Bread Wheat Breeding Research Articles

Functional Analysis of the "Green Revolution" Gene Photoperiod-1 and Its Selection Trends During Bread Wheat Breeding.

Flowering is central to the transformation of plants from vegetative growth to reproductive growth. The circadian clock system enables plants to sense the changes in the external environment and to modify the growth and development process at an appropriate time. Photoperiod-1 (Ppd-1), which is controlled by the output signal of the circadian clock, has played an important role in the wheat “Green Revolution.” In the current study, we systematically studied the relationship between Ppd-1 haplotypes and both wheat yield- and quality-related traits, using genome-wide association analysis and transgenic strategies, and found that highly appropriate haplotypes had been selected in the wheat breeding programs. Genome-wide association analysis showed that Ppd-1 is associated with significant differences in yield-related traits in wheat, including spike length (SL), heading date (HD), plant height (PH), and thousand-grain weight (TGW). Ppd-1-Hapl-A1 showed increased SL by 4.72–5.93%, whereas Ppd-1-Hapl-B1 and Ppd-1-Hapl-D1 displayed earlier HD by 0.58–0.75 and 1.24–2.93%, respectively, decreased PH by 5.64–13.08 and 13.62–27.30%, respectively, and increased TGW by 4.89–10.94 and 11.12–21.45%, respectively. Furthermore, the constitutive expression of the Ppd-D1 gene in rice significantly delayed heading date and resulted in reduced plant height, thousand-grain weight, grain width (GW), and total protein content. With reference to 40years of data from Chinese wheat breeding, it was found that the appropriate haplotypes Ppd-1-Hapl-A1, Ppd-1-Hapl-B1, and Ppd-1-Hapl-D1 had all been subjected to directional selection, and that their distribution frequencies had increased from 26.09, 60.00, and 52.00% in landraces to 42.55, 93.62, and 96.23% in wheat cultivars developed in the 2010s. A Ppd-B1 methylation molecular marker was also developed to assist molecular wheat breeding. This research is of significance for fully exploring the function of the Ppd-1 gene and its genetic resource diversity, to effectively use the most appropriate haplotypes and to improve crop yield and sustainability.

The gene Sr38 for bread wheat breeding in Western Siberia

Present-day wheat breeding for immunity exploits extensively closely related species from the family Triticeae as gene donors. The 2NS/2AS translocation has been introduced into the genome of the cultivated cereal Triticum aestivum from the wild relative T. ventricosum. It contains the Lr37, Yr17, and Sr38 genes, which support seedling resistance to the pathogens Puccinia triticina Eriks., P. striiformis West. f. sp. tritici, and P. graminis Pers. f. sp. tritici Eriks. & E. Henn, which cause brown, yellow, and stem rust of wheat, respectively. This translocation is present in the varieties Trident, Madsen, and Rendezvous grown worldwide and in the Russian varieties Morozko, Svarog, Graf, Marquis, and Homer bred in southern regions. However, the Sr38 gene has not yet been introduced into commercial varieties in West Siberia; thus, it remains of practical importance for breeding in areas where populations of P. graminis f. sp. tritici are represented by avirulent clones. The main goal of this work was to analyze the frequency of clones (a)virulent to the Sr38 gene in an extended West Siberian collection of stem rust agent isolates. In 2019–2020, 139 single pustule isolates of P. graminis f. sp. tritici were obtained on seedlings of the standard susceptible cultivar Khakasskaya in an environmentally controlled laboratory (Institute of Cytology and Genetics SB RAS) from samples of urediniospores collected on commercial and experimental bread wheat f ields in the Novosibirsk, Omsk, Altai, and Krasnoyarsk regions. By inoculating test wheat genotypes carrying Sr38 (VPM1 and Trident), variations in the purity of (a)virulent clones were detected in geographical samples of P. graminis f. sp. tritici. In general, clones avirulent to Sr38 constitute 60 % of the West Siberian fungus population, whereas not a single virulent isolate was detected in the Krasnoyarsk collection. The Russian breeding material was screened for sources of the stem rust resistance gene by using molecular markers specif ic to the 2NS/2AS translocation. A collection of hybrid lines and varieties of bread spring wheat adapted to West Siberia (Omsk SAU) was analyzed to identify accessions promising for the region. The presence of the gene was postulated by genotyping with specif ic primers (VENTRIUP-LN2) and phytopathological tests with avirulent clones of the fungus. Dominant Sr38 alleles were identif ied in Lutescens 12-18, Lutescens 81-17, Lutescens 66-16, Erythrospermum 79/07, 9-31, and 8-26. On the grounds of the composition of the West Siberian P. graminis f. sp. tritici population, the Sr38 gene can be considered a candidate for pyramiding genotypes promising for the Novosibirsk, Altai, and Krasnoyarsk regions

Multiple Wheat Genomes Reveal Novel Gli-2 Sublocus Location and Variation of Celiac Disease Epitopes in Duplicated α-Gliadin Genes.

The seed protein α-gliadin is a major component of wheat flour and causes gluten-related diseases. However, due to the complexity of this multigene family with a genome structure composed of dozens of copies derived from tandem and genome duplications, little was known about the variation between accessions, and thus little effort has been made to explicitly target α-gliadin for bread wheat breeding. Here, we analyzed genomic variation in α-gliadins across 11 recently published chromosome-scale assemblies of hexaploid wheat, with validation using long-read data. We unexpectedly found that the Gli-B2 locus is not a single contiguous locus but is composed of two subloci, suggesting the possibility of recombination between the two during breeding. We confirmed that the number of immunogenic epitopes among 11 accessions varied. The D subgenome of a European spelt line also contained epitopes, in agreement with its hybridization history. Evolutionary analysis identified amino acid sites under diversifying selection, suggesting their functional importance. The analysis opens the way for improved grain quality and safety through wheat breeding.

Scientific breeding of winter bread wheat in the Non-Сhernozem zone of Russia: the history, methods and results.

The article describes the main stages and achievements of the breeding of winter bread wheat (Triticum aestivum L.) in the Non-Chernozem zone for more than a century. The beginning of breeding work was laid by D.L. Rudzinsky on the experimental field of the Moscow Agricultural Institute. Beginning from the 1940s, under the leadership of Academician N.V. Tsitsin, and then Prof. G.D. Lapchenko, the method of distinct hybridization with blue wheatgrass (Agropyron glaucum (Desf. ex DC.) Roem. & Schult.) was actively used. The resulting wheat-wheatgrass hybrids had an average winter hardiness, increased grain quality and productivity. Cultivar Zarya developed in the 1970s (by individual selection from the F3 cross combination of cv. Mironovskaya 808×line 126/65 (in the pedigree of this line, there is a wheat-wheatgrass hybrid PPG 599)) had a high yield and was widely used in further crosses. In the 1980s, Academician B.I. Sandukhadze achieved a significant increase in yield by using the method of intermittent backcrosses due to the producing of varieties with a new morphoecotype (cvs Inna, Pamyati Fedina, etc.), namely, winter-hardy, short stemmed (dwarf), and productive. Cultivar Moskovskaya 39 (registration in 1999) was referred to strong wheat, with a stable protein content of 15–16 %, gluten 30–35 %. Produced in the 2000s, cvs Moskovskaya 56, Nemchinovskaya 57, Galina, Nemchinovskaya 24, Nemchinovskaya 17, and Moskovskaya 40 have a high adaptability to the environment of the region; give a high yield and quality of grain. The area of crops of these cultivars in Russia occupies more than 2 million ha. The current trends in wheat breeding are indicated, the production yield of commercial cultivars of breeding by the Federal Research Center “Nemchinovka” over 12.0 tons per ha and the protein content in the grain up to 17 % are shown. As a result of succession, originality and application of the methodology of scientific breeding, the yield of winter bread wheat in the period from the beginning of the last century to the present has increased from 1.0 to 12.0 and more tons per ha.

Identification of Resistance Sources and Genome-Wide Association Mapping of Septoria Tritici Blotch Resistance in Spring Bread Wheat Germplasm of ICARDA.

Septoria tritici blotch (STB) of wheat, caused by the ascomycete Zymoseptoria tritici (formerly Mycosphaerella graminicola), is one of the most important foliar diseases of wheat. In Morocco, STB is a devastating disease in temperate wheat-growing regions, and the yield losses can exceed up to 50% under favorable conditions. The aims of this study were to identify sources of resistance to STB in Septoria Association Mapping Panel (SAMP), which is composed of 377 advanced breeding lines (ABLs) from spring bread wheat breeding program of ICARDA, and to identify loci associated with resistance to STB at seedling (SRT) as well as at the adult plant (APS) stages using genome-wide association mapping (GWAM). Seedling resistance was evaluated under controlled conditions with two virulent isolates of STB (SAT-2 and 71-R3) from Morocco, whereas adult plant resistance was assessed at two hot spot locations in Morocco (Sidi Allal Tazi, Marchouch) under artificial inoculation with a mixture of STB isolates. At seedling stage, 45 and 32 ABLs were found to be resistant to 71-R3 and SAT-2 isolates of STB, respectively. At adult plant stage, 50 ABLs were found to be resistant at hot spot locations in Morocco. Furthermore, 10 genotypes showed resistance in both locations during two cropping seasons. GWAM was conducted with 9,988 SNP markers using phenotypic data for seedling and the adult plant stage. MLM model was employed in TASSEL 5 (v 5.2.53) using principal component analysis and Kinship Matrix as covariates. The GWAM analysis indicated 14 quantitative trait loci (QTL) at the seedling stage (8 for isolate SAT-2 and 6 for isolate 71-R3), while 23 QTL were detected at the adult plant stage resistance (4 at MCH-17, 16 at SAT-17, and 3 at SAT-18). SRT QTL explained together 33.3% of the phenotypic variance for seedling resistance to STB isolate SAT-2 and 28.3% for 71-R3, respectively. QTL for adult plant stage resistance explained together 13.1, 68.6, and 11.9% of the phenotypic variance for MCH-17, SAT-17, and SAT-18, respectively. Identification of STB-resistant spring bread wheat germplasm in combination with QTL detected both at SRT and APS stage will serve as an important resource in STB resistance breeding efforts.

Wheat speciation and adaptation: perspectives from reticulate evolution.

Reticulate evolution through the interchanging of genetic components across organisms can impact significantly on the fitness and adaptation of species. Bread wheat (Triticum aestivum subsp. aestivum) is one of the most important crops in the world. Allopolyploid speciation, frequent hybridization, extensive introgression, and occasional horizontal gene transfer (HGT) have been shaping a typical paradigm of reticulate evolution in bread wheat and its wild relatives, which is likely to have a substantial influence on phenotypic traits and environmental adaptability of bread wheat. In this review, we outlined the evolutionary history of bread wheat and its wild relatives with a highlight on the interspecific hybridization events, demonstrating the reticulate relationship between species/subspecies in the genera Triticum and Aegilops. Furthermore, we discussed the genetic mechanisms and evolutionary significance underlying the introgression of bread wheat and its wild relatives. An in-depth understanding of the evolutionary process of Triticum species should be beneficial to future genetic study and breeding of bread wheat.

Genetic analysis of grain protein content and dough quality traits in elite spring bread wheat (Triticum aestivum) lines through association study

Wheat quality parameters are complex traits predominantly influenced by the genetic background of varieties. A total of 802 spring bread wheat breeding lines were tested at Marchouch station, Morocco in 2018 aimed at mining invaluable QTNs for grain protein content (PR), gluten content (GL), alveograph strength (W) and zeleny sedimentation test (Z). A single-locus (MLM) and multi-locus (FarmCPU) GWAS models were implemented using 5,095 SNP markers generated from the genotyping-by-sequencing (GBS) platform. A total of 36 and 92 QTNs were detected for the four quality traits from the MLM and FarmCPU GWAS models, respectively. The FarmCPU model detected markers on homoeologous chromosome group one having highly significant QTNs with PR, GL, W and Z traits. The two implemented GWAS models detected significant QTNs on the short arm of homoeologous chromosome groups 2 and 6 for GL, PR, W and Z traits. FarmCPU model detected SNP_615302 marker on chromosome 3B with highly significant MTAs and concurrent effect for PR, GL and W traits. Moreover, significant MTAs were detected on chromosomes 3D, 4A, 4B, 5A, 5B, 7A, 7B and 7D for the four studied quality traits across the two GWAS models. The in-silico gene annotation for QTNs using the high confidence gene models detected genes involved in numerous functions including regulating plant growth, development and tolerance to biotic and abiotic stresses. The identified markers could potentially be useful tool for quality improvement through marker-assisted selection in future breeding programs.

Functional gene assessment of bread wheat: breeding implications in Ningxia Province

BackgroundThe overall genetic distribution and divergence of cloned genes among bread wheat varieties that have occurred during the breeding process over the past few decades in Ningxia Province, China, are poorly understood. Here, we report the genetic diversities of 44 important genes related to grain yield, quality, adaptation and resistance in 121 Ningxia and 86 introduced wheat cultivars and advanced lines.ResultsThe population structure indicated characteristics of genetic components of Ningxia wheat, including landraces of particular genetic resources, introduced varieties with rich genetic diversities and modern cultivars in different periods. Analysis of allele frequencies showed that the dwarfing alleles Rht-B1b at Rht-B1 and Rht-D1b at Rht-D1, 1BL/1RS translocation, Hap-1 at GW2-6B and Hap-H at Sus2-2B are very frequently present in modern Ningxia cultivars and in introduced varieties from other regions but absent in landraces. This indicates that the introduced wheat germplasm with numerous beneficial genes is vital for broadening the genetic diversity of Ningxia wheat varieties. Large population differentiation between modern cultivars and landraces has occurred in adaptation genes. Founder parents carry excellent allele combinations of important genes, with a higher number of favorable alleles than modern cultivars. Gene flow analysis showed that six founder parents have greatly contributed to breeding improvement in Ningxia Province, particularly Zhou 8425B, for yield-related genes.ConclusionsVarieties introduced from other regions with rich genetic diversity and landraces with well-adapted genetic resources have been applied to improve modern cultivars. Founder parents, particularly Zhou 8425B, for yield-related genes have contributed greatly to wheat breeding improvement in Ningxia Province. These findings will greatly benefit bread wheat breeding in Ningxia Province as well as other areas with similar ecological environments.

Integration of Genomic Selection into Winter-Type Bread Wheat Breeding Schemes: A Simulation Pipeline including Economic Constraints

Background: Relatively little effort has been made yet to optimize the allocation of resources when using genomic predictions to maximize the return to investment in terms of genetic gain per unit of time and cost. Methods: We built a simulation pipeline in the R environment designed to become a decision tool to help breeders adjusting breeding schemes, according to their either short or long-term objectives. We used it to explore different scenarios in order to investigate under which conditions (at what step of the breeding program) genomic predictions could improve genetic gain. For a given budget per cycle, we compared 36 scenarios, varying strategies (phenotypic selection PS or genomic selection + phenotypic selection: GPS), trait heritability, relative selection rate at two key steps and genotyping cost. With GPS strategy, we also optimized mating using genomic predictions. The reference population is a 20 years historical data set from the INRAE-Agri-Obtentions bread wheat breeding program. We simulated 3 cycles of 5 years selection. Results: We showed that GPS selection using mating optimization significantly improved genetic gain for all scenarios while GPS without mating optimization and PS had similar efficiency in terms of genetic gain. Our results also highlighted that the loss of genetic diversity over successive cycles was faster using GPS strategies. Those were more efficient to increase favourable allele frequency, rare alleles in particular.

Identification of prospective sources of agronomically-valuable traits of bread wheat (Triticum aestivum L.) among breeding lines in the condition of Forest-Steppe of Ukraine

The aim of work was the estimation of valuable traits of bread wheat breeding lines, obtained from interspecies crosses with wild Aegilops and Triticum species growing in a condition of the Forest- Steppe of Ukraine. We used the seed proteins electrophoresis in PAAG for confirmation of the presence of rye seed storage components in the wheat parental lines genomes. The biochemical compositions of seeds had determined by the infrared spectroscopy method. As a result of researching from the set of 600 breeding lines were selected best lines with increased grain yield from 1 m2, with high protein content in grain, disease resistance, and winter hardiness significantly exceeded the standard variety Polesskaya-90. All lines have high and moderate resistance against diseases: Powdery Mildew, Brown Rust, Septoria Blotch. Based on obtained data had selected breeding lines, which were promising sources of single and complex agronomically valuable traits for bread wheat breeding and genetic researches.

Genetic Variability, Heritability and Genetic Advance Study in Bread Wheat Genotypes (<i>Triticum aestivum </i>L.)

Wheat (Triticum aestivum L.) is a high-yielding crop with a wide range of adaptability, and it is the world's and Ethiopia's principal source of food. In Ethiopia, however, wheat productivity has increased in recent years. Due to abiotic like heat, drought, frost and others and biotic like rusts (Stem, yellow and leaf), Septoria, fusarium and others causes, it is still quite low when compared to other wheat-producing countries. The objectives were to test variability of genotypic and phenotypic and also heritability and genetic advance in bread wheat genotypes. Hence, in this studied conducted on 30 bread wheat genotypes of yield and associated traits was assessed. A trial was undertaken Holetta in Ethiopia in 2018/19 cropping season. The materials were tested using a three-replication alpha lattice pattern. Data on yield and associated traits were analyzed using SAS versions 9.3 software. The heritability estimates for 1000 kernel weight were found to be very high, at 81.14 percent. The trait 1000 kernel weight was also shown to have a high heritability couple with a high genetic advance as a percentage of the mean. So it concluded that 1000 kernel weight may be targeted as the selection criteria for the grain yield improvement However, further study needs to be conducted the future bread wheat breeding effort should be focus on varietal development.

Production of synthetic wheat lines to exploit the genetic diversity of emmer wheat and D genome containing Aegilops species in wheat breeding

Due to the accumulation of various useful traits over evolutionary time, emmer wheat (Triticum turgidum subsp. dicoccum and dicoccoides, 2n = 4x = 28; AABB), durum wheat (T. turgidum subsp. durum, 2n = 4x = 28; AABB), T. timopheevii (2n = 4x = 28; AAGG) and D genome containing Aegilops species offer excellent sources of novel variation for the improvement of bread wheat (T. aestivum L., AABBDD). Here, we made 192 different cross combinations between diverse genotypes of wheat and Aegilops species including emmer wheat × Ae. tauschii (2n = DD or DDDD), durum wheat × Ae. tauschii, T. timopheevii × Ae. tauschii, Ae. crassa × durum wheat, Ae. cylindrica × durum wheat and Ae. ventricosa × durum wheat in the field over three successive years. We successfully recovered 56 different synthetic hexaploid and octaploid F2 lines with AABBDD, AABBDDDD, AAGGDD, D1D1XcrXcrAABB, DcDcCcCcAABB and DvDvNvNvAABB genomes via in vitro rescue of F1 embryos and spontaneous production of F2 seeds on the Fl plants. Cytogenetic analysis of F2 lines showed that the produced synthetic wheat lines were generally promising stable amphiploids. Contribution of D genome bearing Aegilops and the less-investigated emmer wheat genotypes as parents in the crosses resulted in synthetic amphiploids which are a valuable resource for bread wheat breeding.

Aerial high‐throughput phenotyping enables indirect selection for grain yield at the early generation, seed‐limited stages in breeding programs

AbstractBreeding programs for wheat (Triticum aestivum L.) and other crops require one or more generations of seed increase before replicated trials can be sown to assess yield. Extensive phenotyping at this stage is challenging because of the small sizes of plots and large numbers of lines under evaluation, and therefore, breeders typically rely on visual selection to promote lines to yield evaluation. Aerial high‐throughput phenotyping (HTP) enables the rapid acquisition of traits that may be useful for selection among early generation lines. With the objective of assessing the potential for aerial measurements recorded on seed increase plots to improve indirect selection for grain yield (GY), two sets of 1,008 early generation bread wheat breeding lines were sown both as replicated yield trials (YTs) and as small, unreplicated plots (SPs) at the International Maize and Wheat Improvement Center during two breeding cycles. Normalized difference vegetation indices (NDVI) collected with an unmanned aerial vehicle (UAV) in the SPs were observed to be heritable and moderately correlated with GY assessed in YTs. Furthermore, NDVI was more predictive of GY than univariate genomic selection (GS), with still higher overall predictive abilities from multitrait approaches. A related experiment showed that selection based on NDVI would have outperformed visual selection, though this approach would have driven a directional response in phenology because of confounding between phenology, NDVI, and GY. A restricted selection index was proposed to address this issue. These results provide a promising outlook for the use of aerial HTP to improve selection at the early generation, seed‐limited stages of breeding programs.

Identification of prospective sources of agronomically-valuable traits of bread wheat (Triticum aestivum L.) among breeding lines in the condition of Forest-Steppe of Ukraine

The aim of work was the estimation of valuable traits of bread wheat breeding lines, obtained from interspecies crosses with wild Aegilops and Triticum species growing in a condition of the Forest-Steppe of Ukraine. We used the seed proteins electrophoresis in PAAG for confirmation of the presence of rye seed storage components in the wheat parental lines genomes. The biochemical compositions of seeds had determined by the infrared spectroscopy method. As a result of researching from the set of 600 breeding lines were selected best lines with increased grain yield from 1 m2, with high protein content in grain, disease resistance, and winter hardiness significantly exceeded the standard variety Polesskaya-90. All lines have high and moderate resistance against diseases: Powdery Mildew, Brown Rust, Septoria Blotch. Based on obtained data had selected breeding lines, which were promising sources of single and complex agronomically valuable traits for bread wheat breeding and genetic researches.

Quo vadis wheat breeding: a case study in Central Europe

Bread wheat (Triticum aestivum) is one of the most important crop species. It has been further developed since its initial domestication, with significant acceleration of wheat breeding within the last 100 years. In this study, a set of 355 wheat accessions were selected to document the history of bread wheat breeding in Central Europe. Although six periods of breeding were assumed, a notable turning point was identified between periods 3 and 4 around the year 1970 based on phenotype and genotype data, dividing the more than 100 years of bread wheat breeding into only two periods. While the first period corresponded to the use of landraces and genetically diverse varieties for breeding, the second period was typically characterized by reliance on relatively few varieties, leading to modern varieties with very good yields and high resistance to lodging and powdery mildew. A drawback of these breeding programmes was a substantial reduction in genetic diversity. The analysis of population structure showed that genetic diversity is influenced more by pedigree than by the period of breeding. In total, five genetic populations were identified, corresponding (especially within the last 50 years) to the leading genotypes used in breeding programmes: Bankuti 1205, Mironovskaja 808 and Moisson. A high level of correlation was found between the genotype and phenotype data (R = 0.91; p < 0.01). The results of this study indicated the need to broaden the genetic diversity of bread wheat by including landraces and possibly wild relatives of crops in new breeding or prebreeding programmes.

Multi-Locus GWAS of Quality Traits in Bread Wheat: Mining More Candidate Genes and Possible Regulatory Network.

In wheat breeding, improved quality traits, including grain quality and dough rheological properties, have long been a critical goal. To understand the genetic basis of key quality traits of wheat, two single-locus and five multi-locus GWAS models were performed for six grain quality traits and three dough rheological properties based on 19, 254 SNPs in 267 bread wheat accessions. As a result, 299 quantitative trait nucleotides (QTNs) within 105 regions were identified to be associated with these quality traits in four environments. Of which, 40 core QTN regions were stably detected in at least three environments, 19 of which were novel. Compared with the previous studies, these novel QTN regions explained smaller phenotypic variation, which verified the advantages of the multi-locus GWAS models in detecting important small effect QTNs associated with complex traits. After characterization of the function and expression in-depth, 67 core candidate genes involved in protein/sugar synthesis, histone modification and the regulation of transcription factor were observed to be associated with the formation of grain quality, which showed that multi-level regulations influenced wheat grain quality. Finally, a preliminary network of gene regulation that may affect wheat quality formation was inferred. This study verified the power and reliability of multi-locus GWAS methods in wheat quality trait research, and increased the understanding of wheat quality formation mechanisms. The detected QTN regions and candidate genes in this study could be further used for gene cloning and marker-assisted selection in high-quality breeding of bread wheat.

The Variability of Puroindoline-Encoding Alleles and Their Influence on Grain Hardness in Modern Wheat Cultivars Cultivated in Poland, Breeding Lines and Polish Old Landraces (Triticum aestivum L.)

Wheat (Triticum aestivum L.) grain hardness is determined mainly by variations in puroindoline genes (Pina-D1 and Pinb-D1), which are located on the short arm of chromosome 5D. This trait has a direct effect on the technological properties of the flour and the final product quality. The objective of the study was to analyze the mutation frequency in both Pin genes and their influence on grain hardness in 118 modern bread wheat cultivars and breeding lines cultivated in Poland, and 80 landraces from Poland. The PCR products containing the Pin gene coding sequences were sequenced by the Sanger method. Based on detected the SNPs (single-nucleotide polymorphisms) we designed CAPS (cleaved amplified polymorphic sequence) markers for the fast screening of Pinb alleles in a large number of genotypes. All analyzed cultivars, breeding lines, and landraces possess the wild-type Pina-D1a allele. Allelic variation was observed within the Pinb gene. The most frequently occurring allele in modern wheat cultivars and breeding lines (over 50%) was Pinb-D1b. The contribution of the remaining alleles (Pinb-D1a, Pinb-D1c, and Pinb-D1d) was much less (approx. 15% each). In landraces, the most frequent allele was Pinb-D1a (over 70%), followed by Pinb-D1b (21% frequency). Pinb-D1c and Pinb-D1g were found in individual varieties. SKCS (single-kernel characterization system) analysis revealed that grain hardness was strictly connected with Pinb gene allelic variation in most tested cultivars. The mean grain hardness values were significantly greater in cultivars with mutant Pinb variants as compared to those with the wild-type Pinb-D1a allele. Based on grain hardness measured by SKCS, we classified the analyzed cultivars and lines into different classes according to a previously proposed classification system.

An Analysis of the Genetic Diversity of Bread Wheat x Spelt Breeding Lines in Terms of Their Resistance to Powdery Mildew and Leaf Rust

The main aim of this study was to analyze the genetic diversity of breeding lines derived from bread wheat and spelt (bread wheat cvs. Zebra, Torka and Kontesa; spelt breeding lines S10–S14) in terms of their resistance to infections caused by Blumeria graminis f. sp. tritici and Puccinia triticina Eriks. The genomes of all analyzed lines harbored the markers for Pm2a, Pm4b and Pm6a alleles, which confer resistance to the infection caused by B. graminis f. sp. tritici. The markers for Pm4c and Pm4a alleles were also identified in many objects. The high number of Pm markers was noted in the crosses Zebra × S11 and Zebra × S12 whose genomes harbored the markers for Pm2a, Pm3d, Pm4a-4c and Pm6. Most of the studied lines harbored the marker linked to the Lr10 gene, which encodes resistance to the infection caused by P. triticina in wheat. The analysis of the presence of markers linked to the resistance to infections caused by B. graminis f. sp. tritici and P. triticina demonstrated that Zebra × S12 was the most promising breeding line with the highest number of markers for genes/alleles encoding resistance to powdery mildew and leaf rust. This breeding line was also highly resistant to both pathogens under field conditions.

Evaluation of yield and quality performance of some spring bread wheat (Triticum aestivum L.) genotypes under rainfall conditions

The study was conducted in randomized complete block design with four replications at two locations (Sanliurfa and Diyarbakir) under rainfall conditions during 2013-2014 growing season. The purpose of the study is to determine the bread wheat genotypes with high yield, large adaptation ability and high grain quality. Twenty advanced bread wheat lines and five check varieties were used as material. The data were evaluated by using variance and GGE-biplot analysis methods. Significant differences among genotypes were determined for test weight (TW), thousand grain weight (TGW), grain yield (GY) and heading time (HT) at the significant level of 1%, while, less significant levels (p&amp;lt;5%) were found for wet gluten content (WG), zeleny sedimentation (ZS) and protein content (PR). According to GGE-biplot analysis results, positive correlations were determined between TW and TGW, and also PR, WG and ZS. It has also been determined that there is a negative relationship between HT and TW, TGW. According to the stability graph, the genotypes of G23 and G8 were found to be highly efficient and moderately stable and both could be candidate varieties. Additionally, Dinç variety and G11 advanced line can be used as genitor in bread wheat breeding programs for grain yield and quality.

Designing Innovative Management for Cultivated Biodiversity: Lessons from a Pioneering Collaboration between French Farmers, Facilitators and Researchers around Participatory Bread Wheat Breeding

The industrialization of farming has significantly threatened cultivated biodiversity. Participatory breeding endeavours to overcome this issue by enabling farmers to select a wide range of crop varieties in different conditions, and to foster genetic mixing through seed exchanges, crosses or mixtures. This necessitates the design of new forms of coordination and organization for the farmers and partners involved. This article reports on an ongoing initiative, aiming to facilitate the participatory design of such forms of coordination and organization. It first outlines the method used (Knowledge–Concept–Proposals or KCP), and how it has been tailored to this highly decentralized context involving politically engaged actors on a quest for autonomy. It then presents the exploratory results of the first two workshops: these include group consolidation, the sharing of heterogeneous knowledge, the generation of innovative ideas, and the elaboration of preliminary projects. Finally, this empirical case is compared with other initiatives supporting the participatory design of natural resource management strategies and tools. Its key original dimensions and benefits are that the workshop protocol is replicable, the data produced can be easily exploited, and it allows for testing hypotheses in the field of design science.