Yield Traits In Wheat Research Articles

Wheat Developmental Traits as Affected by the Interaction between Eps-7D and Temperature under Contrasting Photoperiods with Insensitive Ppd-D1 Background

Earliness per se (Eps) genes are important to fine tune adaptation, and studying their probable pleiotropic effect on wheat yield traits is worthwhile. In addition, it has been shown that some Eps genes interact with temperature and therefore determining the likely Eps × temperature interaction is needed for each newly identified Eps gene. We studied two NILs differing in the newly identified Eps-7D (carrying insensitive Ppd-D1 in the background) under three temperature regimes (9, 15 and 18 °C) and two photoperiods (12 and 24 h). Eps-7D affected time to anthesis as expected and the Eps-7D-late allele extended both the period before and after terminal spikelet. The interaction effect of Eps-7D × temperature was significant but not cross-over: the magnitude and level of significance of the difference between NILs with the late or early allele was affected by the growing temperature (i.e., difference was least at 18 °C and largest at 9 °C), and the differences caused due to temperature sensitivity were influenced by photoperiod. The rate of leaf initiation was faster in NIL with Eps-7D-early than with the late allele which compensated for the shorter duration of leaf initiation resulting in similar final leaf number between two NILs. Eps-7D-late consistently increased spike fertility through improving floret primordia survival as a consequence of extending the late reproductive phase.

Genotype × Environment Interaction for Wheat Yield Traits Suitable for Selection in Different Seed Priming Conditions.

Different seed priming treatments are widely used in order to improve the nutritional status of wheat, as well as to improve its grain yield and yield- related traits. The present study aimed to evaluate the impact of seed priming with zinc oxide nanoparticles (ZnO NPs) on the yield related traits, such as, field emergence, plant height, spike length and grain yield per plant of four winter wheat genotypes (Triticum aestivum L.) during two vegetation seasons of 2018/2019 and 2019/2020. The seeds of each wheat genotypes were primed with different concentrations of ZnO NPs (0 mg L−1, 10 mg L−1, 100 mg L−1 and 1000 mg L−1) for 48 h in a dark box by continuous aeration and were sown in soil pots with 60–70% moisture content until full maturity. The additive main effects and multiplicative interaction (AMMI) models were used to study the genotype environment effects. The results indicated that the plants response to ZnO nanoparticles significantly increased all of the observed traits of the wheat, while its maximum rates reduced the traits of the wheat. The AMMI analysis revealed the very complex nature of the variation observed in the trial and showed the significant effect of the G×E interaction, in which the first main component was significant for all components.

Impact of high night temperature stress on different growth stages of wheat

Increasing temperature especially the High night temperature (HNT) is a major constriction for sustaining global food production under changing climate scenario. Recent climate change has resulted into events of abrupt night temperature rise either throughout the crop period or at specific growth stage. Historical temperature observations and model projections have predicted a more pronounced increase in night temperature [minimum temperature (Tmin.)] compared to that of day temperatures [maximum temperature (Tmax.)]. Hence, the present study was carried out to identify the most critical growth stage affected by HNT and their effects on physiological, growth and yield traits of wheat. A unique field-based movable temperature controlling system was designed to enhance the night temperature by 5 °C than ambient temperature. The three critical phenological stages of wheat i.e. at GS 15 (before tillering initiation), GS 45 (booting) and GS 75 (grain filling) of Zadok’s scale were separately subjected to HNT treatment. The results reveals that GS 75 (grain filling) was the most sensitive stage affected by HNT, which has recorded remarkable reduction in grain yield (GY), Harvest Index (HI), Thousand grain weight (TGW) and grain weight per spike (GWPS) compared to control treatment. Pearson correlation analysis showed that breeders can choose lines with higher TGW, GWPS and grain number per spike (GNPS) for obtaining better GY under HNT conditions and vegetative/booting stage HNT in field condition may not attribute for any significant yield loss.

Appraising the Genetic Architecture of Kernel Traits in Hexaploid Wheat Using GWAS.

Kernel morphology is one of the major yield traits of wheat, the genetic architecture of which is always important in crop breeding. In this study, we performed a genome-wide association study (GWAS) to appraise the genetic architecture of the kernel traits of 319 wheat accessions using 22,905 single nucleotide polymorphism (SNP) markers from a wheat 90K SNP array. As a result, 111 and 104 significant SNPs for Kernel traits were detected using four multi-locus GWAS models (mrMLM, FASTmrMLM, FASTmrEMMA, and pLARmEB) and three single-locus models (FarmCPU, MLM, and MLMM), respectively. Among the 111 SNPs detected by the multi-locus models, 24 SNPs were simultaneously detected across multiple models, including seven for kernel length, six for kernel width, six for kernels per spike, and five for thousand kernel weight. Interestingly, the five most stable SNPs (RAC875_29540_391, Kukri_07961_503, tplb0034e07_1581, BS00074341_51, and BobWhite_049_3064) were simultaneously detected by at least three multi-locus models. Integrating these newly developed multi-locus GWAS models to unravel the genetic architecture of kernel traits, the mrMLM approach detected the maximum number of SNPs. Furthermore, a total of 41 putative candidate genes were predicted to likely be involved in the genetic architecture underlining kernel traits. These findings can facilitate a better understanding of the complex genetic mechanisms of kernel traits and may lead to the genetic improvement of grain yield in wheat.

Effects of high temperature stress during anthesis and grain filling periods on photosynthesis, lipids and grain yield in wheat

BackgroundShort episodes of high temperature (HT) stress during reproductive stages of development cause significant yield losses in wheat (Triticum aestivum L.). Two independent experiments were conducted to quantify the effects of HT during anthesis and grain filling periods on photosynthesis, leaf lipidome, and yield traits in wheat. In experiment I, wheat genotype Seri82 was exposed to optimum temperature (OT; 22/14 °C; day/night) or HT (32/22 °C) for 14 d during anthesis stage. In experiment II, the plants were exposed to OT or HT for 14 d during the grain filling stage. During the HT stress, chlorophyll index, thylakoid membrane damage, stomatal conductance, photosynthetic rate and leaf lipid composition were measured. At maturity, grain yield and its components were quantified.ResultsHT stress during anthesis or grain filling stage decreased photosynthetic rate (17 and 25%, respectively) and grain yield plant− 1 (29 and 44%, respectively), and increased thylakoid membrane damage (61 and 68%, respectively) compared to their respective control (OT). HT stress during anthesis or grain filling stage increased the molar percentage of less unsaturated lipid species [36:5- monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG)]. However, at grain filling stage, HT stress decreased the molar percentage of more unsaturated lipid species (36:6- MGDG and DGDG). There was a significant positive relationship between photosynthetic rate and grain yield plant− 1, and a negative relationship between thylakoid membrane damage and photosynthetic rate.ConclusionsThe study suggests that maintaining thylakoid membrane stability, and seed-set per cent and individual grain weight under HT stress can improve the photosynthetic rate and grain yield, respectively.

Multivariate Cluster and Principle Component Analyses of Selected Yield Traits in Uzbek Bread Wheat Cultivars

Investigation of genetic diversity of geographically distant wheat genotypes is a useful approach in wheat breeding providing efficient crop varieties. This article presents multivariate cluster and principal component analyses (PCA) of some yield traits of wheat, such as thousand-kernel weight (TKW), grain number, grain yield and plant height. Based on the results, an evaluation of economically valuable attributes by eigenvalues made it possible to determine the components that significantly contribute to the yield of common wheat genotypes. Twenty-five genotypes were grouped into four clusters on the basis of average linkage. The PCA showed four principal components (PC) with eigenvalues > 1, explaining approximately 90.8% of the total variability. According to PC analysis, the variance in the eigenvalues was the greatest (4.33) for PC-1, PC-2 (1.86) and PC-3 (1.01). The cluster analysis revealed the classification of 25 accessions into four diverse groups. Averages, standard deviations and variances for clusters based on morpho-physiological traits showed that the maximum average values for grain yield (742.2), biomass (1756.7), grains square meter (18,373.7), and grains per spike (45.3) were higher in cluster C compared to other clusters. Cluster D exhibited the maximum thousand-kernel weight (TKW) (46.6).

SCREENING OF WHEAT (Triticum aestivum L.) VARIETIES WITH HIGH NITROGEN USE EFFICIENCY UNDER RAINFED AND IRRIGATED CONDITIONS

The aim of this study was to clarify the relationship of nitrogen accumulation and transport with yield of wheat and determine the indicators for the screening of wheat varieties with high nitrogen use efficiency (NUE). A total of sixteen winter wheat (Triticum aestivum L.) varieties were used to determine fourteen nitrogen accumulation and transport-related traits as well as yield-related traits in field under irrigated and rainfed conditions. The correlations between the major nitrogen accumulation and transport-related traits and yield traits of wheat were analyzed, and the nitrogen use type of the wheat varieties was classified. Results showed that eight nitrogen accumulation and transport-related traits had significant or highly significant genetic correlations with yield per plant under the two water regimes. These eight traits were transport amount of pre- flowering reserve nitrogen and contribution of pre-flowering reserve nitrogen to grain nitrogen, nitrogen accumulation and transport amount after flowering, nitrogen transport efficiency after flowering, contribution of nitrogen assimilation to grain nitrogen after flowering, nitrogen utilization efficiency for grain production and biomass production. These eight traits were used as indicators for a comprehensive clustering of the wheat materials, and the sixteen varieties were classified into three groups representing the high NUE, intermediate, and low NUE types, respectively. From the perspective of nitrogen utilization, efforts must be made in the following aspects to obtain higher yields regardless of irrigated or rainfed conditions: 1) to improve nitrogen utilization efficiency for grain production and biomass production, as well as nitrogen accumulation and transport amount after flowering, nitrogen transport efficiency and contribution of nitrogen assimilation to grain nitrogen after flowering, and 2) to decrease transport amount of pre- flowering reserve nitrogen and contribution of pre-flowering reserve nitrogen to grain nitrogen.

Genetic Analysis of Some Physiological and Yield Traits in Wheat by F3 Families under Normal and late Season Water Deficit Conditions

Genetic Analysis of Some Physiological and Yield Traits in Wheat by F3 Families under Normal and late Season Water Deficit Conditions

Genetic Analysis of Response to Water Deficit Stress in Wheat Yield Traits with Generation Means and Variance Analysis

Genetic Analysis of Response to Water Deficit Stress in Wheat Yield Traits with Generation Means and Variance Analysis

ACC Deaminase Producing PGPR Bacillus amyloliquefaciens and Agrobacterium fabrum along with Biochar Improve Wheat Productivity under Drought Stress

Drought stress retards wheat plant’s vegetative growth and physiological processes and results in low productivity. A stressed plant synthesizes ethylene which inhibits root elongation; however, the enzyme 1-Aminocyclopropane-1-Carboxylate (ACC) deaminase catabolizes ethylene produced under water stress. Therefore, the ACC deaminase producing plant growth promoting rhizobacteria (PGPR) can be used to enhance crop productivity under drought stress. Biochar (BC) is an organically active and potentially nutrient-rich amendment that, when applied to the soil, can increase pore volume, cation exchange capacity and nutrient retention and bioavailability. We conducted a field experiment to study the effect of drought tolerant, ACC deaminase producing PGPR (with and without timber waste BC) on plant growth and yield parameters under drought stress. Two PGPR strains, Agrobacterium fabrum or Bacillus amyloliquefaciens were applied individually and in combination with 30 Mg ha−1 BC under three levels of irrigation, i.e., recommended four irrigations (4I), three irrigations (3I) and two irrigations (2I). Combined application of B. amyloliquefaciens and 30 Mg ha−1 BC under 3I, significantly increased growth and yield traits of wheat: grain yield (36%), straw yield (50%), biological yield (40%). The same soil application under 2I resulted in greater increases in several of the growth and yield traits: grain yield (77%), straw yield (75%), above- and below-ground biomasses (77%), as compared to control; however, no significant increases in chlorophyll a, b or total, and photosynthetic rate and stomatal conductance in response to individual inoculation of a PGPR strain (without BC) were observed. Therefore, we suggest that the combined soil application of B. amyloliquefaciens and BC more effectively mitigates drought stress and improves wheat productivity as compared to any of the individual soil applications tested in this study.

Inheritance pattern of genes for morpho-physiological and yield traits in wheat (Triticum aestivumL.)

Inheritance pattern of genes for morpho-physiological and yield traits in wheat (<i>Triticum aestivum</i>L.)

Impact of Salinity and Zinc Application on Growth, Physiological and Yield Traits in Wheat

Impact of Salinity and Zinc Application on Growth, Physiological and Yield Traits in Wheat

Efficacy of Extraction Methods of Moringa oleifera Leaf Extract for Enhanced Growth and Yield of Wheat

A field study was conducted to assess effective method to get Moringa leaf extract, through its response on growth and yield traits of wheat. Extracts of whole or chopped and dry or fresh Moringa leaves were used exogenously i.e. pre-sowing seed soaking as well as water diluted solution based foliar spray application at tillering and booting stages. Significantly higher growth response in term of leaf area index, leaf area duration, and crop growth rate was observed when combination of 30 times diluted moringa leaf extract (MLE) was applied at both crop stages. Yield contributing traits of wheat such as fertile tillers, spikelet’s spikelet’s per spike, grains per spike, 1000 grain weight, biological and grain yields were recorded in significantly higher due to 30 times diluted fresh MLE followed by 20 times dilution of Moringa dried leaf powder (DLP). While, control treatment and hydro-priming showed at comparable results in the form of significantly lesser fertile tillers, grains per spike, 1000-grain weight and grain or biological yields. Conclusively, 30 times diluted MLE proved the best among the treatments combinations for improved wheat growth and yield however, the biochemical features responsible for such promotive response are yet to be investigated prior to dissemination of this technology to the farmer field.

Effect of Foliar Applied Urea on Growth and Yield of Wheat (Triticum Aestivium L.)

The aim of this study is to assess effect of foliar application of urea on growth and yield of wheat crop. The field experiment was conducted to observe the effect of foliar applied urea on growth and yield of wheat. The experiment was laid out in a three replicated randomized complete block design (RCBD) having net plot size 5×4m= (20 m2). The wheat verity TJ-83 (Tando Jam-83) was tested against six treatments of foliar applied urea such as (T1= control (sole water), T2=1%, T3= 2%, T4=3%, T5=4%, and T6=5%). Basal dose of phosphorus @ 84 kg ha-1 and nitrogen @ 120 kg ha-1 was applied at the time of sowing. The results indicated that the maximum plant height (97.1 cm), number of tillers plant-1 (10.0), spike length (12.4 cm), spikeletes spike-1 (22.5) number of grains spike-1 (65.4), grain weight spike-1 (26.4) seed index (73.2 g), straw yield (6275.3 kg ha-1) andgrain yield (5774.6 kg ha-1) was observed in foliar applied urea @ 5%. The results were statistically significant. However, foliar applied urea @ 4% was ranked 2nd and it was recorded the plant height (96.2 cm), number of tillers plant-1 (20.4), spike length (12.0 cm), spikeletes spike-1 (21.8) number of grains spike-1 (63.9), grain weight spike-1 (25.3) seed index (71.7 g), straw yield (6035.3 kg ha-1) and grain yield (5534. 6 kg ha-1). However the foliar applied urea @ 3%, 2% and 1% were also significantly affected on all the growth and yield traits of wheat, whereas, the lowest values were also recorded in control treatment in all the yield traits of wheat.

Gene actions involved in the inheritance of yield related traits in bread wheat (Triticum aestivum L.)

One of the successful ways in breeding program and determining breeding methodology is information about the type of gene action involved in the inheritance of a character in different wheat generations. The objective of this study was to estimate gene effects for grain yield traits in wheat (Triticum estivum L.) in four selected crosses, involving five parents, their first and second filial generations (F1, F2) and first back crosses generations (BC1). The gene effects were estimated on the basis of generation mean analysis, using an additive-dominant model with three and six-parameters. The adequacy of the additive-dominance model with three-parameters was tested using the Scaling test and Chi-square (χ2) test. The significant Scaling tests and Joint-scaling test indicated the presence of digenic epistasis for the most of studied traits. The application of six-parameter models revealed that genetic effects for certain traits were depending upon the particular cross and differed on an overall basis. The significant type of non-allelic interactions which was observed in most of cross combinations was additive×additive (i) and dominance×dominance (l). Duplicate gene interactions were also observed, which are quite difficult to exploit in breeding programs. From these observations it is suggested that selection for the improvement of some traits should be effective in advanced segregating generations due to non-allelic gene interaction, while in cross combination where epistasis did not make a significant contribution among the generation means, selection in early segregating generations would be effective.

Single nucleotide polymorphism markers linked to QTL for wheat yield traits

Continuous improvement in grain yield is one of the major challenges for wheat (Triticum aestivum L.) breeding worldwide. This study characterized quantitative trait loci (QTL) underlying wheat grain yield and its components using a high-density genetic linkage map developed from a recombinant inbred line (RIL) population derived from ‘Ning7840’ × ‘Clark’. The map consisted of 594 single nucleotide polymorphism and 404 simple sequence repeat markers covering a genetic distance of 4225.7 cM. The RIL population was evaluated for grain yield (GY), spike number per m2 (SNPM), kernel number per spike (KNPS), and thousand-kernel weight (TKW) in three Oklahoma locations from 2001 to 2003. A total of 29 additive QTL (eight for GY, two for SNPM, five for KNPS, and 14 for TKW) were mapped on 13 chromosomes. Eight pairs of epistatic QTL were detected for different yield components: four for GY, two for KNPS, and two for TKW. Four additive QTL, including two for GY and two for KNPS, showed additive × environment interactions. QTL that were repeatable in multiple environments were identified for all traits except SNPM. Positive alleles were dispersed between the two parents for all traits, with ‘Clark’ contributing slightly more. Seven pleiotropic loci were co-localized for at least two traits. Interestingly, all co-localized loci overlapped for TKW, and four of them overlapped for GY. Thus, selecting QTL for TKW may simultaneously select for or against yield or other yield components in breeding.

UTLIZATION OF UNIFORMITY TRIALS TO ESTIMATE THE OPTIMUM PLOT SIZE AND SHAPE AND THE NUMBER OF REPLICATIONS IN WHEAT YIELD TRIALS

In the present work, two uniformity trials were carried out during thefirst and the second winter seasons of 2011/2012 and 2012/2013 in theExperimental farm Demo, Faculty of Agriculture, Fayoum University. Themain objectives were to estimate the optimum plot size, plot shape andnumber of replicates for wheat yield traits using the variety Sakha 93 as plantmaterial. The cultivated area of each field trial was divided into 12 strips;each of which consisted of 100 rows, 0.2 m width and 3.0 m long. Twostatistical methods including soil variability index and maximum curvaturewere used to estimate the optimum plot size and shape using the yield data of1200 basic units (each of 0.6 m2). The data were subjected to two proceduresof statistical analysis to estimate the optimum plot size, when the cost ofconducting the experiment is not taken into consideration and to evaluate theeffect of changing the plot shape on the variability. The first statistical methodwas that of maximum curvature which is based on the exponentialrelationship between plot size and the coefficient of variability. The secondmethod was that developed by smith’s method (1938). Bartlett's test forhomogeneity of variances, as outlined by Steel and Torrie (1980), was usedto study the effect of changing plot shape. The obtained results could besummarized as follows: Increasing the plot size decreased the variance perbasic unit and the coefficient of variability. However, the reduction was not inproportion with the increase in plot size. The index of soil variability rangedfrom 0.6433 to 0.6018 as an average for the 1st and the 2nd seasons,respectively. The relationship between the coefficient of variability (C.V.)and plot size (X) were mathematically expressed by the following equationC.V. = 19.21 X-0.2595 for the 1st season and C.V. = 19.60 X – 0.2725 for the 2ndone. Accordingly, using the soil variability index, the optimum plot size was2 basic units (1/3500 fed.) for the two seasons, while it was 4 basic units(1/1750 fed.) in both seasons when the maximum curvature method wasapplied. The required number of replications for the optimum plot size usingSmith method detecting a 15% difference among treatment means varied 13and 14 in the 1st and the 2nd seasons, respectively. But, for detecting a 20%difference among treatment means, 7 replications in the 1st season and 8replications in the 2nd one were found necessary. Optimum plot size estimatedusing the maximum curvature method detecting a 15% difference amongtreatment means varied 7 and 8 in the 1st and the 2nd seasons, respectively. But, for detecting a 20% difference among treatment means, 4 replications inthe 1st and 2nd season's one were found necessary. Generally, the plot shapedid not affect on the precision of wheat yield trial in most cases in the twogrowing seasons.

Diverse approaches to achieving grain yield in wheat

Artificial selection (domestication and breeding) leaves a strong footprint in plant genomes. Second generation high throughput DNA sequencing technologies make it possible to sequence the gene complement of a plant genome within 3 to 5 months, and the costs of doing so are declining very quickly. This makes it practical to identify genomic regions that have undergone very strong selection. Available reference sequences of important crops such as rice, maize, and sorghum will promote the wide use of re-sequencing strategies in these crops. Marker/trait associations, especially haplotype (or haplotype block) association analyses, will help the precise mapping of important genomic regions and location of favored alleles or haplotypes for breeding. This mini-review examines a genomics approach to defining yield traits in wheat.

Estimation of heritability and genetic advance of yield traits in wheat (Triticum aestivum L.) under drought condition

Four varieties/lines of wheat and their crosses namely, Sakha8 , Sids1, line 1 Line3 and Line1x Sakha8, Line3x Sakha8, Line1x Sids1, Line3x Sids1 were evaluated to estimate heritability and genetic advance for yield traits. The experimental material was planted under irrigation as well as drought stress conditions. The mean average for plant height, spike length, number of spikes per plant, number of grains per spike, 50% heading date and 1000 grain-weight revealed highly significant differences among genotypes and crosses under both sowing conditions. Low, medium and high heritability was found in different yield traits under study. High heritability accompanied by high genetic advance was observed for spike length and 1000 grain-weight. Low heritability coupled with low genetic advance was for plant height and number of grains per spike. However, the heritability was generally found to be lower under drought stress conditions. Greater magnitude of heritability coupled with higher genetic advance in some traits under study provided that these parameters were under the control of additive genetic effects. This indicates that selection should lead to fast genetic improvement of the material. Moreover, the genetic correlations in study were high for most of the traits, suggesting a strong inherent association among these traits at the genetic level. These traits therefore deserve better attention in future breeding programs for evolving better wheat in stress environments. Key words: Wheat, heritability, genetic advance, yield traits.

Impact of Nighttime Temperature on Physiology and Growth of Spring Wheat

Climate models predict greater increases in nighttime temperature in the future. The impacts of high nighttime temperature on wheat (Triticum aestivum L.) are not well understood. Objectives of this research were to quantify the impact of high nighttime temperatures during reproductive development on phenology, physiological, vegetative, and yield traits of wheat. Two spring wheat cultivars (Pavon‐76 and Seri‐82) were grown at optimum temperatures (day/night, 24/14°C; 16/8 h light/dark photoperiod) from sowing to booting. Thereafter, plants were exposed to four different nighttime temperatures (14, 17, 20, 23°C) until maturity. The daytime temperature was 24°C across all treatments. There were significant influences of high nighttime temperatures on physiological, growth, and yield traits, but no cultivar or cultivar by temperature interactions were observed. High nighttime temperatures (&gt;14°C) decreased photosynthesis after 14 d of stress. Grain yields linearly decreased with increasing nighttime temperatures, leading to lower harvest indices at 20 and 23°C. High nighttime temperature (≥20°C) decreased spikelet fertility, grains per spike, and grain size. Compared to the control (14°C), grain filling duration was decreased by 3 and 7 d at night temperatures of 20 and 23°C, respectively. High nighttime temperature increased the expression of chloroplast protein synthesis elongation factor in both cultivars suggesting possible involvement of this protein in plant response to stress.