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

Ethics in scientific results application: gene and life forms patenting

Konstantinov K., S. Mladenovic Drinic, V. Andelkovic and M. Babic (2010): Ethics in scientific results application: gene and life forms patenting - Genetika, Vol 42, No. 1, 195 -208. The remarkable development and application of new genetic technologies over the past decades has been accompanied by profound changes in the way in which research is commercialized in the life sciences. As results, new varieties of commercially grown crops with improved or new traits are developed. Many thousands of patents which assert rights over DNA sequences have been granted to researchers across the public and private sector. The effects of many of these patents are extensive, because inventors who assert rights over DNA sequences obtain protection on all uses of the sequences. Extremely valuable to breeders in the national agricultural research system is the ability to genotype their collections to get a clear picture of their diversity and how diversity could be enhanced through sharing and access to global collections. The issue of the eligibility for patenting of DNA sequences needs to be reopened. Patents that assert rights over DNA sequences and their uses are, in some cases, supportable, but in others, should be treated with great caution. Rights over DNA sequences as research tools should be discouraged. That the best way to discourage the award of such patents is by stringent application of the criteria for patenting, particularly utility. A more equitable, ethically based food and agricultural system must incorporate concern for three accepted global goals: improved well being, protection of the environment and improved public health (particular point food from GMO). To mitigate conflict one of the approach to solve problem is ethical and truthful label of GM food, because consumers have a right to choose whether to eat genetically modified foods or not. Interesting examples and risks as consequences of free availability of genetic resources utilization, its transformation, patenting of "new" organism and selling it back to the genetic resource owner are presented. Society has obligations to raise levels of nutrition and standards living by all respect to ethics at each step

ESTs analysis in maize developing kernels exposed to single and combined water and heat stresses

Molecular and metabolic response of plants to a combination of two abiotic stresses is unique and cannot be directly extrapolated from the response of plants to each of the stresses individually. cDNA macroarray has become a useful tool to analyze expression profiles and compare the similarities and differences of various expression patterns. A macroarray of approximately 2,500 maize (Zea mays 1,.) cDNAs was used for transcriptome profiling in response to single and simultaneous application of water and high temperature stress of maize developing kernels at 15 days after pollination. All stress treatments (water stress-WS, heat stress-HS and their combined application-CS) induced changes in expression of 106 transcripts with 54 up-regulated and 52 down-regulated. There were 11 up-regulated and 15 down-regulated transcripts in common for all three stresses. Although these common transcripts showed existence of a mutual mechanism in stress response, the 23 transcripts induced only in CS indicate that plants responded in a different manner when exposed to simultaneous effects of both stresses. A glimpse of functions regulated under WS, HS and CS is provided, and also the common and different responses between individual and simultaneous stresses

Comparison of morphological and molecular genetic distances of maize inbreds

Babic M., V. Babic, S. Prodanovic, M. Filipovic, and V. Andelkovic (2012): Comparison of morphological and molecular genetic distances of maize inbreds - Genetika, Vol 44, No. 1, 119-128. Due to an unknown mechanism of genetic control and great environmental effects in the process of trait expression, morphological markers are often considered unreliable indicators of genetic relationships. Morphological characterisation of 19 maize inbreds was done according to the UPOV descriptor, while molecular characterisation was performed with RAPD markers. Based on the estimation of phenotypes according to the UPOV descriptor, the squared Euclidean distance was calculated and then, on the basis of this distance, a morphological similarity matrix was formed. Jaccard similarity coefficients were calculated on the basis of presence-absence of bands on gels in the RAPD analysis. When data were standardised, the comparison between morphological and genetic similarity of observed maize inbreds was done. The correlations varied from 0.47 (inbred L 217) to 0.76 (inbred L 86). The average value of correlations for all studied inbreds amounted to 0.64. Furthermore, the results of the cluster analysis for both markers, molecular and morphological, had high concordance with pedigree data. Environmental effects were decreased in morphological markers (according to the UPOV descriptor) by rescaling a measurement scale from a scale to an ordinal level of measurement and in such a way results of morphological markers approached results of molecular markers in the estimation of the genetic distance (GD) of maize inbred lines

The identification of bands related to yields and stability in maize hybrids and their parental components

Geneticists have been trying to explain adaptability and stability of a genotype in terms of a desirable combination of alleles expressed via epistasis. Stability determined in one set of data is very often stability of a genotype to a prevalent stress factor in a moment of carrying out the experiment. However, grain stability of a certain genotype can be a result of different factors, such as tolerance to drought, or to some important diseases and pests. Yield and yield stability of 15 maize hybrids were observed in 24 environments. The level of the interaction effect of studied maize hybrids was identified by the AMMI analysis, while a number of bands positively related to yield and stability of studied maize hybrids were identified by a genetic characterisation by RAPD markers. Bands positively related to yields were present to a greater extent in parents originating from the BSSS population, while bands positively related to stability were more present in parents originating from the Lancaster population

Odgovor korenovog sistema klijanaca kukuruza na osmotski stres

Field testing for drought tolerance was performed on 6,000 accessions from the Maize Research Institute gene bank, under severe drought conditions in Egypt, as well as, under moderate climate conditions in Zemun Polje and Skopje. Five inbred lines, considered as drought tolerant, were chosen for further investigations under controlled experimental conditions. Osmotic stress caused by drought is one of the most important abiotic stresses. In this study osmotic stress was applied with polyethylene glycol (PEG) 10 000. The response to the PEG treatment of these genotypes was analysed in respect to their root morphology, root length, root fresh and dry weight, proline content and peroxidase activity. Results showed that the root development was less in all genotypes under the PEG treatment. The proline content increased, while the peroxidase activity declined in PEG-treated plants.Suša je jedan od najznačajnijih abiotičkih faktora, koji značajno utiče na smanjenje konačnog prinosa zrna kod kukuruza. Predviđanja globalnih klimatskih promena za XXI vek idu u pravcu povećanja temperature vazduha, veće evapotranspiracije i učestalije pojave suše. Za selekciju kukuruza danas, kao i u doglednoj budućnosti, izvori poželjnih svojstava koji se nalaze u bankama gena biće od velikog značaja. Materijal koji se čuva u banci gena Instituta za kukuruz, po obimu i sadržaju, pruža velike mogućnosti. Na osnovu ispitivanja tolerantnosti na sušu kod 6.000 uzoraka iz banke gena Instituta za kukuruz u poljskim uslovima umerenog (Zemun Polje i Skoplje) i aridnog klimata (Egipat), odabrano je pet inbred linija, okarakterisanih kao tolerantne, za dalja ispitivanja u kontrolisanim laboratorijskim uslovima. Linije pripadaju različitim FAO grupama zrenja (A5 - FAO 400 i A1, A2, A3 i A4 - FAO 500). Osmotski stres izazvan sušom je jedan od najznačajnijih abiotičkih faktora. U ovom radu je ispitivan efekat polietilen glikola (PEG) 10.000, kao osmotikuma, na rast korena klijanaca. Merena je dužina, sveža i suva masa korena, određivan je sadržaj prolina u korenu i merena je aktivnost antioksidativnih enzima. Rezultati ispitivanja pokazuju smanjenje porasta korenovog sistema, povećanje sadržaja prolina, kao i smanjenje specifične aktivnosti peroksidaza kod svih tretmana u odnosu na kontrolnu varijantu, kao odgovor na primenjeni osmotski stres. Naredna istraživanja vezana za odgovor biljke na osmotski stres bi uključila i nadzemni deo klijanaca, kao i molekularnu karakterizaciju genotipova tolerantnih prema suši. Odabrani genotipovi poslužiće za formiranje core kolekcije koja će u sebi sadržati ovo svojstvo i biti osnova u programima oplemenjivanja kukuruza

Genetički resursi u oplemenjivanju kukuruza

Maize, wheat and rice are the most important cereals grown in the world. It is predicted that by 2025 maize is likely to become the crop with the greatest production globally. Conservation of maize germplasm provides the main resources for increased food and feed production. Conservation in gene banks (ex-situ) is dominant strategy for maize conservation. More than 130 000 maize accessions, e.g. about 40% of total number, are stored in ten largest gene banks worldwide and Maize Research Institute Zemun Polje (MRIZP) gene bank, with about 6000 accessions, is among them. Organized collecting missions started in 1961. in the former Yugoslavian territory, and up today, more than 2000 local maize landraces were stored. Pre-breeding activities that refer to identification of desirable traits from unadapted germplasm within genebank, result in materials expected to be included in breeding programs. Successful examples are LAMP, GEM and GENRES projects. At the end of XX century, at MRIZP genebank two pre-breeding activities were undertaken: eco-core and elite-core collections were created and landraces fulfilled particular criteria were chosen. In the last decade, MRIZP genebank collection was used for identification of sources for drought tolerance and improved grain quality. According to agronomic traits and general combining ability, two mini-core collections were created and included in commercial breeding programs.Pšenica, pirinač i kukuruz su tri najznačajnije žitarice u svetu, ali se procenjuje da će se do 2025. godine kukuruz najviše proizvoditi. Konzervacija germplazme kukuruza predstavlja glavni izvor poželjnih gena koji mogu poslužiti za povećanje obima i kvaliteta proizvodnje kukuruza, a time i hrane za ljude i životinje. Dominantna strategija za konzervaciju kukuruza je ex-situ (čuvanje uzoraka semena u bankama gena). Više od 130 000 uzoraka kukuruza, tj. oko 40% od ukupnog broja, nalazi se u deset najvećih banaka gena u svetu, a banka gena Instituta za kukuruz Zemun Polje (MRIZP), sa oko 6000 uzoraka je jedna od njih. Organizovano kolekcionisanje započeto je u bivšoj Jugoslaviji 1961. godine, i do danas je sakupljeno i čuva se više od 2000 uzoraka lokalnih populacija kukuruza. Predoplemenjivačke aktivnosti, koje se odnose na identifikaciju poželjnih svojstava u neadaptiranoj germplazmi u banci gena, rezultiraju u materijalu za koji se očekuje da bude uključen u oplemenjivačke programe. Uspešni primeri su LAMP, GEM i GENRES projekti. Krajem XX veka, u MRIZP banci gena, preduzete su predoplemenjivačke aktivnosti, formirane su eco-core i elite-core kolekcije, i odabrane su populacije koje su ispunile potrebne kriterijume. U prethodnoj deceniji, kolekcija banke gena korišćena je za identifikaciju izvora tolerantnosti na sušu i poboljšan kvalitet zrna. Na osnovu agronomskih osobina i opšte kombinacione sposobnosti, formirane su dve mini-core kolekcije koje su već uključene u programe oplemenjivanja

Interakcija genotipa i spoljašnje sredine u oplemenjivanju kukuruza

Because proximity measures occur in pairs where both, similarity and dissimilarity measures exploit the same type of information, companion classification and ordination techniques can be applied. They complement each other in analysis of genotype by environment interaction (GxE) data. Choice of method, companion diagnostics and graphical presentation are required within each of methodologies. By clustering of 12 genotypes into 5 groups, 96.26% of variability for genotypes contained in original data is kept. By applying same analysis for environments, 96.45% of variability contained in original data matrix is kept with grouping of 31 environments into 11 groups. Caused by genotypes and environments grouping 78.10% of GxE variability contained in original data matrix remained in analysis of such two-way reduced data. Based on shown results, it is not possible to define smaller growing regions. Clustering of environment can be useful not only for defining mega environments but also for smaller growing regions defining only in combination with some of additional analysis (AMMI, discrimination analysis, correspondent analysis etc.). In such kind of analysis experience of investigator would be of great importance. Choice of test sites for breeding programme can be made based on obtained grouping to a limited extent (rather for restructuring existing test sites network in order to obtain 'better' information with same number of test sites then for its rationalization with number of test sites decreasing).Kako se mere sličnosti i različitosti uvek javljaju u paru, i kako obe koriste isti tip informacije, moguće je istovremeno primeniti združene tehnike klasifikacije i ordinacije. One dopunjuju jedna drugu u analizi interakcije genotipa i spoljašnje sredine. Izbor metoda, dijagnostike i grafičkog predstavljanja se pojavljuje kao zahtev u okviru svake od metodologija. Grupisanjem 12 genotipova u pet grupa, 96.26% varijabilnosti sadržane u originalnim podacima je sadržano. Primenom iste analize za spoljašnje sredine, 96.45% varijabilnosti je zadržano u analizi grupisanjem 31 spoljašnje sredine u 11 grupa. Usled ovakvog grupisanje 78.10% interakcijske varijabilnosti sadržane u originalnoj matrici je zadržano u analizi ovako dvostruko redukovanih podataka. Na osnovu iznetih rezultata nije moguće jasno definisanje manjih regiona gajenja. Grupisanje spoljašnjih sredina može biti korisno ne samo za definisanje velikih regiona gajenja, već i manjih, samo u kombinaciji primenjene metodologije sa nekim dodatnim analizama (AMMI, Diskriminaciona analiza, korespodenciona analiza itd.). U takvim analizama, iskustvo istraživača je od velikog značaja. Na osnovu iznetih rezultata, izbor test lokacija može biti učinjen u ograničenoj meri (pre u smislu restruktuiranja mreže ogleda u cilju dobijanja pouzdanijih informacija nego njenoj racionalizaciji u smislu smanjenja broja lokacija)

Utilization of Maize Genetic Resources for Agro-Biodiversity Enhancement

Maize Research Institute „Zemun Polje“ gene bank preserves ex-situ an active collection (5806 accessions). Local landraces are the most significant, since they were created by natural selection and adapted to local growth conditions. In the last 15 years, in MRIZP gene bank was conducted identification of superior genotypes for specific traits and drought tolerant and improved grain quality core collections were established. Moreover, exchange of inbred lines from MRIZP gene bank and Agricultural Institute Osijek working collections, genotyping and phenotyping of inbreds, and statistical analysis of molecular and agronomic data, is conducted through ongoing Project “Harmonization of methods for phenotyping, genotyping and management of genetic resources in maize”. Although the accessions conserved in gene banks are valuable sources for breeding varietes more nutritious, productive and resilient to pests, diseases and climatic changes, there is a limited information of their agronomic characteristics. To overcome this, the European Evaluation Network (EVA) was established in 2019 by the European Cooperative Programme for Plant Genetic Resources (ECPGR). All activities within the EVA networks are intended at the pre-breeding stage, to increase the knowledge about publicly available crop germplasm, with aim to introducing these into breeding programmes. Through crop-specific public–private partnerships, maize EVA is generating standardized evaluation data (both the phenotypic and the genotypic) for numerous accessions and landraces available in European gene banks. During the project, a total of 95 MRIZP accessions will be genotyped and evaluated in multilocation experiments for futher use by breeding companies

Maize genebank collections as potentially valuable breeding material

Vancetovic J., S. Mladenovic Drinic, M.Babic, D. Ignjatovic Micic and V.Andelkovic (2010): Maize genebank collections as potentially valuable breeding material. - Genetika, Vol. 42, No. 1, 9 - 21. Characterization and evaluation of the genetic resources provide breeders with valuable information on an effective utilization of the genetic resources in breeding programs. In this paper we present the results of different research programs aimed at identification of superior genotypes among MRI gene bank accessions, regarding stress tolerance (drought and herbicides), better nutritional quality (phosphorus) and specific traits (cytoplasmic male sterility - CMS). Fifty-two genotypes were identified as a potential source for drought tolerance. Considering herbicide tolerance only genotypes with resistance to the Pivot were found. Within 100 sources of CMS in the collection S cytoplasm was identified as the predominant type. Phytate analysis of 60 maize populations identified three groups of populations with low (8), intermediate (25) and high (27) phytate content. The results of these researches, which are a part of pre-breeding activities, will be included in MRI breeding programs, with the aim of developing new genotypes with improved traits important in commercial maize breeding and seed production