In the present study genetic diversity of 119 accessions of common bean (Phaseolus vulgaris) from five former Yugoslav republics constituting the Western Balkans was assessed by 13 microsatellite markers. This set of markers has proven before to efficiently distinguish between bean genotypes and assign them to either the Andean or the Mesoamerican gene pool of origin. In the present study 118 alleles were detected or 9.1 per locus on average. Four groups, i.e., Slovene, Croatian, Bosnian, and Serbian, showed similarly high levels of genetic diversity as estimated by the number of different alleles, number of effective alleles, Shannon’s information index and expected heterozygosity. Mildly narrower genetic diversity was identified within a group of Macedonian accessions; however, this germplasm yielded the highest number of private alleles. All five germplasms share a great portion of genetic diversity as indicated by analysis of molecular variance. Based on the scored number of migrants we conclude that the most intensive gene flow in the region exists in Bosnia and Herzegovina. Cluster analysis based on collected molecular data classified the accessions into two large clusters that corresponded to two gene pools of origin, i.e., Andean and Mesoamerican. We found that Andean genotypes are more prevalent than Mesoamerican in all studied countries, except Macedonia, where the two gene pools are represented evenly. This could indicate that common bean was introduced into the Western Balkans mainly from the Mediterranean Basin. Bayesian cluster analysis revealed that in the area studied additional variation exists which is related to the Andean gene pool. Different scenarios of the origin of this variation are discussed in the paper.
COBISS.SI-ID: 4823400
Four pospiviroid detection methods consisting of a pair of RT-PCR (ANSES 1-2), a pair of real time RT-PCR (Botermans 1-2) and two single RT-PCR methods (Luigi and Olivier) were evaluated for their relative accuracy, diagnostic sensitivity, diagnostic specificity, analytical sensitivity and reproducibility through a comparison in eight laboratories. All detection methods were tested on 13 tomato leaf and nine tomato seed samples as well as on 100-fold dilutions of the corresponding RNA extracts. Two different RNA extraction kits and three combinations of RNA extraction and RT-PCR kits were assessed. According to the statistical analysis of the results, ANSES 1-2 method provided the best performance criteria and is proposed as international standard for the generic detection of pospiviroids on tomato leaves and seeds. No statistical differences were observed between accuracies obtained for the two extraction kits or the three combinations of extraction and RT-PCR kits used.
COBISS.SI-ID: 4863080
Secondary metabolites of a strain of Microcyclospora malicola (Capnodiales) were analyzed for the identification of potentially novel bioactive natural products. The fungus belongs to a group of slowly growing sooty blotch fungi that can survive in the wax layers of plant cuticles, specifically apple fruits, without causing significant fruit rot or plant diseases. Bioassay guided fractionation and subsequent structure elucidation by spectroscopic and spectrometric methods led to the identification of obionin A and additional derivatives (pyranonaphtoquinone metabolites) showing cytotoxic effects and antifungal activity. The compound, originally isolated from the marine ascomycete Leptosphaeria obiones, may account for the antagonism between M. malicola and other epiphytic fungi competing for the same ecological niche on fruit surfaces.
COBISS.SI-ID: 4984424
Like other pathogens, plant parasitic nematodes employ effector proteins to alter plant cellular functions and successfully infect their hosts. We have generated a library of ORFs encoding putative Globodera rostochiensis apoplastic effectors in vectors for expression in planta. These clones were assessed for morphological and developmental effects on plants as well as their ability to induce or suppress plant defenses. Predicted cell wall-modifying proteins induced necrosis and chlorosis, consistent with roles in cell fate alteration and tissue invasion, respectively. We showed a novel role for an apoplastic expansin-like protein (GrEXPB2) in suppressing intra-cellular defense responses. GrEXPB2 also elicited defense response in species- and sequence-specific manner.
COBISS.SI-ID: 4630888
BACKGROUND: A 2 year study was conducted to evaluate the efficacy of biological control with optimally timed Trichogramma brassicae releases as an integrated pest management tool against the European corn borer (ECB), Ostrinia nubilalis (Hübner), in on-farm experiments (i.e. real field conditions) in three European regions with dissimilar geoclimatic conditions and ECB pressure and conventional management (i.e. insecticide treated and untreated). RESULTS: Biological control with Trichogramma (1) provided ECB protection comparable with conventional management, (2) in all cases maintained mycotoxin levels below the EU threshold for maize raw materials destined for food products, (3) was economically sustainable in southern France and northern Italy, but not in Slovenia where it resulted in a significant decrease in gross margin, mainly owing to the cost of Trichogramma product, and (4) enabled avoidance of detrimental environmental effects of lambda-cyhalothrin use in northern Italy. CONCLUSION: Optimally timed mass release of T. brassicae could be considered a sustainable tool for IPM programmes against ECB in southern France and northern Italy. Better involvement of regional advisory services is needed for the successful dissemination and implementation of biological control. Subsidy schemes could also motivate farmers to adopt this IPM tool and compensate for high costs of Trichogramma product.
COBISS.SI-ID: 4813928