Genetic Mapping of Flavonoid Grain Pigments in Durum Wheat

Pigmented cereal grains with high levels of flavonoid compounds have attracted the attention of nutritional science backing the development of functional foods with claimed health benefits. In this study, we report results on the genetic factors controlling grain pigmentation in durum wheat using a segregant population of recombinant inbred lines (RILs) derived from a cross between an Ethiopian purple grain accession and an Italian amber grain cultivar. The RIL population was genotyped by the wheat 25K SNP array and phenotyped for total anthocyanin content (TAC), grain color, and the L*, a*, and b* color index of wholemeal flour, based on four field trials. The mapping population showed a wide variation for the five traits in the different environments, a significant genotype x environment interaction, and high heritability. A total of 5942 SNP markers were used for constructing the genetic linkage map, with an SNP density ranging from 1.4 to 2.9 markers/cM. Two quantitative trait loci (QTL) were identified for TAC mapping on chromosome arms 2AL and 7BS in the same genomic regions of two detected QTL for purple grain. The interaction between the two QTL was indicative of an inheritance pattern of two loci having complementary effects. Moreover, two QTL for red grain color were detected on chromosome arms 3AL and 3BL. The projection of the four QTL genomic regions on the durum wheat Svevo reference genome disclosed the occurrence of the candidate genes Pp-A3, Pp-B1, R-A1, and R-B1 involved in flavonoid biosynthetic pathways and encoding of transcription factors bHLH (Myc-1) and MYB (Mpc1, Myb10), previously reported in common wheat. The present study provides a set of molecular markers associated with grain pigments useful for the selection of essential alleles for flavonoid synthesis in durum wheat breeding programs and enhancement of the health-promoting quality of derived foods.

The Chelating Ability of Plant Polyphenols Can Affect Iron Homeostasis and Gut Microbiota

In the past decades, many studies have widely examined the effects of dietary polyphenols on human health. Polyphenols are well known for their antioxidant properties and for their chelating abilities, by which they can be potentially employed in cases of pathological conditions, such as iron overload. In this review, we have highlighted the chelating abilities of polyphenols, which are due to their structural specific sites, and the differences for each class of polyphenols. We have also explored how the dietary polyphenols and their iron-binding abilities can be important in inflammatory/immunomodulatory responses, with a special focus on the involvement of macrophages and dendritic cells, and how they might contribute to reshape the gut microbiota into a healthy profile. This review also provides evidence that the axes “polyphenol–iron metabolism–inflammatory responses” and “polyphenol–iron availability–gut microbiota” have not been very well explored so far, and the need for further investigation to exploit such a potential to prevent or counteract pathological conditions.

Phytochemical Profiling and Untargeted Metabolite Fingerprinting of the MEDWHEALTH Wheat, Barley and Lentil Wholemeal Flours

An important research target is improving the health benefits of traditional Mediterranean, durum wheat-based foods using innovative raw materials. In this study, we characterised wholemeal flours obtained from a traditional durum wheat cv. Svevo, two innovative durum wheat varieties (Svevo-High Amylose and Faridur), the naked barley cv. Chifaa and the elite lentil line 6002/ILWL118/1-1, evaluating them for targeted phytochemicals, untargeted metabolomics fingerprints and antioxidant capacity. To this aim, individual phenolic acids, flavonoids, tocochromanols and carotenoids were identified and quantified through HPLC-DAD, and the antioxidant capacities of both the extracts and whole meals were detected by ABTS assays. An untargeted metabolomics fingerprinting of the samples was conducted through NMR spectroscopy. Results showed that the innovative materials improved phytochemical profiles and antioxidant capacity compared to Svevo. In particular, Svevo-HA and Faridur had higher contents of ferulic and sinapic acids, β-tocotrienol and lutein. Moreover, Chifaa is a rich source of phenolic acids, β-tocopherols, lutein and zeaxanthin whereas lentil of flavonoids (i.e., catechin and procyanidin B2). The NMR profiles of Svevo-HA and Faridur showed a significant reduction of sugar content, malate and tryptophan compared to that of Svevo. Finally, substantial differences characterised the lentil profiles, especially for citrate, trigonelline and phenolic resonances of secondary metabolites, such as catechin-like compounds. Overall, these results support the potential of the above innovative materials to renew the health value of traditional Mediterranean durum wheat-based products.

Characterization of a Collection of Colored Lentil Genetic Resources Using a Novel Computer Vision Approach

The lentil (Lens culinaris Medik.) is one of the major pulse crops cultivated worldwide. However, in the last decades, lentil cultivation has decreased in many areas surrounding Mediterranean countries due to low yields, new lifestyles, and changed eating habits. Thus, many landraces and local varieties have disappeared, while local farmers are the only custodians of the treasure of lentil genetic resources. Recently, the lentil has been rediscovered to meet the needs of more sustainable agriculture and food systems. Here, we proposed an image analysis approach that, besides being a rapid and non-destructive method, can characterize seed size grading and seed coat morphology. The results indicated that image analysis can give much more detailed and precise descriptions of grain size and shape characteristics than can be practically achieved by manual quality assessment. Lentil size measurements combined with seed coat descriptors and the color attributes of the grains allowed us to develop an algorithm that was able to identify 64 red lentil genotypes collected at ICARDA with an accuracy approaching 98% for seed size grading and close to 93% for the classification of seed coat morphology.

Qualitative Characterization of Unrefined Durum Wheat Air-Classified Fractions

Durum wheat milling is a key process step to improve the quality and safety of final products. The aim of this study was to characterize three bran-enriched milling fractions (i.e., F250, G230 and G250), obtained from three durum wheat grain samples, by using an innovative micronization and air-classification technology. Milling fractions were characterized for main standard quality parameters and for alveographic properties, starch composition and content, phenolic acids, antioxidant activity and ATIs. Results showed that yield recovery, ash content and particle size distributions were influenced either by the operating conditions (230 or 250) or by the grain samples. While total starch content was lower in the micronized sample and air-classified fractions, the P/L ratio increased in air-classified fractions as compared to semolina. Six main individual phenolic acids were identified through HPLC-DAD analysis (i.e., ferulic acid, vanillic acid, p-coumaric acid, sinapic acid, syringic and p-hydroxybenzoic acids). Compared to semolina, higher contents of all individual phenolic components were found in all bran-enriched fractions. The highest rise of TPAs occurred in the F250 fraction, which was maintained in the derived pasta. Moreover, bran-enriched fractions showed significant reductions of ATIs content versus semolina. Overall, our data suggest the potential health benefits of F250, G230 and G250 and support their use to make durum-based foods.

Use of Almond Skins to Improve Nutritional and Functional Properties of Biscuits: An Example of Upcycling

Upcycling food industry by-products has become a topic of interest within the framework of the circular economy, to minimize environmental impact and the waste of resources. This research aimed at verifying the effectiveness of using almond skins, a by-product of the confectionery industry, in the preparation of functional biscuits with improved nutritional properties. Almond skins were added at 10 g/100 g (AS10) and 20 g/100 g (AS20) to a wheat flour basis. The protein content was not influenced, whereas lipids and dietary fiber significantly increased (p < 0.05), the latter meeting the requirements for applying "source of fiber" and "high in fiber" claims to AS10 and AS20 biscuits, respectively. The addition of almond skins altered biscuit color, lowering L* and b* and increasing a*, but improved friability. The biscuits showed sensory differences in color, odor and textural descriptors. The total sum of single phenolic compounds, determined by HPLC, was higher (p < 0.05) in AS10 (97.84 µg/g) and AS20 (132.18 µg/g) than in control (73.97 µg/g). The antioxidant activity showed the same trend as the phenolic. The p-hydroxy benzoic and protocatechuic acids showed the largest increase. The suggested strategy is a practical example of upcycling when preparing a health-oriented food product.

Meat Production from Dairy Breed Lambs Due to Slaughter Age and Feeding Plan Based on Wheat Bran

Simple Summary

The sheep meat sector in southern Italy, based mainly on light milk-fed lambs, requires technical innovations to improve the production system, the product quality, and enhance the consumption of lamb meat. To fulfill these requirements, this investigation aimed to implement feeding strategies to reduce the cost and energy level of diets for dairy breed lambs slaughtered at an older age than the light lambs, applying a feed restriction at 75% and/or including an inexpensive and local byproduct, such as durum wheat bran (DWB), as a fiber source. The proposed feeding plans were suitable to increase the slaughter age of lambs up to 120 days and produce lean carcasses that, compared to those from 90-day-old lambs, were heavier and with improved meat quality in terms of major water retention and tenderness. The dietary inclusion of DWB limited the fat content and improved the health properties of lamb meat with regard to its antioxidant capacity and fatty acid profile, whereas it reduced lambs’ growth when associated with feed restriction.

Abstract

This experiment aimed to investigate the possibility to increase the carcass weight of dairy breed lambs and produce moderate-fat meat by applying inexpensive feeding strategies based on restriction and through the use of a fibrous byproduct such as the durum wheat bran (DWB). Sixty-five 45-day-old lambs of the Valle del Belice breed, divided into 6 groups, were fed alfalfa hay supplemented with concentrate feeds including DWB at 0% or 20% (DWB0, DWB20), supplied ad libitum (L) or restricted at 75% (R), and slaughtered at 90 or 120 days of age. The groups were as follows: DWB0-90L (n = 14), DWB20-90L (n = 14), DWB0-120R (n = 10), DWB20-120R (n = 9), DWB0-120L (n = 9), DWB20-120L (n = 9). The diet did not affect feed intake, growth or carcass weight of lambs fed ad libitum, whereas 120-day-old lambs fed DWB associated to restriction showed the lowest weight gain (105 vs. 170, 185 and 190 g/day in DWD20-120R, DWB0-120R, DWB0-120L and DWB20-120L; p = 0.04). The incidence of fat tissue in the hind leg increased (p < 0.0001) from 90L (5.82 and 5.45% with DWB0 and DWB20) to 120R (8.80 and 8.43% with DWB0 and DWB20) and 120L lambs (10.7 and 11.8% with DWB0 and DWB20). Older lambs’ meat, compared to that of 90L lambs, showed analogous levels of intramuscular fat, higher water retention, tenderness and lightness, and a more intense red colour. In meat from 120-day-old lambs, DWB intake tended to reduce the fat level (p = 0.009) and increased polyphenol content (1.10 vs. 1.62, and 1.02 vs. 1.65 g GAE/kg dry matter (DM) in 120R and 120L lambs; p = 0.02), antioxidant capacity (12.8 vs. 14.9, and 12.8 vs. 15.7 mmol trolox eq/kg DM in 120R and 120L lambs; p = 0.02), and the presence of n-3 polyunsaturated fatty acids (FA) (1.61 vs. 2.81, and 1.43 vs. 2.61 g/100 g FA in 120R and 120L lambs; p = 0.007), thereby improving the meat’s health properties. The panelists perceived the effects of DWB inclusion as well as the feeding level with triangle tests.

Phenolic extracts from whole wheat biofortified bread dampen overwhelming inflammatory response in human endothelial cells and monocytes: major role of VCAM-1 and CXCL-10

PURPOSE

The aim of the study was to evaluate the vascular health properties of extracts from biofortified bread, obtained by adding different durum wheat milling by-products rich in phenolic compounds, by analyzing their effects on overwhelming inflammatory response in endothelial cells and monocytes, two main players of atherogenesis.

METHODS

Human umbilical vein endothelial cells or U937 monocytes were incubated with increasing concentrations (1, 5, 10 μg/mL) of biofortified bread polyphenol extracts or corresponding pure phenolic acids before stimulation with lipopolysaccharide (LPS). We analyzed the endothelial-monocyte adhesion and related endothelial adhesion molecules. The expression of chemokines and pro-inflammatory cytokines was also measured in LPS-stimulated endothelial cells and monocytes as well as intracellular oxidative stress.

RESULTS

Biofortified bread extracts inhibited monocyte adhesion to LPS-stimulated endothelial cells, in a concentration-dependent manner by reducing mainly endothelial VCAM-1 expression. Phenolic acid extracts contained in 10 mg biofortified bread downregulated the LPS-induced expression of chemokines MCP-1, M-CSF, and CXCL-10 as well as pro-inflammatory cytokines TNF-α and IL-1β, in endothelial cells and monocytes, with CXCL-10 as the most reduced inflammatory mediator. Among phenolic acids of biofortified bread, ferulic, sinapic, and p-coumaric acids significantly inhibited the LPS-stimulated CXCL-10 expression in vascular cells. The reduced pro-inflammatory response was related to a slightly but significant reduction of intracellular oxidative stress.

CONCLUSIONS

Our findings suggest the bread biofortified with selected durum wheat milling by-products as a source of phenolic acids with multiple anti-inflammatory and anti-atherosclerotic properties, which could help to counteract or prevent inflammatory vascular diseases.

Improvement of Oxidative Status, Milk and Cheese Production, and Food Sustainability Indexes by Addition of Durum Wheat Bran to Dairy Cows' Diet

Durum wheat bran (DWB) is a by-product mostly used in feeding ruminants, contributing to decrease in the utilization of feeds suitable as foods for human consumption, thus improving the sustainability of livestock production. However, the potential benefits of DWB, due to its content in phenolic acids, mainly consisting of ferulic acid with antioxidant properties, have not been well clarified yet. Accordingly, in this experiment, 36 lactating cows divided into three groups received, over a period of 100 days, one of three concentrates including DWB at 0% (DWB0), 10% (DWB10), or 20% (DWB20). The concentrates were formulated to be isoproteic and isoenergetic and, to balance the higher fiber content of the concentrates with DWB, the hay in the diets was slightly reduced. During the trial, the group feed intake and the individual milk production were monitored, and cheese was made with bulk milk from each group. Milk yield and microbiological characteristics of milk and cheese were similar among groups, indicating no DWB effect on cows performance and fermentation process. Milk from DWB20 group resulted slightly higher in casein and curd firmness (a_2r). In cows fed DWB, the higher polyphenol intake was responsible for higher blood contents of these bioactive compounds, that seemed to have contributed in reducing the level of reactive oxygen metabolites (ROMs), which were higher in DWB0 cows. DWB20 cheeses showed a higher polyphenol content, lower number of peroxides, and higher antioxidant capacity than DWB0 cheeses. DWB20 and DWB10 diets resulted less expensive. In addition, the DWB20 group showed the best indexes heFCE (human edible feed conversion efficiency = milk/human edible feed) and NFP (net food production = milk - human edible food), expressed as crude protein or gross energy. In conclusion, the DWB fed to dairy cows at 12% of diet dry matter (DM) can lead to benefits, such as the improvement of oxidative status of cows, milk quality, shelf-life, and functional properties of cheese, and might contribute to reduce the feeding cost and limit the human-animal competition for feeding sources.

Effect of processing variables on the physico-chemical characteristics and aroma of borş, a traditional beverage derived from wheat bran

Borş is a traditional Romanian beverage obtained by naturally fermenting an aqueous suspension of wheat bran and corn flour, used as flavoring enhancer in local gastronomy since ancient times, and more recently consumed as refreshing drink. To investigate the changes in sensory, physico-chemical, phenolic and aroma composition resulted after two successive fermentations, borș samples were subjected to standard, sensory, HPLC and GC/MS analysis. Total phenolic compounds and ferulic acid, the most abundant phenolic compound, were positively influenced by natural starter addition, increase of fermentation temperature, and thermal treatment, whereas the effect on less abundant phenolic acids was not univocal. The variables had the same effect on antioxidant activity and brown index. Volatiles (alcohols, carboxylic acids, esters), pungent-sour and goat milk-cheese odor notes increased at higher fermentation temperature, whereas bran and yogurt odor notes decreased. The addition of a natural starter at 4 °C allowed balancing odor intensity and antioxidant activity.

Effect of Supplementation with Wheat Bran Aqueous Extracts Obtained by Ultrasound-Assisted Technologies on the Sensory Properties and the Antioxidant Activity of Dry Pasta

Phenolic compounds have antioxidant properties and activate endogenous detoxification defense systems able to scavenge the reactive species of oxygen. The external layers of wheat caryopsis, largely constituting by-products of the milling industry such as bran and various middlings, contain relevant amounts of phenolic compounds. The aim of the research has been to evaluate the effect of supplementation with wheat bran aqueous extracts, obtained by ultrasound-assisted technologies, on the sensory properties and antioxidant activity of dry pasta. The HPLC-DAD characterization of the extract evidenced the presence of ferulic and p-coumaric acids. The supplemented pasta showed significantly higher antioxidant activity and phenolic content than the control, coupled to good overall sensory judgment. In addition, two different pasta drying diagrams were adopted, and the comparison of the corresponding end-products allowed it to be pointed out that the processing technology has to be carefully set up to prevent possible detrimental effects on the antioxidant activity. The proposed utilization of bran might add value to a milling by-product that, otherwise, is mostly employed in animal feeding.

Effect of Supplementation with Wheat Bran Aqueous Extracts Obtained by Ultrasound-Assisted Technologies on the Sensory Properties and the Antioxidant Activity of Dry Pasta

Phenolic compounds have antioxidant properties and activate endogenous detoxification defense systems able to scavenge the reactive species of oxygen. The external layers of wheat caryopsis, largely constituting by-products of the milling industry such as bran and various middlings, contain relevant amounts of phenolic compounds. The aim of the research has been to evaluate the effect of supplementation with wheat bran aqueous extracts, obtained by ultrasound-assisted technologies, on the sensory properties and antioxidant activity of dry pasta. The HPLC-DAD characterization of the extract evidenced the presence of ferulic and p-coumaric acids. The supplemented pasta showed significantly higher antioxidant activity and phenolic content than the control, coupled to good overall sensory judgment. In addition, two different pasta drying diagrams were adopted, and the comparison of the corresponding end-products allowed it to be pointed out that the processing technology has to be carefully set up to prevent possible detrimental effects on the antioxidant activity. The proposed utilization of bran might add value to a milling by-product that, otherwise, is mostly employed in animal feeding.

Wheat Bran Phenolic Acids: Bioavailability and Stability in Whole Wheat-Based Foods

Wheat bran is generally considered a byproduct of the flour milling industry, but it is a great source of fibers, minerals, and antioxidants that are important for human health. Phenolic acids are a specific class of wheat bran components that may act as antioxidants to prevent heart disease and to lower the incidence of colon cancer. Moreover, phenolic acids have anti-inflammatory properties that are potentially significant for the promotion of gastrointestinal health. Evidence on the beneficial effects of phenolic acids as well as of other wheat bran components is encouraging the use of wheat bran as an ingredient of functional foods. After an overview of the chemistry, function, and bioavailability of wheat phenolic acids, the discussion will focus on how technologies can allow the formulation of new, functional whole wheat products with enhanced health-promoting value and safety without renouncing the good-tasting standards that are required by consumers. Finally, this review summarizes the latest studies about the stability of phenolic acids in wheat foods fortified by the addition of wheat bran, pearled fractions, or wheat bran extracts.

Phytochemical composition and anti-inflammatory activity of extracts from the whole-meal flour of Italian durum wheat cultivars

In this study, the quali-quantitative composition of hydrophilic (phenolic acids) and lipophilic (isoprenoids) extracts from whole-meal flour of five elite Italian durum wheat cultivars was determined. Significant differences in the content of bioactive compounds were observed among the wheat extracts, in particular concerning the content of bound phenolic acids, lutein and β-tocotrienols. The cultivars Duilio and Svevo showed the highest amount of phenolic acids and isoprenoids, respectively. Extracts were evaluated for their anti-inflammatory activity on HT-29 human colon cells by measuring the levels of interleukin 8 (IL-8) and transforming growth factor β1 (TGF-β1). Durum wheat extracts significantly inhibited the secretion of the pro-inflammatory IL-8 mediator at 66 µg/mL of phenolic acids and at 0.2 µg/mL of isoprenoids. Conversely, the secretion of the anti-inflammatory mediator TGF-β1 was not modified by neither hydrophilic nor lipophilic extracts. These results provide further insight into the potential of durum wheat on human health suggesting the significance of varieties with elevated contents of bioactive components.

Volatile Metabolite Profiling of Durum Wheat Kernels Contaminated by Fusarium poae

Volatile metabolites from mold contamination have been proposed for the early identification of toxigenic fungi to prevent toxicological risks, but there are no such data available for Fusarium poae. F. poae is one of the species complexes involved in Fusarium head blight, a cereal disease that results in significant yield losses and quality reductions. The identification of volatile organic compounds associated with F. poae metabolism could provide good markers to indicate early fungal contamination. To this aim, we evaluated the volatile profile of healthy and F. poae-infected durum wheat kernels by SPME-GC/MS analysis. The production of volatile metabolites was monitored for seven days, and the time course analysis of key volatiles was determined. A total of 29 volatile markers were selected among the detected compounds, and multivariate analysis was applied to establish the relationship between potential volatile markers and fungal contamination. A range of volatile compounds, including alcohols, ketones, esters, furans and aromatics, were identified, both in contaminated and in healthy kernels. However, the overall volatile profile of infected samples and controls differed, indicating that the whole volatile profile, rather than individual volatile compounds, could be used to identify F. poae contamination of durum wheat grains.

Effects of sodium alginate bead encapsulation on the storage stability of durum wheat (Triticum durum Desf.) bran oil extracted by supercritical CO2

The aim of this study was to investigate the influence of encapsulation on the storage stability of oil extracted by supercritical carbon dioxide from a micronized durum wheat bran fraction. Wheat bran oil was encapsulated in 2% (w/v) sodium alginate beads. Encapsulated and unencapsulated oil samples were stored at 4 or 25 °C, in daylight or darkness, over 90 days, and, at defined time points, subjected to stability evaluation based on fatty acid hydroperoxide production and tocopherol (α, β, and γ forms), tocotrienol (α, β, and γ forms) and carotenoid (lutein, zeaxanthin, and β-carotene) degradation. The encapsulation of the oil into alginate beads significantly increased stability, optimally when stored at 4 °C, maintaining high levels of isoprenoids and low content of fatty acid hydroperoxides over 30 days of storage.

Over-expression of a grape stilbene synthase gene in tomato induces parthenocarpy and causes abnormal pollen development

A novel strategy to induce parthenocarpy in tomato fruits by the induction of resveratrol biosynthesis in flower tissues was exploited. Two transgenic tomato lines were considered: a higher resveratrol-producing (35SS) line, constitutively expressing a grape stilbene synthase cDNA, and a lower resveratrol-producing (LoxS) line, expressing stilbene synthase under a fruit-specific promoter. The expression of the stilbene synthase gene affected flavonoid metabolism in a different manner in the transgenic lines, and in one of these, the 35SS line, resulted in complete male sterility. Resveratrol was synthesised either in 35SS or LoxS tomato flowers, at an even higher extent (about 8-10 times) in the former line. We further investigated whether stilbene synthase expression may have resulted in impaired naringenin accumulation during flower development. In the 35SS flowers, naringenin was significantly impaired by about 50%, probably due to metabolic competition. Conversely, the amount of glycosylated flavonols increased in transgenic flowers, thereby excluding the diminished production of flavonols as a reason for parthenocarpy in tomato. We further investigated whether resveratrol synthesis may have resulted changes to pollen structure. Microscopic observations revealed the presence of few and abnormal flake-like pollen grains in 35SS flowers with no germination capability. Finally, the analysis of coumaric and ferulic acids, the precursors of lignin and sporopollenin biosynthesis, revealed significant depletion of these compounds, therefore suggesting an impairment in structural compounds as a reason for pollen ablation. These overall outcomes, to the best of our knowledge, reveal for the first time the major role displayed by resveratrol synthesis on parthenocarpy in tomato fruits.

Characterisation of lab in typical Salento Pecorino cheese

Twenty-nine strains of Lactic Acid Bacteria isolated from the typical Pecorino cheese of the Salento area of Italy, were identified and grouped according to their genetic similarity. A preliminary characterisation of the strains was conducted by means of morphological and biochemical analysis, but molecular approaches were necessary for the clear identification of the species. For the species detection, the amplification and sequencing of the 16S rDNA gene was employed In addition, restriction analysis of amplified rDNA (ARDRA) and PCR and AFLP fingerprinting enabled inter- and intra-specific variation to be estimated UPGMA cluster analysis was used to divide the strains into distinct clusters which corresponded with the species delineation obtained by molecular identification. The data obtained show that the community of lactobacilli responsible for the fermentation and aging of Pecorino cheese is composed of a limited number of species. The main identified strains were Lactobacillus brevis, L. plantarum, L. casei, L. sakei, L. pentosus, L. farciminis and Leuconostoc mesenteroides.

Molecular mapping of segregation distortion loci in Aegilops tauschii

Distorted segregation ratios of genetic markers are often observed in progeny of inter- and intraspecific hybrids and may result from competition among gametes or from abortion of the gamete or zygote. In this study, 194 markers mapped in an Aegilops tauschii F2 population were surveyed for distorted segregation ratios. Region(s) with skewed segregation ratios were detected on chromosomes 1D, 3D, 4D, and 7D. These distorter loci are designated as QSd.ksu-1D, QSd. ksu-3D, QSd.ksu-4D, and QSd.ksu-7D. Three regions of segregation distortion identified on chromosome 5D were analyzed in two sets of reciprocal backcross populations to analyze the effect of sex and cytoplasm on segregation distortion. Extreme distortion of marker segregation ratios was observed in populations in which the F1 was used as the male parent, and ratios were skewed in favor of TA1691 alleles. There was some evidence of differential transmission caused by nucleo-cytoplasmic interactions. Our results agree with other studies stating that loci affecting gametophyte competition in male gametes are located on 5DL. The distorter loci on 5DL are designated as QSd.ksu-5D.1, QSd.ksu-5D.2, and QSd.ksu-5D.3.