425 research outputs found
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 znaÄaj suncokretovog ulja, cilj ovog istraživanja je bio da se procene efekti gena i kombinacione sposobnosti Å”est sorti suncokreta. Sorte su ukrÅ”tene metodom nepotpunog dialela i proizvedeno je petnaest F1 potomstava. PoredeÄi srednje vrednosti F1 potomstava sa srednjim vrednostima roditelja u veÄini sluÄajeva kao naÄin nasleÄivanja ispoljila se superdominacija. Pored toga, dominacija boljeg roditelja i parcijalna dominacija boljeg roditelja su takoÄe zabeležene kao naÄin nasleÄivanja. OKS/PKS odnos je ukazao na veÄi znaÄaj neaditivne genetiÄke komponente u ekspresiji sadržaja ulja. Analiza genetiÄke varijanse je pokazala da je dominantna komponenta bila važnija i dominantni geni su preovlaÄivali 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 zemljiÅ”tima ÄaÄansko-kraljevaÄke 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 ÄaÄak-Kraljevo Basin. For these purposes, 102 soil pits were dug in 2009 in several sites around the ÄaÄak-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 zemljiÅ”ta i toksiÄnost aluminijuma se smatraju najvažnijim faktorima koji ograniÄavaju rast biljaka na kiselim zemljiÅ”tima. U ovom radu su ispitivani pH vrednost zemljiÅ”ta i sadržaj pokretljivog aluminijuma (Al) u profilima zemljiÅ”ta pseudogleja ÄaÄansko-kraljevaÄke kotline. Ukupno 102 zemljiÅ”na profila su otvorena tokom 2009. godine na pojedinim lokalitetima ÄaÄansko-kraljevaÄke kotline. Istraživanjima je obuhvaÄeno 54 uzorka sa oranica, 28 sa livada i 20 uzoraka iz profila koji su otvoreni pod Å”umskom vegetacijom. Iz otvorenih profila, uzeti su uzorci zemljiÅ”ta u poremeÄenom stanju iz Ah i Eg horizonta (102 profila), a zatim iz B1tg horizonta sa 39 oranica, 24 livade i 15 Å”umskih profila (ukupno 78) i iz B2tg horizonta 14 oranica, 11 livada i 4 Å”umska profila (ukupno 29). ProseÄna pH vrednost (1 M KCl) ispitivanih zemljiÅ”nih profila je 4,28, 3,90 i 3,80, za Ah, Eg i B1tg horizonte. TakoÄe, pH vrednost zemljiÅ”ta Å”umskih profila je niža u poreÄenju sa livadama i obradivim zemljiÅ”tem (4,06, 3,97 i 3,85, za obradivo zemljiÅ”te, livade i Å”ume). ZemljiÅ”na kiselost je posebno izražena u dubljim horizontima, jer 27 (Ah), 77 (Eg) i 87 % (B1tg) zemljiÅ”nih profila imaju pH vrednost nižu od 4,0. Srednja ukupna razmenljiva kiselost (TEA) ispitivanih zemljiÅ”nih profila je 1,55, 2,33 i 3,40 meq (100 g)-1, u Ah, Eg i B1tg horizontima. MeÄutim, kod Å”umskim zemljiÅ”tima TEA je znatno viÅ”a (proseÄno 3,39 meq (100 g)-1) nego kod obradivog zemljiÅ”ta i livada (1,96 i 1,93). ProseÄan sadržaj pokretljivog Al u ispitivanim zemljiÅ”tima 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 Å”umskim zemljiÅ”tima je znatno viÅ”i (proseÄno 26,08 mg Al (100 g)-1) nego kod obradivog zemljiÅ”ta i livada (16,85 i 16,00 Al (100 g)-1). Eg i B1tg horizonti Å”umskog zemljiÅ”ta imaju posebno visok sadržaj pokretljivog Al (28,50 i 32,95 mg Al (100 g)-1). UÄestalost visokog nivoa pokretljivog Al u Å”umskim zemljiÅ”tima postoji zbog toga Å”to 35 (Ah), 85.0 (Eg) i 93.3 % (B1tg) ispitivanih profila poseduju viÅ”e 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
GenetiÄka analiza svojstava tolerantnosti prema suÅ”i u sintetiÄkim 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.OplemenjivaÄi kukuruza smatraju tolerantnost prema suÅ”i jednim od najznaÄajnijih kriterijuma u komercijalnim oplemenjivaÄkim programima. Äini se da su dva svojstva, zakaÅ”njenje u svilanju i stay green tesno povezani sa tolerantnoÅ”Äu prema suÅ”i. Cilj ovog rada bio je da se odrede srednje vrednosti, varijabilnost, heritabilnost i genetiÄke korelacije za nekoliko svojstava u dve sintetiÄke populacije kukuruza. Vrednosti S1 potomstava ocenjivane su u nepotpunom blok dizajnu na Äetiri lokaliteta. UtvrÄena je zadovoljavajuÄa varijabilnost svih svojstava u obe populacije, a najveÄa za zakaÅ”njenje u svilanju. Visoko signifikantne korelacije izmeÄu svojstava tolerantnosti prema suÅ”i i sadržaja vlage u zrnu mogu biti uzrok nepoželjnih korelativnih odgovora kroz cikluse selekcije
Nova formulacija zakona ojaÄanja u konstitutivnim relacijama prekonsolidovanih glina
ImajuÄi u vidu da je za praktiÄnu primenu konstitutivnih modela imperativ jednostavna
formulacija i jasno fiziÄko znaÄenje parametara modela, formiran je HASP model za
opisivanje mehaniÄkog ponaÅ”anja prekonsolidovanih glina, koristeÄi teoriju kritiÄnog stanja
i koncept graniÄne povrÅ”i. Formulacijom zakona ojaÄanja u funkciji parametra stanja i
stepena prekonsolidacije, omoguÄeno je opisivanje brojnih elemenata mehaniÄkog
ponaÅ”anja prekonsolidovanih glina. Validacija modela je izvrÅ”ena kroz poreÄenje sa
publikovanim rezultatima triaksijalnih opita na Ŕirokom 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 poveÄanje prinosa semena i sadržaja ulja u semenu, a preko njih i prinosa ulja po jedinici povrÅ”ine. Za realizacija navedenog cilja neophodno je posedovanje odgovarajuÄe genetiÄke varijabilnosti, kao i informacije o naÄinu nasleÄivanja, heterozisu, heritabilnosti i odnosu prinosa semena sa drugim osobinama biljke. Å est sorti suncokreta ukrÅ”teno je dialelnom metodom. Ispitivane su osobine prinos semena po biljci, masa 1000 semena, sadržaj ulja, visina biljke i preÄnik glave. Analizirani su naÄin nasleÄivanja, kombinacione sposobnosti, komponente genetiÄke varijanse sa regresionom analizom, heritabilnost i korelacija izmeÄu prinosa semena po biljci i ostalih ispitivanih osobina. U nasleÄivanju prinosa semena po biljci ispoljile su se superdominacija, dominacija boljeg i loÅ”ijeg roditelja, parcijalna dominacija boljeg roditelja i intermedijarnost. Aditivna i neaditivna komponenta bile su od znaÄaja u nasleÄivanju prinosa semena po biljci, a dominantni geni su preovlaÄivali u odnosu na recesivne. Vrednost heritabilnosti ukazala je na velik uticaj spoljaÅ”nje sredine u formiranju prinosa semena po biljci. U nasleÄivanju mase 1000 semena kao naÄini nasleÄivanja ispoljili su se negativna superdominacija, dominacija boljeg roditelja, parcijalna dominacija loÅ”ijeg i boljeg roditelja kao i intermedijarnost. Analize su pokazale da su i aditivna i neaditivna komponenta bile od znaÄaja u nasleÄivanju mase 1000 semena. Frekvencija dominantnih gena bila je veÄa od recesivnih za masu 1000 semena. UtvrÄeno je da na formiranje mase 1000 semena velik uticaj imaju faktori spoljaÅ”nje sredine. U nasleÄivanju sadržaja ulja preovlaÄivala je superdominacija. Neaditivna komponenta genetiÄke varijanse imala je znaÄajniju ulogu u nasleÄivanju sadržaja ulja, a zastupljenost dominantnih gena bila je veÄa od recesivnih. Heritabilnost u užem smislu ukazala je da selekcija na visok sadržaj ulja može biti uspeÅ”na. NajÄeÅ”Äi naÄin nasleÄivanja 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 geotehniÄkom inženjerstvu su adekvatno predviÄanje pomeranja u tlu, proraÄun nosivosti tla i stabilnosti geotehniÄkih konstrukcija. Primena analitiÄkih metoda kod reÅ”avanja ovih zadataka je ograniÄena na neke veoma jednostavne probleme. Varijacije u geometriji, graniÄnim uslovima i optereÄenjima zahtevaju primenu numeriÄkih metoda (metoda konaÄnih elemenata, metoda konaÄnih razlika), koje mogu da obuhvate veliki broj elemenata realnog ponaÅ”anja tla i konstrukcija, kao i njihovu interakciju. Veliki napredak u razvoju savremenog numeriÄkog modeliranja postignut je neprekidnim usavrÅ”avanjem terenskog i laboratorijskog ispitivanja tla, kao i formulacijom i koriÅ”Äenjem 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 geotehniÄkih konstrukcija. MeÄutim, opisati naponsko-deformacijsko ponaÅ”anje tla kao nehomogenog i anizotropnog materijala, koji se plastiÄno deformiÅ”e od ranih stadijuma optereÄivanja, predstavlja izazov sa kojim se geotehnika intenzivno suoÄava poslednjih decenija. Nije moguÄe opisati ponaÅ”anje svih vrsta tla pri razliÄitim stanjima i uslovima optereÄivanja pomoÄu jednog konstitutivnog modela. Brojni konstitutivni modeli razvijeni do danas se uz odreÄen nivo aproksimacija primenjuju za razliÄite probleme u geotehnici. Osnovni imperativ je postiÄi dobar balans izmeÄu sofisticiranosti i jednostavnosti, sa materijalnim parametrima koji imaju jasno fiziÄko znaÄenje i koji mogu da se odrede iz konvencionalnih laboratorijskih opita.
ZnaÄajan deo u oblasti konstitutivnog modeliranja tla predstavlja opisivanje naponsko-deformacijskih relacija prekonsolidovanih glina. U prirodi su retke normalno konsolidovane gline, Å”to nameÄe potrebu da se intenzivno razvijaju konstitutivni modeli koji Äe opisivati mehaniÄko ponaÅ”anje normalno konsolidovanih i prekonsolidovanih glina. Prekonsolidovane gline su u proÅ”losti bile optereÄene vertikalnim efektivnim naponom koji je veÄi od tekuÄe veliÄine vertikalnog efektivnog napona. U poreÄenju sa normalno konsolidovanim glinama, imaju manji koeficijent poroznosti i veÄu smiÄuÄu ÄvrstoÄu. U prirodi su najÄeÅ”Äe ispucale, Å”to dovodi do nehomogenog polja deformacija. Iz tog razloga ispoljavaju najsloženiji oblik ponaÅ”anja tla pri lomu koji podrazumeva poveÄanje smiÄuÄeg napona do maksimalne veliÄine, a zatim opadanje smiÄuÄeg napona pri daljem deformisanju do konstantne veliÄine (krto-plastiÄni lom). Na ponaÅ”anje prekonsolidovnih glina znaÄajno utiÄe prethodna istorija napona i deformacija.
Konstitutivno modeliranje prekonsolidivanih glina predstavlja u mehaniÄkom i matematiÄkom smislu složen zadatak, s obzirom na kompleksno ponaÅ”anje takvih materijala i na nehomogeno polje deformacija usled pojave lokalnih zona smicanja. Sa druge strane, koristeÄi mehaniku kontinuuma i teoriju plastiÄnosti, uz odreÄen nivo aproksimacija moguÄe je simulirati kljuÄne karakteristike ponaÅ”anja prekonsolidovanih glina. Iako pojedini elasto-plastiÄni modeli dobro opisuju naponsko-deformacijsko ponaÅ”anje prekonsolidovanog tla, osnovni nedostatak je ukljuÄivanje velikog broja konstitutivnih konstanti koje nemaju jasno fiziÄko znaÄanje. Iz tog razloga se teži da se unapreÄenje konstitutivnog modela vrÅ”i kroz adekvatno definisanje parametara koji uvode stanje tla kao bitnu odrednicu njegovog mehaniÄkog ponaÅ”anja. Razvijeni konstitutivni model omoguÄava da se adekvatno opiÅ”e elasto-plastiÄno ponaÅ”anje prekonsolidovanih glina od ranih stadijuma optereÄivanja pa sve do loma, u dreniranim i nedreniranim uslovima, koristeÄi samo parametre sa jasnim fiziÄkim znaÄenjem
- ā¦