Pravci selekcije novih ZP hibrida

This paper presents the newly released sixth generation of ZP maize hybrids characterized by high and stable yields obtained under different agroenvironmental conditions on soils with different natural fertility and production capacity. The newly developed ZP hybrid genotypes have exhibited remarkable yield stability and wide adaptability to different climatic conditions in numerous trials throughout Serbia. These studies serve as the basis for recommendations to grow new hybrids of FAO 300-600 maturity groups i.e. mid-early, middle maturity and mid-late hybrids, which have a number of improved properties compared to the older generation ZP hybrids. The main properties of the new ZP hybrids are shorter growing season, higher kernel drydown rate during maturation, excellent adaptability to adverse environmental conditions (high drought tolerance), lower stalks with ears formed low on the plant, resistance to lodging, causal agents of diseases and pests, etc. Among the new hybrids, standouts include ZP 333, ZP 366, ZP 388, ZP 427, ZP 555, ZP 560, ZP 600, ZP 606, ZP 666, ZP 388, ZP 427, ZP 555, ZP 560, ZP 600, ZP 606 ZP 666, ZP 552b, etc. harvested for grain and ear for food and feed. The genetic potential of the new high-yielding hybrids is above 20 t ha-1 dry kernel. Their yield is 14-46 t ha-1 in experiments and 14-15 t ha-1 by large producers and in favourable seasons (2014).U radu je prikazana najnovija VI generacija ZP hibrida kukuruza koja se odlikuje visokim i stabilnim prinosima gajenjem u različitim agroekološkim uslovima na zemljišta različite prirodne plodnosti i proizvodne sposobnosti. Najnoviji genotipovi ZP hibrida ispoljili su zavidnu stabilnost prinosa na široku adaptibilnost u različitim klimatskim uslovima, koja je ispitana u brojnim ogledima širom Srbije. Na osnovu ovih istraživanja data je preporuka za gajenje novih hibrida FAO grupe zrenja 300-600, tj. od rednje ranih, srednje stasnih do srednje kasnih hibrida, koji imaju niz poboljšanih osobina u odnosu na ZP hibride starijih generacija. Glavne osobine novih ZP hibrida su: kraća vegetacija i brže otpuštanje vlage iz zrna u procesu sazrevanja, odlična adaptibilnost na nepovoljne uslove spoljne sredine (visoka tolerantnost na stresne uslove suše), niže stablo sa nisko formiranim klipovima, otpornost na poleganje, prouzrokovače bolesti i štetočine, itd. Posebno se izdvajaju novi hibridi: ZP 333, ZP 366, ZP 388, ZP 427, ZP 555, ZP 560, ZP 600, ZP 606, ZP 666, ZP 388, ZP 427, ZP 555, ZP 560, ZP 600, ZP 606, ZP 666, ZP 552b itd za kombajniranje u zrnu, berbu u klipu za ishranu ljudi i stoke. Genetski potencijal novih, visokorodnih hibrida je iznad 20 t ha-1 suvog zrna, u ogledima se ostvaruje 14-46 t ha-1, a kod boljih proizvođača i u rodnoj godini (2014), 14-15 t ha-1

Characterization of maize inbred lines based on molecular markers, heterosis and pedigree data

Information about the genetic diversity of inbred lines is essential in planning maize breeding programmes. Utilization of diverse parents in the process of hybridization has the greatest influence on producing high yielding hybrids. The aim of this research was to determine genetic diversity of ten maize inbred lines of different origin on the basis of protein and RAPD markers and to compare these results with pedigree and grain yield heterosis data. Results of genetic distances, based on protein and RAPD markers were similar and in concurrence with the date on the origin of inbreds. Usefulness of protein and RAPD markers for assigning inbreds to heterotic groups was examined by the cluster analysis. Cluster analysis based on protein markers, RAPD and heterosis showed clear grouping of lines into two main heterotic groups. Only few deviations were noticed, and those among inbreds not belonging to those heterotic groups. According to the observed results it could be concluded that grouping of inbred lines based on molecular markers, generally agrees with their pedigrees and that clusters are representatives of heterotic groups. Very high and highly significant estimate of rank correlation coefficient between RAPD and heterosis (0,876**) also confirmed that.Stvaranje visokoprinosnih hibrida kukuruza u direktnoj je zavisnosti od genetičke udaljenosti roditeljskih komponenti, te je za proces selekcije neophodno poznavanje genetičke divergentnosti samooplodnih linija kukuruza. Cilj ovog rada bio je da se utvrdi genetička divergentnost 10 samooplodnih linija kukuruza različitog porekla na osnovu proteinskih i RAPD markera i da se ti podaci uporede sa podacima o heterozisu i njihovim poreklom. Izračunata genetička distanca na osnovu proteinskih i RAPD markera pokazala je podudarne rezultate, koji su takođe bili saglasnosti sa podacima o poreklu tih linija. Klasterima na osnovu heterozisa, proteinskih i RAPD markera, linije su grupisane u dve osnovne heterotične grupe. Primećeno je nekoliko odstupanja i to kod linija koje po poreklu nisu pripadale tim heterotičnim grupama. Na osnovu ovoga može se zaključiti da je karakterizacija linija putem podataka dobijenih molekularnim markerima uglavnom u saglasnosti sa podacima o njihovom poreklu i da se na osnovu klastera može dobiti jasna i precizna slika o njihovom klasifikovanju u odgovarajuće heterotične grupe. Ovo je potvrđeno i vrednostima koeficijenta korelacije ranga koji su bili visoko značajni između oba metoda markera i heterozisa, a naročito između RAPD i heterozisa (0,876**)

The application of ecological fertilisers in different maize hybrids

U okviru razvojnih istraživanja iz oblasti ekološke poljoprivrede poređeni su efekti primene različitih đubriva kako bi se ukazalo na prednosti mikrobioloških i organskih đubriva koja takođe mogu doprineti većem prinosu, ali za razliku od mineralnh đubriva, pozitivnije utiču na zemljište i agroekosistem. Ispitivanja su sprovedena kako bi se utvrdilo u kolikoj meri agronomska biofortifikacija doprinosi povećanju rodnog potencijala specifičnih genotipova kukuruza kao i kako utiče na pojavu i zastupljenost korova. Hibrid kukuruza crvenog perikarpa ZP 5048 crveni, hibrid tvrdunac sa povećanim učešćem proteinskog dela ZP 737 i hibrid belog zrna ZP 552b su gajeni uz primenu mineralnog đubriva Urea, mikrobiološkog đubriva Team Micorriza Plus i organskog đubriva Fertor koja sadrže neophodne elemente za ishranu gajenih biljaka. Na kontrolnoj površini đubrenje nije primenjeno. Rezultati su pokazali da u 2017. godini koja je bila ekstremno sušna, ima značajnih razlika u nivou zakorovljenosti i nešto manjih razlika u prinosu zrna gajenih genotipova zavisno od vrste primenjenog đubriva. Najveća masa korova utvrđena je kod hibrida ZP 737 nakon primene organskog đubriva dok je najmanja masa korova kod svih hibrida zabeležena nakon primene mikrobiološkog đubriva. Đubrenje je uglavnom doprinelo povećanju mase korova u poređenju sa neđubrenom kontrolnom varijantom. Najveći prinos zrna je imao ZP 5048 crveni (5,83 t/ha), a najmanji ZP 737 (3,36 t/ha). Razlike u prosečnom prinosu zrna između tretmana, kao i u poređenju sa kontrolom, su bile neznatne što se može objasniti nepovoljnim meteorološkim uslovima. Primena đubriva u kukuruzu, u toku vegetacije, najčešće nije efikasna u uslovima suše zbog čega će se istraživanja nastaviti.The effects of different fertilisers have been compared within developmental research in the field of ecological agriculture to point up the advantages of microbiological and organic fertilisers, since these fertilisers can contribute to higher yields, but unlike mineral fertilisers, they positively affect the soil and agro-ecosystem. The studies have been carried out to determine to what extent agronomic biofortification contributed to the increase of yielding potential of maize genotypes with specific traits as well as how it affected the occurrence and distribution of weeds. The red-seeded maize hybrid ZP 5048 crveni, high-protein flint maize hybrid ZP 737 and white-seeded maize hybrid ZP 552b were grown in variants with mineral fertiliser Urea, microbiological fertiliser Team Micorriza Plus and organic fertiliser Fertor that contain essential elements necessary for the nutrition of cultivated plants. No fertiliser was applied to the control surface. The obtained results show that there were significant differences in the weed infestation level in extremely dry 2017, while differences in grain yields of cultivated genotypes were somewhat lower, depending on the type of applied fertilisers. The highest weed mass was recorded in the hybrid ZP 737 in the variant with organic fertiliser. On the other hand, the lowest weed mass was recorded in all hybrids when microbiological fertiliser had been applied. The fertilisation mainly contributed to the increase of weed mass in comparison with the non- fertilised control variant. The highest, i.e. Iowest grain yield was recorded in the hybrid ZP 5048 crveni (5.83 t/ha), i.e. the hybrid ZP 737 (3.36 t/ha), respectively. Differences in the average grain yield among treatments, was well as compared to the control, were insignificant, which can be explained unfavourable meteorological conditions. The application of fertilisers in the maize crop during the growing season was not particularly effective under the conditions of drought, which is why the studies will be continued

Maize productivity in sustainable system of cultivation

Održivi sistemi gajenja useva su alternativa intenzivnoj, industrijalizovanoj poljoprivredi u kojoj je dudgogodišnja primena pesticida ugrozila životnu sredinu. U održivim sistemima gajenja, prioritet je smanjiti upotrebu herbicida i đubriva i povećati efikasnost proizvodnje uz korišćenje postojećih resursa radi zaštite agroekosistema. U tom smislu, pokrovni usevi i sistemi obrade zemljišta mogu doprineti značajnom smanjenju zakorovljenosti kukuruza, održanju kvaliteta zemljišta uz ostvarenje visokog i kvalitetnog prinosa. Istraživanja su sprovedena u Institutu za kukuruz Zemun Polje, Beograd, sa ciljem da se utvrdi koliki je doprinos održivog sistema gajenja (sa pokrovnim usevima) u poređenju sa konvencionalnim/intenzivnim sistemom gajenja, plodnosti zemljišta i produktivnosti kukuruza. Ogled je postavljen 2020. godine i čine ga tri sistema gajenja kukuruza:- ekstenzivni sistem: posle žetve strnine (oz. pšenica), zemljište je ostalo neobrađeno, krajem leta je primenjen totalni herbicid radi suzbijanja izniklih korova, u proleće je direktnom setvom posejan kukuruz - intenzivni sistem: posle žetve strnine (oz. pšenica), strnište je plitko zaorano (ljuštenje strništa), kasnije su primenom totalnog herbicida suzbijeni iznikli korovi, u jesen je zemljište duboko uzorano a u proleće je obavljena predsetvena priprema zemljišta frezom i setva kukuruza -održivi sitem: posle žetve strnine (oz. pšenica), strnište je plitko zaorano (ljuštenje strništa) nakon čega su posejani ozimi pokrovni usevi – ozimi ovas, ozimi stočni kelj i ozimi stočni grašak; pokrovni usevi su u proleće pokošeni i kada je biomasa svela i delom se razgradila, direktnom setvom je posejan kukuruz.Setva visokorodnog hibrida kukuruza najnovije generacije, ZP5601 je obavljena 6. maja 2021. u gustini od 60 606 biljka po ha. U navedenim sistemima gajenja kukuruza analiziran je sadržaj ukupnog N i C, kao i odnos C:N iz uzoraka zemljišta uzetih pre setve kukuruza kao i prinos kukuruza, obračunat na 14% vlage u zrnu. Na početku vegetacione sezone 2021. godine, najveći sadržaj organskog C je imala varijanta sa konvencionalnim sistemom gajenja, najveći sadržaj ukupnog N je utvrđen takođe u ovoj i varijanti sa ekstenzivnim sistemom gajenja, dok su najpovoljniji odnos C:N imale varijante sa pokrovnim usevima od ozimog stočnog kelja i stočnog graška. Na kraju vegetacionog perioda u promenljivoj i, za kukuruz, nepovoljnoj 2021. godini, najveći prinos je imao ekstenzivni sistem gajenja (6,70 t ha-1) a nešto niži konvencionalni sistem (6,38 t ha-1) dok je od pokrovnih useva najproduktivnije bilo gajenje kukuruza nakon stočnog graška (5,61 t ha-1).Sistemi gajenja kukuruza, posebno kada se radi o proizvodnji za ljudsku ishranu, će ubuduće sve više težiti održivosti i upotrebi alternativnih mera kad je u pitanju upotreba pesticida.Sustainable systems of crop cultivation are an alternative to intensive, industrialised agriculture in which a long-term application of pesticides has endangered the environment. The priority in these systems is to reduce the use of herbicides and fertilisers and to increase the production efficiency while using existing resources to protect agro-ecosystems. In this sense, cover crops and tillage systems can contribute to a significant reduction in maize weediness, maintenance of soil quality while achieving high and quality yields. Studies were conducted at the Maize Research Institute, Zemun Polje, Belgrade, with the aim to determine the contribution of the sustainable cultivation system (with cover crops) in comparison to the conventional/intensive cultivation system, soil fertility and maize productivity. The trial was set up in 2020 and encompassed three maize growing systems:- extensive system: after stubble (winter wheat) harvest, soil remained untilled and at the end of summer a total herbicide was applied to control emerged weeds, while in spring, maize was sown by direct sowing - intensive system: after stubble (winter wheat) harvest, stubble was shallowly ploughed (shallow ploughing), later the total herbicide was applied to suppress emerged weeds; in autumn, soil was deeply ploughed up, while seedbed preparation with a cultivator and maize sowing were done in spring -sustainable system: after stubble (winter wheat) harvest, stubble was shallowly ploughed (shallow ploughing) and then winter cover crops (winter oats, winter fodder kale and winter field pea) were sown; cover crops were mowed in spring and when biomass was wilted and partially decomposed, maize was sown by direct sowing. Sowing of a high-yielding maize hybrid of the latest generation, ZP5601, was performed on May 6, 2021 at the sowing density of 60,606 plants ha-1. In the stated maize cultivation systems, the contents of total N and C, as well as the C:N ratio were analysed in soil samples drawn prior to maize sowing and maize yield was calculated at 14% grain moisture. At the beginning of the 2021 growing season, the highest content of organic C was recorded in the variant with the conventional cultivation system, whereas the highest content of total N was also determined in this variant but with the extensive cultivation system; the most favourable the C:N ratio was established in variants with cover crops consisted of winter fodder kale and field pea. At the end of the 2021 growing season that was variable and unfavourable for maize, the highest yield (6.70 t ha-1) was recorded in the extensive cultivation system; a slightly lower yield (6.38 t ha-1) was achieved in the conventional system, while the most productive (5.61 t ha-1) in the cover crop system was maize cultivation after field pea. Maize cultivation systems, especially when it comes to the production for human consumption, will increasingly tend to sustainability and the use of alternative measures instead of the pesticide application

The application of protein markers in conversion of maize inbred lines to the cytoplasmic male sterility basis

A total of seven maize inbred lines of different origin and maturity group were used in the trial set up according to the split-plot randomized complete block design in five environments. Each inbred was observed in five variants: original inbred (N); cytoplasmic male sterile C-type (CMS-C); restorer for CMS-C (RfC); cytoplasmic male sterile S-type (CMS-S) and restorer for CMS-S (RfS). The objective was to compare grain yield of original inbreds and their CMS and Rf variants and to apply Isoelectric focusing (IEF) to determine whether the conversion of original inbreds to their CMS and Rf counterparts have been done completely. Protein markers have shown that conversion of almost all inbreds was done good and completely. Only original inbreds ZPL2 and ZPL5 did not concur on banding patterns with their RfC variants. The type of cytoplasm had a very significant impact on grain yield. Namely, CMS-C counterparts significantly out yielded their CMS-S versions, while the inbreds with C and S cytoplasm over yielded inbreds with N cytoplasm, as well as their RfC and RfS versions