253 research outputs found
The conventional and contemporary technologies in maize (Zea mays L) breeding at Maize Research Institut Zemun Polje
Broad genetic variability of starting biological material is crucial prerequisite for the successful breeding program. Maize Research Institute, owning Gene bank with more than 6,000 accessions consisted of the local and introduced collection, has the opportunity for the investigation both fundamental genetic processes, pre-breeding and breeding for commercial purposes. To search for new sources of maize drought tolerance Gene bank accessions were scored visually on stay-green phenotype and total appearance. More than 50 genotypes have been identified as a potential source for drought tolerance. Besides breeding on improved storage protein quality decreasing of phytate content in kernel is also under the consideration, because the most phosphorous is bound in phytate. In breeding program it is desirable to have genotypes with higher content of available phosphorous (P) not bound in phytate. Among 60 analyzed populations from Gene bank only one has been determined to have very low phytate content and will be used in maize breeding program on low phytate in kernel. Process of maize breeding, to get high yielding hybrids, begins by the genetic variability determination of starting breeding material, either populations or selected inbred lines. Genetic divergence of parental inbred lines is main step to get high heterotic effect in yield after crossing. Use of different molecular markers allowed cluster analysis by use of UPGMA methods and select high number of genotypes to be included in crossing process
Biotechnology: reality or dream
The development of molecular biology and molecular genetics, especially of the recombinant DNA technology enabled improvement of experimental methods that provide manipulation within a cell-free system, such as cell and tissue cultures. Such methods resulted in the development of different new technologies with specific properties in relation to the conventional definitions. According to PERSLEY and lantin (2000) the following components are essential for the contemporary biotechnology: (i) genomics - a molecular characterization of all genes and gene products of an organism (ii) bioinformatics - the assembly of data from genomic analysis into accessible forms; (iii) transformation - the introduction of genes controlling a trait of interest into a genome of a desired organism (micro organisms, plants, animal systems). By the application of cotemporary biotechnology new methods in the field of diagnostic are developed such as rapid and more accurate identification of the presence and absence of genes in the genome of the organism of interest (identification of pathogens prenatal diagnostics, molecular markers assisted breeding for plants, etc). The traits of an organism are determined by its genetic material, i.e. by a molecule of deoxyribonucleic acid (DNA). watson and crick (1953) were the first scientists to describe the structure of DNA as a double-stranded helix. Higher organisms contain a set of linear DNA molecules - chromosomes and a full set of chromosomes of an organism is a genome. Each genome is divided into a series of functional units, i.e. genes. The traits of an organism depend on genes, but their expression depends not only on genes but also on many other factors, including whether a gene, controlling the trait, expresses, specific cells in which it expresses and specially the mode by which the gene and its product interact with the environment. A special aspect within the application of biotechnology occurs as an interaction of a foreign gene with a genome of an integrated organism. Also application of biotechnology provides transfer of one or several favorable genes from any evolutionary category into other category of an organism and in such a way it is possible to develop genetically modified organisms (GMO) having expressed desired, target traits. A survey of the application of biotechnology in the world and our country is presented in this paper
Palynomorphological study of dianthus petraeus waldst. Et kit. (caryophyllaceae)
The pollen morphology of Dianthus petraeus (Caryophyllaceae), which is endemic to the Balkans, has been examined by both light and scanning electron microscopy in order to provide taxonomically valuable characters that might be used in the classification of the Caryophyllaceae, as well as to contribute to the pollen atlas of Serbian apiflora. The pollen grains of D. petraeus are radially symmetrical, apolar, spheroidal and medium-sized. The mean of the pollen diameter is 45.5 +/- 1.4 mu m. The sculpturing pattern of exine is microechinate-microperforate, and the tectum is covered with minute echini averaging 0.8 +/- 0.1 mu m in length, more or less evenly distributed between the perforations. The microechini average number per sample area of 5 mu m x 5 mu m is 3.2 +/- 0.6. In view of the number, position and type of the apertures, the grains are polypantoporate, with about 13 operculate pores, averaging 6.4 +/- 0.7 mu m in diameter. Each operculum is covered with 4-6 conical spinules, which are longer than those on the exine surface. The obtained palynological results provide information that contribute towards a better understanding of the taxonomic status of D. petraeus
Detekcija mehanizama rezistencije na karbapeneme kod enterobakterija i vrste Pseudomonas aeruginosa
The aims of the research: to examine the presence of genes which encode
carbapenemases among enterobacteria and Pseudomonas aeruginosa isolates with
reduced sensitivity to carbapenems by using the polymerase chain reaction (PCR); to
determine the most common mechanisms of resistance to carbapenems using
phenotypic methods. To evaluate the phenotypic methods in relation to PCR as a
reference method, and determine the most common phenotypes.
Methods: 107 isolates from the Enterobacteriaceae family and 75 isolates of the
species Pseudomonas aeruginosa were examined. Antimicrobial susceptibility was
determined by the Kirby-Bauer disc-diffusion method and the automated Vitek2 system
according to the recommendations of the Institute for Clinical and Laboratory Standards
(CLSI). Using PCR and phenotypic methods, 56 enterobacterial isolates and 14 isolates
of P. aeruginosa were tested. The results of the phenotypic tests were validated by a
comparison with genotypic data and expressed through sensitivity, specificity, and
positive and negative predictive value (PPV and NPV). Results: Carbapenemase genes
were detected by the PCR method in 52 Enterobacteriaceae isolates: 24 blaNDM, 16
blaOXA-48, 10 blaNDM/ blaOXA-48, one isolate blaNDM/ blaOXA-48/ blaKPC , one isolate blaKPC/
blaNDM and six blaNDM genes in Pseudomonas aeruginosa. All of the tested isolates were
negative for the blaVIM genes.
Among the applied phenotypic tests, high specificity (in excess of 95%) was found for
the modified Hodge test, the CARBA NP test, combined disc test and synergistic test,
while high sensitivity (greater than 95%) was determined for thechromID CARBA
agar. The most common phenotypes of resistance in enterobacteria were isolates
resistant to all the tested antibiotics except for colistin and tigecycline, and in the case
of Pseudomonas aeruginosa to colistin and piperacillin-tazobactam.
Conclusions: Based on the results of sensitivity, specificity, PPV and NPV, the
phenotypic methods for the detection of carbapenemase production represent reliable
tests for the detection of this resistance mechanism both in enterobacteria and in
Pseudomonas aeruginosa
Genetic characterization of early maturing maize hybrids (Zea mays L.) obtained by protein and RAPD markers
Knowledge of maize germplasm genetic diversity is important for planning breeding programmes, germplasm conservation per se etc. Genetic variability of maize hybrids grown in the fields is also very important because genetic uniformity implies risks of genetic vulnerability to stress factors and can cause great losts in yield. Early maturing maize hybrids are characterized by shorter vegetation period and they are grown in areas with shorter vegetation season. Because of different climatic conditions in these areas lines and hybrids are developed with different features in respect to drought resistance and disease resistance. The objective of our study was to characterize set of early maturing maize hybrids with protein and RAPD markers and to compare this clasification with their pedigree information. RAPD markers gave significantly higher rate of polymorphism than protein markers. Better corelation was found among pedigree information and protein markers
Innovative solutions in crop utilization biofortification as a function of quality food production
Globalni trend industrijalizacije poljoprivrede, naročito od pojave „zelene
revolucije“, karakteriše povećanje prinosa biomase, zrna i plodova useva. Ovakav trend
ima za posledicu paralelno smanjenje hranljive vrednosti poljoprivrednih proizvoda, koje
se ogleda u smanjenoj koncentraciji minerala i vitamina, posebno kada su u pitanju gvožđe,
magnezijum, cink i selen. Kada se uzme u obzir visok stepen erozije, kao i narušavanje
zemljišnog ekosistema, uz intenzivnu upotrebu mineralnih đubriva, baziranih uglavnom
na azotu, fosforu i kalijumu, a bez unosa organskih đubriva, zamljišta se „ispošćuju“ i
rapidno se gubi plodnost. Važno je istaći da je skoro polovina svetskih zemljišta
deficitarna mineralima. Ovo se dalje, preko ciklusa ishrane, vrlo nepovoljno odražava na
zdravstveno stanje ljudi i životinja, dovodeći do sistemske neishranjenosti i pojave
brojnih hroničnih bolesti. Da bi se stalo na put navedenim trendovima, potrebno je
proizvesti poljoprivredne proizvode bogate hranivima.
Akumulacija minerala u biljkama, posebno u zrnu, kao i sinteza vitamina je
kontrolisan brojnim biohemijskim procesima. Biofortifikacija ima za cilj povećanje
koncentracije minerala i vitamina u jestivim delovima biljaka. Mere gajenja koje utiču na
povećanje apsorpcije minerala i sintezu vitamina, kao i metode oplemenjivanja i
genetičkog inženjeringa koje imaju za cilj stvaranje genotipova poželjnih osobina, mogu
povoljno uticati na povećanje koncentracije minerala i vitamina u jestivim delovima
gajenih biljaka. Paralelno sa povećanjem koncentracije esencijalnih minerala i vitamina,
potrebno je razviti i mere kojima se utiče na smanjenje anti-nutritiva, koji sprečavaju
resorpciju minerala i vitamina iz organa za varenje, odnosno njihovo iskorišćenje od
strane animalnih organizama. Povećanje koncentracije esencijalnih minerala i vitamina,
kao i njihova iskoristljivost od strane ljudskih i životinjskih organizama je vrlo
kompleksna problematika, koja se bazira na primeni brojnih inovativnih rešenja i koja bi
trebalo da predstavlja integralni deo i sponu između agronomskih i medicinskih nauka, sa
ciljem poboljšanja kvaliteta agroekositema, gajenih biljaka i života, uopšte.The globally present trend of agriculture industrialization, particularly from arising of
"green revolution" was characterised with increase of biomass, grain and fruit yields. In parallel,
this trend had as a consequence decrease of nutritional quality of agricultural products, reflected
through reduced concentration of minerals and vitamins, especially of iron, magnesium and
selenium. When high intensity of erosion and depletion of soil ecosystem was taken into account,
together with intensive usage of mineral fertilizers, based on nitrogen, phosphorus and potassium,
without incorporation of organic fertilizers, soils became exhausted, rapidly losing their fertility. It
is important to underline that almost half of soils worldwide is deficient in minerals. In further,
through the nutrition cycle, this situation is transmitting to health depletion of humans and animals,
towards systemic malnutrition and arising of numerous chronically diseases. To combat present
trends, it is necessary to produce agricultural commodities rich in essential nutrients.
Various biochemical processes control accumulation of mineral nutrients in plant tissues,
particularly in grains, as well as vitamins synthesis. The goal of bio-fortification is increase of
concentration of essential minerals and vitamins in edible parts of plants. Thus, growing measures
that enhance absorption of minerals and vitamins synthesis, as well as methods of breeding and
genetic engineering, having as a target creation of genotypes with desirable traits, could be
positively reflect to increase in concentration of minerals and vitamins in edible parts of agricultural
plants. Correspondingly to the increase in concentration of essential minerals and vitamins, it is
necessary to develop measures that will reduce concentration of anti-nutrients, which diminish
absorption of minerals and vitamins from digestive organs, thus obstruct their utilization by animals
and humans. The increase of concentration of essential minerals and vitamins, as well as their bioavailability and utilization by animal and human organisms is very complex issue, based on the
application of various innovative solutions and it should present integral part, i.e. connection
between agricultural and medical sciences, aimed to increase quality of agro-ecosystem, agricultural
plants, and life, in general
Antagonističko dejstvo saprofitne bakterije serratia liquefaciens prema fitopatogenim gljivama kukuruza i potencijalni biohemijski i molekularni mehanizmi njenog dejstva
The objective of our study was to investigate effect of saprophytic bacterium Serratia liquefaciens derived from sunflower on maize phytopathogenic fungi in vitro and in vivo conditions, as well as, potential biochemical and molecular mechanisms. Obtained results indicate that production of an antibiotic is not a biochemical background of the antagonistic effect. Concurrence advantage of the saprophytic bacterial isolate S. liquefaciens isolated from sunflower, over the parasitic fungus Ph. ambiguum when limited quantities of carbon compounds were used in the joint culture, caused antagonistic effect between these two groups of microorganisms. The de novo synthesis new polypeptides of different molecular weight occurred in interactions with phytopathogenic fungi. The successful activities of isolates of the saprophytic bacterium under in vivo conditions were observed and manifested as lack of disease symptoms (root and stalk rots), and stimulatory effects on the rowth of both, roots and above-ground plant parts. The bacterial isolate S. liquefaciens showed the greatest inhibition rate of colonies growth of fungus Ph. ambiguum under in vivo conditions.Ispitivan je antagonistički efekat saprofitne bakterije Serratia liquefaciens, poreklom iz rizosfere suncokreta na fitopatogene gljive kukuruza u in vitro i in vivo uslovima, kao i potencijalni mehanizmi dejstva na biohemijskom i molekularnom nivou. Uočeno je da bakterijska vrsta S. liquefaciens ne poseduje sposobnost sinteze antibiotika. Antagonistički efekat koji je ova vrsta ispoljila prema Ph.ambiguum pri gajenju na hranljivoj podlozi sa različitim koncentracijama glukoze rezultat je postojanja kompeticijskog odnosa. U interakciji sa fitopatogenim gljivama došlo je do de novo sinteze proteinskih frakcija različitih molekulskih težina. Uspešno delovanje ovog bakterijskog izolata na razvoj fitopatogene gljive Ph. ambiguum ustanovljeno je i u in vivo uslovima, koje se ispoljavalo izostankom simptoma bolesti (truleži korena i stabla) i stimulativnom dejstvu na porast korena kao i nadzemnih delova biljke
Poljoprivedna biotehnologija - stanje i perspektive
The development of the DNA recombinant technology has provided the transfer of a single or several genes within or among species whereby organisms with new traits were developed. Such organisms have been called genetically modified organisms. The first genetically modified varieties of cultivated plants entered the market in 1996 and since then areas sown with such crops has been increasing, amounting to 60 M ha in 2002. During the stated period, genetically modified varieties and hybrids of cultivated plants were developed with a gene introduced for tolerance to herbicides, resistance to insects, prolonged maturity period and improved quality. However, heavy disputes have arisen all over the world relating the possible gain and potential risks from the growth and utilization of modified crops. First of all, there are ethical issues related directly to gene transfer from a species to a species, then effects of the introduced gene on the environment and human health, economical justification of cultivating genetically modified crops, consumers confidence in the legislation, labeling the products encompassing a genetic modification, effects on the global market and ever increasing food requirements. The effect of products derived from genetically modified plants on human health depends on a specific content of a product itself and can potentially be useful if a product contains an increased content of vitamins, with an allergen removed, or potentially harmful, if a new allergen or a toxin were introduced by genetic modifications. Each genetically modified product is subjected to a rigorous testing of its safety prior to its introduction into a food chain. It encompasses molecular, biochemical, toxicological, nutritional and allergenic tests. Many countries apply legislation that stipulates labeling of genetically modified products, whereby the fact that the commodity encompasses products of genetic modification is clearly pointed out.Razvoj tehnologije rekombinantne DNK omogućio je prenos pojedinačnog ili nekoliko gena unutar ili između vrsta pri čemu su dobijeni organizmi sa novim svojstvima, koji se nazivaju genetički modifikovani organizmi. Prve genetički modifikovane sorte gajenih biljaka su se pojavile na tržištu 1996. godine i od tada su površine zasejane ovim usevima povećane na 58.7 miliona hektara u 2002. godini. U navedenom periodu stvorene su genetički modifikovane sorte i hibridi gajenih biljaka sa unetim genom za tolerantnost na herbicide, otpornost na insekte, produženo vreme sazrevanja i poboljšan kvalitet. Ipak, u svetu postoje ogromna neslaganja oko moguće dobiti i potencijalnih rizika koji mogu nastati gajenjem i korišćenjem modifikovanih useva. Pre svega to su etička pitanja vezana za direktno prenošenje gena iz jedne u drugu vrstu, uticaj unetog gena na spoljnu sredinu i zdravlje ljudi, ekonomska opravdanost gajenja genetički modifikovanih useva, poverenje potrošača u zakonsku regulativu, obeležavanje proizvoda koji sadrže genetičku modifikaciju, uticaj na globalno tržište i rastuće potrebe za hranom
Korišćenje proteinskih markera za karakterizaciju i utvrđivanje genetičke čistoće semena kukuruza
Purity control and genetically characterization of maize inbred lines and hybrids have great importance in every phase of experimental or commercial hybrid seed production and inbred maintenance. Embryo proteins as genetic markers for maize genotypic identification as well as genetic purity determination were used. By electrophoresis embryo proteins have been separated into numerous components and showed great heterogeneity. All analyzed genotypes have specific protein pattern. Some of protein fraction appeared for each genotype at the same position and could be use as reference bands. The differences of protein complex among various maize varieties could be use to detect relationship between hybrids and their parental lines. The method is rapid, cheap and date can be use to form genetically identification card of inbred lines and hybrids.Kontrola genetičke čistoće i identifikacija genotipa je od velikog značaja u svim fazama proizvodnje eksperimentalnih i komercijalnih hibrida i održavanju linija kukuruza. U radu su korišćeni proteini klice za genetičku karakterizaciju genotipova kukuruza kao i za utvrđivanje genetičke čistoće semena. Elektroforezom proteini klice su razdvojeni na veliki broj frakcija koje pokazuju visoku heterogenost. Svi ispitani genotipovi kukuruza imali su jedinstvenu proteinsku sliku pri čemu se određen broj proteinskih frakcija nalazi na približno istoj poziciji u svim ispitanim uzorcima tako da se koriste kao referentne. Razlike u proteinskom sastavu linija mogu da se koriste i za utvrđivanje veze između hibrida i roditeljskih linija. Metod je brz, jeftin i podaci mogu da se koriste za formiranje genetičke identifikacione karte linija i hibrida kukuruza
- …