Genetic control and prospects of predictive breeding for European winter wheat's Zeleny sedimentation values and Hagberg-Perten falling number

Sedimentation values and falling number in the last decades have helped maintain high baking quality despite rigorous selection for grain yield in wheat. Allelic combinations of major loci sustained the bread-making quality while improving grain yield. Glu-D1, Pinb-D1, and non-gluten proteins are associated with sedimentation values and falling number in European wheat. Zeleny sedimentation values (ZSV) and Hagberg-Perten falling number (HFN) are among the most important parameters that help determine the baking quality classes of wheat and, thus, influence the monetary benefits for growers. We used a published data set of 372 European wheat varieties evaluated in replicated field trials in multiple environments. ZSV and HFN traits hold a wide and significant genotypic variation and high broad-sense heritability. The genetic correlations revealed positive and significant associations of ZSV and HFN with each other, grain protein content (GPC) and grain hardness; however, they were all significantly negatively correlated with grain yield. Besides, GPC appeared to be the major predictor for ZSV and HFN. Our genome-wide association analyses based on high-quality SSR, SNP, and candidate gene markers revealed a strong quantitative genetic nature of ZSV and HFN by explaining their total genotypic variance as 41.49% and 38.06%, respectively. The association of known Glutenin (Glu-1) and Puroindoline (Pin-1) with ZSV provided positive analytic proof of our studies. We report novel candidate loci associated with globulins and albumins-the non-gluten monomeric proteins in wheat. In addition, predictive breeding analyses for ZSV and HFN suggest using genomic selection in the early stages of breeding programs with an average prediction accuracy of 81 and 59%, respectively

Efficiency of a Seedling Phenotyping Strategy to Support European Wheat Breeding Focusing on Leaf Rust Resistance

Leaf rust resistance is of high importance for a sustainable European wheat production. The expression of known resistance genes starts at different developmental stages of wheat. Breeding for resistance can be supported by a fast, precise, and resource-saving phenotyping. The examination of detached leaf assays of juvenile plants inoculated under controlled conditions and phenotyped by a robotic- and computer-based, high-throughput system is a promising approach in this respect. Within this study, the validation of the phenotyping workflow was conducted based on a winter wheat set derived from Central Europe and examined at different plant developmental stages. Moderate Pearson correlations of 0.38–0.45 comparing leaf rust resistance of juvenile and adult plants were calculated and may be mainly due to different environmental conditions. Specially, the infection under controlled conditions was limited by the application of a single rust race at only one time point. Our results suggest that the diversification with respect to the applied rust race spectrum is promising to increase the consistency of detached leaf assays and the transferability of its results to the field

A Haplotype-Based GWAS Identified Trait-Improving QTL Alleles Controlling Agronomic Traits under Contrasting Nitrogen Fertilization Treatments in the MAGIC Wheat Population WM-800

The multi-parent-advanced-generation-intercross (MAGIC) population WM-800 was developed by intercrossing eight modern winter wheat cultivars to enhance the genetic diversity present in breeding populations. We cultivated WM-800 during two seasons in seven environments under two contrasting nitrogen fertilization treatments. WM-800 lines exhibited highly significant differences between treatments, as well as high heritabilities among the seven agronomic traits studied. The highest-yielding WM-line achieved an average yield increase of 4.40 dt/ha (5.2%) compared to the best founder cultivar Tobak. The subsequent genome-wide-association-study (GWAS), which was based on haplotypes, located QTL for seven agronomic traits including grain yield. In total, 40, 51, and 46 QTL were detected under low, high, and across nitrogen treatments, respectively. For example, the effect of QYLD_3A could be associated with the haplotype allele of cultivar Julius increasing yield by an average of 4.47 dt/ha (5.2%). A novel QTL on chromosome 2B exhibited pleiotropic effects, acting simultaneously on three-grain yield components (ears-per-square-meter, grains-per-ear, and thousand-grain-weight) and plant-height. These effects may be explained by a member of the nitrate-transporter-1 (NRT1)/peptide-family, TaNPF5.34, located 1.05 Mb apart. The WM-800 lines and favorable QTL haplotypes, associated with yield improvements, are currently implemented in wheat breeding programs to develop advanced nitrogen-use efficient wheat cultivars

Adaptive selection of founder segments and epistatic control of plant height in the MAGIC winter wheat population WM-800

Abstract Background Multi-parent advanced generation intercross (MAGIC) populations are a newly established tool to dissect quantitative traits. We developed the high resolution MAGIC wheat population WM-800, consisting of 910 F4:6 lines derived from intercrossing eight recently released European winter wheat cultivars. Results Genotyping WM-800 with 7849 SNPs revealed a low mean genetic similarity of 59.7% between MAGIC lines. WM-800 harbours distinct genomic regions exposed to segregation distortion. These are mainly located on chromosomes 2 to 6 of the wheat B genome where founder specific DNA segments were positively or negatively selected. This suggests adaptive selection of individual founder alleles during population development. The application of a genome-wide association study identified 14 quantitative trait loci (QTL) controlling plant height in WM-800, including the known semi-dwarf genes Rht-B1 and Rht-D1 and a potentially novel QTL on chromosome 5A. Additionally, epistatic effects controlled plant height. For example, two loci on chromosomes 2B and 7B gave rise to an additive epistatic effect of 13.7 cm. Conclusion The present study demonstrates that plant height in the MAGIC-WHEAT population WM-800 is mainly determined by large-effect QTL and di-genic epistatic interactions. As a proof of concept, our study confirms that WM-800 is a valuable tool to dissect the genetic architecture of important agronomic traits

Evaluación de los factores socioculturales en el aprendizaje del idioma inglés en los estudiantes del vii ciclo, de educación secundaria, de la Institución Educativa San Cristóbal de Paria Willkawain - Huaraz, 2014

TesisEn la presente investigación se evaluó la relación de los factores socioculturales en el Aprendizaje del inglés en los estudiantes del VII ciclo de educación secundaria, de la Institución Educativa pública "San Cristóbal" de Paria- Huaraz, en el año 2014. El tipo de estudio empleado fue descriptivo, medido por el diseño no experimental transversal. Donde se examina datos obtenidos, en base a la evaluación inferencia! de los estudiantes (34) del 4° año, del nivel secundario, de la Educación Básica Regular. Así, se aplicó la prueba de cuestionario sociocultural y se tomó de referencia las notas de la evaluación final del área de inglés a fin de correlacionar los datos. En la investigación se encontró que: (i) Existe una correlación directa entre los factores socioculturales y el aprendizaje del idioma inglés en los estudiantes de la Institución Educativa "San Cristóbal" de Paria Willkawain - Huaraz (2014); (ii) Existe una correlación directa entre el factor sociocultural afectivo, y expresión y comprensión oral en el aprendizaje del idioma inglés en los estudiantes de referencia; (iii) Se ha demostrado que existe una correlación directa entre el factor sociocultural lingüístico y el aprendizaje del inglés. Y; (iv) Existe una correlación directa entre el factor sociocultural antropológico y la producción de textos dentro del aprendizaje del idioma inglés, en los estudiantes de la Institución Educativa "San Cristóbal" de Paria Willkawain. A partir de los resultados se propone algunas alternativas y políticas sociales dentro del sistema educativo como "la promoción de la Educación Sociocultural Andina

Genome-metabolite associations revealed low heritability, high genetic complexity, and causal relations for leaf metabolites in winter wheat (Triticum aestivum)

We investigated associations between the metabolic phenotype, consisting of quantitative data of 76 metabolites from 135 contrasting winter wheat (Triticum aestivum) lines, and 17 372 single nucleotide polymorphism (SNP) markers. Metabolite profiles were generated from flag leaves of plants from three different environments, with average repeatabilities of 0.5-0.6. The average heritability of 0.25 was unaffected by the heading date. Correlations among metabolites reflected their functional grouping, highlighting the strict coordination of various routes of the citric acid cycle. Genome-wide association studies identified significant associations for six metabolic traits, namely oxalic acid, ornithine, L-arginine, pentose alcohol III, L-tyrosine, and a sugar oligomer (oligo II), with between one and 17 associated SNPs. Notable associations with genes regulating transcription or translation explained between 2.8% and 32.5% of the genotypic variance (pG). Further candidate genes comprised metabolite carriers (pG 32.5-38.1%), regulatory proteins (pG 0.3-11.1%), and metabolic enzymes (pG 2.5-32.5%). The combinatorial use of genomic and metabolic data to construct partially directed networks revealed causal inferences in the correlated metabolite traits and associated SNPs. The evaluated causal relationships will provide a basis for predicting the effects of genetic interferences on groups of correlated metabolic traits, and thus on specific metabolic phenotypes.</p

Whole Genome Association Mapping of <em>Fusarium</em> Head Blight Resistance in European Winter Wheat (<em>Triticum aestivum</em> L.)

<div><p>A total of 358 recent European winter wheat varieties plus 14 spring wheat varieties were evaluated for resistance to <i>Fusarium</i> head blight (FHB) caused by <i>Fusarium graminearum</i> and <i>Fusarium culmorum</i> in four separate environments. The FHB scores based on FHB incidence (Type I resistance)×FHB severity (Type II resistance) indicated a wide phenotypic variation of the varieties with BLUE (best linear unbiased estimation) values ranging from 0.07 to 33.67. Genotyping with 732 microsatellite markers resulted in 782 loci of which 620 were placed on the ITMI map. The resulting average marker distance of 6.8 cM allowed genome wide association mapping employing a mixed model. Though no clear population structure was discovered, a kinship matrix was used for stratification. A total of 794 significant (−log₁₀(p)-value≥3.0) associations between SSR-loci and environment-specific FHB scores or BLUE values were detected, which included 323 SSR alleles. For FHB incidence and FHB severity a total of 861 and 877 individual marker-trait associations (MTA) were detected, respectively. Associations for both traits co-located with FHB score in most cases. Consistent associations detected in three or more environments were found on all chromosomes except chromosome 6B, and with the highest number of MTA on chromosome 5B. The dependence of the number of favourable and unfavourable alleles within a variety to the respective FHB scores indicated an additive effect of favourable and unfavourable alleles, i.e. genotypes with more favourable or less unfavourable alleles tended to show greater resistance to FHB. Assessment of a marker specific for the dwarfing gene <i>Rht-D1</i> resulted in strong effects. The results provide a prerequisite for designing genome wide breeding strategies for FHB resistance.</p> </div

Additional file 1 of Adaptive selection of founder segments and epistatic control of plant height in the MAGIC winter wheat population WM-800

Table S1. SNP genotypes, plant height, QTL detection rate and genotype and allele frequencies for 910 MAGIC WHEAT lines and eight founders. Table S2. Plant height (cm) raw data for MAGIC WM-lines and founders for year 2015 and 2016. Table S3. Distribution of polymorphic SNPs within WM-800 according to genome positions of Wang et al.... [36]. Table S4. Mean, minimum, maximum and coefficient of variation (CV, in %) of linkage disequilibrium (r2) in WM-800, calculated per chromosome, subgenome and across the whole wheat genome. Table S5. Genetic similarity (GS) between founders and WM-800 lines based on 7849 polymorphic SNPs. Table S6. Principle Component Analysis (PCO) based on genetic similarities (GS) between founders and WM-800 lines. Table S7. Distribution of segregation distortion (SD) SNPs and segregation distortion regions (SDR) across the wheat genome and across allele frequency groups. Table S8. Selection of unique SNPs from AFG 1 and AFG 7 in WM-800. Major selection events, represented by > 10 SNPs, are indicated in bold. (XLSX 6618 kb