt emulsion able to encapsulate insectofungicidal natural compounds as bioproducts with agronomical applications.
Steliana Paula Barbu, Aurel Giura, Daniel Cristina and Călina Petruţa Cornea
The decrease of variability sources and the genotypes instability as a result of climate changes from the last years were issues addressed in the breeding programs. For breeders the stability of some parameters like plant height is very important in selection process, therefore the influence of climatic variations it is aimed to be reduced by genetic response of the genotypes. Semi-dwarf genotypes are preferred by breeders because in this way is avoided the lodging risk. A set of 307 mutant and mutant/recombinant wheat DH lines, along with parental genotypes, was analyzed in three different years for plant height and the semi-dwarf selected lines were evaluated for stability of this parameter. The material was also analyzed for the presence of Lr34, or genes and 1A/1R translocation. In our study the reduced plant height and its stability was not associated with any of the genetic background
The excessive use of synthetic pesticides for plant pathogens control could cause possible harmful side-effects to humans and animals, environmental pollution, residual toxicity, affects soil characteristics or induce the development of fungal resistance. Alternative ways for fungal contamination control involve natural products, based on microorganisms, many of them being already available for use. The selection and characterization of new biological agents useful for plant pathogens control are permanent goals for plant protection researches. In the last decade, several studies revealed that Streptomyces species are promising biocontrol agents against a wide range of phytopathogenic fungi, including Fusarium spp., one of the most important wheat pathogens. In our study, 60 strains of Streptomyces spp. were isolated from soil or compost and evaluated for in vitro antifungal abilities by dual confrontation method. At least 30% of the isolates presented inhibitory activity against F. culmorum and F. graminearum. The bacterial strains were also tested for their ability to produce various bioactive compounds, possible involved in fungal inhibition. The capacity of some of the bacterial isolates to produce cellulases, amylases, lipases and volatile metabolites was proved. In addition, a new screening method for chitinases production was developed, based on the use of a combination of Congo red and Lugol solutions, which allowed the detection of chitinases in several Streptomyces spp. strains. Moreover, the reduction of the level of some Fusarium mycotoxins was detected by HPTLC analysis. As a conclusion, antagonistic interactions between Streptomyces isolates and fusaria could involve antibiosis, competition and parasitism and suggested that at least some of the selected isolates could be used in obtaining biological control products.