Spring Wheat Cv Research Articles

Balancing water and radiation productivity suggests a clue for improving yields in wheat under combined water deficit and terminal heat stress.

Sustaining crop yield under abiotic stresses with optimized resource use is a prerequisite for sustainable agriculture, especially in arid and semi-arid areas. Water and heat stress are major abiotic stresses impacting crop growth and yield by influencing complex physiological and biochemical processes during the life cycle of crops. In a 2-year (2015-2017) research, spring wheat cv. HD-2967 was grown under deficit irrigation and delayed sowing conditions to impose water and terminal heat stresses, respectively. The data were analyzed for seasonal crop water use, radiation interception, water productivity (WP), and radiation productivity (RP) under combined water deficit and terminal heat stresses. Seasonal crop water use was significantly affected by stresses in the order of water + terminal heat > water > terminal heat. Water stress showed minimal effect on the light extinction coefficient and consequently on seasonal intercepted photosynthetically active radiation (IPAR). However, seasonal IPAR was primarily affected by combined water + terminal heat and terminal heat stress alone. The slope of crop water use and IPAR, i.e., canopy conductance, an indicator of canopy stomatal conductance, was more influenced by water stress than by terminal heat stress. Results showed that linear proportionality between WP and RP is no longer valid under stress conditions, as it follows a curvilinear relation. This is further supported by the fact that independent productivity (either water or radiation) lacked the ability to explain variability in the final economic yield or biomass of wheat. However, the ratio of RP to WP explained the variability in wheat yield/biomass under individual or combined stresses. This suggests a clue for improving higher wheat yield under stress by managing WP and RP. The highest biomass or yield is realized when the ratio of RP to WP approaches unity. Screening of genotypes for traits leading to a higher ratio of RP to WP provides an opportunity for improving wheat productivity under stressed environments.

Влияние депонированной формы комплексного пестицидного препарата на структуру урожая зерновых культур и заболеваемость корневыми гнилями

The use of chemical plant protection products is essential to obtain a quality crop, but entails the risks of spreading pesticides in the biosphere and causing damage to beneficial biota. Therefore, the development of new approaches to the delivery of pesticides, which reduce the negative impact on agroecosystems, is an important direction for sustainable agriculture development. The effect of a complex preparation containing the fungicide tebuconazole and the herbicide tribunuron-methyl, embedded in a biodegradable polymer base of poly(3-hydroxybutyrate) and birch sawdust, on the several indicators was studied: the number of rhizospheric micromycetes of spring wheat cv. Novosibirskaya 15 and spring barley cv. Biom, the effectiveness of root pathogens control, and the structure and quality of the crop. In field experiments, a prolonged fungicidal action of the complex embedded preparation was demonstrated, which was superior in duration and efficiency to the traditional pre-sowing seed dressing. During the growing season, there was a significant (p <0.05) decrease in the number of micromycetes in the rhizosphere of wheat and barley by 1.5-2 times in comparison with the control, as well as a decrease in the prevalence of root phytopathogenic fungi (Alternaria, Bipolaris, and Fusarium). A high level of biological efficiency of the embedded fungicide was demonstrated in different phases of plant development - from 73.4 to 100% on wheat and from 68 to 100% on barley. As a result, the use of a complex embedded preparation increased the yield of spring wheat and barley, respectively, by 10.8 and 4.4 c/ha compared to the control and contributed to the improvement of the grain quality of crops. Keywords: PESTICIDES, EMBEDDING, TEBUCONAZOL, TRIBUNURON-METHYL, POLY(3-HYDROXYBUTYRATE), ROOT ROTS, YIELD, WHEAT, BARLEY

The effect of Fusarium culmorum inoculation and deoxynivalenol application on proteome response in wheat cultivars Sumai 3 and SW Kadrilj

Fusarium head blight (FHB) represents a damaging disease of cereal spikes caused by mycotoxin-producing Fusarium fungi revealing adverse effects on grain quality and yield. Chinese spring wheat (Triticum aestivum L.) cv. Sumai 3 represents a major source of FHB resistance thanks to Fhb1 QTL on 3BS chromosome conferring resistance to FHB and encoding a lectin-like protein. The aim of our study lied in a comparison of proteome response to Fusarium culmorum inoculation and mycotoxin deoxynivalenol (DON) application at 10 d after inoculation (dai) in spikes of resistant wheat cultivar Sumai 3 and susceptible wheat cultivar SW Kadrilj. Proteome analysis revealed profound impact of Fusarium inoculation and mycotoxin application on plant energy metabolism. Fusarium inoculation decreased photosynthesis and ATP biosynthesis and increased the level of stress-protective proteins (chaperones such as Hsc70, lectins). Genotype related differences observed at 10 dai indicated an active acclimation in Sumai 3 as indicated by increased content of some enzymes involved in phenolics biosynthesis (phenylalanine ammonia lyase PAL, BAHD acyltransferase), jasmonate biosynthesis (lipoxygenase LOX), and oligosaccharide biosynthesis (sucrose synthase SuSy, UDP-glucose uridylyltransferase) which are an important part of glycoproteins such as lectins and other pathogen-responsive biomolecules. The study thus provides data on plant acclimation to Fusarium infection which may underlie superior resistance of Sumai 3 cultivar.

Improving Phenolic-Linked Antioxidant, Antihyperglycemic and Antibacterial Properties of Emmer and Conventional Wheat Using Beneficial Lactic Acid Bacteria

Beneficial lactic acid bacteria (LAB)-based fermentation is an effective bioprocessing approach to improve human-health-targeted functional benefits of plant-based food substrates, such as cereal grains. Previously, we observed high phenolic bioactive-linked antioxidant and anti-hyperglycemic properties in whole grain Emmer (hulled). In this study, beneficial LAB (Lactiplantibacillus plantarum) was recruited to ferment (0–72 h) aqueous extracts (0.4 g/mL concentration) of previously optimized hulled Emmer wheat and conventional red spring wheat cv. Barlow. The fermented and unfermented (control) wheat extracts were analyzed for phenolic content, phenolic profile, antioxidant activity, and antihyperglycemic properties (α-amylase and α-glucosidase enzyme inhibitory activity) using in vitro assay models. Additionally, antimicrobial activity against pathogenic bacteria Helicobacter pylori, and potential prebiotic activity supporting the growth of beneficial Bifidobacterium longum were also investigated. Improvement in antioxidant activity and antihyperglycemic functional benefits were observed, while soluble phenolic content remained high after 72 h fermentation. Antimicrobial activity against H. pylori was also observed in 48 and 72 h fermented wheat extracts. This study provides an insight into the efficacy of LAB-based fermentation as a safe bioprocessing tool to design health-targeted functional foods and ingredients from underutilized whole grains like Emmer for targeting type 2 diabetes dietary benefits.

ПОДВИЖНОСТЬ СИЛИКАТОВ, ПОКАЗАТЕЛИ ПЛОДОРОДИЯ ДЕРНОВО-ПОДЗОЛИСТОЙ ПОЧВЫ, БИОАККУМУЛЯЦИЯ КРЕМНИЯ И ПРОДУКТИВНОСТЬ СЕЛЬСКОХОЗЯЙСТВЕННЫХ КУЛЬТУР ПОД ДЕЙСТВИЕМ ЦЕОЛИТА

ПОДВИЖНОСТЬ СИЛИКАТОВ, ПОКАЗАТЕЛИ ПЛОДОРОДИЯ ДЕРНОВО-ПОДЗОЛИСТОЙ ПОЧВЫ, БИОАККУМУЛЯЦИЯ КРЕМНИЯ И ПРОДУКТИВНОСТЬ СЕЛЬСКОХОЗЯЙСТВЕННЫХ КУЛЬТУР ПОД ДЕЙСТВИЕМ ЦЕОЛИТА

MOBILITY OF SILICON, FERTILITY OF SOD-PODZOLIC SOIL, BIOACCUMULATION OF SILICON AND YIELDS OF AGRICULTURAL CROPS UNDER THE INFLUENCE OF ZEOLITE

MOBILITY OF SILICON, FERTILITY OF SOD-PODZOLIC SOIL, BIOACCUMULATION OF SILICON AND YIELDS OF AGRICULTURAL CROPS UNDER THE INFLUENCE OF ZEOLITE

Impact of Cultivar and Growing Conditions on Alpha‐Amylase Properties in Wheat

AbstractAlpha amylase (α‐amylase) is an endo‐amylolytic enzyme that plays an important role in the starch metabolism in developing wheat grains. However, excessive enzyme activity in post‐harvest wheat grains has adverse effects on grain quality. Therefore, the objective of the study is to determine the influence of cultivars with different growth habits (spring vs winter) and weather conditions on the characterization of native α‐amylase. The results show that winter wheat cultivar (cv.) Cubus show a lower α‐amylase activity than those of spring wheat cv. Amaretto, by escaping the humid weather before harvest. Grains exposed to higher temperatures in Gladebeck have lower enzyme activity in the later stages of ripening than the grains in Torland. On the other hand, wheat α‐amylases from both cultivars have similar properties. They show thermal inactivation at 30 °C and acid lability at increasing pH values. The results indicate that a better understanding of the α‐amylase properties could be helpful to develop a suitable management to avoid quality losses in wheat.

Modification of starch composition, structure and properties through editing of TaSBEIIa in both winter and spring wheat varieties by CRISPR/Cas9.

SummaryFoods high in amylose content and resistant starch (RS) offer great potential to improve human health and lower the risk of serious noninfectious diseases. Common wheat (Triticum aestivum L.) is a major staple food crop globally. However, the RS contents in the grains of modern wheat varieties are low. Here, we report the generation of high‐amylose wheat through targeted mutagenesis of TaSBEIIa in a modern winter wheat cv Zhengmai 7698 (ZM) and a spring wheat cv Bobwhite by CRISPR/Cas9, respectively. We generated a series of transgene‐free mutant lines either with partial or triple‐null TasbeIIa alleles in ZM and Bobwhite, respectively. Analyses of starch composition, structure and properties revealed that the effects of partial or triple‐null alleles were dosage dependent with triple‐null lines demonstrated more profound impacts on starch composition, fine structures of amylopectin and physiochemical and nutritional properties. The flours of triple‐null lines possessed significantly increased amylose, RS, protein and soluble pentosan contents which benefit human health. Baking quality analyses indicated that the high‐amylose flours may be used as additives or for making cookies. Collectively, we successfully modified the starch composition, structure and properties through targeted mutagenesis of TaSBEIIa by CRISPR/Cas9 in both winter and spring wheat varieties and generated transgene‐free high‐amylose wheat. Our finding provides deep insights on the role of TaSBEIIa in determining starch composition, structure, properties and end‐use quality in different genetic backgrounds and improving RS content with multiple breeding and end‐use applications in cereal crop species through genome editing for health benefits.

Effect of Foliar Applied Acetylsalicilic Acid on Wheat (Triticum aestivum L.) under Field Conditions

The exogenous application of salicylic acid prevents plant damage caused by various abiotic stresses (drought, high and low temperatures, salinity) and helps plants to build resistance to biotic stresses (pathogens). Acetylsalicylic acid, which is a synthetic salicylic acid derivative, has the same properties. In the face of climate change and a greater likelihood of extreme weather events, the use of these acids can significantly help to ensure proper growth and development of plants, especially sensitive species, even under stress conditions. The problem, however, is choosing the right dose (concentration) and time of application, and individual species sensitivity. The aim of the study was to assess the effect of acetylsalicylic acid on the growth and yield parameters of spring wheat. A field trial was carried out in 2013 and 2014 at the Institute of Plant Protection—National Research Institute in Poznan (Poland). The experiment was established on spring wheat cv. ‘Tybalt’, in four replications. Acetylsalicylic acid was tested in two concentrations: 0.3 and 0.5 mM. Each concentration was applied to the crop twice at growth stage BBCH 29 (end of tillering) and 7 days afterwards, and at growth stage BBCH 37 (flag leaf just visible) and 7 days afterwards. The study evaluated 12 traits of the crop, including plant height, chlorophyll content in the flag leaf, length of the ear, and quality and quantity parameters of the yield. The study showed that both the selection of the appropriate concentration and the time of acetylsalicylic acid application have a significant impact on the growth and development of the wheat. The acetylsalicylic acid increased the amount of chlorophyll in the leaves, the number of grains in the ear, the mass of a thousand grains, and grain yield. The present study did not confirm significant differences between the acetylsalicylic acid concentrations. The concentration of 0.5 mM proved more effective only for such traits as plant height and protein content in the grain. The study showed that it is not the concentration but the time of acetylsalicylic acid application that is more important for the growth of the wheat. Although there were no significant differences between the effects of earlier and later application time on plant height or chlorophyll content, most of the structural and qualitative parameters of the yield (number of grains in the ear, grain density, grain hardness, protein, gluten and starch content) were better after later application of acetylsalicylic acid (GS BBCH 37).

Advantages of bi-cropping field beans (Vicia faba) and wheat (Triticum aestivum) on cereal forage yield and quality

ABSTRACT In organic production systems, penalties in cereal forage yield and low crude protein (CP) concentration are mainly caused by limited soil nitrogen (N) availability, which can be addressed by using cereal/grain legume bi-cropping systems. To confirm this, a bi-cropping experiment with spring wheat cv. Paragon and faba beans cvs. Fuego and Maris Bead were conducted in 2 years, using a randomised complete block design and sowing the crops in a replacement design series. In 2016, the wheat forage yield in sole cropping exceeded that in bi-cropping by 58%. In 2015, the wheat forage harvest index (HI) in bi-cropping was 14% higher than that in sole cropping, but in 2016 it was 7% lower. In both years, bi-cropping increased the CP and the grain N uptake in the wheat compared with that sole cropping, by 25% and 17%, respectively. The chlorophyll concentration index (CCI) in the wheat was 2.2 times higher in bi-cropping than in sole cropping and 34% higher in the alternate rows systems compared with the broadcast system. In 2015, the efficiency of N use (NLER) in bi-cropping was 50.7% higher than that in sole cropping. Alternate row bi-cropping improved NLER over broadcast by 37.9%. Faba bean rust disease was more severe in Fuego than in Maris Bead. In conclusion, bi-cropping in uniform alternate row spacing can improve productivity and nutritional quality of wheat forage, compared with sole cropping. The bi-crop bean cultivars Fuego and Maris Bead can, improve wheat straw CP and reduce rust disease severity, respectively.

Antagonistic Activity of Chilean Strains of Pseudomonas protegens Against Fungi Causing Crown and Root Rot of Wheat (Triticum aestivum L.).

Seed treatments with antagonistic bacteria could reduce the severity of crown and root rot diseases in wheat crops. The objective of this study was to evaluate the potential antagonistic activity of a bacterial consortium of three Chilean strains of Pseudomonas protegens against the wheat crown and root rot pathogens Gaeumannomyces graminis var. tritici, Rhizoctonia cerealis, and Fusarium culmorum. Two field experiments were carried out on artificially infested soil during two consecutive seasons (2016–2017 and 2017–2018) in an Andisol soil of southern Chile. Control treatments (not inoculated with fungi) were also included. Each treatment included a seed treatment of spring wheat cv. Pantera-INIA with and without the bacterial consortium. Both phytosanitary damage (incidence and severity) and agronomic components were evaluated. Bacterial populations with the phlD+ gene in the wheat plant rhizosphere during anthesis state (Z6) were also quantified. In both seasons, infection severity decreased by an average of 16.8% in seeds treated with P. protegens consortium, while yield components such as spikes m−1 and number of grains per spike increased. The use of antagonistic bacteria resulted in a total yield increase only during the first experimental season (P < 0.05). In general, accumulated rainfall influenced the antagonistic effect of the consortium of P. protegens strains, accounting for the differences observed between the two seasons. The results suggest that this P. protegens consortium applied on seeds can promote plant growth and protect wheat crops against crown and root rot pathogens in Southern Chile under field conditions.

Effects of soil‐plastic mulching on water consumption characteristics and grain yield of spring wheat in a semi‐arid area

AbstractRegulating the water consumption characteristics of crops is an important way to achieve efficient water use and develop water‐saving agriculture in semi‐arid rainfed areas. Using spring wheat cv. Longchun 27 as test material, a field experiment involved two treatments: (i) whole‐field soil plastic mulching and bunch seeding (PM); (ii) uncovered and bunch seeding (CK). The results showed that soil water storage in the 0–300 cm profile for PM was higher than that of CK. Before the jointing stage, the periodic water consumption, water consumption modulus coefficient and water consumption intensity of PM were lower than CK by 10.7–36.2 mm, 19.8–52.4% and 9.1–52.7%; However, from jointing to heading, they were correspondingly higher by 15.8–21.8 mm, 19.5–34.1% and 18.2–32.9% (P &lt; 0.05). The above‐ground biomass, crop growth rate and water consumption efficiency of PM were significantly higher than that of CK. Based on the significantly increased spike length, grain number per spike and 1000‐grain weight, PM increased grain yield by 8.9–22.8%, and WP by 9.9–25.2% without significant change of evapotranspiration, as compared with CK. Consequently, PM regulated the water consumption characteristics of spring wheat, resulting in significantly increased water productivity and grain yield. © 2020 John Wiley &amp; Sons, Ltd.

Genetic dissection of Fusarium head blight resistance in spring wheat cv. ‘Glenn’

Fusarium head blight (FHB) is a major disease of wheat in many wheat-growing regions affecting wheat yield and quality. Glenn is arguably the most FHB-resistant spring wheat cultivar in the USA. To decipher the genetics of FHB resistance in Glenn, a population of 112 recombinant inbred lines was developed from the cross Glenn × MN00261-4 and evaluated for various FHB related traits at multiple locations in two states (North Dakota and Minnesota) over 3 years. Quantitative trait loci (QTL) analysis detected 15 QTL for FHB resistance related traits and heading date (HD). One QTL for FHB incidence (INC; type I resistance), six QTL for FHB severity (SEV; type II resistance), one QTL for Fusarium damaged kernels (FDK; type IV resistance), four QTL for disease index (DI), and three QTL for HD were detected. Major QTL defined as those consistent across multiple environments and explaining > 10% of the phenotypic variation were detected on chromosomes 5BL, 6BS, and 7AS. They were associated with multiple FHB variables and HD. The stable 6BS QTL with a large effect for FHB SEV resistance corresponded to the Fhb2 gene in Sumai 3. In addition, potentially novel QTL were identified on 1AS, 5BL and 7DS. Our study showed that FHB resistance in the GM population was contributed by loci other than Fhb1. The major QTL detected for FHB resistance have potential for use in marker-assisted breeding for FHB resistance.

Yield and Quality in Purple-Grained Wheat Isogenic Lines

Breeding programs for purple wheat are underway in many countries but there is a lack of information on the effects of Pp (purple pericarp) genes on agronomic and quality traits in variable environments and along the product chain (grain-flour-bread). This study was based on unique material: two pairs of isogenic lines in a spring wheat cv. Saratovskaya-29 (S29) background differing only in Pp genes and grain color. In 2017, seven experiments were conducted in Kazakhstan, Russia, and Turkey with a focus on genotype and environment interaction and, in 2018, one experiment in Turkey with a focus on grain, flour, and bread quality. The effect of environment was greater compared to genotype for the productivity and quality traits studied. Nevertheless, several important traits, such as grain color and anthocyanin content, are closely controlled by genotype, offering the opportunity for selection. Phenolic content in purple-grained lines was not significantly higher in whole wheat flour than in red-colored lines. However, this trait was significantly higher in bread. For antioxidant activities, no differences between the genotypes were detected in both experiments. Comparison of two sources of Pp genes demonstrated that the lines originating from cv. Purple Feed had substantially improved productivity and quality traits compared to those from cv. Purple.

Mitigation mechanism of ozone-induced reduction in net photosynthesis of Bangladeshi wheat under soil salinity stress

To clarify the combined effects of O3 and soil salinity on net photosynthetic rate, stomatal conductance, and radical scavenging system of Bangladeshi spring wheat cv. BAW1059, plants were grown in two soil salinity levels (irrigated with 0 and 150 mM NaCl solutions) and exposed to three O3 concentrations [charcoal-filtered air (CF), 1.0-fold the ambient O3 concentration (1.0×O3), and 1.5-fold the ambient O3 concentration (1.5×O3)]. The soil salinity mitigated adverse effects of O3 on net photosynthesis in the 7th and flag leaves. The soil salinity did not induce stomatal closure, indicating no limitation of stomatal O3 uptake. The activities of ascorbate peroxidase and catalase were stimulated by the soil salinity in the 7th and flag leaves, especially under 1.5×O3 concentration. In the flag leaf, the soil salinity induced a significant increase in dehydroascorbate reductase activity and ascorbate concentration. These results suggest that the soil salinity activated detoxification capacity related to mitigation of O3 damage on net photosynthesis in both 7th and flag leaves, while the activated enzymes and antioxidants were different between the leaves.

An efficient and reproducible Agrobacterium-mediated transformation method for hexaploid wheat (Triticum aestivum L.)

BackgroundDespite wheat being a worldwide staple, it is still considered the most difficult to transform out of the main cereal crops. Therefore, for the wheat research community, a freely available and effective wheat transformation system is still greatly needed.ResultsWe have developed and optimised a reproducible Agrobacterium-mediated transformation system for the spring wheat cv ‘Fielder’ that yields transformation efficiencies of up to 25%. We report on some of the important factors that influence transformation efficiencies. In particular, these include donor plant health, stage of the donor material, pre-treatment by centrifugation, vector type and selection cassette. Transgene copy number data for independent plants regenerated from the same original immature embryo suggests that multiple transgenic events arise from single immature embryos, therefore, actual efficiencies might be even higher than those reported.ConclusionWe reported here a high-throughput, highly efficient and repeatable transformation system for wheat and this system has been used successfully to introduce genes of interest, for RNAi, over-expression and for CRISPR–Cas9 based genome editing.

The effect of bi-cropping wheat (Triticum aestivum) and beans (Vicia faba) on forage yield and weed competition

ABSTRACTField experiments were conducted from April 2015 to September 2016 at the Royal Agricultural University, UK to explore the impact of drilling pattern and species mixtures on weed growth and forage yield. The bi-crops of spring field bean (Vicia faba) cv. Maris Bead and Fuego with spring wheat (Triticum aestivum) cv. Paragon were evaluated at four drilling patterns in a randomized complete block design with four replicates and compared against their respective sole crops. Weed DM was 59% higher in the sole cropping systems than the bi-cropping systems. The sole cropping systems outperformed the bi-cropping systems for wheat (in 2016 only) and for bean forage DM yield. However, the bi-cropping systems produced higher total forage DM yields than sole cropping systems. Weed DM was higher in broadcast than in alternate rows systems. Bean forage DM was 74% higher in treatments with alternate rows than in the broadcast treatment. Wheat forage DM was not affected by the drilling patterns. Maris Bead had higher forage DM than Fuego (in 2016 only). It was concluded that bi-cropping can increase land productivity per unit area over sole cropping, whilst improving forage DM yield and providing low cost integrated weed management. Alternate row drilling can improve bi-cropping productivity over the broadcast practice.Abbreviations: LER - Land Equivalent Ratio

Herbicides with natural and synthetic biostimulants in spring wheat

ABSTRACT: Although the knowledge on agricultural using of biostimulants increases, there is still little information on their interactions with other chemicals i.e. herbicides. The aim of the study was to assess the influence of popular herbicides (MCPA + dicamba, dicamba + triasulfuron, florasulam+2,4-D) used with and without biostimulants based on seaweed extract (Kelpak) and nitrophenols (Asahi) on weed control efficiency, yield and quality of the crop. Field trial was carried out in the years 2014 and 2015 in the Institute of Plant Protection - National Research Institute in Poznan (Poland). The experiment was established on spring wheat cv.‘Torridon’, in 4 replications, using randomized block design. In the experiment two variants of application were tested. In the first variant preparations (herbicide and biostimulant) were applied as tank mixtures at the crop growth stage BBCH 30 and in the second variant in some combinations herbicide application was followed by biostimulant used alone. Weather conditions had a profound impact on tested preparations activity. Addition of biostimulants to herbicide had not affected weed control efficacy but application of herbicide and biostimulant mixture revealed its influence on yield parameters of wheat. Biostimulants influenced yield quality parameters e.g. by enhancing gluten amount in grains.

Soil microbial activity of faba bean (Vicia faba L.) and wheat (Triticum aestivum L.) rhizosphere during growing season

Plant–microorganism relationships in the rhizosphere soil are crucial for nutrient cycling, plant productivity, and health. The study was conducted to assess the effects of faba bean and wheat on enzyme activities and metabolic potential in the soil rhizosphere as well as their changes during the vegetative season. The field experiment was performed on a Haplic Luvisol. Faba bean (Vicia faba L.) cv. Granit (F) and spring wheat (Triticum aestivum L.) cv. Kandela (W) rhizosphere soils were taken for analysis three times during the vegetation. The activities of dehydrogenase, protease, urease, and acid phosphomonoesterase as well as the metabolic diversity of the microbial community were assessed. Although soil enzyme activity was related to the sampling terms, the activities of dehydrogenase, protease, and urease were higher under F than W at the later growth phases. Similarly, metabolic diversity indices were significantly greater under F than W at the flowering stage of faba bean and head emergence of wheat. Significant differences between plants and sampling terms were observed in respect to utilization of different groups of carbon substrates, especially carboxylic acids, amides, and amines. This result demonstrates higher soil microbial activity and functionality in the rhizospheres of faba bean than wheat. The plant effect on soil microbial activity increased with time. This study expands our knowledge of the ecological effects of plant species on interactions between the plant rhizosphere and soil microorganisms.

Mapping and validation of powdery mildew resistance loci from spring wheat cv. Naxos with SNP markers

Powdery mildew, caused by Blumeria graminis f.sp. tritici, is a major wheat disease in maritime and temperate climates. Breeding for race-non-specific or partial resistance is a cost-effective and environmentally friendly disease control strategy. The German spring wheat cultivar Naxos has proven to be a good source for partial resistance to powdery mildew. The objectives of the present study were to map the resistance loci in Naxos with use of high-density SNP markers in the Shanghai3/Catbird x Naxos inbred line population and validate the results in a different genetic background; Soru#1 x Naxos. Both populations were genotyped with the Illumina iSelect 90K wheat chip, and integrated linkage maps developed by inclusion of previously genotyped SSR and DArT markers. With the new linkage maps, we detected a total of 12 QTL for powdery mildew resistance in Shanghai3/Catbird x Naxos, of which eight were derived from Naxos. Previously reported QTL on chromosome arms 1AS and 2BL were more precisely mapped and the SNP markers enabled discovery of new QTL on 1AL, 2AL, 5AS and 5AL. In the Soru#1 x Naxos population, four QTL for powdery mildew resistance were detected, of which three had resistance from Naxos. This mapping verified the 1AS and 2AL QTL detected in Shanghai3/Catbird x Naxos, and identified a new QTL from Naxos on 2BL. In conclusion, the improved linkage maps with SNP markers enabled discovery of new resistance QTL and more precise mapping of previously known QTL. Moreover, the results were validated in an independent genetic background.