Search

Durum wheat is the tenth most valuable crop on a global scale. The aim of this study was to compare the phenotypic variation of T. durum accessions of different origin with contemporary spring cultivars of this cereal species. One hundred and two accessions and 12 contemporary cultivars of Triticum durum Desf. as well as Kamut® wheat (T. turanicum), a Triticum species closely related to T. durum, were analyzed. The aim of this study was to describe the degree of variation in the phenotypic traits of grain and selected traits associated with technological quality. The examined genotypes were characterized by considerable phenotypic variation, and they can be a valuable source of material for genetic recombination in durum wheat breeding. The analyzed accessions were characterized by a higher average content of protein (16.48 vs. 14.56%) and wet gluten (38.04 vs. 32.07%), higher Zeleny sedimentation values (69.7 vs. 60.4ml), and higher flour strength (W index values of 404.64 vs. 353.47) than the reference cultivars. The kernels of the evaluated accessions and cultivars did not differ significantly in average crease depth, but significant differences were observed in the values of descriptors directly linked with kernel size, especially kernel image area and minimal Feret diameter. The traits responsible for the processing suitability of grain were more strongly correlated with color descriptors than shape descriptors, which suggests that color parameters can be used to select high-quality breeding material. The analyzed accessions have two major weaknesses, namely relatively low yields (22.6 dt ha-1 on average) and undesirable grain color, indicative of low carotenoid concentration. The accessions deposited in gene banks do not meet the relevant agronomic requirements. However, both grain yield and carotenoid concentration are polygenic traits which can be improved if desirable combinations of QTLs are assembled in breeding lines and cultivars., Competing Interests: Authors declare that there are no conflicts of interest. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

In wheat, resistance to Fusarium is conditioned by anatomical, morphological, and physiological traits. The aim of this study was to evaluate selected elements of constitutive barriers in common wheat, spelt, Polish wheat, emmer, and einkorn. The activity of the phenylalanine ammonia-lyase (PAL) enzyme and rate of reactive oxygen species (ROS) production were evaluated in the tissues of common wheat and spelt inoculated with Fusarium culmorum . Most of the relict wheat species were more abundant in morphological barriers than common wheat. F. culmorum penetrated constitutive barriers, which increased PAL activity and intensified ROS production 24 h after inoculation in wheat tissues. The lowest increase in PAL activity after inoculation was observed in cv. Sumai3, which resistance is based on limiting the spread of F. culmorum within the spike. Spelt line Tas 581 glumes were characterized by the highest concentration of ROS 24 h after inoculation. The ROS content remained high for five days. The results of this study indicate that high trichome density plays a key role in resistance to pathogens. In the resistant spelt line with effective constitutive barriers, PAL activity and ROS content were higher than those observed in susceptible wheats after inoculation with F. culmorum .

[This corrects the article DOI: 10.1371/journal.pone.0192862.].

Fluorescent in situ hybridization (FISH) relies on fluorescent-labeled probes to detect specific DNA sequences in the genome, and it is widely used in cytogenetic analyses. The aim of this study was to determine the karyotype of T. aestivum and T. spelta hybrids and their parental components (three common wheat cultivars and five spelt breeding lines), to identify chromosomal aberrations in the evaluated wheat lines, and to analyze the distribution of polymorphisms of repetitive sequences in the examined hybrids. The FISH procedure was carried out with four DNA clones, pTa-86, pTa-535, pTa-713 and 35S rDNA used as probes. The observed polymorphisms between the investigated lines of common wheat, spelt and their hybrids was relatively low. However, differences were observed in the distribution of repetitive sequences on chromosomes 4A, 6A, 1B and 6B in selected hybrid genomes. The polymorphisms observed in common wheat and spelt hybrids carry valuable information for wheat breeders. The results of our study are also a valuable source of knowledge about genome organization and diversification in common wheat, spelt and their hybrids. The relevant information is essential for common wheat breeders, and it can contribute to breeding programs aimed at biodiversity preservation.

The saprotrophic fungus Alternaria alternata is widespread in the agro-environment and produces more than ten allergenic proteins, mostly protein Alt a 1. The frequency of the Alt a 1 gene was analyzed in a group of A. alternata isolates from winter wheat kernels obtained in Poland, and the effectiveness of various fungicides targeting the pathogen was evaluated. The Alt a 1 gene was identified in four of the seven tested isolates. A. alternata colonized 35.67% kernels on average, but its frequency increased in stored grain where the presence of epiphytes was noted on 23.09 to 51.38% kernels, and endophytes-in 26.21 to 42.01% of kernels. The efficacy of field-applied fungicides did not exceed 50%, despite the fact that A. alternata is highly sensitive to propiconazole, fenpropimorph, and tebuconazole under in vitro conditions. The analyzed isolates were characterized by limited sensitivity to azoxystrobin (EC 50 ranged from 0.505 to 1.350 μg cm -3 ) due to a mutation at codon 143 of the CYT b gene, responsible for resistance to quinone outside inhibitor fungicides, which was noted in all isolates. The spread of A. alternata can be effectively controlled with suitable fungicides and by monitoring the prevalence of pathogenic isolates in the environment.

Fungi of the genus Fusarium infect cereal crops during the growing season and cause head blight and other diseases. Their toxic secondary metabolites (mycotoxins) contaminate grains. Several dozen toxic compounds produced by fungal pathogens have been identified to date. Type B trichothecenes-deoxynivalenol, its acetyl derivatives and nivalenol (produced mainly by F. graminearum and F. culmorum )-are most commonly detected in cereal grains. "T-2 toxin" (produced by, among others, F. sporotrichioides ) belongs to type-A trichothecenes which are more toxic than other trichothecenes. Antagonistic bacteria and fungi can affect pathogens of the genus Fusarium via different modes of action: direct (mycoparasitism or hyperparasitism), mixed-path (antibiotic secretion, production of lytic enzymes) and indirect (induction of host defense responses). Microbial modification of trichothecenes involves acetylation, deacetylation, oxidation, de-epoxidation, and epimerization, and it lowers the pathogenic potential of fungi of the genus Fusarium . Other modifing mechanisms described in the paper involve the physical adsorption of mycotoxins in bacterial cells and the conjugation of mycotoxins to glucose and other compounds in plant and fungal cells. The development of several patents supports the commercialization and wider application of microorganisms biodegrading mycotoxins in grains and, consequently, in feed additives., Competing Interests: The authors declare no conflict of interest.

Triticum genus encloses several tetraploid species that are used as genetic stocks for expanding the genetic variability of wheat (Triticum aestivum L.). Although the T. aestivum (2n = 6x = 42, AABBDD) and T. durum (2n = 4x = 28, AABB) karyotypes were well examined by chromosome staining, Giemsa C-banding and FISH markers, other tetraploids are still poorly characterized. Here, we established and compared the fluorescence in situ hybridization (FISH) patterns on chromosomes of 20 accessions of T. polonicum species using different repetitive sequences from BAC library of wheat 'Chinese Spring'. The chromosome patterns of Polish wheat were compared to tetraploid (2n = 4x = 28, AABB) Triticum species: T. durum, T. diccocon and T. turanicum, as well. A combination of pTa-86, pTa-535 and pTa-713 probes was the most informative among 6 DNA probes tested. Probe pTa-k374, which is similar to 28S rDNA sequence enabled to distinguish signal size and location differences, as well as rDNA loci elimination. Furthermore, pTa-465 and pTa-k566 probes are helpful for the detection of similar organized chromosomes. The polymorphisms of signals distribution were observed in 2A, 2B, 3B, 5B, 6A and 7B chromosomes. Telomeric region of the short arm of 6B chromosome was the most polymorphic. Our work is novel and contributes to the understanding of T. polonicum genome organization which is essential to develop successful advanced breeding strategies for wheat. Collection and characterization of this germplasm can contribute to the wheat biodiversity safeguard.

Several cultivars and pure lines of Triticum monococcum, T. dicoccon, T. polonicum, T. spelta and T. aestivum were inoculated with Fusarium culmorum, the causal agent of Fusarium head blight in wheat. During the three-year study, the infection decreased the values of the analyzed yield components: spike weight (by 5.6% to 15.8%), number of kernels per spike (by 2.8% to 11.8%) and one kernel weight (by 8.4% to 10.7%). T. spelta was characterized by the weakest average response to infection. The grain from inoculated spikes contained significantly higher concentrations of deoxynivalenol (DON) and its 3-β-D-glucoside (D3G) than control grain. The D3G/DON ratio ranged from 11.4% to 21.4% in control grain and from 8.1% to 11.6% in inoculated grain. The lowest levels of mycotoxins were found in spelt, and the highest in T. polonicum lines and Kamut. PCA revealed that the grain of T. polonicum was characterized by an entirely different mycotoxin profile. The weakest response to F. culmorum infections was noted in T. spelta, and the strongest response in T. polonicum breeding lines and Kamut.

The SPE-HPLC method was developed to determine an isosalipurposide (5) and its derivative, 6"-O-p-coumaroyl ester (6) in the bark of eight taxa (I-VIII) belonging to three species of the genus Salix and originating from a natural habitat or cultivated for pharmaceutical purposes. The chalcones were separated by HPLC under gradient elution with the concentration of ACN increasing from 20% to 50% in 0.1% aqueous H3PO, (tG 15 min). The content of both compounds was determined by an external standardization with the use of isoliquiritigenin (7) as a reference substance - a commercially available chalcone, and also isosalipurposide (5) and its derivative, 6"-O-p-coumaroyl ester (6). The latter compound was isolated from the bark of Salix daphnoides (IV) by a CC and semi-preparative HPLC and its structure was elucidated by MS and NMR spectra. It was stated that 6"-O-p-coumaroylisosalipurposide (6), in addition to isosalipurposide (5), is a characteristic flavonoid for the S. daphnoides species. Moreover, the presence of these two chalcones was confirmed in the bark of S. acutifolia (I). Differences were observed in the results obtained from a quantitative analysis due to the type of reference substance used. The content of chalcones was varied and dependent on the species selected for analysis, namely from 22.01/21.08 mg/g in S. daphnoides clone 1095 (III) to 2.47/2.44 mg/g in S. daphnoides (II), collected from a natural habitat. Isosalipurposide (5) was determined in all the investigated species and clones of Salix, besides a number of naringenin derivatives. Separation of all flavonoids: flavanones - naringenin (1), naringenin (+)-5-O-glucoside (2), (-)-5-O-glucoside (3), 7-O-glucoside (4) and chalcones (5 and 6) was performed under gradient elution with the same solvents and changes in ACN concentration from 2% to 37% (tG 60 min). The total amount of flavanones ranged from 4.69 mg/g in S. purpurea clone 1132 (VII) to 41.93 mg/g in S. purpuea (VIII) from Herbapol Wrocław.

Concentrations of trichothecenes and the amounts of microbial biomass were compared in grain of bread wheat, durum wheat, triticale, rye, oat and barley. Grain samples came from lines regionalised in Poland grown under identical climatic and agricultural conditions in 2007. Among the six analysed cereals, the highest mean concentration of toxic metabolites of 151.89 µg/kg was found for grain of Triticum durum, whereas the lowest was for barley grain (25.56 µg/kg). The highest contamination with microscopic fungi was recorded in case of barley and rice grain (mean concentrations of ergosterol were 12.53 mg/kg and 11.24 mg/kg, respectively). In case of the analysed cereals, the total microbial biomass expressed in the amount of ATP turned out to be the highest (4.7 × 10⁵ relative light units [RLU]) for rye and oat (3.2 × 10⁵ RLU). The results of the applied classical discrimination analysis indicate a significant diversification of species in terms of all the 11 analysed metabolites.

Analyses of ergosterol (ERG), adenosine-5'-triphosphate (ATP) and groups A and B trichothecenes were performed in three Triticum monococcum cultivars registered in Germany (Albini, Terzino and Tifi), grown in the organic system. The experiment was carried out on two dates: the first - in the final phase of flowering (BBCH 69) and the second -- in the phase of full ripeness (BBCH 89). The analyses were performed on shanks, glumes, grain and awns. Concentrations of analyzed metabolites in different parts of T. monococcum plants varied significantly. Mean ERG concentration in the first term was more than 30 times higher than immediately before harvest, whereas for group B trichothecenes it was 4 times higher. Contents of ATP and concentrations of group A trichothecenes were similar at both times. When analyzing parts of the spike, the highest amount of metabolites was recorded in shanks (ERG - 114 mg/kg, ATP 900,000 RLU, group A and B trichothecenes - 0.07 and 0.20 mg/kg, respectively), while the lowest in grain (ERG - 5 mg/kg, ATP 55,000 RLU, group A and B trichothecenes - 0.03 and 0.08 mg/kg, respectively). A higher ERG concentration was found in awns (65 mg/kg) than in glumes (41 mg/kg), whereas for ATP and group A and B trichothecenes by contrast higher concentrations were recorded in glumes (160,000 RLU, 0.06 and 0.029 mg/kg, respectively) than in awns (77,000 RLU, 0.05 and 0.014 mg/kg, respectively). Recorded results indicate a potential occurrence of trichothecenes in shanks, awns and glumes already during flowering, when grain has not yet developed. In these parts of plants, after harvest, the highest amounts of microorganisms and Fusarium toxins were found, which pose a threat for farmers and workers employed in the cereal industry.

Background: The aim of study was to investigate mycotoxin profiles in the grain of spring lines of Triticum monococcum (12 lines), T. dicoccum (13 lines) and T. spelta (five lines), in comparison to the T. aestivum cultivar Sumai-3 which is resistant to Fusarium head blight. The grain was obtained from control heads and heads artificially inoculated in the field with Fusarium culmorum. Mycotoxins were determined by LC-MS/MS., Results: A total of 11 toxins were identified in control grain samples. Deoxynivalenol (DON) concentrations exceeded 0.5 mg kg(-1) in only three samples of T. monococcum grain and in one sample of T. dicoccum grain. Inoculation with F. culmorum resulted in a substantial increase in the concentrations of DON (to 63 mg kg(-1)) in the T. monococcum and DON-3-glucoside (to 5.6 mg kg(-1)) in the T. dicoccum. Inoculation contributed to a drop in tentoxin levels (by 57% in T. spelta) and to an increase of cyclodepsipeptide concentrations (in particular enniatins B and B(1)) being two-fold (T. monococcum) to four-fold (T. dicoccum) higher on average than in control samples. The Sumai-3 responded to inoculation with nearly a two-fold drop in the levels of the cyclodepsipeptides., Conclusion: The results of a discriminant analysis for all identified toxins indicate that einkorn, emmer and spelt differ significantly with regard to the mycotoxin profiles of their grain.

Oat plants, similar to other cereals, are susceptible to invasion by fungal pathogens and saprophytes, but the severity of disease symptoms and the extent of fungal growth depend to a considerable degree on environmental conditions. This study aimed to analyse the dependence of ergosterol and trichothecene production in oat grain on environmental conditions. Three oat cultivars were cultivated in 10 localities across Poland under natural conditions of fungal infection. Analysis of the effect of weather conditions during the growing season on ergosterol content and total trichothecene Fusarium toxin content in grain showed that they are negatively correlated with the sum of precipitation in the dry month of June, i.e. at the flowering stage of oats. Significant rainfall in July (256 % multiannual average) resulted in a considerable growth of saprophytic fungi and, as a consequence, in high ERG levels in grain (mean 14.0 mg/kg). Although the total trichothecene content was relatively low (< 150 microg/kg), a significant correlation was observed between this trait and ergosterol content of grain (r = 0.7313). Higher values of correlation coefficients were recorded for the dependence of trichothecene A, as well as trichothecene A and NIV, and ERG levels, amounting to r = 0.8703 and r = 0.7748, respectively. This was probably caused by specific weather conditions manifested by slight precipitation during panicle flowering, which promoted the growth of pathogens (F. poae, F. sporotrichioides) producing trichothecenes A (T-2 toxin, HT-2 toxin and NIV). In addition, a significant influence of locality on values of both traits was recorded. Variation between cultivars was not significant.

Bilobetin and 4'''-O-methylamentoflavone were isolated and identified in the needles of Taxus baccata, for the first time in this species. The antifungal activity of biflavones from T. baccata and Ginkgo biloba, namely amentoflavone, 7-O-methylamentoflavone, bilobetin, ginkgetin, sciadopitysin and 2,3-dihydrosciadopitysin towards the fungi Alternaria alternata, Fusarium culmorum, Cladosporium oxysporum was determined employing computer-aided image analysis couplet to a microscope. Bilobetin exhibited a significant antifungal activity with values of ED50 14, 11 and 17 microM respectively. This compound completely inhibited the growth of germinating tubes of Cladosporium oxysporum and Fusarium culmorum at a concentration 100 microM. Activity of ginkgetin and 7-O-methylamentoflavone towards Alternaria alternata was stronger than that of bilobetin. Moreover, slight structural changes in the cell wall of Alternaria alternata exposed to ginkgetin at concentration of 200 microM were observed.

From the leaves of Microbiota decussata (Cupressaceae) biflavones: cupressuflavone, amentoflavone and 7-O-methylamentoflavone were isolated and identified. The amount of cupressuflavone in Microbiota decussata and xCupressocyparis leylandii (Leyland cypress) (Cupressaceae) was determined by HPLC (1.82% and 0.83%, respectively). The chemical composition of essential oils from bark and leaves of Microbiota decussata was established by GC-MS (GC-FID) analysis. As a major component thujopsene (39.2% and 45.9%, respectively) was identified. Wiridiflorol (3.0%) and tau-muurolol (0.3%) were present only in leaves but globulol (1.5%) exclusively in bark. The content of essential oils in M. decussata was high--5.4% in bark and 12.6% in leaves. The essential oils from M. decussata and xC. leylandii were bioassayed towards different fungi of the genus Fusarium. Leyland cypress essential oil at 2% concentration fully inhibited the growth of all fungi.

The chemical composition of the essential oils from the needles of Pinus ponderosa (north american pine), P. resinosa (red pine) and P. strobus (eastern white pine) has been determined by GC/MS (FID). The essential oils from P. resinosa and P. ponderosa in comparison to P. strobus have been characterized by the higher content of beta-pinene (42.4%, 45.7% and 7.9% respectively). On the other hand, a-pinene (17.7%) and germacrene D (12.2%) were dominant compounds of P strobus. Moreover the essential oil from P. resinosa was more rich in myrcene-15.9%. Estragole and delta-3-carene, each one in amount ca 8% were identified only in P. ponderosa. The content of essential oils in the needles slightly varied--0.65%--P. resinosa, 0.4%--P strobus, 0.3%--P. ponderosa. The antifungal activity has been investigated towards Fusarium culmorum, F solani and F. poae. The strongest activity was observed for the essential oil from P. ponderosa, which fully inhibited the growth of fungi at the following concentrations--F. culmorum, F. solani at 2% and F. poae at 5%.

The degree of similarity among dissolvable in water proteins obtained from 10Fusarium nivale isolates was studied. Tandem crossed Immunoelectrophoresis method was applied. Two immunological antisera: anti-F. nivale 4 and anti-F. nivale 15 were used in the investigation. Their homologous reactions resulted in 13 and 12 precipitation bands, respectively. The results allow to divide the isolates into three groups, according to their protein composition.

The extend of physiological variability of five Isolates of Fusarium nivale /Fr./ Ces. using a tandem - crossed Immunoelectrophoresis was studied. In the homological reaction of antiserum antl-F. nivale fourteen precipiration lines were obtained. The variability of antigens originated from different isolates was found. The studied isolates showed differentiation In pathogenicity to three rye genotypes.