Waxy Genotypes Research Articles

Lupeol a predisposing factor in grey mould (Amphobotrys ricini [N.F. Buchw.]) Hennebert disease pathogenesis in castor (Ricinus communis L.)

AbstractTo understand the castor wax layer's multifaceted contribution to Amphobotrys ricini pathogenesis, the hydrophobic components of cuticular wax were analysed from waxy and non‐waxy castor genotypes. Gas chromatography–mass spectrometry (GC–MS) technology enabled the stable detection and quantitative determination of various fatty acids and terpenoids. The investigation revealed a significant presence of triterpenoid compound ‘lupeol’, accounting for approximately 53.6% of the wax composition in the waxy genotype (DCH‐519), which was absent in non‐waxy genotype (ICS‐324). On exposure to lupeol, about 93.3% of conidia germinated leading to rapid mycelium growth and sporulation of A. ricini. SEM analysis of waxy and non‐waxy genotypes infected with A. ricini confirmed faster germination and production of longer germ tubes on waxy genotype compared with non‐waxy genotype, which may likely due to early recognition of the suitable host in the presence of lupeol, ultimately aiding in speedy germination and growth of the pathogen setting pace for pathogenesis.

Effects of the waxy genotype and storage temperature of pearled barley on the volatile compounds after cooking

Effects of the waxy genotype and storage temperature of pearled barley on the volatile compounds after cooking

Molecular insights on the origin and development of waxy genotypes in major crop plants.

Starch is a significant ingredient of the seed endosperm with commercial importance in food and industry. Crop varieties with glutinous (waxy) grain characteristics, i.e. starch with high amylopectin and low amylose, hold longstanding cultural importance in some world regions and unique properties for industrial manufacture. The waxy character in many crop species is regulated by a single gene known as GBSSI (or waxy), which encodes the enzyme Granule Bound Starch Synthase1 with null or reduced activity. Several allelic variants of the waxy gene that contribute to varying levels of amylose content have been reported in different crop plants. Phylogenetic analysis of protein sequences and the genomic DNA encoding GBSSI of major cereals and recently sequenced millets and pseudo-cereals have shown that GBSSI orthologs form distinct clusters, each representing a separate crop lineage. With the rapidly increasing demand for waxy starch in food and non-food applications, conventional crop breeding techniques and modern crop improvement technologies such as gene silencing and genome editing have been deployed to develop new waxy crop cultivars. The advances in research on waxy alleles across different crops have unveiled new possibilities for modifying the synthesis of amylose and amylopectin starch, leading to the potential creation of customized crops in the future. This article presents molecular lines of evidence on the emergence of waxy genes in various crops, including their genesis and evolution, molecular structure, comparative analysis and breeding innovations.

Identification of waxy genotype in sorghum genetic resources using waxy gene-based markers and iodine staining methods

Sorghum is widely recognized as a versatile crop with significant value in the production of food and energy. Sorghum with waxy trait (low amylose) is more palatable to the food industries and more appealing to consumers than nonwaxy variety. However, waxy sorghum has not yet been introduced to Indonesia, making it difficult to use sorghum to support the government of Indonesia's initiative to diversify the country's main foods. This study aimed at identify the waxy traits in a set of sorghum germplasm collected in Indonesia using waxy gene-based markers and iodine staining screening approaches. A total of 48 (27 introduced and 21 local) sorghum accessions collected in the IAARD gene bank along with 4 national sorghum varieties, which were subjected to both molecular analysis and iodine staining assay. The presence of waxy allele in the sorghum gene bank collection was identified using DNA markers associated with two waxy alleles (wxa and wxc). Iodine staining assay performed in the present study was applied to verify the waxy phenotype in sorghum grain and waxy genotypes in sorghum pollen. Based on molecular analysis and pollen staining, five local sorghum accessions were classified as heterowaxy sorghum. These accessions showed reddish-brown color in their endosperm after treated by iodine staining which confirmed them as waxy phenotype. These findings would be beneficial for further improvement of grain quality in sorghum breeding programs

Near-infrared spectroscopy for early selection of waxy cassava clones via seed analysis.

Cassava (Manihot esculenta Crantz) starch consists of amylopectin and amylose, with its properties determined by the proportion of these two polymers. Waxy starches contain at least 95% amylopectin. In the food industry, waxy starches are advantageous, with pastes that are more stable towards retrogradation, while high-amylose starches are used as resistant starches. This study aimed to associate near-infrared spectrophotometry (NIRS) spectra with the waxy phenotype in cassava seeds and develop an accurate classification model for indirect selection of plants. A total of 1127 F2 seeds were obtained from controlled crosses performed between 77 F1 genotypes (wild-type, Wx_). Seeds were individually identified, and spectral data were obtained via NIRS using a benchtop NIRFlex N-500 and a portable SCiO device spectrometer. Four classification models were assessed for waxy cassava genotype identification: k-nearest neighbor algorithm (KNN), C5.0 decision tree (CDT), parallel random forest (parRF), and eXtreme Gradient Boosting (XGB). Spectral data were divided between a training set (80%) and a testing set (20%). The accuracy, based on NIRFlex N-500 spectral data, ranged from 0.86 (parRF) to 0.92 (XGB). The Kappa index displayed a similar trend as the accuracy, considering the lowest value for the parRF method (0.39) and the highest value for XGB (0.71). For the SCiO device, the accuracy (0.88-0.89) was similar among the four models evaluated. However, the Kappa index was lower than that of the NIRFlex N-500, and this index ranged from 0 (parRF) to 0.16 (KNN and CDT). Therefore, despite the high accuracy these last models are incapable of correctly classifying waxy and non-waxy clones based on the SCiO device spectra. A confusion matrix was performed to demonstrate the classification model results in the testing set. For both NIRS, the models were efficient in classifying non-waxy clones, with values ranging from 96-100%. However, the NIRS differed in the potential to predict waxy genotype class. For the NIRFlex N-500, the percentage ranged from 30% (parRF) to 70% (XGB). In general, the models tended to classify waxy genotypes as non-waxy, mainly SCiO. Therefore, the use of NIRS can perform early selection of cassava seeds with a waxy phenotype.

Short germination and debranning affect bioactive compounds and pasting properties of rice genotypes

Germination is a natural metabolic process widely used to modify sensory properties and nutritional aspects. Rice containing high amylose content has a larger germ and, consequently, could accumulate higher γ-aminobutyric acid (GABA) levels in this portion. This study aimed to evaluate the effect of short germination and debranning on α-amylase activity, pasting properties, phytochemicals, and amino acid profile of genotypes with distinct amylose content. The results of the falling number showed that BRS Formoso (high amylose) presented the highest value (>1000 s), indicating no activity of α-amylase and higher retrogradation (3793–3593 cP), whereas Mochi (waxy genotype) demonstrated the lowest retrogradation (maximum of 241 cP). Short germination increased L-glutamic acid and GABA contents in all genotypes, but debranning decreased these compounds. Short-time germination led to an expressive increase in umami amino acids, mainly in BRS Guaporé and Mochi, which also showed high levels of proline in both brown and polished grains. Novelty impact statement Short germination (<24 h) did not increase the α-amylase activity High amylose content impacted pasting properties and GABA synthesis Reduction of γ-oryzanol and γ-tocotrienol is more pronounced in polished rices

Rheological behaviors, structural properties and freeze-thaw stability of normal and waxy genotypes of barley starch: a comparative study with mung bean, potato, and corn starches.

The rheological behaviors, structural properties and freeze-thaw stability of starch isolated from Tetonia barley (Normal genotype, Reg. No. CV-334, PI 646199) and Transit barley (Waxy genotype, Reg. No. CV-348, PI 660128) were investigated, along with other common starch sources for comparison. Transit barley starch showed the highest loss tangents (tan δ) during a frequency sweep test, which suggested a predominance of elastic properties over viscous properties. However, the tan δ of Tetonia barley starch was similar to that of potato starch, which indicated more solidity in comparison to Transit barley starch. Transit barley starch had the highest gelatinization temperature and the lowest gelatinization enthalpy (P < 0.05). Moreover, Tetonia and Transit barley starches displayed weak diffraction peak intensities by X-ray diffraction analysis. Additionally, Transit barley starch showed the lowest % syneresis even when freeze-thawed up to five cycles (P < 0.05). However, Tetonia barley starch had the worst freeze-thaw stability (P < 0.05), which was verified via scanning electron microscopy analysis of freeze-thawed starch gels. The results of present study indicate that barley starch can be practically applied as a functional ingredient in some specialty starchy foods.

Variation in amylose concentration to enhance wheat flour extrudability

Composition and functionality of five waxy wheat (Triticum aestivum L.) genotypes were elaborately investigated and related to end-product attributes of extrudates. As such, the interaction between starch biopolymers and protein in extrusion processing could be studied. Furthermore, the effect of an increasing amylose-concentration was studied by the use of blends. Waxy genotypes absorbed more water, gave rise to stiffer doughs and had higher onset and peak gelatinization temperature. In contrast, a lower pasting temperature and final viscosity and higher peak viscosity and breakdown could be observed. The volume percentage of small starch granules showed to be negatively correlated with peak temperature and positively with final viscosity and holding strength as well as with extrudate hardness. This was also positively correlated with amylose concentration. Expansion index was highest at a slightly decreased amylose concentration of 16.6%. Markedly higher moisture content for all amylose-free extrudates was attributed to a combination of increased solubility of amylopectin and reduced water evaporation at die emergence. It was hypothesized that an interplay with protein content and composition was laying at the basis of the observed differences. Moreover, the altered pasting behavior of waxy wheat may enhance the extrudability of gluten containing wheat flour.Starch granule size distribution is related to extrudate texture. Amylose content affects expansion index, water absorption and texture of extrudates. Interaction between starch content and protein composition and quality was observed. Waxy genotypes are strongly varying in their protein composition and functionality. Maximum expansion was obtained for blends containing 25% waxy flour.

Production of ß-glucan enriched flour from waxy barley

Starch (total, amylose and amylopectin), β-glucans (total, soluble and insoluble) and pasting properties of waxy and normal barley genotypes were assessed. Waxy genotypes showed higher β-glucans content, lower starch amount and higher viscosity than normal genotypes. The USA2 waxy genotype characterized by higher β-glucans content, has been subjected to dehulling, pearling, and pin-milling and then to air classification to obtain an enriched flour that showed higher dietary fiber (23.4% d.w.) and β-glucans content (15.3% d.w.) The obtained enriched flour could be used for the production of functional foods (pasta, bread, biscuits etc) that satisfy the requirements of FDA and EU Regulation.

Identification of waxy cassava genotypes using fourier‐transform near‐infrared spectroscopy

AbstractHigh‐throughput phenotyping tools that allow the early and accurate evaluation of important agronomic traits have gained space in current breeding programs. The aim of this study was to evaluate the potential of Fourier‐transform near‐infrared spectroscopy (FT‐NIRS) to identify cassava (Manihot esculenta Crantz) clones with waxy starch (i.e., amylose‐free) by screening leaves rather than roots, and to validate prediction models for classifying these phenotypes. We analyzed the spectra of 162 waxy and 180 nonwaxy genotypes from five different growing environments. The mean FT‐NIRS spectra and principal component analysis (PCA) were used to investigate the potential for grouping the data. For classification, five supervised pattern recognition techniques were tested: Bayesian generalized linear model (BGLM), high‐dimensional discriminant analysis (HDDA), partial least squares‐discriminant analysis (PLS‐DA), parallel random forest (PRANDF), and support vector machines with linear kernel (SVM). The mean spectra and the PCA did not allow discrimination of the genotypes based on starch classification. The SVM and BGLM showed the highest classification accuracy in cross‐validation (.86–.87), with higher concordance rates (.88–.83), sensitivity (.87–.85) and specificity (.88). The BGLM and SVM models also obtained better indices in the external validation, with high accuracy (.85) and correct classification of 93% of the waxy genotypes. Thus, performing early selection of root characteristics based on the indirect selection of variables extracted from leaf spectra is a good potential strategy for more efficient breeding of the waxy phenotype.

Impact of granule hydration on maize and wheat starch chemical reactivity at the granular and molecular levels

Granular and molecular reaction patterns of maize and wheat starches (normal and waxy genotypes) were investigated in relation to extent of granule hydration (equilibrated at 25, 55, 75, 86 or 100% relative humidity [RH]; moisture range ≈ 10–40 g/100 g starch) within a model reaction system utilizing a fluorescent reagent (5-(4,6-dichlorotriazinyl)aminofluorescein). The greatest incremental increase in granule hydration (49–80%) and overall extent of reaction (30-76-fold) occurred between 86 and 100% RH, likely accentuating the starch glass transition temperature (Tg), which was depressed to room temperature via gradual granule hydration. Under limited hydration conditions (25–86% RH; presumably below Tg), reaction was confined to granule surfaces, whereas under conditions of sufficient hydration/plasticization (100% RH; presumably above Tg), reaction occurred throughout the granule matrix, dramatically increasing reaction of amylose and amylopectin branch chains. For normal starches, amylose was more inert to reaction in low moisture conditions (25–87% RH), indicating either a lesser prevalence at granular surfaces or insufficient hydration to react. Waxy starches exhibited more homogenous granular reaction patterns and greater overall extents of reaction than their respective normal starch counterparts, due to reactivity differences amongst amylose and amylopectin medium and long chains. Findings also provide insights for manipulating granular/molecular reaction locale in “dry” starch modifications.

Variation of protein molecular weight distribution parameters and their correlations with gluten and mixing characteristics for winter waxy wheat

AbstractBackground and objectivesLittle data have been reported on protein molecular weight distribution (MWD) for waxy (amylose‐free) wheat (Triticum aestivum L.) despite their importance in quality. This research aimed to investigate variations of protein MWD parameters and their associations with gluten strength in winter waxy wheat.FindingsWinter waxy wheat genotypes varied significantly (p &lt; 0.001) for most protein MWD parameters including SDS‐extractable polymeric protein (EPP) and unextractable polymeric protein (UPP) fractions, which are major components of gluten proteins. Allelic variation of HMW glutenin subunits had significant influence on variations of EPP and UPP in waxy genotypes. Negative correlations for EPP and positive correlations for UPP were observed with mixograph peak time and gluten index for wheat genotypes. In particular, highly significant (p &lt; 0.001) correlations were observed between mixograph peak time and the proportion of EPP in total protein for waxy genotypes.ConclusionsWinter waxy wheat genotypes showed significant variations for EPP and UPP parameters, which were associated with variation of gluten strength.Significance and noveltyThis research identified variation of protein MWD parameters and their associations with gluten strength. The information should be valuable in segregating winter waxy wheat genotypes that have favorable gluten quality as well as unique waxy starch.

Impact of Environment and Genotype‐by‐Environment Interaction on Functional Properties of Amylose‐Free and Wildtype Cassava Starches

Ten and thirty cassava genotypes producing wildtype and amylose‐free (waxy) starch respectively, are grown at low (LA) and intermediate (IA) altitudes (&lt;213 and &gt;900 m above sea level (m.a.s.l.) respectively). The functional properties of the starch from these materials are analyzed. The relative importance of environment, clones (within starch type) and genotype‐by‐environment interaction (GxE) is assessed through an analysis of variance. GxE effects are non‐significant, whereas environment and clones (within starch type) are highly significant in most of the cases (particularly for waxy starches). Results confirm that waxy cassava starches consistently show higher peak viscosity (PV) compared with wildtypes. Peak viscosity is statistically higher in plants grown in IA compared with those from the same genotypes grown in LA, both for waxy and wildtype genotypes. In a second experiment, a single waxy genotype is grown in five locations ranging from 934 to 1485 m.a.s.l. PV is highest in the location with higher altitude. The second highest PV is measured in starches from the second highest location at 1071 m. Both experiments clearly indicate that PV is positively correlated with altitude above sea level where cassava is grown. Altitude above sea level influenced starch granule size: the higher the altitude the larger the average granule size. Waxy starch granules tend to be larger than those from wildtype genotypes.

GGE biplot analysis of yield stability and test location representativeness in proso millet (Panicum miliaceum L.) genotypes

The experiments were conducted for three consecutive years across 14 locations using 9 non-waxy proso millet genotypes and 16 locations using 7 waxy proso millet genotypes in China. The objectives of this study were to analyze yield stability and adaptability of proso millets and to evaluate the discrimination and representativeness of locations by analysis of variance (ANOVA) and genotype and genotype by environment interaction (GGE) biplot methods. Grain yields of proso millet genotypes were significantly influenced by environment (E), genotype (G) and their interaction (G×E) (P<0.1%). G×E interaction effect was six times higher than G effect in non-waxy group and seven times in waxy group. N04-339 in non-waxy and Neimi 6 (NM6) in waxy showed higher grain yields and stability compared with other genotypes. Also, Neimi 9 (NM9, a non-waxy cultivar) and 90322-2-33 (a waxy cultivar) showed higher adaptability in 7 and in 11 locations, respectively. For non-waxy, Dalat, Inner Mongolia (E2) and Wuzhai, Shanxi (E5) were the best sites among all the locations for maximizing the variance among candidate cultivars, and Yanchi, Ningxia (E10) had the best representativeness. Wuzhai, Shanxi (e9) and Yanchi, Ningxia (e14) were the best representative locations, and Baicheng, Jilin (e2) was better discriminating location than others for waxy genotypes. Based on our results, E10 and e14 have enhanced efficiency and accuracy for non-waxy genotypes and waxy genotypes selection, respectively in national regional test of proso millet varieties.

Characterization of milling fractions from new sources of barley for use in food industry

The aim of this work was to characterize three Czech spring and one German winter barley cultivars specifically cultivated for use in the food industry. Two hull‐less and two waxy barleys were roller‐milled and separated into ten milling fractions. Additionally one wholemeal flour was prepared. The chemical composition of flour fractions from all cultivars was compared individually. The starch content was very similar in white flour fraction C1 and coarse bran flour from both waxy genotypes. The highest β‐glucan content was determined in bran fractions in all barley materials. The similar trend was also found for the arabinoxylan content. Czech spring breeding line KM 1057 showed higher arabinoxylan content in all milling fractions than the other varieties. A strong positive correlation between β‐glucan and protein content, as well as β‐glucan and dietary fibre was found. By choosing the suitable milling fractions (flour separated from bran or bran, especially in hull‐less cultivars), as high fibre to starch ratio as 1:0.8 can be achieved. Furthermore these fractions contained a high content of β‐glucan, protein and ash.

Development of a waxy gene real-time PCR assay for the quantification of sorghum waxy grain in mixed cereal products.

BackgroundWaxy-grain sorghum is used in most of the commercial cereal products in Korea. Worldwide, three waxy mutant alleles have been identified in the sorghum germplasm, and DNA markers for these alleles have been developed to identify the waxy genotype. However, that detection method cannot be used to determine the proportion of waxy content in samples containing both waxy and non-waxy sorghum. This study developed an assay that can be used to detect and quantify the waxy content of mixed cereal samples.ResultsAll Korean waxy-grain sorghum used in this study contained the wxa allele, and one wxa allele-containing individual was also heterozygous for the wxc allele. No individuals possessed the wxb allele. The genotyping results were confirmed by iodine staining and amylose content analysis. Based on the sequence of the wxa allele, three different types of primers (wxa allele-specific, non-waxy allele-specific, and nonspecific) were designed for a quantitative real-time PCR (qPCR) assay; the primers were evaluated for qPCR using the following criteria: analytical specificity, sensitivity and repeatability. Use of this qPCR assay to analyze mixed cereal products demonstrated that it could accurately detect the waxy content of samples containing both waxy and non-waxy sorghum.ConclusionsWe developed a qPCR assay to identify and quantify the waxy content of mixed waxy and non-waxy sorghum samples as well as mixtures of cereals including sorghum, rice and barley. The qPCR assay was highly specific; the allele-specific primers did not amplify PCR products from non-target templates. It was also highly sensitive, detecting a tiny amount (>0.5%) of waxy sorghum in the mixed samples; and it was simple and repeatable, implying the robust use of the assay.Electronic supplementary materialThe online version of this article (doi:10.1186/s12896-015-0134-z) contains supplementary material, which is available to authorized users.

Genetic variation of the granule-bound starch synthase I (GBSSI) genes in waxy and non-waxy accessions of Chenopodium berlandieri ssp. nuttalliae from Central Mexico

Huauzontle (Chenopodium berlandieri ssp. nuttalliae) is a locally important vegetable crop native to the highland valleys of Central Mexico and a potential source of genes for improving its Andean sister crop, quinoa (Chenopodium quinoa). A previous work involving two huauzontle lines identified one waxy genotype that lacked amylose due to mutations in granule-bound starch synthase I (GBSSI), major amylose-synthesis genes with two constituent subgenomes, A and B. We conducted this study to determine the extent of waxy genotypes and cryptic GBSSI mutations in 11 huauzontle accessions or landrace populations extending from Puebla in the southeast to Jalisco in the northwest. This represents one of the first published studies of genetic variation in C. berlandieri ssp. nuttalliae. Accessions were phenotyped for opaque versus translucent seed morphology and their seed starches were stained with Lugol's Stain. In addition, complete or partial GBSSI genes from their A and B genomes were polymerase chain reaction (PCR)-amplified, cloned and sequenced. Seven accessions were either wholly or partially non-waxy while six were either entirely or partially waxy. All waxy accessions carried the same putatively null alleles, designated gbssIa-tp (A-genome) and gbssIb-del (B-genome). The identification of publicly available genotypes carrying gbssIa-tp and their potential use in breeding waxy grain quinoa is discussed.

Aktywność mszycy zbożowej (Sitobion avenae) oraz czeremchowo-zbożowej (Rhopalosiphum padi) w procesie żerowania mszyc na sztucznych pożywkach z ekstraktami wosków powierzchniowych

Summary Electrical Penetration Graphs (EPG) were used to monitor the feeding behaviour of cereal aphids exposed to the surface waxes in artificial diets. The EPG patterns generated by aphids feeding on plants were used to interpret the patterns generated on the artificial diets. The surface waxes from waxy genotype (RAH 122) completely stopped salivation (as indicated by EPG pattern p-E1), passive and active ingestion (as indicated by pattern p-E2 and pattern p-G) and also delayed the onset of stylet activity (EPG pattern p-C). The surface waxes from waxless genotype (RAH 366) applied into the artificial diets prolonged the period of stylet activity in the diet (pattern p-C), passive ingestion of the diet (pattern p-E2), reduced non-probing (pattern p-np) and active ingestion of the diet (pattern p-G). Results presented in the paper suggest that chemical compounds which occur within epicuticular waxes of the waxy genotype (RAH 122) and waxless genotype (RAH 366) play an important role during feeding behaviour of the grain aphid and bird cherry-oat aphid. Summing up the epicuticular wax compounds clearly affected feeding behavior of the cereal aphids, thus waxy triticale genotype might be useful for limiting the population of cereal pest.

Wheat genome specific granule-bound starch synthase I differentially influence grain starch synthesis

Wheat grain development is a complex process and is characterized by changes in physicochemical and structural properties of starch. The present study deals with endosperm starch physicochemical properties and structure during development in different granule-bound starch synthase I (GBSSI) null also known as waxy (Wx) genotypes. The study was conducted with pure starch isolated from wheat grains at 3–30 days post anthesis (DPA), at 3-day intervals. Amylose concentration increased throughout grain development in non-waxy (7.2–30.5%) and partial waxy genotypes (6.0–26.8%). Completely waxy genotype showed 7.0% amylose at 3 and 6DPA, which declined during development and reached non-detectable quantities by 30DPA. Amylopectin structure had a higher content of short chains at 3DPA, which decreased continuously until 12DPA, after which there were only minor changes in amylopectin chain length distribution. Similarly, the average degree of polymerization (DP) increased from 3DPA (12.3) to 12DPA (15.0), and then did not differ significantly up to 30DPA (15.0). This suggests the formation of basic amylopectin architecture in wheat by 12DPA. Wx-B and Wx-D affected amylopectin short chains mostly of DP 6–8 at 3 and 6DPA. Wx-A affected the same fraction of chains at 9 and 12DPA, and Wx-D affected DP 18–25 chains from 18 to 30DPA, suggesting differential effect of waxy isoproteins on amylopectin structure formation.

Effect of heating temperature on the particle size distribution in waxy wheat flour

The particle size of waxy (amylose-reduced) wheat (Triticum aestivum L.) starch was determined at isothermal temperatures by laser diffraction analysis. Flour samples were suspended in deionized water at temperatures ranging from 30 to 90 °C for 20–60 min. At 30 °C, all of the flour particles exhibited trimodal size distributions, i.e., the particles in the first, second, and third modes were <10 μm, 10–50 μm, and 51–300 μm, respectively. Control experiments with isolated starch indicated that the first and second modes were associated mainly with starch granules, whereas the third mode may have been related to gluten and gluten adhesion. The particle size distributions of waxy segregant wheat flours were temperature dependent. At 60 °C, there were significant changes in the particle size and distribution of waxy flours, which indicated the swelling of starch granules in response to elevated temperature. As the temperature increased, the peak particle size of waxy segregant wheat flours increased in different ways. The results suggest that variations in the swelling properties of selected waxy genotype flours may be due to the strength of starch–protein interaction and the capacity for starch granule gelatinization.