Genetic advance and regression analysis in sunflower

The knowledge about the magnitude and nature of variability that is present in a breeding population is an important prerequisite for designing efficient breeding programme in order to improve the yield potential of genotypes. The objective of this research was to evaluate heritability and genetic advance of important quantitative traits in new crosses of sunflower as well as to evaluate ratio of dominant and recessive genes in parental genotypes. The plant material selected for this research consisted of 6 sunflower genotypes, which according to literary data possess important characteristics for the production of sunflower. According to presented results there is significant variability of evaluated quantitative traits. Phenotypic variance was higher than genotypic demonstrating strong environment effect in expression of traits. The broad sense heritability was found very high for plant height (83.25%), high for 1000 seed weight (69.33%), moderate for seed yield/plant (46.53%) and head diameter (56.89%), while low for oil content (29.35%). Genetic advance expressed as a percentage of the mean ranged between 2.23% and 19.96%. Placement of array points displayed that the highest frequency of dominant genes for seed yield/plant, 1000 seed weight and head diameter was found in parental genotype Rodnik. Position of expected line of regression pointed over dominance in inheritance for seed yield/plant, oil content and head diameter, while for 1000 seed weight and plant height additive gene action played role in inheritance suggesting that selection in early generations for these traits will be effective. By testing the coefficients of regression interallelic interaction was not determined

Efekat gena i kombinacione sposobnosti za sadržaj ulja u suncokretu

Considering the worldwide importance of sunflower oil, objective of this study was to evaluate gene effects and combining abilities of six sunflower open pollinated varieties. Varieties were crossed according to incomplete diallel method and produced fifteen F1 progenies. Comparing the mean values of F1 progenies to parents mean in most cases superdominance was expressed as a mode of inheritance. Nonetheless, dominance of better parent and partial dominance of better parent were also recorded as a mode of inheritance. GCA/SCA ratio indicated greater importance of non-additive genetic component in oil content expression. The genetic variance analysis showed that dominant component was more important and dominant genes prevailed compared to recessive genes for oil content in sunflower.S obzirom na svetski značaj suncokretovog ulja, cilj ovog istraživanja je bio da se procene efekti gena i kombinacione sposobnosti šest sorti suncokreta. Sorte su ukrštene metodom nepotpunog dialela i proizvedeno je petnaest F1 potomstava. Poredeći srednje vrednosti F1 potomstava sa srednjim vrednostima roditelja u većini slučajeva kao način nasleđivanja ispoljila se superdominacija. Pored toga, dominacija boljeg roditelja i parcijalna dominacija boljeg roditelja su takođe zabeležene kao način nasleđivanja. OKS/PKS odnos je ukazao na veći značaj neaditivne genetičke komponente u ekspresiji sadržaja ulja. Analiza genetičke varijanse je pokazala da je dominantna komponenta bila važnija i dominantni geni su preovlađivali u odnosu na recesivne za sadržaj ulja kod suncokreta

Genetic analysis of grain yield and oil content in two maize populations

Background and purpose: The objectives of this study were to estimate correlations between kernel oil content and morphological traits in two studied maize populations, and to estimate direct and indirect effects of yield components on kernel oil content. Materials and methods: The material for this study was developed by crossing progenies of high oil maize populations with two testers. The traits analyzed were kernel row number, 100-kernel weight, grain yield per plant and kernel oil content. Correlation coefficients were based on the ratio of joint variation and summary of individual variation of two traits (8). Standardized partial regression coefficients and levels of their significance were calculated according to the method of the inverse matrix (10). Results: In B73 testcrosses, oil content was in negative, and medium strong correlations with all studied traits were observed. In the second population, relation between these traits was also negative, but medium strong and weak between oil content and kernel row number, and between oil content and other studied traits. Significantly positive coefficient of correlations was found between grain yield and 100-kernel weight in both estimated populations. Conclusions: Coefficients of correlations between kernel oil content and other traitswere estimated. Significantly negative direct effectswere estimated of all studied traits to kernel oil content but indirect effects were significantly positive and negative

Kiselost i sadržaj pokretljivog aluminijuma u pseudoglejnim zemljištima Čačansko-kraljevačke kotline

Soil acidity and aluminum toxicity are considered the most damaging soil conditions affecting the growth of most crops. This paper reviews the results of tests of pH, exchangeable acidity and the mobile aluminum (Al) concentration in profiles of pseudogley soils from the Čačak-Kraljevo Basin. For these purposes, 102 soil pits were dug in 2009 in several sites around the Čačak-Kraljevo Basin. The tests encompassed 54 field, 28 meadow, and 20 forest soil samples. Samples of soil in a disturbed state were taken from the Ah and Eg horizons (102 samples), from the B1tg horizon in 39 field, 24 meadow and 15 forest pits (a total of 78 samples) and from the B2tg horizon in 14 field, 11 meadow, and 4 forest pits (a total of 29 samples). The mean pH values (1 M KCl) of the tested soil profiles were 4.28, 3.90 and 3.80 for the Ah, Eg and B1tg horizons, respectively. The soil pH of the forest samples was lower than those in the meadow and arable land samples (mean values of 4.06, 3.97 and 3.85 for arable land, meadow and forest samples, respectively). The soil acidification was especially intensive in the deep horizons; thus, 27 (Ah), 77 (Eg) and 87 % (B1tg) of the soil samples had a pH value below 4.0. The mean values of the total exchangeable acidity (TEA) were 1.55, 2.33 and 3.40 meq (100 g)-1 for the Ah, Eg and B1tg horizons, respectively. The TEA values in the forest soils were considerably higher (3.39 meq (100 g)-1) than those in the arable and meadow soils (1.96 and 1.93 meq (100 g)-1, respectively). The mean mobile Al contents of the tested soil samples were 11.02, 19.58 and 28.33 mg Al (100 g)-1 for the Ah, Eg and B1tg horizons, respectively. According to the pH and TEA values, mobile Al was considerably higher in the forest soils (a mean value of 26.08 mg Al (100 g)-1) than in the arable and meadow soils (mean values of 16.85 and 16.00 mg Al (100 g)-1, respectively). The Eg and B1tg horizons of the forest soil had especially high mobile Al contents (mean values of 28.50 and 32.95 mg Al (100 g)-1, respectively). High levels of mobile Al were especially frequent in the forest soils, with 35 (Ah), 85.0 (Eg) and 93.3 % (B1tg) of the tested samples ranging above 10 mg Al (100 g)-1.Kiselost zemljišta i toksičnost aluminijuma se smatraju najvažnijim faktorima koji ograničavaju rast biljaka na kiselim zemljištima. U ovom radu su ispitivani pH vrednost zemljišta i sadržaj pokretljivog aluminijuma (Al) u profilima zemljišta pseudogleja Čačansko-kraljevačke kotline. Ukupno 102 zemljišna profila su otvorena tokom 2009. godine na pojedinim lokalitetima Čačansko-kraljevačke kotline. Istraživanjima je obuhvaćeno 54 uzorka sa oranica, 28 sa livada i 20 uzoraka iz profila koji su otvoreni pod šumskom vegetacijom. Iz otvorenih profila, uzeti su uzorci zemljišta u poremećenom stanju iz Ah i Eg horizonta (102 profila), a zatim iz B1tg horizonta sa 39 oranica, 24 livade i 15 šumskih profila (ukupno 78) i iz B2tg horizonta 14 oranica, 11 livada i 4 šumska profila (ukupno 29). Prosečna pH vrednost (1 M KCl) ispitivanih zemljišnih profila je 4,28, 3,90 i 3,80, za Ah, Eg i B1tg horizonte. Takođe, pH vrednost zemljišta šumskih profila je niža u poređenju sa livadama i obradivim zemljištem (4,06, 3,97 i 3,85, za obradivo zemljište, livade i šume). Zemljišna kiselost je posebno izražena u dubljim horizontima, jer 27 (Ah), 77 (Eg) i 87 % (B1tg) zemljišnih profila imaju pH vrednost nižu od 4,0. Srednja ukupna razmenljiva kiselost (TEA) ispitivanih zemljišnih profila je 1,55, 2,33 i 3,40 meq (100 g)-1, u Ah, Eg i B1tg horizontima. Međutim, kod šumskim zemljištima TEA je znatno viša (prosečno 3,39 meq (100 g)-1) nego kod obradivog zemljišta i livada (1,96 i 1,93). Prosečan sadržaj pokretljivog Al u ispitivanim zemljištima je 11,02, 19,58 i 28,33 mg Al (100 g)-1, u Ah, Eg i B1tg horizontima. Usled razlika u pH i TEA vrednostima njegov sadržaj u šumskim zemljištima je znatno viši (prosečno 26,08 mg Al (100 g)-1) nego kod obradivog zemljišta i livada (16,85 i 16,00 Al (100 g)-1). Eg i B1tg horizonti šumskog zemljišta imaju posebno visok sadržaj pokretljivog Al (28,50 i 32,95 mg Al (100 g)-1). Učestalost visokog nivoa pokretljivog Al u šumskim zemljištima postoji zbog toga što 35 (Ah), 85.0 (Eg) i 93.3 % (B1tg) ispitivanih profila poseduju više od 10 mg Al (100 g)-1

Genetic analysis of grain yield and oil content in two maize populations

Background and purpose: The objectives of this study were to estimate correlations between kernel oil content and morphological traits in two studied maize populations, and to estimate direct and indirect effects of yield components on kernel oil content. Materials and methods: The material for this study was developed by crossing progenies of high oil maize populations with two testers. The traits analyzed were kernel row number, 100-kernel weight, grain yield per plant and kernel oil content. Correlation coefficients were based on the ratio of joint variation and summary of individual variation of two traits (8). Standardized partial regression coefficients and levels of their significance were calculated according to the method of the inverse matrix (10). Results: In B73 testcrosses, oil content was in negative, and medium strong correlations with all studied traits were observed. In the second population, relation between these traits was also negative, but medium strong and weak between oil content and kernel row number, and between oil content and other studied traits. Significantly positive coefficient of correlations was found between grain yield and 100-kernel weight in both estimated populations. Conclusions: Coefficients of correlations between kernel oil content and other traitswere estimated. Significantly negative direct effectswere estimated of all studied traits to kernel oil content but indirect effects were significantly positive and negative

Evaluation of sunflower hybrids in multi-environment trial (met)

Sunflower has been proposed as a potential crop model for an adaptation to a changing environment and special attention should be paid to testing hybrids under different environments. Additive main effects and multiplicative interaction model (AMMI) supplemented with genotype main effects and genotype by environment interaction effects (GGE) were used for dissection of genotype by environment interaction and evaluation of hybrids and testing environments. The research included 24 sunflower hybrids grown across twelve environments. AMMI analysis identified four significant interaction principal components (IPC), while in GGE biplot the first two IPCs accounted together for 44.59% Environmental factors contributed the largest proportion in the total variation of seed yield (67.40%), followed by interaction and genotypes. High yielding hybrids H1, H14 and H11 showed specific adaptation to environments E10 and E1, respectively. The average environment coordination (AEC) view of GGE biplot indicated H17 as the most desirable genotype regarding seed yield. From the results of this study it can be concluded that MET trials are important not just for evaluation of stability and choosing the most stable genotypes, but also the genotypes that will perform well in low yielding environments and be able to take advantage of the favourable environmental conditions

Genetička analiza svojstava tolerantnosti prema suši u sintetičkim populacijama kukuruza

Maize breeders consider tolerance to drought as an important criterion in commercial breeding programs. Two traits, stay green and anthesis-silking interval seem to be closely associated with drought tolerance. The main objective of this study was to obtain estimates of means, variability, heritability and estimates of genetic correlations for several traits in two maize synthetic populations. S1 progenies were evaluated in an incomplete block design in four environments. Large genetic variability existed for all traits in both populations but highest variability was found for anthesis-silking interval. Strong, highly significant correlations between drought adaptive traits and grain moisture may cause some undesirable correlative response throughout cycles of selection.Oplemenjivači kukuruza smatraju tolerantnost prema suši jednim od najznačajnijih kriterijuma u komercijalnim oplemenjivačkim programima. Čini se da su dva svojstva, zakašnjenje u svilanju i stay green tesno povezani sa tolerantnošću prema suši. Cilj ovog rada bio je da se odrede srednje vrednosti, varijabilnost, heritabilnost i genetičke korelacije za nekoliko svojstava u dve sintetičke populacije kukuruza. Vrednosti S1 potomstava ocenjivane su u nepotpunom blok dizajnu na četiri lokaliteta. Utvrđena je zadovoljavajuća varijabilnost svih svojstava u obe populacije, a najveća za zakašnjenje u svilanju. Visoko signifikantne korelacije između svojstava tolerantnosti prema suši i sadržaja vlage u zrnu mogu biti uzrok nepoželjnih korelativnih odgovora kroz cikluse selekcije

Nova formulacija zakona ojačanja u konstitutivnim relacijama prekonsolidovanih glina

Imajući u vidu da je za praktičnu primenu konstitutivnih modela imperativ jednostavna formulacija i jasno fizičko značenje parametara modela, formiran je HASP model za opisivanje mehaničkog ponašanja prekonsolidovanih glina, koristeći teoriju kritičnog stanja i koncept granične površi. Formulacijom zakona ojačanja u funkciji parametra stanja i stepena prekonsolidacije, omogućeno je opisivanje brojnih elemenata mehaničkog ponašanja prekonsolidovanih glina. Validacija modela je izvršena kroz poređenje sa publikovanim rezultatima triaksijalnih opita na širokom spektru prekonsolidovanih glina

Inheritance of quantitative traits in diallel hybrids of sunflower

Suncokret je jedna od najvažnijih uljanih biljnih vrsta u svetu i u mnogim zemljama primaran izvor jestivog ulja. Osnovni ciljevi u oplemenjivanju suncokreta jesu povećanje prinosa semena i sadržaja ulja u semenu, a preko njih i prinosa ulja po jedinici površine. Za realizacija navedenog cilja neophodno je posedovanje odgovarajuće genetičke varijabilnosti, kao i informacije o načinu nasleđivanja, heterozisu, heritabilnosti i odnosu prinosa semena sa drugim osobinama biljke. Šest sorti suncokreta ukršteno je dialelnom metodom. Ispitivane su osobine prinos semena po biljci, masa 1000 semena, sadržaj ulja, visina biljke i prečnik glave. Analizirani su način nasleđivanja, kombinacione sposobnosti, komponente genetičke varijanse sa regresionom analizom, heritabilnost i korelacija između prinosa semena po biljci i ostalih ispitivanih osobina. U nasleđivanju prinosa semena po biljci ispoljile su se superdominacija, dominacija boljeg i lošijeg roditelja, parcijalna dominacija boljeg roditelja i intermedijarnost. Aditivna i neaditivna komponenta bile su od značaja u nasleđivanju prinosa semena po biljci, a dominantni geni su preovlađivali u odnosu na recesivne. Vrednost heritabilnosti ukazala je na velik uticaj spoljašnje sredine u formiranju prinosa semena po biljci. U nasleđivanju mase 1000 semena kao načini nasleđivanja ispoljili su se negativna superdominacija, dominacija boljeg roditelja, parcijalna dominacija lošijeg i boljeg roditelja kao i intermedijarnost. Analize su pokazale da su i aditivna i neaditivna komponenta bile od značaja u nasleđivanju mase 1000 semena. Frekvencija dominantnih gena bila je veća od recesivnih za masu 1000 semena. Utvrđeno je da na formiranje mase 1000 semena velik uticaj imaju faktori spoljašnje sredine. U nasleđivanju sadržaja ulja preovlađivala je superdominacija. Neaditivna komponenta genetičke varijanse imala je značajniju ulogu u nasleđivanju sadržaja ulja, a zastupljenost dominantnih gena bila je veća od recesivnih. Heritabilnost u užem smislu ukazala je da selekcija na visok sadržaj ulja može biti uspešna. Najčešći način nasleđivanja visine biljke bila je superdominacija...Sunflower is one of the most important oilseed crops in the world and primary source of edible oil in many countries. The main objectives in sunflower breeding are increased seed yield and oil content in seed and thus oil yield per unit area. To achieve this goal, it is necessary to possess appropriate genetic variability, as well as information about inheritance, heterosis, heritability and relationship between seed yield and other characteristics of the plant. Six sunflower varieties were crossed using diallel method. Seed yield per plant, 1000-seed weight, oil content, plant height and head diameter were studied. Analysis included mode of inheritance, combining abilities, components of genetic variance with regression analysis, heritability and correlation between seed yield per plant and other studied traits. The inheritance of seed yield per plant exhibited superdominance, dominance of the better and poorer parent, partial dominance of the better parent and the intermediary. Additive and nonadditive components were important in the inheritance of seed yield per plant and dominant genes prevailed in relation to recessive. Heritability estimates indicated that environment had great effect on seed yield per plant. The mode of inheritance of 1000-seed weight exhibited negative superdominance, dominance of the better parent, partial dominance of poorer and better parent as well as intermediary. Analysis showed that both, additive and nonadditive, components were important in the inheritance of 1000-seed weight. The frequency of dominant genes was higher than recessive for 1000-seed weight. It was found that environmental factors had great influence on the formation of 1000-seed weight. Superdominance was prevailing as a mode of inheritance for oil content. Nonadditive component of genetic variance played a significant role in the inheritance of oil content and the presence of dominant genes was higher than recessive. Estimation of narrow sense heritability indicated that selection for high oil content can be successful. Superdominance was the most common mode of inheritance for plant height. Additive component had greater importance in the inheritance of plant height, whereas the frequency of dominant genes was higher than recessive..

Konstitutivni model za prekonsolidovane gline "HASP" model

Osnovni zadaci u geotehničkom inženjerstvu su adekvatno predviđanje pomeranja u tlu, proračun nosivosti tla i stabilnosti geotehničkih konstrukcija. Primena analitičkih metoda kod rešavanja ovih zadataka je ograničena na neke veoma jednostavne probleme. Varijacije u geometriji, graničnim uslovima i opterećenjima zahtevaju primenu numeričkih metoda (metoda konačnih elemenata, metoda konačnih razlika), koje mogu da obuhvate veliki broj elemenata realnog ponašanja tla i konstrukcija, kao i njihovu interakciju. Veliki napredak u razvoju savremenog numeričkog modeliranja postignut je neprekidnim usavršavanjem terenskog i laboratorijskog ispitivanja tla, kao i formulacijom i korišćenjem naprednih konstitutivnih modela za tlo. Razvoj naprednih, ali sa druge strane, za upotrebu dovoljno jednostavnih konstitutivnih modela za tlo je neophodan uslov za racionalno projektovanje geotehničkih konstrukcija. Međutim, opisati naponsko-deformacijsko ponašanje tla kao nehomogenog i anizotropnog materijala, koji se plastično deformiše od ranih stadijuma opterećivanja, predstavlja izazov sa kojim se geotehnika intenzivno suočava poslednjih decenija. Nije moguće opisati ponašanje svih vrsta tla pri različitim stanjima i uslovima opterećivanja pomoću jednog konstitutivnog modela. Brojni konstitutivni modeli razvijeni do danas se uz određen nivo aproksimacija primenjuju za različite probleme u geotehnici. Osnovni imperativ je postići dobar balans između sofisticiranosti i jednostavnosti, sa materijalnim parametrima koji imaju jasno fizičko značenje i koji mogu da se odrede iz konvencionalnih laboratorijskih opita. Značajan deo u oblasti konstitutivnog modeliranja tla predstavlja opisivanje naponsko-deformacijskih relacija prekonsolidovanih glina. U prirodi su retke normalno konsolidovane gline, što nameće potrebu da se intenzivno razvijaju konstitutivni modeli koji će opisivati mehaničko ponašanje normalno konsolidovanih i prekonsolidovanih glina. Prekonsolidovane gline su u prošlosti bile opterećene vertikalnim efektivnim naponom koji je veći od tekuće veličine vertikalnog efektivnog napona. U poređenju sa normalno konsolidovanim glinama, imaju manji koeficijent poroznosti i veću smičuću čvrstoću. U prirodi su najčešće ispucale, što dovodi do nehomogenog polja deformacija. Iz tog razloga ispoljavaju najsloženiji oblik ponašanja tla pri lomu koji podrazumeva povećanje smičućeg napona do maksimalne veličine, a zatim opadanje smičućeg napona pri daljem deformisanju do konstantne veličine (krto-plastični lom). Na ponašanje prekonsolidovnih glina značajno utiče prethodna istorija napona i deformacija. Konstitutivno modeliranje prekonsolidivanih glina predstavlja u mehaničkom i matematičkom smislu složen zadatak, s obzirom na kompleksno ponašanje takvih materijala i na nehomogeno polje deformacija usled pojave lokalnih zona smicanja. Sa druge strane, koristeći mehaniku kontinuuma i teoriju plastičnosti, uz određen nivo aproksimacija moguće je simulirati ključne karakteristike ponašanja prekonsolidovanih glina. Iako pojedini elasto-plastični modeli dobro opisuju naponsko-deformacijsko ponašanje prekonsolidovanog tla, osnovni nedostatak je uključivanje velikog broja konstitutivnih konstanti koje nemaju jasno fizičko značanje. Iz tog razloga se teži da se unapređenje konstitutivnog modela vrši kroz adekvatno definisanje parametara koji uvode stanje tla kao bitnu odrednicu njegovog mehaničkog ponašanja. Razvijeni konstitutivni model omogućava da se adekvatno opiše elasto-plastično ponašanje prekonsolidovanih glina od ranih stadijuma opterećivanja pa sve do loma, u dreniranim i nedreniranim uslovima, koristeći samo parametre sa jasnim fizičkim značenjem