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The objective of this study was to evaluate boron tolerance of wheat genotypes using mature embryo culture. The analysis involved 79 recombinant inbred lines of the International Triticeae Mapping Initiative (ITMI) population and three Serbian varieties with known boron (B) tolerance (Pobeda – sensitive S, Balerina -medium tolerant MT, and Nevesinjka – tolerant T). The evaluation was performed on a modified MS medium to which 15 mM of boric acid was added. The control medium contained no excess B. Callus fresh weight (CFW) and reduction of fresh callus weight (RFCW) were determined after one month of cultivation. ANOVA has shown highly significant effect of genotype, the media, and their interaction to callus tissue growth and also significant genotypic effect on RFCW. Majority of genotypes (39) had sensitive reaction to excess boron, twenty-three were medium tolerant, while four of them were tolerant. The obtained results can be potentially used for mapping QTLs associated with tolerance to excess B in wheat breeding program. Cilj ovog istraživanja bio je da se proceni tolerantnost genotipova pšenice na suvišak bora primenom kulture zrelog embriona. Analizom je obuhvaćeno 79 rekombinantnih inbred linija ITMI mapirajuće populacije i 3 sorte poznate tolerantnosti na bor (Pobeda – osetljiva, Balerina – srednje tolerantna i Nevesinjka – tolerantna) poreklom iz Srbije. Procena tolerantnosti je rađena na modifikovanoj MS hranljivoj podlozi u koju je dodato 15 mM borne kiseline. Kontrolna podloga nije sadržala suvišak bora. Sveža masa kalusa i redukcija sveže mase kalusa, određene su nakon mesec dana gajenja. ANOVA je pokazala veoma značajan efekat genotipa, hranljive podloge i njihove interakcije na rast kalusa, kao i značajan genotipski efekat na redukciju sveže mase kalusa. Većina genotipova (39) je imala osetljivu reakciju na suvišak bora, 23 su bila srednje tolerantna dok su 4 genotipa bila tolerantna. Dobijeni rezultati se potencijalno mogu koristiti za mapiranje gena i QTL-ova povezanih sa tolerancijom na suvišak B u oplemenjivanju pšenice.

Plant height and heading time are important agronomic traits that significantly contributed to the improvement of wheat adaptability and yield. The aim of this study was to analyse genetic diversity of a collection of wheat species, originating from 20 countries, based on the microsatellite loci associated with the previously mapped quantitative trait loci of plant height and heading time, to estimate potential of microsatellites to detect polymorphism in different wheat species and reveal allelic patterns in relation to the geographical origin and to evaluate the level of phenotypic diversity. The principal coordinate analysis distinguished wheat genotypes by their origin and ploidy level. Wheat varieties from America, South and Southeast Europe, and West and Central Europe had the highest molecular diversity, as was evidenced by higher number of alleles, number of group-specific alleles, Shannon's information index and gene diversity. The Nei’s genetic identity indicated genetic similarity of geographically distinct groups, such as South and Southeast Europe and Russian (0.901) and South and Southeast Europe and American genotypes (0.638). The significant differences in plant height and heading time among different wheat groups were observed, while the differences in means among three different growing seasons and the group by season interactions were significant only for heading time. The evaluated collection with high observed level of both molecular and phenotypic diversity for plant height and heading time may be a valuable source of variation for wheat breeders to fine adjust these traits in order to achieve better agronomic performance in certain local environments. Visina i vreme klasanja su važne agromonske osobine koje značajno doprinose poboljšanju sposobnosti pšenice da se prilagodi na uslove spoljašnje sredine i povećanju prinosa. Cilj ovog rada je da se oceni nivo fenotipske varijabilnosti ove dve osobine u kolekciji pšenica koje potiču iz 20 zemalja sveta, da se oceni njen molekularni diverzitet pomoću mikrosatelitskih markera povezanih sa prethodno mapiranim lokusima za kvantitativne osobine, i da se proceni potencijal mikrosatelita da utvrde polimorfizam različitih vrsta pšenice i alelne kombinacije u vezi sa geografskim poreklom. Značajne razlike između grupa pšenice utvrđene su za visinu biljke i vreme klasanja, dok su razlike između tri vegetacione sezone ustanovljene samo za vreme klasanja. Analizom glavnih kordinata razdvojeni su genotipovi pšenice prema poreklu i ploidnosti. Najveće vrednosti pokazatelja molekularnog diverziteta utvrđene su kod tri grupe pšenice: iz Amerike, južne i jugoistočne Evrope, i zapadne i centralne Evrope. Indeks genetičkog identiteta prema Nei-u ukazao je na genetičku sličnost između geografski udaljenih grupa pšenice južne i jugoistočne Evrope i Rusije (0.901) i grupa južne i jugoistočne Evrope i Amerike (0.638). Visok stepen diverziteta visine i vremena klasanja u ocenjenoj kolekciji pšenice predstavlja vredan izvor varijabilnosti za fino podešavanje ovih osobina u oplemenjivanju pšenice u cilju postizanja boljih prinosa u određenim agroekonomskim uslovima.

The permanent need for efficient plant breeding comes from the increment of human population, which is projected to reach 9.7 million by 2050. Novel approaches could be used to reach these goals more rapidly, raising the question of efficiency, as well. Spike length is one of the important components of grain yield formation in wheat. The influence of individual plan traits is getting more important to grain yield formation per area unit in stressful growing conditions, which are increasingly present due to global climate changes. The objectives of the present research were three-fold: (i) to determine the influence of a genotype, environment and their interaction on spike length and to evaluate stability of the trait; (ii) to present cause-causing links on a graphical example; (iii) to transform a number of possibly correlated variables into a smaller number of uncorrelated variables called principal components. Samples were obtained from 96 winter wheat cultivars grown in 2011/12 and 2012/13 on two locations. The wheat genotype population was profiled with 28 microsatellites. The ANOVA of the total phenotypic variation of the experiment shows that genotypes took the largest portion, followed by the influence of the GE interaction. Additional analysis of the GE interaction using the PCA analysis shows a statistical significance of the first two main components. In the conducted research, the dispersion of the points represents two subpopulations, but the geographical origin could not explain the grouping of genotypes within the same, so the division into two groups was done on the basis of their lines of descent.

Association analysis or linkage disequilibrium mapping is a method for identification of quantitative trait loci (QTLs) in a panel of divergent unrelated individuals based on historical recombinations during a crop’s domestication and selection. It should account for the population structure, which can be the result of adaptation to local conditions or selection, to reduce the possibility of declaring false-positive associations. The aim of this study was to determine potentially significant and consistent associations between markers and agronomic important maize (Zea mays L.) traits using association analysis in a diverse breeding material that can be ultimately implemented in maize selection. To this end, 96 maize inbred lines were evaluated in field trials at three locations in Serbia for eleven agronomic traits and analysed with microsatellite markers. Twenty five microsatellites were used to assess the population structure using Bayesian model-based clustering method and to test the significance of associations between the markers and the traits with general (GLM) and mixed linear (MLM) models. The cluster analysis divided maize inbred lines in four subpopulations, corresponding to the BSSS (Iowa Stiff Stalk Synthetic), LSC (Lancaster Sure Crop), Iodent heterotic groups and exotic and independent germplasm. The models identified associations between twenty five microsatellite markers and eleven agronomic traits, resulting in 133 and 71 associations across the environments for GLM and MLM, respectively. Some of the identified marker-trait associations were significant and consistent in several environments. The associations stable in several environments were identified between the markers bnlg1067 and two flowering traits; nc005 and bnlg434 and plant height, bnlg434 and ear height; bnlg1643 and umc1127 and leaf number, bnlg1360 and ear diameter; umc1019 and umc1506 and number of rows per ear; bnlg2305 and bnlg1451 and ear length, and between bnlg1175 and thousand-kernel weight. The results of this study indicate that these microsatellites could be used in marker-assisted selection of inbred lines, after validation of the marker-trait associations and testing combining abilities of the inbreds during hybrid development. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR-31073]

Creation of new higher yield cultivars, adaptation of existing germplasm to a global climate change, increasing resistance to diseases in new genotypes are some of the tasks that breeding have in front of it. The objectives of this research were to assess GE interaction in two different environments across two vegetation seasons and to do association analysis based on the results of the phenotypic and molecular evaluation. Grain samples were obtained from 96 winter wheat cultivars grown in 2011/12 and 2012/13 at two locations in the South Pannonia Basin region and population was profiled with 28 microsatellites. The share of genotype is high and amounts 24.84%, while the share of environments was 21.06%, when yield was evaluated. The GE interaction was also statistically significant and amounts 51.58% of the total variance. Microsatellites that exhibited a relation with yield by GLM and MLM model were: gwm357, gwm339, cfa2114, gwm631, gwm495, gwm190, barc1121 and gwm437. Markers that have demonstrated the stability of the relationship with yield in different environments can be recommended as potentially useful in wheat breeding.

Microsatellite markers (SSR) were used to study wheat genetic diversity. A set of 87 wheat genotypes was analysed with four SSR markers. Primers used for the amplification of adequate microsatellite loci (Xgwm) are according to RODER et al. (2002). Results were obtained using Applied Biosystems 3130 genetic analyser. Total of 28 alleles were determined, i.e. average of 7 alleles per marker. Number of alleles for individual markers ranged from six (Xgwm3) to eight (Xgwm18). The presence of two null alleles for Xgwm18 and Xgwm155 was found. There were five rare alleles (frequency

The aim of this study was to investigate the possibilities of applying molecular markers-microsatellites in breeding boron tolerant wheat. The study comprised the investigation of allelic variability of sixty bread wheat accessions in two microsatellite loci (Xgwm46-7B and Xgwm577-7B) for which was assumed that are placed near the 7B chromosome locus involved in the expression of boron tolerance in wheat. Phenotypic variability concerning boron tolerance was assessed via root length reduction of wheat seedlings grown in the presence of high external boron, applied as boric acid solution (concentrations 50, 100 and 150 mg/l, boron treatments B50, B100 and B150). The indication of marker-trait associations was determined by comparing the allelic variability in the two microsatellite loci with the phenotypic variability in boron tolerance. Nonparametric Kruskal-Wallis test was used for the comparisons. The indication of marker-trait association was found for both Xgwm46-7B and Xgwm577-7B; on B150 and B50 treatments, respectively. Allelic forms identified in Xgwm577-7B locus may be related to tolerance, medium tolerance and sensitivity to high boron. This was not the case for Xgwm46-7B, where the identified alleles were related only to boron tolerance and sensitivity. Therefore, Xgwm577-7B may be preferred over Xgwm46-7B when studying boron tolerance in wheat. However, a considerable portion of boron tolerant accessions carried different alleles in the investigated loci, implying boron tolerance as a quantitative trait with more than one chromosomal region involved in its expression. Therefore, the allelic variability of more than the analyzed two loci should be investigated. Cilj ovog rada je bilo ispitivanje mogućnosti primene molekularnih markera-mikrosatelita u oplemenjivanju pšenice tolerantne na bor. Ispitana je alelna varijabilnost kod šezdeset genotipova hlebne pšenice u dva mikrosatelitna lokusa (Xgwm46-7B i Xgwm577-7B) za koje se pretpostavlja da su pozicionirani u blizini lokusa na 7B hromozomu koji utiče na ekspresiju ovog svojstva. Fenotipska varijabilnost u pogledu tolerantnosti na bor je utvrđena na osnovu redukcije dužine korenčića klijanaca pšenice gajenih u uslovima suviška bora (rastvor borne kiseline koncentracija 50, 100 i 150 mg/l, tretmani B50, B100, B150). Indikacija veze marker-svojstvo je utvrđivana na osnovu poređenja alelne varijabilnosti mikrosatelitnih lokusa i fenotipske varijabilnosti u pogledu tolerantnosti na bor. Za poređenja je korišćen neparametarski Kruskal-Wallis test. Indikacija veze marker-svojstvo je konstatovana za Xgwm46-7B na tretmanu B150, a za Xgwm577-7B na tretmanu B50. Alelne forme identifikovane u lokusu Xgwm577-7B se mogu dovesti u vezu sa tolerantnošću, srednjom tolerantnošću i osetljivošću na bor. Ovo nije bio slučaj kod Xgwm46-7B, gde su identifikovani aleli dovedeni u vezu samo sa tolerantnošću i osetljivošću na bor. Prema tome, za dalji rad se preporučuje Xgwm577-7B. Međutim, kod značajnog dela tolerantnih genotipova su identifikovani različiti aleli u proučavanim lokusima, što upućuje na zaključak da je u pitanju kvantitativno svojstvo u čiju ekspresiju je uključeno više od jednog hromozomskog regiona. Potrebno je ispitati alelnu varijabilnost više od dva mikrosatelitna lokusa.