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

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

Genetički modifikovane biljke - koristi i rizici

Modern biotechnology is applied in agriculture, together with classical technology, in aim to increase production and improve quality of food. Revolutionary event for the plant biotechnology was possibility of creations of genetically modified plants, in fact, possibility of introducing of the genes from any organisms, to the plant genome. A genetic modified plant has the potential to offer very significant improvements in the quantity quality and acceptability of the world's food supply. First genetically modified plant were generated less than 18 years ago and now many GM plants are beginning to widely grown and products of these plants are available in the market place. Since the first commercial introduction of a genetically modified plant growing area has increase rapidly to more than 50 mill ha. The first generation of genetically modified crops with "input "traits as insect resistance, herbicide tolerance, delayed ripening, virus resistance are currently on the market.Moderna biotehnologija se primenjuje u poljoprivredi, zajedno sa klasičnim tehnologijama, u cilju povećanja proizvodnje hrane i poboljšanja njenog kvaliteta. Revolucioni pomak na polju biotehnologije biljaka predstavlja mogućnost stvaranja genetički modifikovanih biljaka tj. mogućnost ugrađivanja gena poreklom iz bilo kog organizma u genom biljke. Genetički modifikovane biljke imaju mogućnost da obezbede više, bolje i bezbednije proizvode koji zajedno sa klasičnom tehnologijom, povećavaju proizvodnju hrane koja će moći da zadovolji potrebe rastuće ljudske populacije. Prva genetički modifikovana biljka je dobijena pre osamnaest godina, a danas se gaje komercijalno mnoge genetički modifikovane biljke i proizvodi od njih su dostupni na tržištu. Prva generacija genetički modifikovanih biljaka za takozvane ²input² osobine obuhvata tolerantnost na totalne herbicide rezistentnost na insekte, rezistentnost na viruse. Od prve komercijalizacije genetički modifikovanih biljaka površine na kojima se gaje su značajno povećane na više od 50 mil ha

Genetička divergentnost samooplodnih linija kukuruza i heterozis

The genetic diversity of six maize inbred lines, as well as, the genetic similarity between parental inbred lines and heterosis for yield in their F1 crosses was studied. Three inbred lines (ZPL 142, ZPL 680 and ZPL 357/3) are of the BSSS origin and another three (ZPL 257/3, ZPL 17/5 and ZPL 173/3) are of the non-BSSS genetic background. Molecular markers provide a direct determination of a number for which two inbred lines are different for a given number of loci. Maize inbred lines were genetically characterized with RAPD markers. Genetic similarity among genotypes was done by a statistical analysis with NTSYSpc v2.0 and by the application of the cluster analysis. Parental inbred lines, 30 F1 crosses with reciprocals, were included in a randomized complete block design with four replications in two densities (44,640 and 64,935 plants ha-1) at the location of Zemun Polje in 2003 and 2004. The differences among genotypes (F1 and inbreds line per se), densities and years were statistically significant. The highest value of mid-parent heterosis (192.2 %), as well as, the best-parent heterosis (178.0 %) was obtained for the cross ZPL 173/3 x ZPL 680 over investigated densities and years. The Spearman's correlation coefficient was used to determine correlations between the values of heterosis obtained in the field experiment and the value of genetic distances based on RAPD markers. The obtained results indicate that RAPD markers can be used to study the genetic diversity of maize inbred lines, although their application in the prediction of heterosis for grain yield is limited.U radu je ispitivana genetička različitost šest samooplodnih linija kukuruza na osnovu RAPD markera i odnos genetičke sličnosti između roditeljskih linija i heterozisa za prinos zrna u njihovim ukrštanjima (F1 hibridima). Roditeljske linije i 30 F1 hibrida, dobijenih ukrštanjem roditeljskih linija u potpunom dijalelu, su testirani po slučajnom blok dizajnu sa četiri ponavljanja u dve gustine useva (G1=44.640 i G2=64.935 biljaka ha-1) u Zemun Polju tokom 2003 i 2004. godine. Razlike u prinosu zrna između ispitivanih genotipova (F1 i samooplodne linije per se), ispitivanih gustina i spoljnih sredina su bile statistički značajne. Najveći heterozis dobijen je kod kombinacije ZPL 173/3 x ZPL 680 i u odnosu na vrednost srednjeg roditelja (192.2 %) i u odnosu na boljeg roditelja (178.0 %) u ispitivanim gustinama i godinama. Za određivanje korelacija između vrednosti za heterozis u kombinacijama dobijenim u poljskom ogledu i vrednosti genetičkih distanci izračunatih na osnovu RAPD markera korišćen je Spearman-ov koeficijent korelacije. Dobijeni rezultati ukazuju da se RAPD markeri mogu koristiti za ispitivanje genetičke divergentnosti samooplodnih linija kukuruza, mada je njihova primena za predviđanje heterozisa za prinos zrna ograničena

Genetički modifikovane biljke - nutritivni i zdravstveni aspekti

Genetically modified plants (GMP) with specific traits, have been developed by transfer of a single or several genes within or among species. Already, genetically modified sorts of cotton, soybean, oilseed rape as well as corn hybrids with gene for herbicide tolerance, insect and virus resistance, improving nutrition characteristics have been created. The use of genetically modified crops as animal feed from nutritional aspects have great potential but otherwise raised concerns about potentional risks in scientific community all over the world. Potential risks include development of allergic reactions, transfer of antibiotic gene to gut bacteria of animal and development of antibiotic resistance and potential adverse health effect in animals. The study of food safety obtained from genetically modified crops in the nutrition of animals has been conducted throughout the whole world. The results obtained have demonstrated no difference in the quality of the milk, meat and eggs of animals that had eaten either transgenic or no-transgenic feed. Of course, long term and thorough research should give more reliable results.Genetički modifikovane biljke (GMB), sa specifičnim karakteristikama, stvorene su zahvaljujući visokom razvoju tehnologije koja je omogućila prenos gena unutar ili između vrsta. Tako su već stvorene genetički modifikovane sorte soje, pamuka, uljane repice kao i hibridi kukuruza sa unetim genom za tolerantnost na herbicide, otpornost na insekte ili sa poboljšanim nutritivnim karakteristikama. Primena GM biljaka u ishrani domaćih životinja sa nutritivnog aspekta pruža velike mogućnosti dok sa druge strane potencijalni rizici njihovog korišćenja izazivaju brojne polemike u naučnim i stručnim krugovima. Kao najveći potencijalni rizik njihove primene navodi se opasnost od pojave rezistentnosti na antibiotike alergijske reakcije ali i razni drugi mogući neželjeni efekti na zdravstveno stanje. U cilju rešavanja ovih dilema sprovedena su brojna istraživanja koja su obuhvatila ispitivanje bezbednosti hrane dobijene od GM biljaka kod ishrane domaćih životinja. Rezultati dosadašnjih istraživanja su pokazala da se životinjski proizvodi dobije-ni od životinja hranjenih genetički modifkovanim biljkama ne razlikuju od onih hranjenih nemodifikovanim biljakama i nemaju uticaj na kvalitet mesa, mleka i jaja. Naravno, pravi potpun odgovor treba da pruže buduća obimnija istraživanja koja bi trebalo da daju relevantne podatke kako bi se ove dileme resile

Primena molekularnih markera i bioinformatike u oplemenjivanju biljaka

In the past decade development of molecular genetics brought new dimension of a plant breeding. Molecular markers as universally methods for all biological system virtually effect on a success of directly examination of structure and function of genome and well as determination of genetic polymorphism of plant genomes. The potential applications of molecular markers in plant breeding are: analysis of molecular basis of evolution; germ plasma identification classification and management; assessing genetic diversity; identification of genes underlying agronomy important traits as yield, resistance to stress and disease as well as heterosis. High density genetic linkage maps for a number of plant species as a basis for marker assisted selection of agronomically useful traits and isolation of these genes have been established. Important factor in the successes of the genetic improvement of crops was the development of faster and more reliable methods, which allowed easier analysis of date as well as rapid information exchange. The application of information technology and development of statistical techniques to analyze genomic information is know as 'bioinformatics'. By integrating genetics with informatics investigations of whole genomes aims to elucidate the structure function and evolution of plant genomes are faster. Together these technologies as integral part of classical breeding programs contributing significantly to shorting of plant breeding process and cycles of selection.Tokom poslednje decenije razvoj molekularne biologije uneo je novu dimenziju u oplemenjivanje biljaka. Molekularni markeri kao univerzalna metoda za sve sisteme je značajno uticala na uspeh direktnog ispitivanja strukture i funkcije genoma kao i ispitivanje genetičkog polimorfizma. Potencijalne primene molekularnih markera u oplemenjivanju biljaka su: ispitivanje molekularne osnove evolucije; identifikacija, klasifikacija i održavanje germplazme; ispitivanje genetičke raznovrsnosti; identifikacija gena koji kontrolišu prinos, heterosis, stres ili bolesti. Formirane su visoko zgusnute genetičke mape za brojne biljne vrste kao osnova selekcije zasnovane na markerima za agronomski važne osobine kao i izolovanje gena. Važan faktor u uspehu genetičkog poboljšanja biljaka je razvoj brzih i pouzdanih metoda koji omogućavaju lakšu analizu podataka kao i brzu razmenu informacija. Primena informatike i razvoj statističkih metoda za analizu genetičkih informacija poznata je kao 'bioinformatika'. Integracijom genetike sa informatikom ispitivanja na nivou genoma sa ciljem da se rasvetli struktura, funkcija i evolucija biljnog genoma su ubrzana. Zajedno ove tehnologije kao sastavni deo konvencionalnih programa oplemenjivanja značajno doprinose skraćenju procesa selekcije

Različiti aspekti inhibicije rastenja i fotosinteze kukuruza (Zea mays L.) uzrokovanog herbicidom sulfosatom, 1 - manipulacija statusom korena

Effects of the herbicide sulphosate on growth, accumulation and partitioning of dry weight and photosynthesis in maize plants subjected to source-sink manipulation at the root were studied. The findings indicate that growth and dry weight accumulation correlate significantly only with the dry mass ratio and/or volume of the root (RMR, Vr, respectively), while a significant negative correlation was found with stem mass ratio (SMR) and generally with leaf mass ratio (LMR), which reflects an irregular distribution of carbohydrate metabolism in maize plants. As the root is where cytokinins, the plant hormons essential for maintaining photosynthetic structures, are synthesized, we assumed that the root status under stress caused by the herbicide sulphosate could be one of the factors of stability/sensitivity of photosynthesis/photosynthetic structures in plants exposed to this herbicide.U radu je razmatran uticaj herbicida sulfosata na rastenje, akumulaciju i preraspodelu suve mase, kao i fotosintezu biljaka kukuruza na kojima je vršena manipulacija "proizvod-potrošač" odnosa na nivou korena. Nađeno je da akumulacija suve mase značajno Koreliše samo sa zapreminom i/ili udeonom suvom masom korena (Vr, RMR), a negativno značajno sa udeonom suvom masom stabla (SMR) i (uglavnom) listova (LMR), što je u skladu sa neravnomernom preraspodelom ugljenohidratnog metabolizma kod biljaka kukuruza. Poznato je da je koren mesto sinteze citokinina, biljnih hormona neophodnih u održavanju fotosintetskih struktura. Pošto rezultati ukazuju na značaj statusa korena u uslovima stresa izazvanim herbicidom sulfosatom, smatramo da isti može biti jedan od faktora stabilnosti /osetljivosti fotosinteze/ fotosintetskih struktura kod biljaka izloženih dejstvu pomenutog herbicida

Utvrđivanje genetičke divergentnosti ZP hibrida kukuruza (Zea mays L) Iz različitih ciklusa selekcije primenom proteinskih markera

Five cycles (periods) have determined breeding of hybrid maize in Yugoslavia Each period has been characterised by the introduction of new significantly yielding hybrids. The objective of our study was to investigate the utility of protein markers in characterisation of a set of 30 maize hybrids from five different selection cycles, validate pedigrees, and show association among hybrids. Knowledge of the genetic diversity and relationships among maize hybrids is important for planning breeding strategies, hybrid identification, germplasm identification. We also investigated if there was a change in the genetic variability among cycles. This is important for evaluating and decreasing risks of future pathogen and stress induced damage which is mainly responsible for significant decrease in yield. The analysis of embryo salt soluble proteins shows that all studied genotypes have a specific protein pattern. Grouping of 30 ZP maize hybrids from different selection cycles generally agreed with the pedigrees. Our study shows that embryo salt soluble proteins can be used for characterization of hybrids. They have restricted use in estimating a genetic relationship among maize hybrids because of a small number of protein fractions observed that represent the whole genome. They can be used in combination with more informative DNA markers. According to obtained results there was no significant change in the genetic variability among selection cycles. This information is very important for sustaining genetic variability of the germplasm in the selection process.Poznavanje genetičke varijabilnosti hibrida kukuruza koji se gaje na jednom području važno je zbog planiranja selekcionih programa, procene rizika od štetnog delovanja faktora spoljašnje sredine u uslovima genetičke uniformnosti, identifikacije hibrida, identifikacije germplazme. Genetička sličnost dva genotipa se može proceniti indirektno iz pedigre podataka ili direktno pomoću biohemijskih (izozimi, proteini) i molekularnih markera (DNK markeri). Cilj ovog rada bila je karakterizacija 30 ZP hibrida kukuruza iz pet različitih ciklusa selekcije primenom proteinskih markera i određivanje genetičke varijabilnosti unutar svakog ciklusa selekcije. Grupisanje hibrida iz različitih ciklusa selekcije pomoću proteinskih markera se generalno slaže sa pedigre informacijama. Naš rad pokazuje da se proteinski markeri mogu koristiti za karakterizaciju hibrida kukuruza. Rezultati dobijeni primenom proteinskih markera pokazuju da tokom selekcionih ciklusa nije došlo do smanjenja u genetičkoj varijabilnosti komercijalnih hibrida

Kernel modifications and tryptophan content in QPM segregating generations

Maize has poor nutritional value due to deficiency of two essential amino acids - tryptophan and lysine. Although recessive opaque2 (o2) mutation significantly increases their content in the endosperm, incorporation of opaque2 into high yielding cultivars was not commercially successful, because of its numerous agronomic and processing problems due to soft endosperm. Quality protein maize - QPM has lately been introduced as opaque2 maize with improved endosperm hardness and improved agronomic traits, but mostly within tropical and subtropical germplasm. The ongoing breeding project at MRI includes improvement of MRI opaque2 lines and conversion of standard lines to QPM germplasm. The main selection steps in QPM breeding involve assessing kernel modifications and tryptophan level in each generation. Herein, we present the results of the analysis for these traits on F3 and BC1F1 generations of QPM x opaque2, opaque2 x QPM and standard lines x QPM crosses. The results showed that the majority the genotypes had kernel types 2 and 3 (good modifications). The whole grain tryptophan content in F3 and BC1F1 genotypes of crosses between QPM and opaque2 germplasm was at the quality protein level, with a few exceptions. All BC1F1 genotypes of standard lines x QPM had tryptophan content in the range of normal maize, while majority of F3 genotypes had tryptophan content at level of QPM. The progeny (with increased tryptophan levels) of QPM and opaque2 crosses had significantly higher tryptophan content compared to the progeny of crosses between standard and QPM lines - 0.098 to 0.114 and 0.080, respectively. All genotypes that had poorly modified kernels and/or low tryptophan content will be discarded from further breeding

Biohemijska analiza F2 zrna genotipova kukuruza visokog kvaliteta proteina

Protein quality of standard maize kernels is poor, due to the low levels of two essential aminoacids - lysine and tryptophan. The opaque2 mutation which increases lysine and tryptophan content also confers an undesirable phenotype leading to low yields, soft and chalky kernels that renders seeds susceptible to storage pest and ear rots. Quality protein maize (QPM) is the maize with increased levels of these amino acids and good agronomic performances. At the Maize Research Institute, a program on creating QPM germplasm developed for conditions of temperate climatic zone is in progress. The aim of this study was to test quality traits of F2 kernels derived from the crosses between 24 QPM inbred lines with three standard inbred lines and two opaque2 lines. Most of the analyzed 108 genotypes had tryptophan content under the threshold of 0.075 set for QPM (83.5%). However, 50% had elevated tryptophan content in the range from 0.065 to 0.074. High tryptophan content was found in 16.5% of the analyzed genotypes, the highest being 0.088. Only one genotype had quality index over 0.80 (threshold for QPM). Biochemical analysis identified genotypes with good protein quality which will be further tested for agronomic performances in order to potentially be considered as QPM hybrids.Proteini kukuruza su siromašni u sadržaju dve esencijalne aminokiseline - lizina i triptofana. Prirodna opaque2 mutacija udvostručava nivo ovih aminokiselina, ali istovremeno smanjuje prinos, čini endosperm kukuruza mekim i brašnjavim, a seme osetljivim na trulež klipa i štetočine skladištenog zrna. Kukuruz visokog kvaliteta proteina (Quality Protein Maize - QPM) se može definisati kao kukuruz sa visokom nutritivnom vrednošću proteina endosperma i istovremeno dobrim agronomskim performansama. U Institutu za kukuruz već nekoliko godina postoji program stvaranja genotipova kukuruza visokog kvaliteta proteina, adaptiranih na umereno klimatsko područje. Cilj ovog rada je bio da se ispita kvalitet proteina F2 zrna kukuruza dobijenog ukrštanjem 24 QPM inbred linija sa tri standardne inbred linije i dve opaque2 linije. Većina od 108 analiziranih genotipova (83,5%) je imala sadržaj triptofana ispod praga od 0,075, od čega je poboljšani nivo triptofana (0,065-0,074) imalo 50% genotipova. Visok sadržaj je imalo 16,5% analiziranih genotipova, od kojih je najviša vrednost bila 0,088. Samo jedan genotip je imao indeks kvaliteta proteina iznad praga od 0,80. Biohemijskom analizom utvrđeni su genotipovi poboljšanog kvaliteta čija će agronomska svojstva biti ispitana kako bi se utvrdilo da li se mogu smatrati potencijalnim QPM hibridima