Bread Wheat Yield Research Articles

Foliar application of chlormequat chloride improves lodging resistance and grain yield in bread wheat

Foliar application of chlormequat chloride improves lodging resistance and grain yield in bread wheat

A Study on the Allelopathic Effects of Wild Barley (Hordeum spontaneum) Residue Incorporated with Soil on Growth of Some Plant species

This study examines the allelopathic effects of wild barley (Hordeum spontaneum) on the growth and yield of bread wheat (Triticum aestivum), barley (Hordeum vulgare), and wild barley (Hordeum spontaneum). The experiment was conducted in a greenhouse at Shamamar-Hawler/ Kurdistan Region of Iraq using a complete randomized factorial design (CRD) within 3 replications. The roots, shoots, and seeds of wild barley were dried, powdered, and added to the soil at different concentrations (0%, 10%, 20%, 30%, and 40%) in 500 g pots. Each pot was planted with 5 seeds, which were later reduced to 3 seedlings. Growth parameters such as shoot and root lengths, dry weights, number of tillers, weight of spikes, seeds number per plant, and biological yield was measured. The results indicated significant effects of wild barley residues on the studied crops. Wheat showed the highest roots, shoots and total lengths were (29.56 cm, 17.05 cm and 46.58 cm, respectively) and the highest shoots and roots dry weights were (0.24 g and 0.30 g). Barley showed the highest number of stems (1.96) but the lowest shoots and dry weights of roots were (0.11 g and 0.23 g). Wild barley had the highest biological weight and harvest index (HI). Among the plant parts, seed extracts significantly enhanced growth parameters, while roots and shoots extract had the greatest inhibitory effects as wild barley residue concentrations increased. Nevertheless, the HI showed a decline as the concentrations increased, suggesting a detrimental effect on growth efficiency. The study shows the potential of wild barley as a bio-herbicide, emphasizing its allelopathic effects. This suggests that agricultural practices should be carefully considered to maximize the efficiency of crops. Incorporating these results into precision agriculture can greatly improve crop management and increase yield.

Estimation of Genetic Parameters in Bread Wheat (Triticum aestivum L.) Genotypes Evaluated Under High Temperature Yield Trial in Ethiopia

The study was carried out to estimate genetic parameters of 49 bread wheat genotypes and standard check evaluated at Kulumsa and Melkasa using alpha lattice design with two replications. The analysis of variance result showed highly significant differences among the genotypes for all traits (P< 0.001), implying the presence of considerable genetic variability for these traits. Out of 50 genotypes, four genotypes such as EBW2113062, EBW2113039, EBW2113037 and EBW2113056 were the top yielding genotypes across the locations. Furthermore, 30 of the 50 genotypes gave grain yield above grand mean whereas 14 genotypes had grain yield above the check, Dursa(1295.05kg/ha). In the other word, about 60% of genotypes were with mean grain yield above the overall mean and 30% of them provided mean grain yield above the check, Dursa, variety. High and moderate heritability estimates were found for most of traits showing that the variation observed was mainly under genetic control. The highest PCV and GCV values were observed for grain yield at both locations indicating better opportunity for improvement in this trait via selection. The phenotypic coefficient of variation (PCV) was generally higher than the genotypic coefficient of variation (GCV) for all characters at both locations. The difference between PCV and GCV was large in TKW followed by PHT and Grain yield indicating that these traits are influenced by the environment. However, differences between them were small for most of the traits indicating low effect of environment on the expression of characters at both locations. The genotypic correlations between grain yield with thousand kernel weights and hectoliter weight were highly significant showing their important contribution to grain yield. Therefore, the identified genotypes with better performance could be utilized in advanced bread wheat yield trial targeted for high temperature condition in the country.

Graphical Analysis of Multi-environmental Trials for Bread Wheat (Triticum aestivum L.) Grain Yield Based on GGE Bi-Plot Analysis

Bread wheat (Triticum aestivum L.) is a crucial crop in Ethiopia, and breeders test newly developed elite lines for superiority to existing cultivars to boost national productivity. The study was undertaken during the 2021–22 to 2022–23 cropping seasons at seven environments in optimum moisture areas of Ethiopian using 36 diverse and advanced bread wheat genotypes to evaluate the GEI by the graphical method of GGE biplot and to identify the genotypes with high mean yield performance and stability. Field experiments were conducted at the Adet, Asasa, Kulumsa, and Sinana research centers in Ethiopia. The experiments were planted in an alpha lattice design replicated three times in six rows of 2.5m long. Row-to-row distance and distance between blocks were 0.2m and 1.5m, respectively. The analysis of variance revealed that genotype, environment, and their interaction showed a highly significant effect on the yield as reflected in the GGE model and the GGE model indicated the suitability of the genotypes EBW202136 (33), Boru (1), and EBW202172 (12), with high mean yield and stability, whereas the genotypes EBW202185 (16) and Deka (36) produced high mean yield, but unstable. Likewise, the genotypes EBW202164 (27) and EBW202192 (29) produced low mean yield and unstable. The AMMI analysis of variance for grain yield across the environments showed that 17.26% of the total variation was attributed to genotypic effects, 64.03% to environmental effects, and 18.71% to GEI effects. Two mega environments were identified based on GGE biplot analysis and the which-won–model indicated the adaptation of genotypes Boru (1), EBW202159 (4), EBW202172 (12), EBW202171 (19), and EBW202136 (33) to first mega-environment and genotypes EBW202157 (3), EBW202166 (5), EBW202160 (6), EBW202162 (9), EBW202185 (16), Dursa (17) and Deka (36) in the second. These approaches allowed the identification of stable and high-yielding genotypes (EBW202136 (33) and EBW202172 (12)) which can be included in the national verification program, with a plan to release a new variety, and other genotypes with high yield could be utilized in breeding programs to further improve grain yield in bread wheat.

Developing early-estimating normalized difference vegetation index calibrations for grain yield and technological quality of bread wheat in semi-arid rainfed conditions

In this study, the usability of in-season estimated yield (INSEY) and optical-read sensor Normalized Difference Vegetation Index (NDVI) at the Zadoks30 stage (Z 30) in rainfed conditions for predicting bread wheat grain yield and technological quality was evaluated. Data from nitrogen fertilizer application field trials conducted in eight consecutive years in 14 environments were used to develop regression equations to predict yield and some quality attributes in rainfed conditions. The trials were divided into two groups, low NDVI (LNE) and high NDVI (HNE), according to the magnitude of NDVI. Technological bread quality parameters and yield were higher in the HNE. The increase in grain protein content (GPC) and macro SDS (MSDS) sedimentation against nitrogen rates became significant beyond 60 kg N ha−1 in the LNE and 30 kg N ha−1 in the HNE. Linear relationships occurred between NDVI and observed values of grain yield (R2 = 0.743, p<0.001) and GPC (R2 = 0.963, p<0.001). The use of NDVI and INSEY values at Z 30 stage facilitated the development of equations capable of predicting grain yield, GPC, and gluten quality. The developed equations can be used in the nitrogen fertilization strategy during the tillering stage to achieve specific yield and protein.

Optimizing inorganic blended fertilizer application for the maximum grain yield and profitability of bread wheat and food barley in Dawuro Zone, Southwest Ethiopia

Abstract In a specific area, fertilizer application for a crop depends on the soil type and profitability. Optimizing chemical fertilizer utilization in crop production is crucial from an environmental and economic point of view. However, there is limited information available on the optimum NPSB fertilizer rate for the production of wheat and barley in the study area. Thus, the study aimed to establish area-specific NPSB (18.9% N, 16.44% P, 6.95% S, and 0.1% B) blended fertilizer rate recommendations for the optimal grain yield and profitability of wheat and barley. The field experiment was conducted in two locations in the 2021 and 2022 cropping seasons using a randomized complete block design with three replications. The nine treatments included 0, 25, 50, 75, 100, 125, 150, 175, and 200 kg ha−1 NPSB fertilizer rates. Growth, yield, and yield component data in wheat and barley were collected from randomly selected individual plants and the net plot area. An economic analysis was conducted for grain yield using the procedure established by the International Maize and Wheat Improvement Center. The analysis of variance results showed that blended fertilizer significantly (p &lt; 0.01) affected plant height, number of productive tillers, spike length, number of kernels, thousand seed weight, biomass yield, grain yield, and harvest index traits. The application of a 150 kg ha−1 NPSB rate produced the highest grain yield (5419.0 kg ha−1) in wheat, whereas the application of a 125 kg ha−1 NPSB rate gave the maximum grain yield (4708.0 kg ha−1) in food barley. The economic analysis revealed that the application of a 150 kg ha−1 NPSB fertilizer rate for wheat gave the highest net benefits (309711.50 ETB ha−1) and marginal rate of return (MRR) (4096.96%), while the application of a 125 kg ha−1 NPSB fertilizer rate for barley obtained the highest net benefits (184424.00 ETB ha−1) and MRR (2195.39%). Therefore, to optimize the productivity and profitability of wheat and barley in the study area and similar agroecologies, farmers are recommended to use 150 kg ha⁻¹ NPSB for wheat and 125 kg ha⁻¹ NPSB for barley.

Determining Optimal Nitrogen Level and Soil test-based Phosphorus Calibration study for Bread Wheat (Triticum aestivum L.) in Dugda District, East Shewa Zone, Oromia, Ethiopia

Nutrient mining due to sub-optimal fertilizer use on one hand and unbalanced fertilizer use on the other have favored the emergence of multi-nutrient deficiency in Ethiopian soils. Therefore, the study was conducted on twenty-six farmers' fields in Dugda District of East Shewa Zone of Oromia, during the main cropping seasons of 2018-2020. These studies were conducted to determine the economically optimum rate of nitrogen fertilizer in the first year Phosphorus critical (Pc) and phosphorus requirement factor (Pf) in the second year respectively. The treatments consisted of factorial combinations of three levels of TSP (0, 100, and 200) kg ha-1 with six levels of nitrogen (0, 23, 46, 69 92, and 115) kg ha-1 that gave a total of eighteen treatments. However, in the second two consecutive years, the experiment was conducted to determine phosphorus critical (Pc) and phosphorus requirement factor (Pf), and the treatments consisted of six levels of phosphorus (0, 10, 20, 30, 40, and 50) kg ha-1 combined with a single level of nitrogen (69 kg ha-1) that gave a total of seven treatments. The experiments were laid out in randomized complete block design (RCBD) with two replications and the gross plot size was 4 m x 5 m (20 m2) were used to determine optimum nitrogen in the first year and 4m x 5m (20 m2) and phosphorus critical (Pc) and also harvested from 4m2 plot areas. The analysis of variance indicated that Plant height, spike length, number of seeds per spike, biomass yield, and grain yield were highly significantly (p &lt;0.01) influenced by the main effect of nitrogen fertilizer rates. However except for the number of seed per spike, TSP fertilizer significantly (p&lt;0.05) affect plant height and the number of seed per spike as well as highly significantly (p &lt;0.01) biomass and grain yield of bread wheat. The highest (68.76 cm) plant height, the highest (41.02) seed per spike, the highest (8867 kg ha-1) biomass, and the highest (3293 kg ha-1) grain yield were recorded by 200

Impact of Combining Mineral and Biofertilizers on Bread Wheat (Triticum aestivum vulgare L.) Yield and its Economic Viability

Impact of Combining Mineral and Biofertilizers on Bread Wheat (Triticum aestivum vulgare L.) Yield and its Economic Viability

Effect of Nitrogen Fertilizer and Seed rates on Yield and Yield Components of Bread Wheat in the Irrigated Condition of South West Shewa, Central Highland of Ethiopia

Inappropriate seed density and fertilizer management can lead to unstable crop yields. Excessive fertilizer application can potentially cause yield loss and nitrogen (N) leaching that leads to environmental pollution. The aim of this study was to explore the optimal N application rate and seed rate on bread wheat with different nitrogen responding under irrigation condition at two experimental sites in the South West Shewa, Ethiopia. A year field experiment was conducted to explore the effects of five N application rates (N0, N23, N46, N69, and N92) and three seed rates on bread wheat yield components like; - aboveground biomass, harvest index, number of tillers per plant, spike length, number of kernels per plant, grain yield and net return. The results showed that N application rate and seed rate were significantly interaction (P&amp;lt; 0.05) effect on aboveground biomass, harvest index, number of tillers per plant, spike length, number of kernels per plant and grain yield. Generally, spike length, number of tillers per plant and number of kernels per spike of wheat were increased with increased at some level in nitrogen fertilizer rate for the three seed rate at both locations. Highest number of kernels per spike (42.00, 44.00) and the highest mean above ground biomass yield (13.70 t ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;, 7.5 t ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;) were obtained for 150 kg ha &amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; seed rate with 69 N kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; application at Ameya and Woliso sites respectively. The highest net benefit of 171531.88 EB ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; with marginal rate of return of 351.14% was obtained from 175 kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; seed rate with application of 69 kg N ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt;. Therefore, 175 kg ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; seed rate with application of 69 kg N ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; is economical feasible for bread wheat production at Ameya area and also the highest net benefit of 51675 EB ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; with marginal rate of return of 115.22% was obtained from 150 kg ha &amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; seed rate with application of 69 kg N ha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; at Woliso area.

Mitigation of the Negative Effect of Drought and Herbicide Treatment on Growth, Yield, and Stress Markers in Bread Wheat as a Result of the Use of the Plant Growth Regulator Azolen®.

Most chemical pesticides, in addition to their main functions (protection against diseases, weeds, and pests), also have a noticeable inhibitory effect on target crops. In a laboratory experiment and two-year field experiments (Russia, Trans-Urals), a study was made of the effect of the biopreparation Azolen® (Azotobacter vinelandii IB-4) on plants of the Ekada 113 wheat variety under conditions of drought and stress caused by the exposure to the herbicide Chistalan (2.4-D and dicamba). The biopreparation and the herbicide were used separately and together on wheat during the tillering phase. Treatment with the biological preparation under stressful conditions had a significant effect on the hormonal balance of plants (a decrease in the amount of abscisic acid and a normalization of the balance of indolyl-3-acetic acid and cytokinins in shoots and roots of plants was noted), while the osmoprotective, antioxidant, and photosynthetic systems of plants were activated. In drought conditions, the treatment of plants with biological preparation prevented the inhibition of root growth caused by the use of the herbicide. This, in turn, improved the absorption of water by plants and ensured an increase in wheat yield (1.6 times). The results obtained give reason to believe that microbiological preparations can be used as antidotes that weaken the phytotoxic effect of herbicidal treatments, including in drought conditions.

Identification, validation and candidate gene analysis of major QTL for Supernumerary spikelets in wheat

BackgroundThe number of spikelets per spike is a key trait that affects the yield of bread wheat (Triticum aestivum L.). Identification of the QTL for spikelets per spike and its genetic effects that could be used in molecular assistant breeding in the future.ResultsIn this study, four recombinant inbred line (RIL) populations were generated and used, having YuPi branching wheat (YP), with Supernumerary Spikelets (SS) phenotype, as a common parent. QTL (QSS.sicau-2 A and QSS.sicau-2D) related to SS trait were mapped on chromosomes 2 A and 2D through bulked segregant exome sequencing (BSE-Seq). Fourteen molecular markers were further developed within the localization interval, and QSS.sicau-2 A was narrowed to 3.0 cM covering 7.6 Mb physical region of the reference genome, explaining 13.7 − 15.9% the phenotypic variance. Similarly, the QSS.sicau-2D was narrowed to 1.8 cM covering 2.4 Mb physical region of the reference genome, and it explained 27.4 − 32.9% the phenotypic variance. These two QTL were validated in three different genetic backgrounds using the linked markers. QSS.sicau-2 A was identified as WFZP-A, and QSS.sicau-2D was identified a novel locus, different to the previously identified WFZP-D. Based on the gene expression patterns, gene annotation and sequence analysis, TraesCS2D03G0260700 was predicted to be a potential candidate gene for QSS.sicau-2D.ConclusionTwo significant QTL for SS, namely QSS.sicau-2 A and QSS.sicau-2D were identified in multiple environments were identified and their effect in diverse genetic populations was assessed. QSS.sicau-2D is a novel QTL associated with the SS trait, with TraesCS2D03G0260700 predicted as its candidate gene.

Assessment of Genetic Variability for Physiological Traits and Yield in Bread Wheat (Triticum aestivum L. em. Thell.)

Assessment of Genetic Variability for Physiological Traits and Yield in Bread Wheat (Triticum aestivum L. em. Thell.)

Genotype-by-environment interaction and stability analysis of grain yield of bread wheat (Triticum aestivum L.) genotypes using AMMI and GGE biplot analyses

Bread wheat is a vital staple crop worldwide; including in Ethiopia, but its production is prone to various environmental constraints and yield reduction associated with adaptation. To identify adaptable genotypes, a total of 12 bread wheat genotypes (G1 to G12) were evaluated for their genotype-environment interaction (GEI) and stability across three different environments for two years using Additive Main Effect and Multiplicative Interaction (AMMI) and genotype main effect plus genotype-by-environment interaction (GGE) biplots analysis. GEI is a common phenomenon in crop improvement and is of significant importance in genotype assessment and recommendation. According to combined analysis of variance, grain yield was considerably impacted by environments, genotypes, and GEI. AMMI and GGE biplots analysis also provided insights into the performance and stability of the genotypes across diverse environmental conditions. Among the 12 genotypes, G6 was selected by AMMI biplot analysis as adaptive and high-yielding genotype; G5 and G7 demonstrated high stability and minimal interaction with the environment, as evidenced by their IPCA1 values. G7 was identified as the most stable and high-yielding genotype. The GGE biplot's polygon view revealed that the highest grain yield was obtained from G6 in environment three (E3). E3 was selected as the ideal environment by the GGE biplot. The top three stable genotypes identified by AMMI stability value (ASV) were G5, G7, and G10, while the most stable genotype determined by Genotype Selection Index (GSI) was G7. Even though G6 was a high yielder, it was found to be unstable according to ASV and ranked third in stability according to GSI. Based on the study's findings, the GGE biplot genotype view for grain yield identified Tay genotype (G6) to be the most ideal genotype due to its high grain yield and stability in diverse environments. G7 showed similar characteristics and was also stable. These findings provide valuable insights to breeders and researchers for selecting high-yielding and stable, as well as high-yielding specifically adapted genotypes.

Impact of brewery sludge application on heavy metal build-up, translocation, growth and yield of bread wheat (Triticum aestivum L.) crop in Northern Ethiopia

In a field study, the impact of different levels of brewery sludge (BS) enrichment on Triticum aestivum L. (wheat plants) was examined in terms of growth, yield, heavy metal absorption, and potential health risks linked to plant consumption. Using a randomized complete block design with seven treatments and three blocks, the study showed that applying up to 12 t ha−1 brewery sludge significantly improved all agronomic parameters (except harvest index) compared to control and mineral-fertilized soil. Heavy metal translocation was generally low, except for Cu and Pb. The sequence of heavy metal translocation was Cu > Pb > Cd > Ni > Zn > Mn > Cr from soil to spikes and Cu > Zn > Mn > Pb > Ni > Cd > Cr from soil to grain. Heavy metal loads were mostly higher in roots than in the above-ground crop parts. The target hazard quotient (THQ), hazard index (HI), and target cancer risk (TCR) within wheat grain remained within safe limits for all BS treatments. Consequently, consuming this wheat grain is considered safe regarding heavy metals. Thus, utilizing brewery sludge at 12 t ha−1 as a fertilizer for wheat production and as an alternative method for sludge disposal is plausible.

Identifying limiting nutrient(s) for better bread wheat and tef productivity in acidic soils of north‐west Amhara, Ethiopia

AbstractFood crop productivity is still low because of the decline of soil fertility in Ethiopia, particularly in north‐western Amhara. Fine‐tuning the source and rate of nutrients is required to solve soil fertility problems along landscape positions. Therefore, this study was initiated to investigate the need to apply selected nutrients to tef and wheat in acidic soils. This nutrient omission study was conducted in 74 farmers’ fields of Gozamen and Machakel districts. The omitted nutrients were sulfur (S), zinc (Zn), and boron (B). Potassium (K) was added, consisting of N, P, K, S, Zn, and B (All+K). Nitrogen plus phosphorus (NP) and no fertilizer treatments were used as positive and negative controls, respectively. Furthermore, 50% and 150% of the All+K treatments were also included. The finding revealed that the application of different nutrient types at variable rates had a significant role in the grain and biomass yield of both test crops in the acidic soils. No tef yield and the lowest yield of bread wheat were obtained from the no fertilizer application treatment. The application of All+K had no significant yield advantage compared to NP fertilizer alone. This implies that N and P are the most yield‐limiting nutrients to produce tef and bread wheat, whereas KSZnB nutrients are not yield limiting. Therefore, refining the rates of N and P in acidic soils is needed for the economical use of fertilizers. Finally, applying blended fertilizers without empirical evidence is not recommended for smallholder farmers in the study area.

Elevated CO2 improves grain yield in bread wheat by enhancing carbon assimilation, activities of carbohydrate metabolic and antixidant enzymes

This study aimed to explore the effects of elevated CO2 (e[CO2]) on wheat performance under drought stress, while investigating the role of eco-physiology, carbohydrate metabolic and antioxidant enzymes to predict the grain yield. Wheat genotype Lianmai6 was grown under ambient (400 ppm) and elevated (800 ppm) CO2 concentrations, with subsequent exposure to drought stress prior to anthesis. Leaf parameters, including photosynthetic rate (An), stomatal conductance (Gs), and transpiration rate (E), were significantly declined under drought. Grain yield parameters were adversely affected by drought stress, while An with water use efficiency (WUE) and yield traits increased under e[CO2]. Notably, the activities of certain carbohydrate metabolic enzymes were increased in sink tissues but reduced significantly in source tissues under drought conditions. However, activities phosphoglucomutase (PGM and phophoglucoisomerase (PGI) were increased in source tissues under the combined effect of drought and e[CO2]. Total antioxidant potential (TAP) decreased in both leaf and spike under drought conditions, yet increased significantly under e[CO2]. These findings suggest that e[CO2] can enhance CO2 assimilation by boosting antioxidant potential and facilitate increased supply of photosynthates through enhanced activities of various carbohydrate metabolic enzymes, ultimately the better grain yield. These findings could elucidate the partial mechanism of better grain yield in bread wheat under combined effect of e[CO2] and drought stress.

Recessive Winter Growth Habit Allele on 5B Chromosome, vrn-B1, Improves Earliness and Grain Yield of Bread Wheat

Recessive Winter Growth Habit Allele on 5B Chromosome, vrn-B1, Improves Earliness and Grain Yield of Bread Wheat

Correlation and Path Coefficient Analyses for Grain Yield and Its Contributing Traits in Bread Wheat (Triticum aestivum L. em. Thell)

The study on bread wheat for fourteen characters viz., days to heading (50%), days to maturity, plant height (cm), number of productive tillers per plant, chlorophyll content , spike length (cm), number of spikelets per spike, number of grains per spike, weight of grain per spike(g), 1000 grain weight (g), biological yield (g), harvest index (%),protein content (%) and grain yield per plant (g) was conducted by making crosses among ten diverse genotypes in half diallel fashion grown in Randomized Block Design in three replication during Rabi 2022-2023 at SIF, C. S. Azad University of Agriculture &amp; Technology, Kanpur, U.P. to assess the correlation and path coefficient. At genotypic level grain yield per plant showed positive and significant correlation with biological yieldper plant followed by number f productive tillers per plant, weight of grain per spike, harvest index, 1000 grain weight, chlorophyll content and days to maturity. In F2 generation correlation coefficients at genotypic level higher than the corresponding phenotype correlation coefficient for all characters and eight characters viz., biologic yield per plant, weight of grain per spike, number of productive tillers per plant, harvest index, 1000 grain weight, days to maturity, protein content and number of grain per spike showed positive and significant correlation with grain yield per plant. At genotypic level the highest positive direct effect on grain yield per plant was exerted by biological yield per plant followed by harvest index, number of spikelets per spike, spike length, days to 50% heading, 1000 grain weight, number of productive tiller per plant, weight of grain per spike, chlorophyll content and protein content in F1s.At phenotypic level the highest positive direct effect on grain yield per plant was exerted by biological yield per plant followed by harvest index, spike length, days to maturity, number of productive tiller per plant, weight of grain per spike, chlorophyll contend and protein content in F2s. Hence these characters may be considered for selection and improvement of grain yield in bread wheat.

Dissecting the molecular basis of spike traits by integrating gene regulatory networks and genetic variation in wheat

Spike architecture influences both grain weight and grain number per spike, which are the two major components of grain yield in bread wheat (Triticum aestivum L.). However, the complex wheat genome and the influence of various environmental factors pose challenges in mapping the causal genes that affect spike traits. Here, we systematically identified genes involved in spike trait formation by integrating information on genomic variation and gene regulatory networks controlling young spike development in wheat. We identified 170 loci that are responsible for variations in spike length, spikelet number per spike, and grain number per spike through genome-wide association study and meta-QTL analyses. We constructed gene regulatory networks for young inflorescences at the double ridge stage and the floret primordium stage, in which the spikelet meristem and the floret meristem are predominant, respectively, by integrating transcriptome, histone modification, chromatin accessibility, eQTL, and protein–protein interactome data. From these networks, we identified 169 hub genes located in 76 of the 170 QTL regions whose polymorphisms are significantly associated with variation in spike traits. The functions of TaZF-B1, VRT-B2, and TaSPL15-A/D in establishment of wheat spike architecture were verified. This study provides valuable molecular resources for understanding spike traits and demonstrates that combining genetic analysis and developmental regulatory networks is a robust approach for dissection of complex traits.

Investigation of Grain Yield and Biscuit Quality Capacities of Soft Bread Wheat (T. aestivum L.) Advanced Lines

The study was carried out with a total of 24 bread wheat genotypes including 20 advanced lines and 4 check varieties (Gerek79, Carisma, Bayraktar2000, and Artico) with soft grain structure and four replications according to the randomized complete block design in Hamidiye and Karabayır locations of Eskişehir during the 2014-2015 growing season. In the study, grain yield, thousand grain weight, test weight, kernel hardness, Zeleny sedimentation value, ash content and protein content were investigated in the genotypes. According to the results of the analysis of variance performed for the traits examined in the study, the differences between location, bread wheat genotypes and interaction averages were found to be statistically significant, except for Zeleny sedimentation value and protein content, respectively. It is understood that there is a wide variation between genotypes and locations for other traits, except for the protein ratio trait. While location effects are higher than genotype effects for thousand grain weight, test weight, ash content and protein content, genotype effects are higher than location for single kernel characterization system and Zeleny sedimentation value. The mean grain yield of biscuit wheat genotypes ranged from 4425 kg ha-1 to 2000 kg ha-1. Considering the trial quality results; it was observed that there was a high rate of variation between genotypes for thousand grain weight (32.67-48.61 g), test weight (82.40-75.25 kg hl-1), kernel hardness (17.08-39.68), Zeleny sedimentation value (20.63-33.00 ml) and ash content (0.478% - 0.610%), respectively. While BİS-3, BİS-6, BİS-9, BİS-18, BİS-21 and BİS-22 were best-performed lines for grain yield, BİS-3, BİS-9, BİS-11, BİS-12, BİS-13 and BİS-19 were the prominent lines for biscuit-making quality trait. It was concluded that it would be appropriate to include these lines in yield trials before registration as a variety of candidates.