Hexaploid Wheat Varieties Research Articles

Lower Diversity of Amylase-Trypsin Inhibitors and Ex Vivo-Released Opioid-Containing Peptides in Ancestral Compared to Modern Wheat Varieties Assessed by Proteomics and Peptidomics.

This study focused on identifying amylase-trypsin inhibitors (ATIs) in seven Norwegian-cultivated wheat varieties, including common wheat and ancestral species, and identifying potentially harmful opioid peptides within the ex vivo digesta of these wheats. LC-MS/MS analysis of tryptic peptides from ATI fractions revealed that the common wheat variety Børsum exhibited the highest diversity of ATIs (n = 24), while they were less represented in tetraploid emmer (n = 11). Hexaploid wheat Bastian showed low diversity and relative abundance of ATIs. Nevertheless, digestion of Mirakel and Bastian by human gastrointestinal juices released the highest number of opioid-containing peptides, representing both gluten exorphins and gliadorphin. In conclusion, emmer had the lowest levels of ATIs, while einkorn and spelt released the fewest opioid-containing peptides after ex vivo digestion. These results point to the potential lower harmful effects of ancestral wheat compared to common hexaploid wheat varieties for wheat-sensitive individuals.

Enhancing aluminium resistance in wheat ( Triticum aestivum L.) by exploring for novel genes in the wheat genome

Abstract Aluminium (Al 3+ ) toxicity is a major constraint to crop production worldwide and is considered second only to drought for its importance as an agronomic challenge. A common practice to manage the impact is the application of lime but this is expensive, and it can take years for the lime to be effective in ameliorating the subsoil acidity. Plant species with a natural ability to adapt to Al 3+ toxicity offer an option to maintain production while amelioration efforts continue, especially in low-rainfall areas where yield responses to lime is less profitable. In wheat ( Triticum aestivum L.), the genes conferring Al 3+ resistance have been extensively researched over the years through classical inheritance, cytogenetic, quantitative trait locus (QTL) and genome-wide association studies, and transcriptional analyses. As a focal point for this discussion, we assembled a total of 212 QTL from research papers published between 2006 and 2024, and their physical positions were projected on the sequenced genome of the moderately Al 3+ -resistant hexaploid wheat variety, Chinese Spring. The markers were distributed across the 21 wheat chromosomes, with the highest numbers on chromosomes 3B, 4D and 7A and the lowest on chromosomes 3D and 5D. The physical mapping of significantly associated markers onto the reference genome map uncovered novel candidate genes. These include wheat aluminium-induced (Wali) genes, the ATP-binding cassette (ABC) transporters, phytosulfokine receptor (PSKR), PIN-formed (PIN, auxin transporter), NAC (NAC domain), WRKY (WRKY domain) and natural resistance-associated macrophage proteins (NRAMP). These were discussed to provide a contextual review of gaps that can be exploited in enhancing Al 3+ resistance in wheat, which can lead to the discovery of novel genes and the development of improved cultivars.

Effects of heat exposure from late sowing on agronomic traits and the technological quality of hexaploid wheat

Effects of heat exposure from late sowing on agronomic traits and the technological quality of hexaploid wheat

Identification and map-based cloning of an EMS-induced mutation in wheat gene TaSP1 related to spike architecture.

A candidate gene TaSP1 related to spike shape was cloned, and the gene-specific marker was developed to efficiently track the superior haplotype in common wheat. Spike shape, an important factor that affects wheat grain yield, is mainly defined by spike length (SPL), spikelet number (SPN), and compactness. Zhoumai32 mutant 1160 (ZM1160), a mutant obtained from ethyl methane sulfonate (EMS) treatment of hexaploid wheat variety Zhoumai32, was used to identify and clone the candidate gene that conditioned the spike shape. Genetic analysis of an F2 population derived from a cross of ZM1160 and Bainong207 suggested that the compact spike shape in ZM1160 was controlled by a single recessive gene, and therefore, the mutated gene was designated as Tasp1. With polymorphic markers identified through bulked segregant analysis (BSA), the gene was mapped to a 2.65-cM interval flanked by markers YZU0852 and MIS46239 on chromosome 7D, corresponding to a 0.42-Mb physical interval of Chinese spring (CS) reference sequences (RefSeq v1.0). To fine map TaSP1, 15 and seven recombinants were, respectively, screened from 1599 and 1903 F3 plants derived from the heterozygous F2 plants. Finally, TaSP1 was delimited to a 21.9Kb (4,870,562 to 4,892,493bp) Xmis48123-Xmis48104 interval. Only one high-confidence gene TraesCS7D02G010200 was annotated in this region, which encodes an unknown protein with a putative vWA domain. Quantitative reverse transcription PCR (qRT-PCR) analysis showed that TraesCS7D02G010200 was mainly expressed in the spike. Haplotype analysis of 655 wheat cultivars using the candidate gene-specific marker Xg010200p2 identified a superior haplotype TaSP1b with longer spike and more spikelet number. TaSP1 is beneficial to the improvement in wheat spike shape.

Wheat bZIPC1 interacts with FT2 and contributes to the regulation of spikelet number per spike

Key messageThe wheat transcription factor bZIPC1 interacts with FT2 and affects spikelet and grain number per spike. We identified a natural allele with positive effects on these two economically important traits.Loss-of-function mutations and natural variation in the gene FLOWERING LOCUS T2 (FT2) in wheat have previously been shown to affect spikelet number per spike (SNS). However, while other FT-like wheat proteins interact with bZIP-containing transcription factors from the A-group, FT2 does not interact with any of them. In this study, we used a yeast-two-hybrid screen with FT2 as bait and identified a grass-specific bZIP-containing transcription factor from the C-group, designated here as bZIPC1. Within the C-group, we identified four clades including wheat proteins that show Y2H interactions with different sets of FT-like and CEN-like encoded proteins. bZIPC1 and FT2 expression partially overlap in the developing spike, including the inflorescence meristem. Combined loss-of-function mutations in bZIPC-A1 and bZIPC-B1 (bzipc1) in tetraploid wheat resulted in a drastic reduction in SNS with a limited effect on heading date. Analysis of natural variation in the bZIPC-B1 (TraesCS5B02G444100) region revealed three major haplotypes (H1–H3), with the H1 haplotype showing significantly higher SNS, grain number per spike and grain weight per spike than both the H2 and H3 haplotypes. The favorable effect of the H1 haplotype was also supported by its increased frequency from the ancestral cultivated tetraploids to the modern tetraploid and hexaploid wheat varieties. We developed markers for the two non-synonymous SNPs that differentiate the bZIPC-B1b allele in the H1 haplotype from the ancestral bZIPC-B1a allele present in all other haplotypes. These diagnostic markers are useful tools to accelerate the deployment of the favorable bZIPC-B1b allele in pasta and bread wheat breeding programs.

Suppressing ASPARTIC PROTEASE 1 prolongs photosynthesis and increases wheat grain weight.

The elongation of photosynthesis, or functional staygreen, represents a feasible strategy to propel metabolite flux towards cereal kernels. However, achieving this goal remains a challenge in food crops. Here we report the cloning of wheat CO2 assimilation and kernel enhanced 2 (cake2), the mechanism underlying the photosynthesis advantages and natural alleles amenable to breeding elite varieties. A premature stop mutation in the A-genome copy of the ASPARTIC PROTEASE 1 (APP-A1) gene increased the photosynthesis rate and yield. APP1 bound and degraded PsbO, the protective extrinsic member of photosystem II critical for increasing photosynthesis and yield. Furthermore, a natural polymorphism of the APP-A1 gene in common wheat reduced APP-A1's activity and promoted photosynthesis and grain size and weight. This work demonstrates that the modification of APP1 increases photosynthesis, grain size and yield potentials. The genetic resources could propel photosynthesis and high-yield potentials in elite varieties of tetraploid and hexaploid wheat.

Validation of CAPS marker WR003 for the leaf rust resistance gene Lr1 and the molecular evolution of Lr1 in wheat

The wheat leaf rust resistance gene Lr1 encodes a typical coiled-coil nucleotide-binding site leucine-rich repeat (CC-NBS-LRR) of resistance protein containing 1 344 amino acids. WR003, a cleaved amplified polymorphic sequence (CAPS) marker is derived from the LRR regions of Lr1. In this study, a worldwide collection of 120 Aegilops tauschii accessions and 282 hexaploid wheat varieties was screened for Lr1 alleles using WR003, and the specificity of WR003 for Lr1 was confirmed by pathogenicity tests and genotype analysis. The sequence alignment and phylogenetic tree analysis of 38 Lr1 haplotypes provided a further view of the molecular evolution of Lr1. The results showed that there were very few polymorphisms between the Lr1 alleles from Ae. tauschii and hexaploid wheat with the same resistance phenotype. The polymorphisms of the Lr1 haplotypes were mainly between the different resistance lines, rather than between the different ploidy levels. These results indicate that Lr1 originated from Ae. tauschii and differentiated into resistant and susceptible genotypes before its introgression into hexaploid wheat. Therefore, it is likely that wheat Lr1 has at least two major variants for disease resistance and susceptibility, and except for certain point mutations, few gene conversions and genetic re-combinations occurred during the hexaploid wheat domestication.

Marker-assisted transfer of leaf and stripe rust resistance from Triticum turgidum var. durum cv. Trinakria to wheat variety HD2932.

A marker-assisted backcrossing program initiated to transfer leaf rust resistance gene LrTrk from Triticum turgidum cv. Trinakria to hexaploid wheat variety HD2932 cotransferred a stripe rust resistance gene, YrTrk, along with LrTrk. The cross of hexaploid recurrent parent HD2932 with tetraploid donor parent Trinakria produced pentaploid F1 plants. F1s were backcrossed with recurrent parent HD2932 to produce BC1F1 generation. Foreground and background selection was conducted in each backcross generation to identify plants for backcrossing or selfing. While foreground selection for LrTrk was carried out with linked and validated molecular marker Xgwm234, for background selection, 86 polymorphic SSR markers from the A and B genomes were used. Single selected plants from BC1F1 and BC2F1 generations backcrossed and selfed to produce BC2F1and BC2F2 generations, respectively. Background selection resulted in 83.72%, 91.86%, and 98.25% of RPG recovery in BC1F1, BC2F1, and BC2F2 generations, respectively. A total of 27 plants with LrTrk in homozygous state were identified in BC2F2 generation and selfed to produce 27 BC2F3 NILs. All the NILs were tested for leaf and stripe rust resistance at the seedling stage using seven Puccinia triticina and one Puccinia striiformis f.sp. tritici rust pathotypes. All the 27 NILs were found to be resistant to both leaf and stripe rust pathotypes. So, these NILs are designated to carry leaf and stripe rust resistance genes LrTrk/YrTrk.

In-Depth Sequence Analysis of Bread Wheat VRN1 Genes.

The VERNALIZATION1 (VRN1) gene encodes a MADS-box transcription factor and plays an important role in the cold-induced transition from the vegetative to reproductive stage. Allelic variability of VRN1 homoeologs has been associated with large differences in flowering time. The aim of this study was to investigate the genetic variability of VRN1 homoeologs (VRN-A1, VRN-B1 and VRN-D1). We performed an in-depth sequence analysis of VRN1 homoeologs in a panel of 105 winter and spring varieties of hexaploid wheat. We describe the novel allele Vrn-B1f with an 836 bp insertion within intron 1 and show its specific expression pattern associated with reduced heading time. We further provide the complete sequence of the Vrn-A1b allele, revealing a 177 bp insertion in intron 1, which is transcribed into an alternative splice variant. Copy number variation (CNV) analysis of VRN1 homoeologs showed that VRN-B1 and VRN-D1 are present in only one copy. The copy number of recessive vrn-A1 ranged from one to four, while that of dominant Vrn-A1 was one or two. Different numbers of Vrn-A1a copies in the spring cultivars Branisovicka IX/49 and Bastion did not significantly affect heading time. We also report on the deletion of secondary structures (G-quadruplex) in promoter sequences of cultivars with more vrn-A1 copies.

Unveiling the genetic divergence and phenotypic association in elite Pakistani wheat (Triticum aestivum L.) genotypes

The present study was designed to assess genetic divergence between commercial bread wheat genotypes based on yield and its related traits and to carry out phenotypic correlation. Twenty bread hexaploid wheat varieties were assessed for mean performance, correlation analysis and genetic distance. Randomized complete block design was used with three replications during growing season, 2018-2019 at Wheat and Barley Research Institute, Tandojam. The mean squares depicted significant differences (P<0.01) for all the investigated traits among the tested genotypes, proving that used genetic resources possess a great potential for further breeding experiments. Regarding mean performance, the genotypes Sassui and TD-1 displayed desirable performance for a variety of traits, unveiling their importance in wheat breeding programs. The results also showed that tillers plant-1, grains spike-1 and seed index developed significantly positive (P<0.05) interrelationship with grain yield plant-1. This demonstrates that genotypes possessing higher extent of these traits may be chosen in selection for developing high yielding bread wheat genotypes. The larger genetic distance was witnessed between Johar-78 and TD-1, followed by SKD-1 and TJ-83, SKD-1 and Mehran-89, SKD-1 and Johar-78, TD-1 and Khirman, TJ-83 and Imdad-05, Mehran-89 and TD-1 and Johar-78 and TJ-83. These paired showed wide genetic distances, which may also be preferred in wheat hybridization program. Keywords: Genetic distance, hexaploid wheat, morphological traits, trait

Correlation of carotenoid accumulation and expression pattern of carotenoid biosynthetic pathway genes in Indian wheat varieties

Carotenoids are the source of antioxidants and precursor for vitamin A in humans. Several wheat varieties are cultivated in India, but limited information on carotenoid content in grains hamper their nutritional impact in society. A total of 30 Indian hexaploid wheat varieties were subjected to carotenoid profiling in mature seeds. Lutein was the major carotenoid followed by zeaxanthin and β-carotene. Studies in two contrasting wheat varieties, VL907 (1.63 μg/g) and K8962 (0.53 μg/g) revealed varying expression pattern of nine carotenoid biosynthesis pathway genes during the seed developmental stages. The higher expression of TaLCYB suggests a prominent role in enhanced β-carotene content in seed development stages of VL907. While higher expression of TaLCYE inversely correlated with β-carotene deposition in K8962. A strong negative correlation of TaBCH1 and TaBCH2 expression was observed with all carotenoids, except zeaxanthin in K8962, whereas a weak negative correlation of TaPSYs with all major carotenoids was found in both K8962 and VL907. Hence, the results suggest that the carotenoids accumulation in the seed of wheat varieties could be regulated by the expression patterns of TaLCYB, TaPSYs and TaBCHs genes. The present study facilitates the functional characterization of these genes to gain more understanding of their role in carotenoid accumulation in wheat.

Evaluation of a Novel Molecular Marker Associated with the Tan Spot Disease Response in Wheat

After nearly 40 years of DNA molecular marker development in plant breeding, the wheat research community has amassed an extensive collection of molecular markers which have been widely and successfully used for selection of agronomic, physiological and disease resistance traits in wheat breeding programs. Tan spot is a major fungal disease of wheat and a significant global economic challenge and is caused by the necrotrophic fungal pathogen Pyrenophora tritici-repentis (Ptr). Here, the potential for using a PCR-based marker (Ta1AS3422) present on the short arm of wheat chromosome 1A, was evaluated for effectiveness in distinguishing tan spot disease susceptibility. The marker was initially screened against 40 commercial Australian hexaploid wheat varieties, and those that amplified the marker had an overall lower disease score (2.8 ± 0.7 for seedlings and 2.4 ± 0.4 for plants at the tillering stage), compared to those lacking the marker which exhibited a higher disease score (3.6 ± 0.8 for both growth stages). The potential of Ta1AS3422 as a marker for the tan spot disease response was further assessed against a panel of 100 commercial Australian hexaploid wheat varieties. A significant association was observed between marker absence/presence and tan spot disease rating (Pearson’s chi-squared test, χ2 (6) = 20.53, p = 0.002), with absence of Ta1AS3422 associated with susceptibility. This simple and cost-effective PCR-based marker may be useful for varietal improvement against tan spot, although further work is required to validate its effectiveness.

Linkage mapping identifies a non-synonymous mutation in FLOWERINGLOCUST (FT-B1) increasing spikelet number per spike

Total spikelet number per spike (TSN) is a major component of spike architecture in wheat (Triticumaestivum L.). A major and consistent quantitative trait locus (QTL) was discovered for TSN in a doubled haploid spring wheat population grown in the field over 4 years. The QTL on chromosome 7B explained up to 20.5% of phenotypic variance. In its physical interval (7B: 6.37–21.67 Mb), the gene FLOWERINGLOCUST (FT-B1) emerged as candidate for the observed effect. In one of the parental lines, FT-B1 carried a non-synonymous substitution on position 19 of the coding sequence. This mutation modifying an aspartic acid (D) into a histidine (H) occurred in a highly conserved position. The mutation was observed with a frequency of ca. 68% in a set of 135 hexaploid wheat varieties and landraces, while it was not found in other plant species. FT-B1 only showed a minor effect on heading and flowering time (FT) which were dominated by a major QTL on chromosome 5A caused by segregation of the vernalization gene VRN-A1. Individuals carrying the FT-B1 allele with amino acid histidine had, on average, a higher number of spikelets (15.1) than individuals with the aspartic acid allele (14.3) independent of their VRN-A1 allele. We show that the effect of TSN is not mainly related to flowering time; however, the duration of pre-anthesis phases may play a major role.

Genetic diversity and population structure of bread wheat varieties grown in Bulgaria based on microsatellite and phenotypic analyses

Determining the genetic diversity and population structure of the modern hexaploid wheat varieties currently grown in Bulgaria is fundamental for selection of genotypes with desirable traits resilient under climatic fluctuations and development of successful crop improvement programmes. In this study, simple sequence repeat (SSR) markers were used to characterize a population of 117 modern wheat varieties (Triticum aestivum L.) from Bulgaria and several Western, Central and Eastern European countries. The genetic diversity was higher in the Western and Central European varieties than in the Bulgarian and the remaining Eastern European ones. Model-based population structure analysis defined 2 sub-populations (K = 2) dividing the Central and Western European varieties from the Bulgarian ones. Subsequent genetic structure analysis at K = 3 revealed an additional separation of the Bulgarian varieties in two distinct sub-populations. The phenotypic diversity among the varieties was evaluated in the fields of Dobrudzha Agricultural Institute, G. Toshevo in North-Eastern Bulgaria for three consecutive years. The distribution of the varieties in the biplot analysis in terms of grain yield and its components revealed differences in their adaptation to the agro-climatic conditions of North Bulgaria according to their geographical origin. These results and the prevalence of specific SSR alleles in the sub-populations suggest distinct adaptive mechanisms to specific agro-ecological regions. The data will be of interest for both breeders and farmers and could serve as a basis for wheat improvement programmes and further association mapping for important agronomic traits expressed under different environmental conditions. Supplemental data for this article is available online at https://doi.org/10.1080/13102818.2021.1996274 .

Variations in radioactive cesium accumulation in wheat germplasm from fields affected by the 2011 Fukushima nuclear power plant accident

Decreasing the transfer of radioactive cesium (RCs) from soil to crops has been important since the deposition of RCs in agricultural soil owing to the Fukushima nuclear power plant accident of 2011. We investigated the genotypic variation in RCs accumulation in 234 and 198 hexaploid wheat (Triticum spp.) varieties in an affected field in 2012 and 2013, respectively. The effects of soil exchangeable potassium (ExK) content to RCs accumulation in wheat varieties were also evaluated. A test field showed fourfold differences in soil ExK contents based on location, and the wheat varieties grown in areas with lower soil ExK contents tended to have higher grain RCs concentrations. RCs concentrations of shoots, when corrected by the soil ExK content, were positively significantly correlated between years, and RCs concentrations of shoots were significantly correlated with the grain RCs concentration corrected by the soil ExK content. These results indicated that there were genotypic variations in RCs accumulation. The grain to shoot ratio of RCs also showed significant genotypic variation. Wheat varieties with low RCs accumulations were identified. They could contribute to the research and breeding of low RCs accumulating wheat and to agricultural production in the area affected by RCs deposition.

Dmc1 is a candidate for temperature tolerance during wheat meiosis

Key messageThe meiotic recombination gene Dmc1 on wheat chromosome 5D has been identified as a candidate for the maintenance of normal chromosome synapsis and crossover at low and possibly high temperatures.We initially assessed the effects of low temperature on meiotic chromosome synapsis and crossover formation in the hexaploid wheat (Triticum aestivum L.) variety ‘Chinese Spring’. At low temperatures, asynapsis and chromosome univalence have been observed before in Chinese Spring lines lacking the long arm of chromosome 5D (5DL), which led to the proposal that 5DL carries a gene (Ltp1) that stabilises wheat chromosome pairing at low temperatures. In the current study, Chinese Spring wild type and 5DL interstitial deletion mutant plants were exposed to low temperature in a controlled environment room during a period from premeiotic interphase to early meiosis I. A 5DL deletion mutant was identified whose meiotic chromosomes exhibit extremely high levels of asynapsis and chromosome univalence at metaphase I after 7 days at 13 °C, suggesting that Ltp1 is deleted in this mutant. Immunolocalisation of the meiotic proteins ASY1 and ZYP1 on ltp1 mutants showed that low temperature results in a failure to complete synapsis at pachytene. KASP genotyping revealed that the ltp1 mutant has a 4-Mb deletion in 5DL. Of 41 genes within this deletion region, the strongest candidate for the stabilisation of chromosome pairing at low temperatures is the meiotic recombination gene Dmc1. The ltp1 mutants were subsequently treated at 30 °C for 24 h during meiosis and exhibited a reduced number of crossovers and increased univalence, though to a lesser extent than at 13 °C. We therefore renamed our ltp1 mutant ‘ttmei1’ (temperature-tolerant meiosis 1) to reflect this additional loss of high temperature tolerance.

Estimates of Heritability and Average Degree of Dominance by Complete Diallel Crosses Analysis in Hexaploid Wheat (Triticum aestivum L.)

Seven varieties of hexaploid wheat (Triticum aestivum L.) JAWAHIR-20, REYNA-27, ACHTAR, REBWAH-12, REBWAH-12, Ibaa 99and Abo-Gharaib and their full dialed crosses were used in this study. Grains of parental varieties and their hybrids were planted at the college of Agricultural and Forestry University of Mosul using randomized complete block design with four replications, during the growing season (2013-2014), depending on rain fed conditions. Genetical analysis was performed to determine the genetic systems for each of plant height, Number of spikes per plant, biological yield, grain yield, weight of (100) grains and number of grains per spike, and also to estimate, genetical variance components average degree of dominance, heritability. Estimation of genetical parameters ratios indicated that there were different degrees of dominance on the studied traits, and irregular distributions of dominat and receive allels among parents for all traits except for (100) grains weight. There were three groups of dominant genes controlled for (100) grains weight and one for other traits. the broad sense heritability estimate were low for 100 grains weight and height for other traits, however narrow sense heritability estimates were: low for number of spikes, grain yield, and medium for others traits. .

Whole-Genome Association Mapping and Genomic Prediction for Iron Concentration in Wheat Grains.

Malnutrition of iron (Fe) affects two billion people worldwide. Therefore, enhancing grain Fe concentration (GFeC) in wheat (Triticum aestivum L.) is an important goal for breeding. Here we study the genetic factors underlying GFeC trait by genome-wide association studies (GWAS) and the prediction abilities using genomic prediction (GP) in a panel of 369 European elite wheat varieties which was genotyped with 15,523 mapped single-nucleotide polymorphism markers (SNP) and a subpanel of 183 genotypes with 44,233 SNP markers. The resulting means of GFeC from three field experiments ranged from 24.42 to 52.42 μg·g−1 with a broad-sense heritability (H2) equaling 0.59 over the years. GWAS revealed 41 and 137 significant SNPs in the whole and subpanel, respectively, including significant marker-trait associations (MTAs) for best linear unbiased estimates (BLUEs) of GFeC on chromosomes 2A, 3B and 5A. Putative candidate genes such as NAC transcription factors and transmembrane proteins were present on chromosome 2A (763,689,738–765,710,113 bp). The GP for a GFeC trait ranged from low to moderate values. The current study reported GWAS of GFeC for the first time in hexaploid wheat varieties. These findings confirm the utility of GWAS and GP to explore the genetic architecture of GFeC for breeding programs aiming at the improvement of wheat grain quality.

SSR analysis of the genomic DNA of perspective Uzbek hexaploid winter wheat varieties

The objective of this study was to investigate the genetic diversity of hexaploid wheat varieties of Uzbekistan breeding using simple sequence repeat (SSR) markers. These varieties are adapted to local conditions, and can be considered as the most important supplier of genetic resources for cultivation in Uzbekistan and other countries. Microsatellite markers are now most widely used and effective classes of DNA markers for genotyping, certification and classification of plant varieties. In this paper, genotyping results of 32 hexaploid wheat domestic varieties using 144 microsatellite primer pairs are presented. Microsatellite primer pairs were chosen from literature data and 36 primer pairs (from 144) gave polymorphic well-reproducible PCR-fragments. The individual SSR spectra differing in number of amplicons were obtained for each variety. A total number of 141 alleles for 36 microsatellite loci were detected. The number of alleles per locus ranged from 2 to 6, the mean number of alleles per locus (Na) was 3 alleles. For the studied genotypes group the effective number of alleles (ne) characterizing the loci by the allele frequency, varied from 1.7 to 4.8, the mean number of alleles per locus was 2.8. The expected heterozygosity (He) ranged from 0 to 0.792, averaging 0.626, in studied wheat population. The amplified fragment sizes ranged from 93 to 552 bp. The polymorphic index content (PIC) ranged from 0 to 0.758. A dendrogram was constructed using the alleles set of microsatellite loci, reflecting the phylogenetic differences of the studied hexaploid wheat varieties. It showed that Uzbekistan breeding varieties are divided into two main clusters, which may be evidence of their common origin. A genetic formula has been developed for each Uzbek wheat variety. It can be used for identification, certification of these varieties, as well as for the selection of parental pairs in the wheat breeding programs.

Color characteristics of white salted, alkaline, and egg noodles prepared from Triticum aestivum L. and a soft kernel durum T. turgidum ssp. durum

AbstractBackground and objectivesDurum wheat (Triticum turgidum L. ssp. durum) may have advantages over bread wheat in making various styles of noodles due to low polyphenol oxidase (PPO) and high yellow pigment. However, the very hard kernel texture of durum wheat may pose a hindrance to its expanded utilization. The development of soft kernel durum wheat prompted this research into comparing the color of white salted, alkaline, and egg noodle sheets over time and three levels of hydration for one durum and 10 hexaploid wheat varieties.FindingsAll noodle sheets darkened over time and “varieties” was a major source of variation. PPO activity was a poor predictor of noodle sheet brightness (L*) at 48 hr for all three styles of noodle. The soft durum variety “Soft Svevo” exhibited about average brightness but tended to have low discoloration (ΔL*) over time. The range in the green‐red axis, a*, was small, and all noodle sheets exhibited a small positive increase with most values near the neutral gray value. All noodle sheets were yellow, with Soft Svevo being markedly more yellow in all three formulations. The alkaline pH increased average yellowness by three units overall, but in Soft Svevo, not at all. In some varieties, a decrease in yellow color occurred from 6 to 48 hr.ConclusionsThe low PPO activity of Soft Svevo did not predict an advantage in white salted, alkaline, and egg noodle sheet brightness over the “best” hexaploid wheat varieties. The reason was not resolved but may be related to marked differences in protein content of the flours.Significance and noveltySoft kernel durum wheat exhibited some advantages over hexaploid wheat, particularly in low discoloration (ΔL*) and high yellow color. In no way was soft durum found to be inferior to hexaploid wheat.