Authors:M. Hudcovicová, V. Šudyová, S. Šliková, E. Gregová, J. Kraic, F. Ordon, D. Mihálik, V. Horevaj, and Z. Šramková
Marker-assisted selection (MAS) is an efficient modern method for transferring alleles or specific chromosome segments including important agronomic traits into elite cultivars. This approach makes genotypic selection possible, whereby the selection process is more effective. The Research Institute of Plant Production Piešťany uses genetic markers linked to important traits in the following pre-breeding programmes: 1. development of winter barley lines resistant to BaYMV/BaMMV, 2. development of spring barley lines resistant to BYDV, 3. development of winter wheat lines resistant to leaf rust (gene pyramiding), 4. improvement of wheat quality by new combination(s) of known HMW-GS and/or by introduction of novel HMW-GS alleles. Several hundreds of genotypes are usually analysed for the presence or absence of linked molecular markers and selected for use in breeding programmes.
Many wheat species and cultivars, independent of genetic markers of hardness, can produce grain with a vitreous, mealy or mixed appearance. This study analyzed selected chemical and physical differences between kernels with a vitreous and mealy appearance, hand-picked from grain of four winter wheat cultivars cultivated in Poland. Separated fractions were examined for protein content and composition, friabilin presence, carotenoids and total phenolic compounds content, specific kernel density, hardness, as well as kernel surface color. It was found that the ratio of vitreous kernels in the cultivars ranged from 39.18% to 76.28%. Vitreous kernels were darker, slightly heavier and harder than mealy kernels. Additionally, these kernels were more abundant in proteins (an average increase of 2.13%, with variation among cultivars from 0.71% to 2.89%). This type of kernels was also richer in phenolic compounds (on average by 4.02%) and less abundant in carotenoids (on average by 4.53%). Mealy (softer) kernels fractured to a finer flour.
Authors:Tulay Elal Mus, Figen Cetinkaya, Recep Cibik, Gul Ece Soyutemiz, Husniye Simsek, and Nilay Coplu
In this study, the presence of genes responsible for the pathogenicity and antibiotic resistance profile of enterococci isolated from various foodstuffs of animal origin was investigated. The percentage prevalence of enterococci was 54.1% (203/375) and the average count was found to be 3.81 log cfu/ml-g. Species-specific primers revealed Enterococcus faecalis as the predominant species carrying one or more virulence-associated traits of efa, gelE, ace, esp and agg genetic markers. Only one E. faecium isolate (from milk) was positive for the esp gene. Regarding antibiotic resistance, the highest frequency of resistance was observed for tetracycline (21.7%), followed by quinupristin/dalfopristin (13.3%), ciprofloxacin (2.0%), penicillin (2.0%), linezolid (1.0%), ampicillin (1.0%), streptomycin (1.0%), and gentamicin (0.5%). Enterococcus faecalis showed a higher prevalence of antibiotic resistance than other enterococci. The percentage of multidrug resistance among the isolates was 3.4%. Twenty-nine E. faecalis isolates (26.6%) carrying one of the virulence-associated traits were at the same time resistant to at least one antibiotic. Our results show that foods of animal origin, including ready-to-eat products, may be reservoirs of antibiotic-resistant and potentially virulent enterococci.
Authors:V. Oslovičová, J.R. Simmonds, J.W. Snape, Z. Gálová, Z. Balážová, and I. Matušíková
In this study we evaluate the genetic diversity of a selection of wheat accessions characteristically grown and adapted to mid-European environments, using various molecular marker systems. Thirty-three simple sequence repeat (SSR) markers were used alongside genic markers for known dwarfing genes, flowering time genes, and grain hardness genes, namely Rht-B1, Rht-D1, Ppd-D1, Vrn-A1, Vrn-B1, Vrn-D1 and Pinb-D1. In addition, variation was scored for the high-molecular-weight glutenin storage proteins, responsible for dough technological quality. A dendrogram was constructed using the UPGMA algorithm, based on the molecular data and the country of origin, giving an overview of their genetic similarity and relationships. The potential for the use of some agronomic traits in breeding, by providing a basis for multi-trait genetic selection in wheat breeding programs is discussed. Estimating the breeding values of crops using multiple genetic markers might help in breeding for varieties with good technological quality for growing under desired climatic conditions.
The main criterion that determines the quality of durum wheat is the degree of suitability for pasta production (pasta-processing quality). In this regard, pigment content and the quantity of oxidative enzymes of durum wheat play important roles in the quality of pasta. It is now possible to examine these features and specify their effects using recently developed genetic markers and spectrophotometric measurement techniques. In the present study, LOX enzyme activity and pigment content are determined using molecular and biochemical scanning. According to the obtained results, Gediz-75, Gdem-12, Line-19, Zenit, Line-7 and Line-20 were determined as the most suitable lines or varieties for the production of quality pasta with regard to LOX enzyme activity. As for pigment content, Kyle, Zenit, Gdem-12, Gdem-2, TMB-1 and TMB-3 showed the highest potential for the production of yellow pasta. When pigment content and LOX enzyme activity were evaluated together, the potential of the Gediz-75, Gdem-12 and Zenit durum wheat varieties and lines to produce yellow pasta products was shown to be very high.
Long polar fimbriae (Lpf) are recently discovered adhesins and increasingly important genetic markers of pathogenic Escherichia coli strains. The presence and genotype diversity of Lpf operons was screened in a collection of 97 Escherichia coli O157 strains representing different pathotypes, isolated from healthy cattle (n = 43) and human patients (n = 54) in several countries. Individual structural genes of Lpf were scanned by PCR, and allelic variants were detected with a recently developed typing scheme. Ninety-five strains carried at least one whole Lpf operon (genes lpfABCD and/or lpfABCDE). The 64 enterohaemorrhagic (EHEC) and 24 enteropathogenic (EPEC) strains all carried two Lpf operons, allele 3 of lpfA1 and allele 2 of lpfA2, a combination characteristic of the O157:H7/NM serotype. Out of the 9 bovine atypical (AT; stx-, eae-) strains, 7 carried one complete Lpf operon, allele 1 of lpfA2. The atypical strains belonged to main phylogenetic groups A and B1, while the EHEC and EPEC strains were from group D. Lpf variants carried by the 72 strains of the Escherichia coli Reference Collection (ECOR) were determined with the same typing scheme. Alleles were detected in 25 strains, of which 6 were found negative for the respective Lpf operons in earlier studies. The marker value of the Lpf allelic combination for the O157:H7/NM serotype was confirmed, and further evidence was given for the presence of at least two different genetic lineages of atypical bovine E. coli O157 strains.
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Williams, J. G. K., Kubelik, A. R., Livak, K. J., Rafalski, J. A. and Tingey, S. V. (1990): DNA polymorphisms amplified by arbitrary primers are useful as geneticmarkers. Nucleic Acids Research 18, 6531
A Toll-like receptor-4-ről, a természetes immunválasz egyik központi mediátoráról ismert, hogy a mikroorganizmusok elleni védekezésen túl más, nem fertőző ágensek okozta betegségben is, mint például az atherosclerosisban fontos szerepet játszik. A Toll-like receptor-4 Asp299Gly és Thr399Ile genotípusáról kimutatták, hogy csökkentheti a proinflammatorikus citokin szintjét, növelheti a Gram-negatív fertőzések iránti fogékonyságot, de csökkentheti a carotisatherosclerosis kockázatát. Célkitűzés: A PhD-munka során három különböző, gyakori, nem fertőző betegségben vizsgálták a Toll-like receptor-4-génpolimorfizmus befolyását: a cukorbetegség és kisérszövődményeiben, az agyi ischaemiás történésben, valamint krónikus periodontitisben. Módszer: A Toll-like receptor-4 genotípus meghatározásához mindhárom vizsgálatban polimeráz láncreakciót és endonukleázhasítást végeztek, amelyet gélelektroforézises módszerrel detektáltak. Eredmények: A Toll-like receptor-4-génpolimorfizmus a diabeteses perifériás neuropathia ritkább előfordulásával mutatott összefüggést 2-es típusú cukorbetegekben, más kisérszövődménnyel nem találtak összefüggést. A polimorfizmus nem mutatott összefüggést az agyi ischaemás történés, valamint a krónikus periodontitis kockázatával. Következtetés: Az eredmények alapján diabetes mellitusban, ischaemiás agyi történésben és krónikus periodontitisben a Toll-like receptor-4 genotípus nem megfelelően érzékeny genetikai marker a különböző kockázatok megbecsüléséhez. Orv. Hetil., 2011, 152, 1855–1858.