Dragan Perovic

SNP markers were developed for the OWBM resistance gene Sm1 that will be useful for MAS. The wheat Sm1 region is collinear with an inverted syntenic interval in B. distachyon. Orange wheat blossom midge (OWBM, Sitodiplosis mosellana Géhin) is an important insect pest of wheat (Triticum aestivum) in many growing regions. Sm1 is the only described OWBM resistance gene and is the foundation of managing OWBM through host genetics. Sm1 was previously mapped to wheat chromosome arm 2BS relative to simple sequence repeat (SSR) markers and the dominant, sequence characterized amplified region (SCAR) marker WM1. The objectives of this research were to saturate the Sm1 region with markers, develop improved markers for marker-assisted selection (MAS), and examine the synteny between wheat, Brachypodium distachyon, and rice (Oryza sativa) in the Sm1 region. The present study mapped Sm1 in four populations relative to single nucleotide polymorphisms (SNPs), SSRs, Diversity Array Technology (DArT...

Recent declines in costs accelerated sequencing of many species with large genomes, including hexaploid wheat (Triticum aestivum L.). Although the draft sequence of bread wheat is known, it is still one of the major challenges to developlocus specific primers suitable to be used in marker assisted selection procedures, due to the high homology of the three genomes. In this study we describe an efficient approach for the development of locus specific primers comprising four steps, i.e. (i) identification of genomic and coding sequences (CDS) of candidate genes, (ii) intron- and exon-structure reconstruction, (iii) identification of wheat A, B and D sub-genome sequences and primer development based on sequence differences between the three sub-genomes, and (iv); testing of primers for functionality, correct size and localisation. This approach was applied to single, low and high copy genes involved in frost tolerance in wheat. In summary for 27 of these genes for which sequences were ...

Development and growth of cereal leaves significantly affect grain yield since dry matter accumulation depends of the leaf area that intercepts light. Phyllochron is defined as time interval between the appearance of successive leaves on the main stem. The aim of this study was to determine the effect of year and cultivars on final leaf number (FLN) and phyllochron (PHY) in winter barley. Thermal unit was used as time scale with 0°C as base temperature. Twelve cultivars differing in origin and time to anthesis (early, medium and late) were tested during six growing seasons (GS), 2002/03-2007/08. FLN across cultivars and GSs was 13.5 and PHY was 75.7 GDD leaf-1. The highest FLN across GSs was in the late, six-rowed barley cultivar Kredit (14.7). The lowest FLN was in the early, two-rowed barley cultivar Novosadski 581 (11.3). In regard to earliness, lowest FLN was in the early cultivars (12.9) and highest in the late ones (13.9). The highest PHY across GSs was in the two-rowed cultiv...

Recent advances in next-generation sequencing techniques allow the detection of a large number of SNPs and their use in a high throughput manner. However, Cleaved Amplified Polymorphic Sequences (CAPSs) still play a significant role as complement to other high throughput methods for SNP genotyping. Therefore, new methods focusing on the acceleration of this type of markers are highly desirable. The combination of the classical CAPS technique and a M13-tailed primer multiplexing assay was used to develop an agarose gel free protocol for the analysis of SNPs via restriction enzyme digestion. PCR products were fluorescence labeled with a universal M13 primer and subsequently digested with the appropriate restriction endonuclease. After mixing differently labeled products, they were detected on a capillary electrophoresis system. This method allows the cost-effective genotyping of several SNPs in a multiplexed manner at an overall low cost in a short period of time. Additionally, this m...

... AFLP u odnosu na druge markere AFLP sistem molekularnih markera ima prednosti u odnosu na druge tehnike odredi-vanja fingerprinta DNK, ukljucujuci poli-morflzam duzine restrikcionih fragmenata (RFLP) i random amplificiranu DNK (RAPD) (Blears et al., 1998). ...

ABSTRACT Phenology of small grains as a complex trait that matches plant development with growing conditions, is an important factor that influences plant adaptation to a particular environment and final yield of the plant. Scales of growth based on plant phenology and scales of development based on apical morphology are very precise, but relationships between them are not always clear. Some morphogenetic features of cereal growth can be predicted on the basis of leaf appearance, which means that shoot apex development is coordinated with leaf appearance and total number of leaves formed. The objective of this research was to study the relationship between apical development and plant phenology and the variability in phenological development of diverse winter barley cultivars under field conditions. Twelve barley cultivars differing in origin, pedigree and agronomic traits were used in this study conducted during six growing seasons in the location of Novi Sad (45o20’N, 15o51’E, altitude 86 m), under rainfed conditions. Phyllochron approach was used as a method for determination of initial/final stages of apex development. The duration of the phases was converted to cumulated growing degree days (GDD). Spikelet initiation started at 2.5 Haun stage and finished at 7.1 Haun stage. Preanthesis phases (single ridge-SR, double ridge-DR, spikelet development-SD, heading-H, anthesis-A) and grain filling period (GFP) were under significant effect of genetic (G), environmental (E) and interaction factors (GxE). Of the total variation in the DR phase, 55.7% was due to GxY, 22.1% due to E and 12.3% due to G. Spikelet development was mainly under control of G and E, 42% and 44%, respectively. Heritability was 0.57 and 0.95 for DR and SD, respectively. Across cultivars and environments, of the total growing period, 138 GDD belonged to sowing-first leaf period, 161 to SR, 326 to DR, 541 to SD, 254 to flag leaf-H, 142 to H-A and 732 to GF. Although variability was found in the duration of the preanthesis phases and GF, especially in spikelet and flower development, positive genotypic correlations were found to exist between most of the phases.

ABSTRACT Development and growth of cereal leaves significantly affect grain yield since dry matter accumulation depends of the leaf area that intercepts light. Phyllochron is defined as time interval between the appearance of successive leaves on the main stem. The aim of this study was to determine the effect of year and cultivars on final leaf number (FLN) and phyllochron (PHY) in winter barley. Thermal unit was used as time scale with 0°C as base temperature. Twelve cultivars differing in origin and time to anthesis (early, medium and late) were tested during six growing seasons (GS), 2002/03-2007/08. FLN across cultivars and GSs was 13.5 and PHY was 75.7 GDD leaf-1. The highest FLN across GSs was in the late, six-rowed barley cultivar Kredit (14.7). The lowest FLN was in the early, two-rowed barley cultivar Novosadski 581 (11.3). In regard to earliness, lowest FLN was in the early cultivars (12.9) and highest in the late ones (13.9). The highest PHY across GSs was in the two-rowed cultivar Cordoba, 81.6 GDD leaf-1, the lowest in the two-rowed cultivar Novosadski 581, 71.0 GDD leaf-1. The early cultivars had fast leaf development, the medium cultivars medium and the late cultivars slow development, 72.5 GDD leaf-1, 75.6 GDD leaf-1 and 78.9 GDD leaf-1, respectively. The tested cultivars showed significant variability in the FLN and PHY, which can be used for selecting most adaptable genotypes for specific conditions.

Landraces of wheat (Triticum aestivum L.), collected from the Western Balkans, were considered as a potential genetic resource of drought resistance for wheat breeding. A group of 20 landraces with 80 wheat accessions of worldwide origin were tested in 4-year field trials under two watering regimes: fully irrigated and under a rain-out plot shelter. Fourteen agronomic traits were evaluated for their responses to drought stress, and four selection indices were calculated: mean productivity (MP), stress tolerance (TOL), stress susceptibility index (SSI) and stress tolerance index (STI). The average yield of landraces was significantly lower than that of accessions under both regimes, and there was no evidence that yield stability of landraces was better than that of accessions. However, TOL was better in landraces than in accessions, and several traits related to yield were shown to suffer less under water deficit (i.e. kernels per spike). Amongst landraces, relatively wide diversity ...

Increased seed production has been a common goal during the domestication of cereal crops, and early cultivators of barley (Hordeum vulgare ssp. vulgare) selected a phenotype with a six-rowed spike that stably produced three times the usual grain number. This improved yield established barley as a founder crop for the Near Eastern Neolithic civilization. The barley spike has one central and two lateral spikelets at each rachis node. The wild-type progenitor (H. vulgare ssp. spontaneum) has a two-rowed phenotype, with additional, strictly rudimentary, lateral rows; this natural adaptation is advantageous for seed dispersal after shattering. Until recently, the origin of the six-rowed phenotype remained unknown. In the present study, we isolated vrs1 (six-rowed spike 1), the gene responsible for the six-rowed spike in barley, by means of positional cloning. The wild-type Vrs1 allele (for two-rowed barley) encodes a transcription factor that includes a homeodomain with a closely linked...

Recent genomic projects reveal that about half of the gene repertoire in plant genomes is made up by multigene families. In this paper, a set of structural and phylogenetic analyses have been applied to compare the differently sized nicotianamine synthase (NAS) gene families in barley and rice. Nicotianamine acts as a chelator of iron and other heavy metals and plays a key role in uptake, phloem transport and cytoplasmic distribution of iron, challenging efforts for the breeding of iron-efficient crop plants. Nine barley NAS genes have been mapped, and co-linearity of flanking genes in barley and rice was determined. The combined analyses reveal that the NAS multigene family members in barley originated through at least one duplication event that occurred before the divergence of rice and barley. Additional duplications appear to have occurred within each of the species. Although we detected no evidence for positive selection of recently duplicated genes within species, codon-based ...