Fusarium populations were investigated on 53 samples of wheat grains and husks collected approximately three weeks before harvest in 53 wheat fields in southeastern Poland. A limited area of sample collection was chosen intentionally to avoid the effect of climate and weather variability. The study was conducted to assess the occurrence of 13 Fusarium species using species-specific PCR assays separately on grains and husks of winter wheat. The obtained data suggest that husks could take a protective role of wheat grain against Fusarium spp. The incidence of Fusarium species decreased in grains vs. husks from 29 to 100%. While Fusarium species were present in husks at 11.32% and less, they were absent in the grain. The presence of Fusarium species on husks is inversely proportional to the percentage reduction of Fusarium spp. in grain. There was a correlation of the presence of certain species of Fusarium in husks and in grains. The number of Fusarium species found on husks was about three times higher in comparison to wheat grain. In conclusion, the presented data indicate the importance of Fusarium populations analysis on wheat husk in seeds pathological studies.

The appropriate selection of various traits in valuable plants is very important for modern plant breeding. Effective resistance to fungal diseases, such as powdery mildew, is an example of such a trait in oats. Marker-assisted selection is an important tool that reduces the time and cost of selection. The aims of the present study were the identification of dominant DArTseq markers associated with a new resistance gene, annotated as Pm11 and derived from Avena sterilis genotype CN113536, and the subsequent conversion of these markers into a PCR-based assay. Among the obtained 30,620 silicoDArT markers, 202 markers were highly associated with resistance in the analysed population. Of these, 71 were selected for potential conversion: 42 specific to resistant and 29 to susceptible individuals. Finally, 40 silicoDArT markers were suitable for primer design. From this pool, five markers, 3 for resistant and 2 for susceptible plants, were selected for product amplification in the expected groups. The developed method, based on 2 selection markers, provides certain identification of resistant and susceptible homozygotes. Also, the use of these markers allowed the determination of heterozygotes in the analysed population. Selected silicoDArT markers were also used for chromosomal localization of new resistance genes. Five out of 71 segregating silicoDArT markers for the Pm11 gene were found on the available consensus genetic map of oat. Five markers were placed on linkage groups corresponding to Mrg12 on the Avena sativa consensus map.

ABSTRACT. Wide hybridization expands the gene pool of cultivated species and can produce genotypes with practical value, often resistant to diseases. In plants, ISSRs are often used for hybrid identification as well as for diversity evaluation. We estimated genetic similarity among advanced genetic stocks of triticale hybrids and identified Aegilops juvenalis introgressions into triticale. Fourteen ISSR primers amplified from 12 to 23 DNA fragments. The number of polymorphic products per primer ranged from three to nine, with a mean of 5.1. The polymorphic information content values ranged from 0.39 to 0.66, with a mean of 0.52. Thirteen primers amplified products indicating presence of A. juvenalis chromatin. The largest mean genetic similarity (0.84) with all other forms was shown by a strain derived from an A. juvenalis 6x × [(Lanca × L506/79) × CZR142/79] hybrid, while A. juvenalis was the least similar (0.33). We conclude that ISSRs can reliably identify A. juvenalis chromatin in the triticale background and efficiently estimate genetic similarity of hybrids and parental forms.

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Occurrence of lodging is a result of environmental stress factors and causes significant losses in crop yields. One of the major factors determining plant resistance to lodging is stem length. Thought, the introduction of the dwarfing genes into genome or application of growth regulators, that inhibit gibberellins biosynthesis, are known as the most important approaches in lodging prevention. In this study we analyzed the influence of chlormequat chloride (CCC) and trinexapac-ethyl application on transcriptome of common wheat (Triticum aestivum L.) 'Bezostaya 1'. For analysis, the tall control line and isogenic line carrying Rht12 dwarfing gene were selected. Subsequently, the real-time PCR technique was used to determine the expression of five genes encoding enzymes involved in gibberellins biosynthesis pathway (CPS, KS, GA20ox, GA3ox and GA2ox).

In cereals, the transition from the vegetative stage to flowering is controlled in the main by the set of vernalization genes. Within these genes the most important role is played by VRN1, which encodes a MADS-box transcription factor, regulating the transition of shoot apical meristem to the reproductive phase. The level of vernalization requirement is strongly linked to the molecular structure of this gene. In this study we analyzed molecular mechanisms regulating the vernalization requirement in triticale on the basis of comparative analysis of the VRN1 locus between triticale (×Triticosecale Witt.) and common wheat (Triticum aestivum L.) genotypes. We also estimated the influence of VRN genotype on heading time and the winter hardiness of these two species. Molecular markers developed for VRN genotype detection in common wheat were successfully applied to an analysis of triticale genomic DNA. Subsequent analysis of the amplicons nucleotide sequence confirmed full similarity of the products obtained between triticale and common wheat. All winter triticale cultivars tested contained the recessive vrn-A1 allele, whereas all spring genotypes carried the dominant Vrn-A1a allele. Molecular analysis of the Vrn-B1 gene revealed the presence of the dominant Vrn-B1b allele in only one of the triticale genotypes analyzed (Legalo). The major system of determination of the vernalization requirement in triticale was transferred from common wheat without changes and is based on an alteration in the VRN1 gene promoter sequence within the A genome.

Genetic diversity analysis is an important tool in crop improvement. Species with high genetic diversity are a valuable source of variation used in breeding programs. The aim of this study was to assess the genetic diversity of four species belonging to the genus Aegilops, which are often used to expand the genetic variability of wheat and triticale. Forty-five genotypes belonging to the genus Aegilops were investigated. Within- and among-species genetic diversity was calculated based on REMAP (retrotransposon–microsatellite amplified polymorphism) molecular markers. Obtained results showed that REMAP markers are a powerful method for genetic diversity analysis, which produces a high number of polymorphic bands (96.09% of total bands were polymorphic). Among tested genotypes, Ae. crassa and Ae. vavilovii showed the highest genetic diversity and should be chosen as a valuable source of genetic variation.

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