Genetička i fenotipska međuzavisnost prinosa zrna i komponenti prinosa zrna kukuruza (Zea mays L.)

For efficient selection of grain yield, like the most importance economic trait, in regard to its on the great influence the environmental factors, has complex mode of inheritance and low heritability, is necessary to know genotypic and phenotypic coefficient of correlations between grain yield and morphological traits of the plant and ear which are influencing on the grain yield. The objective of this paper was to determine relationship between grain yield and morphological traits, in 8 inbred lines and their hybrids. Strong genetic and phenotypic correlations were found between grain yield and other studied traits, except between grain yield, on one side, and kernel row number where we found medium correlations. Between other studied traits, the highest values of genotypic and phenotypic coefficient of correlations were found between ear length and cob weight.Za efikasnu selekciju prinosa zrna, kao najvažnije ekonomske osobine, s obzirom na to da je pod jakim uticajem faktora spoljašnje sredine, ima veoma kompleksno nasleđivanje i uglavnom nisku heritabilnost, neophodno je poznavati genotipske i fenotipske korelacije prinosa i ostalih osobina biljke koje utiču na formiranje prinosa. Cilj ovog istraživanja je bio da se utvrde korelativni odnosi koji vladaju između prinosa zrna i morfoloških osobina biljke i klipa, kod 8 inbred linija i 15 hibrida, dobijenih njihovim međusobnim ukrštanjem. Jaki genetički i fenotipski korelacioni koeficijenti ustanovljeni su između prinosa zrna i svih ostalih proučavanih osobina, izuzev između prinosa i broja redova zrna na klipu, gde je ustanovljena srednje jaka korelacija. Između ostalih proučavanih osobina, najveća vrednost, i genotipskog, i fenotiopskog korelacionog koeficijenta, ustanovljena je između dužine klipa i mase oklaska

Mode of inheritance of cob weight and grain yield in maize

The aim of this paper was to investigate maize inbred lines and their hybrids for the genetic variability and mode of inheritance of plant height, cob weight and grain yield. Twelve inbred lines (eight domestic and four US ones) were used to analyze genetic variability and mode of inheritance. Statistical date analysis showed that there was genetic variability among the inbreds lines for each of the traits analyzed. The results of the study confirmed that superdominance is the mode of inheritance of all three traits studied

Genetička analiza mase oklaska i prinosa zrna kukuruza (Zea mays L)

The aim of this paper was to investigate the genetic variability and the mode of inheritance between inbreed lines and their hybrids, for three very important traits, ear height, cob weight and grain yield. Nine inbreed lines are domestic germplasm made at Institute for Field and Vegetable Crops, and four are from USA. Statistical data analysis shows genetic variability between inbred lines for every analyzed trait. Superdomination was mode of inheritance for ear height and grain yield, found in every observed combination. Obtained results confirmed superdomination and domination as mode of inheritance for cob weight. Highly positive correlations were determined between ear height and grain yield, cob weigh and grain yield and cob weigh and ear heigh.Cilj ovog rada bio je da se utvrdi genetička varijabilnost i način nasleđivanja visine klipa, mase oklaska i prinosa zrna kod inbred linija i njihovih hibrida, kao i njihova međusobna zavisnost. Za analizu genetičke varijabilnosti i načina nasleđivanja odabrano je trinaest inbred linija kukuruza. Korišteno je devet domaćih inbred linija, stvorenih u Naučnom institutu za ratarstvo i povrtarstvo, i četiri linije poreklom iz SAD. Između ispitivanih inbred linija utvrđena je genetička varijabilnost za sva ispitivana svojstva. Način nasleđivanja visine klipa i prinosa zrna bila je superdominacija, a kod mase oklaska kao način nasleđivanja javila se puna dominacija i superdominacija. Utvrđeno je da se prinos zrna po biljci nalazi u jakim pozitivnim korelacionim odnosima sa visinom klipa i masom oklaska. Takođe su utvrđene jake korelacione veze između mase oklaska i visine klipa

Parametri klijanja i rani porast ponika kukuruza u različitim nivoima sonog stresa

Increased salt concentration has a negative effect on germination parameters and early seedling growth. The objective of this study was to evaluate germination parameters and early seedlings growth of maize under different salinity conditions (0, -0.3, -0.6, -0.9 and -1.2 MPa). Germination was tested in double rolled filter paper, moistened with different NaCl solution, in the dark at 25°C. Osmotic stress had significant effects on all examined characteristics, except on final germination. Under the highest osmotic stress, mean germination time and time to 50% germination were 14 h and 30 h longer than at control. Root and shoot length under those conditions (-1.2 MPa) were 76% and 87% shorter compared to control, while root and shoot weight were reduced (81% and 87%). Minor reduction in germination energy was recorded under stress. These results showed different responses of germination parameters and early seedling growth in the observed genotype under different salinity conditions.Povećane koncentracije soli imaju negativan efekat na parametar klijanja i rani porast klijanaca. Cilj istraživanja bio je ocena parametara klijanja i ranog porasta klijanaca kukuruza u uslovima različite zaslanjenosti (0, -0,3, -0,6, -0,9 i -1,2 MPa). Klijanje je testirano na filter papiru, nakvašenom rastvorom NaCl različitog osmotskog potencijala, u mraku na 25°C. Osmotski stres je imao značajan uticaj na sve ispitivane parametre, osim na klijavost. U uslovima najvišeg osmotskog stresa, srednje vreme klijanja i vreme dostizanja 50% klijavosti, bili su 14 h i 30 h duži u odnosu na kontrolu. Dužina korenka i izdanka u navedenim uslovima (-1,2 MPa) je bila za 76% i 87% kraća spram kontrole, dok je masa korena i stabla bila manja za 81% i 87%. Energija klijanja je smanjena u manjoj meri u uslovima stresa. Rezultati pokazuju razliku u reakciji parametara klijanja i ranog porasta ponika posmatranog genotipa u uslovima različitog nivoa osmotskog stresa

Ispitivanje PGP svojstava i antifungalne aktivnosti izolata azotobaktera

Among 50 bacterial isolates obtained from maize rhizosphere, 13 isolates belonged to the genus Azotobacter. Isolates were biochemically characterized and estimated for pH and halo tolerance ability and antibiotic resistance. According to characterization, the six representative isolates were selected and further screened in vitro for plant growth promoting properties: production of indole-3-acetic acid (IAA), siderophores, hydrogen cyanide (HCN), exopolysaccharides, phosphate solubilization and antifungal activity (vs. Helminthosporium sp., Macrophomina sp., Fusarium sp.). Beside HCN production, PGP properties were detected for all isolates except Azt 7 . All isolates produced IAA in the medium without L-tryptophan and the amount of produced IAA increased with concentration of precursor in medium. The highest amount of IAA was produced by isolates Azt 4 (37.69 and 45.86 µg ml -1 ) and Azt 5 (29.44 and 50.38 µg ml -1 ) in the medium with addition of L-tryptophan (2.5 and 5 mM). The isolates showed the highest antifungal activity against Helminthosporium sp. and the smallest antagonistic effect on Macrophomina sp. Radial Growth Inhibition (RGI) obtained by the confrontation of isolates with tested phytopathogenic fungi, ranged from 10 to 48%.Među 50 izolata bakterija iz rizosfere kukuruza, 13 izolata pripadali su rodu Azotobacter. Izolati su biohemijski karakterisani i ispitana je tolerantnost prema reakciji sredine, koncentraciji soli i rezistentnost na antibiotike. Nakon karakterizacije, odabrano je šest reprezentativnih izolata za dalja ispitivanja PGP svojstava: produkcije indol-3-sirćetne kiseline (IAA), siderofora, cijanovodonične kiseline, egzopolisaharida, fosfosolubilizacije i antifungalne aktivnosti (prema Helminthosporium sp., Macrophomina sp., Fusarium sp.). Osim produkcije HCN, PGP svojstva utvrđena su za sve izolate osim Azt 7 . Najveću količinu IAA produkovali su izolati Azt 4 (37,69 i 45,86 µg ml -1 ) i Azt 5 (29,44 i 50,38 µg ml -1 ) u podlozi sa dodatkom L-tryptophan-a (2,5 i 5 mM). Izolati su ispoljili najveću antifungalnu aktivnost prema Helminthosporium sp., a najmanji antagonostički efekat prema Macrophomina sp. Procenat inhibicije rasta (RGI) dobijen suočavanjem izolata sa ispitivanim fitopatogenim gljivama kretao se od 10 do 48%

Efekat S1 rekurentne selekcije na trulež stabla, klipa i korena (Fusarium graminearum) kod sintetičke populacije kukuruza NSB

A study has been conducted to assess the effect of S1 recurrent selection on the occurrence of stalk, ear and root rot (Fusarium graminearum) in the synthetic corn population NSB. After five cycles of S1 recurrent selection, a significant increase was registered in the stalk resistance to the agent of stalk rot. The percentage of lodged plants was reduced from 57.7 to 41.6%. The largest reduction in the number of lodged plants occurred in cycle C5. In all selection cycles, lower percentages of plants infected by stalk rot occurred in the locations of Ada and Sombor, in conditions of natural infection, than in the locations Rimski Šančevi and Srbobran, in conditions of inoculation.U radu je ispitivan uticaj S1 rekurentne selekcije na trulež stabla, klipa i korena Fusarium graminearum u sintetičkoj populaciji kukuruza NSB. Nakon pet ciklusa S1 rekurentne selekcije, došlo je do značajnog povećanja otpornosti stabla prema prouzrokovaču truleži Fusarium graminearum. Procenat poleglih biljaka je smanjen sa 57,7% na 41,6%. Najveće smanjenje procenta poleglih biljaka je utvrđeno u C5 ciklusu. Lokaliteti Ada i Sombor, u uslovima prirodne infekcije imali su manji procenat truleži stabla po ciklusima, nego lokaliteti Rimski Šančevi i Srbobran, u uslovima veštačke inokulacije

Način nasleđivanja i kombinacione sposobnosti broja redova zrna na klipu, broja zrna u redu i prinosa zrna kukuruza (Zea mays L.)

Utilization of heterosis requires the study of combining abilities of potential parents. In view of this, the objective of this paper was to study combining abilities and determine the mode of inheritance and gene effects for the main agronomic character, grain yield, and its components, kernel row number and kernel number per row. Six inbred lines were used in the study, three of which originated in the U.S., while the other three were developed at the Institute of Field and Vegetable Crops in Novi Sad. Kernel row number was inherited by superdominance, partial dominance, complete dominance and intermediacy. The mode of inheritance of kernel number per row and grain yield was superdominance. Additive gene action had the greatest influence on the expression of kernel row number, while the other two traits were influenced the most by nonadditive gene.Iskorištavanje heterozisa zahteva poznavanje kombinacionih sposobnosti potencijalnih roditelja. Imajući ovo u vidu cilj ovog rada je bio proučavanje kombinacionih sposobnosti i utvrđivanje načina nasleđivanja prinosa zrna, kao glavne agronomske osobine, i komponenti prinosa zrna, broj redova zrna na klipu i broj zrna na klipu. U radu je korišteno 6 inbred linija, od kojih su 3 poreklom iz SAD, a 3 su razvijene u Institutu za ratarstvo i povrtarstvo u Novom Sadu. Način nasleđivanja broja redova zrna na klipu bila je superdominacija, parcijalna dominacija, puna dominacija i intermedijarnost, a kod broja zrna na klipu i prinosa zrna po biljci u svim hibridnim kombinacijama pojavila se superdominacija. Aditivni efekat gena imao je najveći uticaj na ekspresiju broja redova zrna na klipu, dok je za druge dve proučavane osobine ustanovljeno da je neaditivan efekat gena imao najveći uticaj

Procena indeksa efikasnosti sistema gajenja kukuruza (Zea mays L.) u višegodišnjem eksperimentu

A simple performance-based index was used to test performance among maize cropping systems referring to the food and raw material production, nutrient cycling and greenhouse gases regulation. Those indices are tools for aggregating and simplifying agroecosystem impact on the environment. The data were acquired from a long-term experiment at the Rimski Šančevi experimental station of the Institute of Field and Vegetable Crops, Novi Sad, Serbia. Observed indicators were compared by using datasets from 2001 to 2010, across five maize cropping systems. Maize continuous cropping resulted with decrease in the utilization of the agroecological potential compared with the fertilized crop rotation. Long term maize-based cropping resulted with differences in soil organic carbon content, soil pH and temporal soil NO3. However, recommended fertilizers application and crop rotation contributed to the overall agroecosystems ability to decrease the anthropogenic pressure. Accordingly, it was found that yield decrease resulted mostly from inability of the cropping systems to utilize agricultural management (tillage, fertilization, etc.) in variable environmental conditions. For the investigated trial the performance based index showed that a 2-year maize cropping had the highest capacity for sustainable maize growing.U radu je prikazana analiza indeksa performansi agroekosistema koja može da posluži kao osnova za unapređenje gajenja kukuruza. Indeksi performansi sistema gajenja kukuruza su korišćeni u cilju razdvajanja njihove efikasnosti u ostvarivanju visine prinosa, količine biljnih ostataka, kruženja hraniva i regulaciji gasova staklene bašte. Korišćeni indikatori su indirektni pokazatelji koji služe za sumiranje i pojednostavljenje tumačenja kompleksnog uticaja agroekosistema na životnu sredinu. Za obračun su korišćeni podaci sa višegodišnjeg ogleda 'Plodoredi' Instituta za ratarstvo i povrtarstvo iz Novog Sada, a praćeno je pet različitih sistema gajenja kukuruza. Istraživani sistemi ratarenja, posmatrano u dužem vremenskom periodu, značajno su uticali na svojstva zemljišta, što je dovelo do razlika u sadržaju organske materije, pH vrednosti i zemljišnog NO3. Međutim, pravilno postavljena tehnologija gajenja kod đubrenih polikultura kukuruza je uspešno kompenzovala antropogeni uticaj. U skladu sa tim, istraživanja su pokazala da opadanje prinosa dolazi kao rezultat smanjene efikasnosti pojedinih sistema gajenja kukuruza da iskoriste efekte primenjene agrotehnike (đubrenje, obradu) pri varijabilnim klimatskim uslovima. Utvrđeno je da dvopolje kukuruza ima najveći indeks efikasnosti i sposobnost da raspolaže resursima agroekosistema, dok neđubrene parcele dugoročno nemaju mogućnost očuvanja agroekosistema

Yugoslav local germplasm in hybrid maize breeding

When the spread of hybrid maize began in the mid-20th century, local breeding materials were collected and assembled in gene banks in order to prevent their deterioration and enable their utilization in breeding to develop hybrid varieties. Numerous inbred lines from local populations were selected. The present study includes only those lines from the first cycle of selection that were used for the development of commercial hybrids. The contribution of domestic inbred lines to modern maize breeding consists in the following: 1) Domestic inbred lines possess great variability for most of the agronomically important traits. In nearly every group of lines (lines of the same origin comprise one group), lines with desirable traits have been found, lines that now represent new sources of variability in breeding programs on: grain yield, resistance to lodging, early maturity, ear bareness, grain quality and other traits. 2) The domestic inbreds differ in their heterotic potential for grain yield when crossed with the inbred testers B73 (BSSS germplasm) and Mo17 (Lancaster Sure Crop germplasm). Lines originating from the populations Vukovarski Žuti Zuban, Šidski Žuti Zuban, Novosadski Zlatni Zuban, and Novosadski Žuti Zuban combine better with the inbred tester Mo17 than with B73, so they belong to the BSSS heterotic group. Lines originating from the populations Bankut Bajsa and Sočice are neutral, i.e. they respond equally to both types of germplasm (BSSS and Lancaster), so they can be said to belong to a new heterotic group

FIRST YEAR STUDENT ATTITUDES TOWARD DISTANCE LEARNING

Over the last two years, since the beginning of the COVID-19 pandemic, Higher Education Institutions (HEIs) in Serbia worked in the modality of distance learning – instructions and students`assignments were performed by distance, while colloquia and exams were realized in traditional conditions. Regardless of modality, HEIs have to ensure high-quality education in every single course. In this sense, the feedback from students is very important. The purpose of this study is to investigate students` attitudes about four dimensions of distance learning – fulfilment of preconditions, organization and realization of instructions, advantages/disadvantages of distance learning, communication and social interactions. Data was collected from 183 first-year students within three courses at The Academy of Applied Technical Studies Belgrade, and was processed in the SPSS software package. The research strategy included descriptive statistics, while the Likert scale was used to assess the satisfaction of the respondents. Analysis of variance and independent-sample t test were used to examine differences in opinions among different groups of respondents. The results of this study could be important for instructors, HEIs that operate in similar conditions, policymakers in the field of HE in Serbia, as well as for present and future research in this area