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

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

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

Kombinacione sposobnosti za broj redova zrna silažnog kukuruza

According to the analysis of variance, a genotype, year and a genotype x year interaction significantly affect variability of the trait number of kernel rows per ear. This number was the highest in the silage maize inbred lines ZPLB402, ZPLB403 and ZPLB405 in both years of investigation, resulting in low both positive and negative values of heterosis. The correct estimation of combining abilities is necessary in order to develop superior hybrids. This estimation was done on the basis of diallel hybrids after the method of Griffing (1956; method II, model I). The analysis of variance for combining abilities for the number of kernel rows per ear points to the significance of general and special combining abilities. The GCA to SCA ratio indicates that additive genes and the additive variance have a significant role in inheritance of this trait. Highly significant values of GCA for the number of kernel rows per ear for both years were found in the silage maize inbred lines ZPLB402 and ZPLB403, whereas inbreds ZPLB401, ZPLB404 and ZPLB406 had negative values. Highly significant positive, i.e. negative values of SCA for the number of kernel rows per ear for both years were found in the hybrid combinations ZPLB402 x ZPLB405 and ZPLB402 x ZPLB406, i.e. ZPLB402 x ZPLB406, respectively. Highly significant effects of SCA in hybrid combinations that include both parents with low GCA values are probably a result of the interaction among additive genes in parents. .Cilj ovog istraživanja je bio da se za broj redova zrna silažnog kukuruza procene: (i) varijabilnost inbred linija i njihovih dialelnih hibrida, (ii) heterozis u odnosu na boljeg roditelja i (iii) opšte i posebne kombinacione vrednosti. Utvrđeno je da na varijabilnost ove osobine značajno utiču genotip, godina i njihova interakcija. Inbred linije ZPLB402, ZPLB403 i ZPLB405 imale su veći broj redova zrna od većine hibrida u obe ispitivane godine, što je rezultiralo kako niskim pozitivnim tako i negativnim vrednostima heterozisa. Za dobijanje superiornijih hibrida neophodna je pravilna procena, kombinacionih sposobnosti. Procena kombinacionih sposobnosti je izvršena na bazi dialelnih hibrida po metodi Griffing-a (1956; metod II, matematički model I). Analiza varijanse kombinacionih sposobnosti za broj redova zrna ukazuje na značajnost i opštih i posebnih kombinacionih sposobnosti. Odnos OKS/PKS pokazuje da u nasleđivanju ove osobine daleko značajniju ulogu imaju aditivni geni i aditivna varijansa. Visoko značajne vrednosti OKS u obe ispitivane godine za broj redova zrna imale su inbred linije silažnog kukuruza ZPLB402 i ZPLB403, a linije ZPLB401, ZPLB404 i ZPLB406 su imale negativne vrednosti u obe ispitivane godine. Visoko značajne pozitivne efekte PKS za broj redova zrna u obe godine ispitivanja imale su hibridne kombinacije ZPLB402 x ZPLB405 i ZPLB402 x ZPLB406, a negativne ZPLB402 x ZPLB406. Visoko značajni efekti PKS kod hibridnih kombinacija koje uključuju oba roditelja sa niskim OKS vrednostima su verovatno posledica interakcije između aditivnih gena roditelja.

Oplemenjivanje kukuruza šećerca za različite načine potrošnje

Sweet maize is consumed as human food in the milk stage of the endosperm development when the kernel is soft, sweet and succulent. The highest number of commercial sweet maize hybrids is based on one or more recessive alleles that alter a carbohydrate content of the endosperm. Sweet maize is produced for different purposes. Each mode of its utilization, beside the yield and softness of the pericarp, has its specific requirements for certain quality. The taste (sweetness) and the ear appearance are the most important for sweet maize fresh market. Sweet maize that is transported needs to be of the uniform maturity in order to reduce the percentage of residues at mechanical harvest of the crop. Maintenance of sweetness after transport is also a very important trait. The shape and uniformity of the ear, the kernel color structure and taste are very important in selection of hybrids for the commercial production. Commercial processing (tinning or freezing) requires the uniform size and shape of the ear. The kernel structure, shape, size and fulfillment after cutting are requirements for several modes of utilization (processing) of sweet maize.Kukuruz šećerac se koristi za ljudsku ishranu u mlečnoj fazi razvoja endosperma, kada je zrno nežno, sočno i slatko. Najveći broj komercijalnih hibrida kukuruza šećerca se zasniva na jednom ili više recesivnih alela koji menjaju ugljenohidratni sastav endosperma. Kukuruz šećerac se proizvodi za različite načine korišćenja. Svaki način iskorišćavanja šećerca, pored prinosa i nežnosti perikarpa, ima specifične zahteve za određenim kvalitetom. Ukus (slatkoća) i izgled klipa su na prvom mestu po važnosti za potrošnju šećerca u svežem stanju. Šećerac koji se transportuje na velika rastojanja treba da ima uniformno stasavanje (sazrevanje) klipova da bi se redukovao procenat otpadaka u mehaničkoj berbi useva. Zadržavanje slatkoće posle transporta je takođe veoma važna osobina. Oblik i ujednačenost klipa, boja zrna, građa i ukus su veoma važni kod izbora hibrida za komercijalnu proizvodnju. Komercijalna prerada (konzerviranje ili zamrzavanje) zahteva ujednačenu veličinu i oblik klipa. Građa zrna, oblik, veličina i ispunjenost zrna posle rezanja su zahtevi za više načina iskorišćavanja (prerade) šećerca

Uloga genotipa u kompetitivnosti kukuruza prema korovima

Growing competitive crops is an important component of the integrated weed management system, although selection of genotypes with the increased competitive ability is rather difficult. The possibility of reducing weed infestation by increasing the competitive activity of crops by growing genotypes, i.e. hybrids that better 'endure' a greater density, depends on the FAO maturity group and morphological properties of a genotype, environmental conditions and the growing regions. The competition between maize and weeds varies over the modified crop arrangement pattern. The greatest weed infestation is recorded in the crops of the sparse-spaced plants, while the height and the weight of weeds are significantly lower in closely-spaced plants. The height, growth intensity in the initial stages, embryo vigour and leaf area of the plant are important for a greater competitive ability, as they are components of competitive effects of crops on weeds. Weed infestation and maize hybrids yielding were studied in dependence on the hybrids arrangement pattern and the application of herbicides. Obtained results show statistically significant differences in the weed fresh weight, but only in certain years and in accordance with differences in the height and the leaf area of ZP maize hybrids.Gajenje kompetitivnijih useva je važna komponenta integralnog sistema suzbijanja korova, iako je selekcija genotipova sa povećanom kompetitivnom sposobnošću dosta teška. Mogućnost smanjenja zakorovljenosti na osnovu povećanja kompetitivnog delovanja useva gajenjem genotipova tj. hibrida koji bolje 'podnose' veću gustinu, zavisi od FAO grupe zrenja i morfoloških karakteristika genotipa, uslova spoljašnje sredine i područja gajenja. Kompeticija između kukuruza i korova se menja sa promenom gustine i rasporeda gajenih biljaka. Najzakorovljeniji su usevi retkog sklopa, dok su visina i masa korova u usevima gustog sklopa znatno niže. Za veću kompetitivnost genotipa kukuruza u odnosu na korove važni su visina, intenzitet rastenja u početnim fazama, vigor klijanaca i lisna površina biljke, koje su komponente konkurentskog delovanja useva na korove. U radu je ispitivana zakorovljenost i produktivnost različitih hibrida kukuruza u zavisnosti od prostornog rasporeda u kome su gajeni i primene herbicida. Rezultati pokazuju da su pri gajenju ispitivanih genotipova kukuruza utvrđene statistički značajne razlike u svežoj masi korova, ali samo u pojedinim godinama, u skladu sa razlikama u visini i lisnoj površini ZP hibrida

Inheritance of ear yield and its components in sweet corn (zea mays l. Saccharat)

Srdic J., Z. Pajic, M. Filipovic, M. Babic and M. Secanski (2011): Inheritance of ear yield and its components in sweet corn (Zea mays L. saccharat). - Genetika, Vol 43, No. 2, 341-348. Sweet corn is mutation of field corn in which greater accumulation of sugars and water soluble polysaccharides provide specific taste and texture. It is consumed in the milky stage of the endosperm, so the product's quality and its appearance are important as well as ear yield. That is why breeders pay the same attention to these traits in breeding process. In this paper we analyzed combining ability and mode of inheritance of ear yield and yield components in sweet corn, such as kernel-row number, and ear length, by the use of diallel crosses of six sweet corn inbred lines. ANOVA showed that estimates of general (GCA) and specific (SCA) combining abilities were highly significant (p lt 0.01) for all observed traits. Nonaditive gene effects were more significant in the expression of ear yield and ear length, while additive gene effects were more important for kernel-row number. Analysis of components of genetic variance was in agreement with the results of ANOVA of combining ability. The mode of inheritance of kernel-row number was partial dominance, while overdominance was of greater importance for ear yield, and ear length. Inbred line L-4 was indicted as the most desirable, among the examined set of inbreds, in the further sweet corn breeding programs, due to its significant GCA effects concerning ear yield and number of kernels per ear, and ear yield performances of the hybrids in which one of the components was this inbred, according to SCA and hetrosis estimates

The plus-hybrid effect on the grain yield of two ZP maize hybrids

Bozinovic S., J.Vancetovic, M.Babic, M.Filipovic and N.Delic (2010): The plus-hybrid effect on the grain yield of two ZP maize hybrids-Genetika, Vol 42, No. 3,475 -484. The combined effect of cytoplasmic male sterility and xenia on maize hybrid traits is referred to as the plus-hybrid effect. Two studied ZP hybrids differently responded to this effect for grain yield. All plus-hybrid combinations of the firstly observed hybrid had a higher yield than their fertile counterparts, but not significantly, while only one combination of the second hybrid positively responded, also without statistical significance. It seems that the observed effect mostly depended on the genotype of the female component

Uticaj efekta genotipa i sredine na prinos klipa kukuruza šećerca (Zea mays L.)

Sweet corn is used as food in the milky stage of endosperm, when its kernel is tender, succulent and sweet. It is consumed in form of fresh ears, or it is industrially processed. Breeding of sweet corn has several equally important aims that are directed by the market demands and different modes of consumption. The ear yield, in sweet corn is the most important but not the only main goal of breeding. In the two year study (2013, 2014) we observed the effect of the genotype, year and their interactions on the yields of 8 sweet corn hybrids. Two of the hybrids were commercial and six were experimental hybrids. The field experiment was arranged according to the RCBD with four replications. Hybrids were harvested 23 days after pollination, i.e. silking. Average yield in 2013 was significantly higher (12.19 t ha-1) than in 2014 (11.49 t ha- 1). In 2013 it ranged from 10.21 t ha-1 for the experimental hybrid ZP 489/1su, up to 13.52 t ha-1 for the commercial hybrid ZP 355su. In 2014 the lowest yielding hybrid was ZP 485/1su (10.14 t ha-1) while the highest yielding was ZP 486/1su (13.41 t ha-1). On average those two were also the highest (13.19 t ha-1) and the lowest yielding (10.66 t ha-1) hybrids. Statistical analysis showed that the effect of genotype and the year, as well as their interactions had significant impact on the yield performances of sweet corn hybrids.Kukuruz šećerac se koristi u mlečnoj fazi razvoja endosperma kada mu je zrno nežno, sočno i slatko. Koristi se za ishranu ljudi u svežem stanju, ili industrijski prerađen. Zahtevi tržišta i različiti načini upotrebe kukuruza šećerca usmeravaju oplemenjivače kukurza šećerca ka stvaranju ne samo visokoprinosnih hibrida. Za ovaj tip kukuruza, više nego za bilo koji drugi, veoma je bitan lep i primamljiv spoljašnji izgled klipa, sa pravilnim rasporedom zrna, a naročito su bitne organoleptičke karakteristike zrna - ukus, miris, tekstura i nežnost perikarpa. U toku dvogodišnjih ispitivanja (2013, 2014), posmatran je uticaj genotipa i spoljašnje sredine na prinos svežeg klipa kukuruza šećerca kod 8 hibrida. Dva hibrida ZP 355su i ZP 424su su komercijalni hibridi, dok je ostalih šest eksperimentalnih. Ogled je organizovan po RCBD principu u četiri ponavljanja. Berba je obavljena 23 dana nakon oprašivanja, tj. svilanja. Prosečan prinos svežeg klipa šećerca bio je značajno viši u 2013 godini (12.19 t ha-1) od prosečnog prinosa u 2014 (11.49 t ha-1). Najprinosniji hibrid 2013 godine bio je ZP 355su sa 13.52 t ha-1, dok je u 2014 najviši prinos postigao ZP 486/1su sa 13.41 t ha-1. Najniže prinose imali su ZP 489/1su (10.21 t ha-1) u 2013 i ZP 485/1su (10.14 t ha-1) u 2014 godini. Analizom varijanse utvrđeno je da efekat genotipa, godine, kao i njihova interakcija značajno utiču na prinos svežeg klipa kukuruza šećerca

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