Assessment of genetic effects on important breeding traits in reciprocal DH populations of winter oilseed rape (Brassica napus L.)

Here we present a study on the genetic effects of agronomic and seed quality traits in double haploid(DH) populations,which were developed by microspore culture from reciprocal F1 hybrids produced between cultivar Californium and DH W-15.Each of the populations consisted of 25 DH lines.The field experiments were conducted in a randomized complete block design with three replications during three growing seasons.Field observations were recorded on seed yield and its structure: the number of branches and pods per plant,the number of seeds per pod,the 1 000-seed weight,the content of fat in the seeds,and three unsaturated fatty acids(oleic,linoleic,linolenic) in the seed oil.In order to investigate the influence of cross direction on the studied traits,parental effects were evaluated on the basis of differences between reciprocal DH populations.The maternal effect was revealed on the number of seeds per pod and the effect of the paternal form on linolenic acid content.The occurrence of transgression effects also depended on the direction of crossing and this was particularly noticeable in terms of the number of seeds per pod.The use of multivariate statistical methods allowed for the simultaneous characterization and grouping of tested lines in terms of several traits.Graphic images of the distribution of DH lines in the space of the two first canonical variates showed a great variation between the two reciprocal populations,both in terms of yield and its components,as well as fat and those unsaturated fatty acids.

IPM Strategies and Their Dilemmas Including an Introduction to www. eurowheat.org

Information about disease management in winter wheat(Triticum aestiva)in eight European countries was collated and analysed by scientists and extension workers within the European Network for the Durable Exploitation of Crop Protection Strategies(ENDURE).This included information about specif ic disease thresholds,decision support systems,host varieties,disease prevalence and pathogen virulence.Major differences in disease prevalence and economic importance were observed.Septoria tritici blotch(Mycosphaerella graminicola)was recognized as the most yield reducing disease in countries with intensive wheat production,but also rust diseases(Puccinia striiformis and Puccinia triticina),powdery mildew(Blumeria graminis)and Fusarium head blight(Fusarium spp.)were seen as serious disease problems.Examples of current integrated pest management(IPM)strategies in different countries have been reported.Disease management and fungicide use patterns showed major differences,with an average input equivalent to 2.3 full dose rates(TFI)in the UK and a TFI of 0.6 in Denmark.These differences are most likely due to a combination of different cropping systems,climatic differences,disease prevalence,and socio-economic factors.The web based information platform www.eurowheat.org was used for dissemination of information and results including information on control thresholds,cultural practices which can infl uence disease attack,fungicide eff icacy,fungicide resistance,and pathogen virulence,which are all elements supporting IPM for disease control in wheat.The platform is open to all users.The target groups of EuroWheat information are researchers,advisors,breeders,and similar partners dealing with disease management in wheat.

The Effect of Fusarium Inoculation and Fungicide Application on Concentrations of Flavonoids(Apigenin,Kaempferol,Luteolin,Naringenin,Quercetin,Rutin,Vitexin)in Winter Wheat Cultivars

Grain of 30 winter wheat cultivars was screened for the content of seven flavonoids (apigenin, kaempferol, luteolin, naringenin, quercetin, rutin, vitexin). In total, 90 samples were analyzed, belonging to three combinations: the control, samples inoculated with Fusarium culmorum, and samples inoculated with Fusarium culmorum and protected with fungicides (Prosaro, Topsin M). Analyzed flavonoids were detected in all tested samples. The highest concentrations were recorded for quercetin (512.9 mg/kg) and luteolin (458.4 mg/kg). Concentration of all compounds was the highest in the inoculated samples, while in the control and in the inoculated samples treated with fungicides their contents were significantly lower and similar, as confirmed by the statistical analysis conducted by multivariate methods. In most cases, significant correlations were obtained between individual flavonoids. Such correlations were observed for all flavonoids in samples covering all the three variants and almost all flavonoids in the inoculated samples. The lowest number of correlations was recorded for samples treated with fungicides.

Null Alleles in Gliadin Coding Loci and Wheat Allergenic Properties

Wheat gliadin proteins-an important, nutritional component of many food products may also act as allergenic proteins causing various, clinical symptoms of IgE-mediated food allergies. Gliadins are coded by six complex loci on the chromosomes 1A, 1B, 1D,6A, 6B and 6D of wheat genome. Each of the loci coding from a few to a dozen of polypeptides may spontaneously mutate to inactive gene variants called null alleles that do not code any proteins at all. The aim of the present work was to find out whether null alleles in some gliadin coding loci may decrease wheat allergenic properties. Six winter wheat genotypes: gliadin deletion lines (GDL) containing null alleles on 1D, 1B and 6B chromosomes and control lines (CL) containing active gene variants in all gliadin coding loci, were developed using plant breeding methods. Allergenic properties of the six analyzed hybrids were estimated by ELISA using polled sera of five patients allergic to gluten. Estimated immunoreactivity of GDLs was from 6% to 18% lower as compared with CLs. The obtained results evidenced that gliadin null alleles decrease wheat allergenic properties and may be used as parental forms for breeding of hypoallergenic wheat genotypes.

The Impact of High Temperature during Growing Season on Potato Cultivars with Different Response to Environmental Stresses

Potato crop is the fourth main food crops in the world after maize, rice and wheat. It is characterized by specific temperature requirements and develops best at about 20°C. Forecasts of global warming prompt us to study the tolerance of potato genotypes to heat during the growing season. The aim of this work was to assess the response of chosen potato cultivars to high temperature during the different stages of plant growth under conditions of good soil moisture and drought. The impact of high temperature 32°C/25°C on potato plants was determined in pot experiment in three growth stages. A main measure of tolerance of the potato cultivars to high temperature during the growing season was an evaluation of the yield in relation to the Control combination. Here we demonstrated that tested potato cultivar’s response to high temperature during the growing season is dependent on the growth stage. The earlier it occurs, the more negative its impact on the growth and yield of potatoes is.

Purified Wheat Gliadin Proteins as Immunoglobulin E Binding Factors in Wheat Mediated Allergies

Some wheat gliadin proteins are strong allergens that may cause various symptoms of food allergies and baker’s asthma. The most immunoreactive ω-5 gliadin fractions are the main allergens in wheat dependent exercise induced anaphylaxis (WDEIA). While the allergenicity of ω-5 is quite well understood, knowledge about α, β, γ and ω-1.2 gliadins is much more scanty. This study examines allergenic properties of other fractions as compared to ω-5. Gliadins were extracted from flour of winter wheat (Triticum aestivum L.) cultivar Ostka strzelecka. Purified samples representing proteins belonging to α, β, γ, ω-1.2 and ω-5 classes were isolated using preparative gel electrophoresis. Immuno-reactivity and allergenic properties of these proteins were analyzed by ELISA using sera from allergic patients with elevated sIgE (> 2KU/L), and by skin prick test (SPT). ELISA showed that ω-5 and ω-1.2 differed considerabely from α-, β- and γ-gliadins in respect of immunoreactivity. Responses of both ω-gliadins were almost twice as high as for other fractions. Significant differences were also observed among individual ω-gliadin fractions as evidenced by ANOVA. SPT showed that patient with symptoms of baker’s asthma and WDEIA had a positive results to all gliadins tested. Another patient with baker’s asthma (but not WDEIA) reacted positively only to ω-5 gliadins. In two patients with skin allergy SPT were negative with all analyzed proteins. Results show ω-1.2 gliadins to be almost as immunorective as ω-5. The α-, β- and γ-gliadins also recognize specific IgE antibodies, but their binding capacity is only about half that of ω-fractions. This kind of immunoreactivity could still be important since a cumulative effect of individual fractions may intensify disease symptoms in allergic patients.