Fenotipska karakterizacija i multivarijacione analize

The mass utilization of personal computers in agricultural studies in recent times has provided the application of multivariate analysis methods that facilitated recognition of simultaneous interdependence among three or more independent variables. If our data base encompasses records on the phenotypic characterization of the breeding material according to principles of the UPOV descriptor, a simple screening of desired traits by the application of some of multivariate analysis methods, a very important information could be gained in just a couple of minutes regardless of monitoring of a few or a complete set of traits. A set of 58 inbreeds, phenotypically described in one year and one replication according to UPOV descriptor, was analyzed. According to the three estimates (the angle between the blade and stem on leaf just above upper ear, leaf attitude of blade and leaf width), the aim of the study was to determine whether the observed lines were actually natural, homogenous groups on the basis of these three properties. The hierarchical cluster analysis, Ward’s method, was applied, and credibility of results was tested by the discrimination analysis. Based on groups predefined by the cluster analysis, linear combinations of independent variables were formed by the discrimination analysis, hence the error of an incorrect classification was minimal. The first three discrimination functions encompassed 100% of a variance, meaning that the smallest error of the incorrect classification was if the given data set was divided into four groups. The formation of the unique data bases, that become an inexhaustible source of information for experts working on planned and directed breeding, dictates a need to ascertain the efficient way for the utilization of the enormous scope of information wherein the applied methodology in such a work can be of an exceptional importance.Masovna upotreba PC računara i u agronomskim istraživanjima u novije vreme omogućila je primenu metoda multivarijacione analize koje omogućavaju sagledavanje simultane međizavisnosti između tri ili više nezavisno promenljivih. Ukoliko u svojoj bazi podataka imamo fenotipsku karakterizaciju selekcionog materijala po principima UPOV-og deskriptora, bilo da smo se odlučili za praćenje manjeg broja osobina ili za kompletan set osobina, jednostavnim skriningom željenih osobina uz primenu neke od metoda multivarijacionih analiza možemo za par minuta dobiti važne informacije. Za analizu je uzet set od 58 linija koje su fenotipski opisane u jednoj godini i jednom ponavljanju po principima UPOV-og deskriptora. Posmatrajući tri ocene: ugao stabla i prvog lista iznad klipa, položaj lista i širina lista, cilj istraživanja je bio da se utvrdi da li ispitivane linije prave prirodne, homogene grupe na osnovu ove tri karakteristike. Primenjena je hijerarhijska klaster analiza Ward-sov metod, a verodostojnost rezultata je testirana diskriminacionom analizom. Na osnovu unapred definisanih grupa klaster analizom, diskriminacionom analizom su formirane linearne kombinacije nezavisno promenljivih tako da je greška pogrešne klasifikacije minimalna. Prve tri diskriminacione funkcije obuhvatile su 100% varijanse to znači da je najmanja greška pogrešne klasifikacije onda kada je dati set podataka podeljen u 4 grupe. Formiranje jedinstvenih baza podataka, koje postaju neiscrpan izvor korisnih informacija za stručnjake koji se bave planskim i usmerenim oplemenjivanjem, diktira potrebu iznalaženja efikasnog načina za korišćenje ogromnog obima informacija u čemu korišćena metodologija u datom radu može biti od izuzetnog značaja

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)

Sistematska varijacija unutar interakcijskog efekta u sortnom ogledu kukuruza

In making decisions on the development of varieties and the identification of certain growing regions, the effects of genotype (G) and genotype by environment (GxE) are very important. Although the main genotype effect and the interaction effect should be partitioned, there is still a need for their integration in the yield, as both simultaneously affect a ranking of the particular genotype within a certain environment. The AMMI (Additive Main Effect and Multiplicative Interaction) analysis, as a hybrid model, provides appropriate partitioning. The AMMI2 model, capturing 98.4% of the treatment sum of squares, was used, and 12 observed environments were classified into three target environments. Hence, out of 15 commercial maize hybrids, used in the trial, the hybrids ZP-677, ZP-570 and ZP-732 were selected as carriers of maximum yields in three target environments. In this way, it was shown that even in a relatively small region a narrow adaptation of genotypes can be exploited.Prilikom donošenja odluka koje se tiču razvoja sorti i identifikacije određenih rejona gajenja, samo je efekat genotipa (G) i interakcije genotipa sa spoljašnjom sredinom (GxE) relevantan. Iako glavni genotipski efekat i efekat interakcije treba razdvojiti, sa druge strane, postoji potreba za njihovim integrisanjem u prinosu jer oba istovremeno utiču na rang određenog genotipa u datoj sredini. AMMI analiza (Additive Main Effect and Multiplicative Interaction), koja predstavlja hibridni model, to omogućava. Koristeći AMMI2 model, koji je obuhvatio 98,4% sume kvadrata tretmana, 12 spoljašnjih sredina je grupisano u tri ciljne sredine. Od 15 ispitivanih hibrida kukuruza, tri hibrida su odabrana kao nosioci maksimalnih prinosa u tri ciljne sredine. Na taj način je prezentovano da se, i u relativno malom regionu, može iskoristiti uska prilagođenost genotipa, za postizanje visokih prinosa

Nastanak i evolucija kukuruza i putevi uvođenja u naše krajeve

The origin and evolution of maize has been attracting attention of researchers of different profiles for decades. Although a few researchers in our country have explicitly been dealing with these issues, it is necessary to survey studies within this field. Not only because of educational reasons, but also because revealing secrets on the origin and evolution provides knowledge about maize genome, which can influence the improvement of current breeding of this very important crop. The enhancement of genetic variability of commercial material is another crucial challenge faced by maize breeders. Therefore, a segment of this study is a reminder indicating that collected and described landraces conserved in the genebank of the Maize Research Institute 'Zemun Polje' are germplasm valuable to breeding programmes intended for moderate climate. Some inbred lines (ZPPE25-10-1; NS796; R70Ž; NS568) developed in our scientific institutions using adapted landraces were of a great commercial importance for maize breeding programmes. However, little has been done on the improvement of landraces. Consequently, it is our opinion that some breeding efforts should be aimed at this topic in order to provide further progress in the maize breeding improvement.Poreklo i evolucija kukuruza već decenijama zaokupljaju pažnju istraživača različitih profila. Iako se kod nas malo istraživača eksplicitno bavilo ovom problematikom postoji potreba da se prate istraživanja iz ove oblasti, ne samo iz obrazovnih razloga, već i stoga što se razotkrivanjem tajni porekla i evolucije stiču saznanja o genomu kukuruza, što može unaprediti savremeno oplemenjivanje ove važne kulture. Povećanje genetičke varijabilnosti komercijalnog materijala još jedan je važan izazov pred oplemenjivačima kukuruza. Stoga, deo ovog rada je podsećanje da sakupljene i opisane lokalne populacije, koje sa nalaze u banci gena Instituta za kukuruz Zemun Polje, predstavljaju vrednu germplazmu za oplemenjivačke programe namenjene umerenom pojasu. Neke inbred linije (ZPPE25-10-1; NS796; R70Ž; NS568) selekcionisane u našim naučnim institutima korišćenjem adaptiranih lokalnih populacija, imale su veliki komercijalni značaj za oplemenjivačke programe kukuruza. Unapređenju lokalnih populacija do sada nije posvećeno dovoljno pažnje. Smatramo da bi deo oplemenjivačkih napora trebalo usmeriti u ovom pravcu kako bi se obezbedio dalji progres u unapređenju dobiti od selekcije

Vizuelna ocena fenotipa linija kukuruza šećerca, po UPOV deskriptoru, kao pokazatelj heterozisa

The organisation of germplasm into genetically divergent groups is of extreme importance for the development of hybrid varieties in which the identification and exploitation of heterosis is very important for the final result of breeding. It can also be beneficial for breeding of self-pollination varieties, clones and synthetics. The discovery of heterotic groups in standard grain quality maize significantly improved the process of testing. The improvement in sweet maize was relatively modest in comparison to standard grain quality maize due to a relatively narrow genetic base of sweet maize, then poorly defined heterotic relations, scarce sources of germplasm that satisfy commercial standards, poor seed vigour, low quality of root and stalk, as well as, a short period of time for the estimation of yield and quality. The efficiency of hybrid breeding programmes would be significantly higher if heterosis could be predicted prior to the evaluation in the field. The application of the multivariate analysis method to data of phenotypic characterization according to the UPOV Descriptor was an attempt to establish whether such a procedure can be beneficial for the determination of related groups and whether the phenotypic distance, obtained on the basis of a visual estimation of a plant group, can be an indicator of heterosis. Obtained results indicate that clustering is highly analogous to the pedigree. Since sweet maize breeders have at their disposal less significant genetic variability and search for the development and defining of heterotic groups, as such a procedure can be useful in both, the process of the hybrids development and the process of new inbreed development and genetic variability increasing. Certainly, further systematic studies aimed at this direction are necessary to reliably ascertain that the phenotypic distance is a justifiable indicator of heterosis.Organizacija germ-plazme u genetički divergentne grupe je od izuzetne važnosti prilikom stvaranja hibridnih sorti, gde je identifikacija i iskorišćavanje fenomena heterozisa veoma važno za krajnji ishod oplemenjivanja. Ali takođe može biti od pomoći u oplemenjivanju slobodno oprašujućih sorti, klonova i sintetika. Otkriće heterotičnih grupa kod standardnog kukuruza je znatno unapredilo proces testiranja. Kod kukuruza šećerca, elativno uska genetička osnova, malobrojni izvori germ-plazme koji zadovoljavaju komercijalne standarde, slaba životna sposobnost semena, loš kvalitet korena i stabla kao i kratak period za ocenu prinosa i kvaliteta su razlozi relativno skromnog unapređenja prinosa u poređenju sa standardnim kukuruzom. Efikasnost hibridnih oplemenjivačkih programa bi se znatno moga povećati ako bi bilo moguće predvideti heterizis pre evaluacije u polju. Primenjujući multivarijacione metode statistike na podatke fenotipske karakterizacije po UPOV deskriptoru pokušano je da se istraži da li ovakva procedura može biti od pomoći prilikom određivanja grupa po srodnosti i da li fenotipska distanca, dobijena na osnovu vizuelne ocene grupe biljaka, može biti indikator heterozisa. Dobijeni rezultati ukazuju da postoji grupisanje koje je u visokoj saglasnosti sa pedigreom. Kako oplemenjivači kukuruza šećerca imaju na raspolaganju manju genetičku varijabilnost i u potrazi su za razvojem i definisanjem heterotičnih grupa, ovakva procedura može biti od koristi kako u procesu stvaranja hibrida tako i u procesu stvaranje novih linija i povećanja genetičke varijabilnosti. Svakako da su sistematska istraživanja u ovom pravcu potrebna da bi se moglo sa pouzdanošću tvrditi da je fenotipska distanca pouzdan indikator heterizisa

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

Determination relevant breeding criteria by the path and factor analysis in maize

In the process of plant breeding the application of relevant breeding criteria is very important. The Path analysis is broadly applied with the aim to define yield components that mostly determine the yield and that can be used as quality breeding criteria. However, the significance of revealed relationships between yield and yield components can be affected by various factors, such as diverse genetic material that is observed, traits included into analysis, environments in which the material is observed, as well as, the applied statistic approach to determine the nature of the relationships itself. The interrelationships of yield and yield components of 15 commercial maize hybrids were observed using the Path and factor analyses. According to results of Path analysis, plant height, ear diameter and grain moisture had highly significant genetic and phenotypic direct effects on grain yield. At the same time, factor analysis points out significant effects of two factors on grain yield. Factor 1 was mostly determined by ear length and number of kernels per row, while grain moisture content, ear and cob diameter mostly determined Factor 2

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

Značaj procesa čišćenja podataka sortnog ogleda za donošenje kvalitetnih odluka u oplemenjivanju

Field trials supposed to enable selection of the most successful genotypes which is critical because of the existence of Genotype by Environment interaction. To assess this interaction we are forced to conduct field trials in several environments and/or years. When we asses grain yield of maize hybrids during the breeding process, it is always based on multi-environment small plot field trial (MESPT). That is why this part of the breeding process is most demanding in terms of technical, financial and labor requirements. In this paper, one possible systematic approach to assessing multi-environment field trials conduction is described. The main goal of the described approach is to provide the best possible results with the use of reasonable resources. As the results of trials cannot be directly interpreted without previous statistical processing, quality of raw data as input for biometrical (statistical) analysis is essential for obtaining a relevant and objective measure of genotype relative value in terms of productivity and adaptability (reliability) of new advanced maize hybrids. There are many definitions of data quality but data is generally considered high quality if it is fit for intended uses in operations, decision making and planning. The main aim of this paper is to underline the importance of the data cleaning process in MESPT.Svrha poljskih ogleda u oplemenjivanju biljaka je da omogući odabir najuspešnijeg genotipa, što nije uvek jednostavan zadatak prevashodno zbog postojanja interakcija genotipa i spoljašnje sredine. Upravo zbog postojanja interakcija sortni ogledi se izvode u brojnim lokacijama i godinama, kako bi se dobila pouzdana procena vrednosti genotipa. U toku oplemenjivačkog procesa, procena prinosa, recimo, hibrida kukuruza, je zasnovana isključivo na rezultatima višelokacijskih sortnih mikro ogleda (VSMO). Ovaj deo oplemenjivačkog procesa je stoga najzahtevniji sa tehničkog i finansijskog aspekta ali i sa stanovišta angažovanja obučene radne snage i specifične opreme. U ovom radu prikazan je jedan od mogućih sistematskih pristupa u proceni višelokacijskog sortnog ogleda. Glavni cilj predstavljenog pristupa je da obezbedi najbolji mogući rezultat uz angažovanje razumnih resursa. Kako rezultati poljskog ogleda ne mogu biti direktno interpretirani bez prethodne obrade podataka, kvalitet ulaznih-sirovih podataka je od krucijalne važnosti za dobijanje relevantnih i objektivnih procena relativne vrednosti novostvorenih genotipova (hibrida kukuruza) u smislu njihove produktivnosti i stabilnosti. Postoje brojne definicije kvaliteta podataka, ali se podaci generalno mogu smatrati visoko kvalitetnim ako su odgovarajući za planirane statističke obrade, donošenje odluka i planova. Cilj izloženog rada je da naglasi značaj pročišćavanja/čišćenja podataka pre procesa statističke obrade podataka sortnih mikro ogleda

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