Hessian Fly Research Articles

Molecular methods for the detection and identification of parasitoids within larval wheat midges.

Three species of cecidomyiid midges (Diptera: Cecidomyiidae) cause significant yield losses on wheat in Europe: Sitodiplosis mosellana (Géhin), Contarinia tritici (Kirby) and Haplodiplosis marginata (von Roser). Eggs and young larvae may be parasitised by a complex of hymenopteran parasitoids belonging to the Pteromalidae and Platygastridae families which contributes to natural pest control. We have developed molecular tools for detecting and identifying seven parasitoid species previously encountered in Belgium inside individual wheat midge larvae. Barcode DNA sequences from COI, 18S and 28S genes were obtained from the midges and parasitoid species. Each of the three genes allowed all the species to be distinguished although 18S was the only one displaying a barcoding gap, both between parasitoids and midges, and at the species level. Based on the 18S gene, we developed a TaqMan assay to assess parasitism in midge larvae, regardless of the midge and parasitoid species. Next, two group-specific PCR primer pairs were generated, allowing the separate amplification of midge DNA or parasitoid DNA in parasitised individuals and subsequent identification by Sanger sequencing. Finally, species-specific primers were designed to identify six parasitoid species by simple PCR amplification. These tools were successfully applied to assess the parasitism rate of S. mosellana larvae in seven Belgian fields.

Triticum monococcum subsp. monococcum and aegilopoides: new sources of resistance to the dipteran pest, Hessian fly (Diptera: Cecidomyiidae).

The Hessian fly, Mayetiola destructor (Say) belonging to the order Diptera (family: Cecidomyiidae), is a destructive pest of host wheat (Triticum aestivum L.) causing significant economic losses. Although planting resistant wheat cultivars harboring an effective Hessian fly resistance gene (H) is the most economical and environmentally friendly pest management strategy, it imposes selection pressure on the insect populations and can lead to the evolution of Hessian fly virulence. This results in the eventual failure of the deployed H gene. New sources and novel types of resistance are urgently needed to expand the repertoire of H genes and enable strategies that are more effective and durable over the long-term. New sources of Hessian fly resistance have been identified from tetraploid (T. turgidum L., AABB) and hexaploid (T. aestivum, AABBDD) wheat species, as well as from wheat's D-genome donor (Aegilops tauschii Coss., DD). In contrast, diploid einkorn wheat (T. monococcum L., AA) has not been extensively explored for Hessian fly resistance. In this study, we phenotyped 506 T. monococcum accessions belonging to 2 subspecies, T. monococcum L. subsp. monococcum (205 accessions) and T. monococcum subsp. aegilopoides (Link) Thell. (301 accessions), for resistance against 2 predominant Hessian fly biotypes, L and GP (Great Plains). Three and 6 accessions belonging to subsp. monococcum and aegilopoides, respectively, showed > 70% resistance. These accessions provide additional resources for improving wheat cultivars as mitigating strategies for Hessian fly management.

AAC Dutton Canada Western Red Spring wheat

AAC Dutton (BW1094) is a hollow-stemmed, awned, and high yielding Canada Western Red Spring (CWRS) wheat cultivar suited to the growing conditions of Western Canada. AAC Dutton was 1% higher yielding than AAC Viewfield, the highest yielding check in the Central Bread Wheat Cooperative registration trials (2019–2021). Within the same test, AAC Dutton was 10% higher yielding than Carberry. AAC Dutton matured 1 day earlier than Glenn, Carberry, and AAC Viewfield and less than a day later than Unity: Unity being the earliest maturing check in the registration trial. AAC Dutton was 10 cm shorter than Unity with lodging score lower than the mean of the checks. The test weight of AAC Dutton was similar to Unity while the 1000-kernel weight was higher than AAC Viewfield. The grain protein content of AAC Dutton was lower than all the checks. AAC Dutton had a moderately resistant reaction to Fusarium head blight ( Fusarium graminearum Schwabe) and stripe rust ( Puccinia striiformis Westend). AAC Dutton had optimal resistance to leaf rust ( Puccinia triticina Erikss.), stem rust ( Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn), common bunt ( Tilletia caries [DC] Tul. & C. Tul.), and to orange blossom wheat midge ( Sitodiplosis mosellana Géhin). AAC Dutton was registered under the CWRS class.

Impact of phytohormones on wheat resistance to Hessian fly under heat stress

The Hessian fly (HF, Mayetiola destructor) is one of the most destructive pests of wheat and wheat-related cereals. Wheat resistance and/or susceptibility to HF are often affected by the levels of phytohormones in plants. In this study, we tested the impact of phytohormones on Molly wheat resistance to HF biotype GP by externally applying phytohormones, including salicylic acid (SA), jasmonic acid (JA), 12-oxophytodienoic acid (OPDA), and auxin (indole acetic acid, IAA) to wheat seedlings under heat conditions. Our results indicated that the impact of externally applied phytohormones on wheat resistance to HF depends on the timing of phytohormone application and/or HF larval density at HF feeding sites in the plants. The early application of SA, OPDA, and IAA enhanced wheat resistance to HF under heat stress at low larval density, while the delayed application of SA, OPDA, and IAA did not affect wheat resistance to HF at high larval density.

Hessian Fly (Diptera: Cecidomyiidae) Management Using Seed Treatments in Winter Wheat1

Abstract The Hessian fly, Mayetiola destructor (Say) (Diptera: Cecidomyiidae), is a potentially severe pest of wheat, Triticum aestivum L. em Thell, in the southeastern United States. Plant resistance is an effective method to control Hessian fly, but when adapted high-yielding varieties with effective resistance are not available, neonicotinoid insecticide seed treatments may provide an alternative method of control of Hessian fly on susceptible varieties of winter wheat. A series of experiments were conducted to examine the efficacy of neonicotinoid seed treatments for control of Hessian fly in winter wheat. Infestations and immature numbers per tiller were assessed during the vegetative stages in autumn and winter and the wheat reproductive stage during the spring. Both imidacloprid 480FS at 0.31 g active ingredient (a.i.)/kg of seed and clothianidin at 0.39 g a.i./kg or higher rates provided consistent reductions in Hessian fly infestations during autumn and early winter. Lower rates were less effective, and they did not provide consistent reductions in autumn infestations. Thiamethoxam was evaluated at one rate in two experiments and was similar in efficacy to imidacloprid and clothianidin at the same rate. None of the seed treatments provided effective control of spring infestations during the wheat reproductive stage. Imidacloprid and clothianidin at rates of 0.31 g a.i./kg of seed or higher rates had a positive yield response in eight of nine comparisons, with an average increase of 285.9 ± 92.7 kg/ha. Neonicotinoid insecticide seed treatments at higher rates provide a useful method for managing Hessian fly on susceptible varieties of winter wheat.

Evaluating a worldwide wheat collection for resistance to Hessian fly biotype ‘Great Plains’

Evaluating a worldwide wheat collection for resistance to Hessian fly biotype ‘Great Plains’

The rearrangement features and phylogenetic signals of mitochondrial genomes of gall midge subfamily Cecidomyiinae (Diptera: Cecidomyiidae) with first complete mitogenome of an economically important mango gall midge pest, Procontarina fructiculi from Guangxi, China

ABSTRACT In this study, we obtained the first complete mitochondrial genome of Procontarina fructiculi, an important mango gall midge pest from Guangxi, China. The mitogenome of P. fructiculi was sequenced and annotated for the first time, and compared with all the published and annotated data of Cecidomyiidae species to summarise the gall midge organisation and rearrangement features of mitochondrial genomes with phylogenetic analysis. The comparison of gall midge mitochondrial genome structure shows that the rearrangement of the mitochondrial gene structure is very common, and most rearrangements are embodied in rearrangement in the order of tRNAs. The phylogenetic results based on the maximum likelihood (ML) and Bayesian inference (BI) methods both highly supported the monophyly of Cecidomyiinae. Cecidomyiinae can be divided into two distinct clades (except Cecidomyiidae sp. 3): A: (Mayetiola destructor + Rhopalomyia pomum) and B: (Asphondylia rosetta + ((Procontarinia fructiculi + Orseolia oryzae) + ((Cecidomyiidae sp. 1 + Aphidoletes aphidimyza) + Cecidomyiidae sp. 2))). Based on the above results, some phylogenetic signals in rearrangement have been found in the mitochondrial genome structure of Cecidomyiinae for the first time.

Volatile Organic Compounds Mediate Host Selection of Wheat Midge, Sitodiplosis Mosellana (Géhin) (Diptera: Cecidomyiidae) between Preanthesis and Postanthesis Stages of Wheat.

The orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a significant wheat pest in the Prairie Provinces of Canada and northern regions of the USA. Wheat phenology plays a critical role in wheat midge oviposition. We hypothesized that S. mosellana oviposition behaviour is influenced by volatile organic compounds (VOCs) emitted by wheat at two adjacent wheat growth stages: preanthesis and postanthesis. A higher number of S. mosellana eggs laid on preanthesis than postanthesis spikes in an oviposition choice experiment using the susceptible spring wheat cultivar 'Roblin'. In preanthesis, wheat emitted higher amounts of Z-3-hexenyl acetate (Z3-06:OAc) than at the postanthesis stage. Higher amounts of methyl ketones such as 2-tridecanone, 2-pentadecanone, and 2-undecanone were emitted by wheat in the postanthesis stage and these VOCs were sensitive to S. mosellana antennae used in the Gas Chromatography-Electroantennographic Detection. Females were attracted to synthetic Z3-06:OAc but were deterred by 2-tridecanone relative to the solvent control in the vertical Y-tube olfactometer. 2-Undecanone and 2-pentadecanone did not show any attractiveness or deterrence. In a no-choice oviposition experiment, fewer eggs were laid in preanthesis wheat exposed to a synthetic VOC blend of Z3-06:OAc, 2-undecanone, 2-tridecanone, and 2-pentadecanone at the concentrations released by postanthesis spikes. This study shows that the reduction of Z3-06:OAc, in the VOC mix, and possibly the increase in 2-tridecanone, are likely responsible for the reduction in oviposition on postanthesis wheat. These results elucidate for the first time the role of specific VOCs mediating S. mosellana oviposition in preanthesis and postanthesis wheat.

Higher levels of virulence to multiple resistance genes were detected in Hessian fly (Mayetiola destructor) populations from Texas

AbstractHessian fly is an important pest of wheat worldwide and is of particular importance in Texas and the southeastern United States. Texas is the highest wheat‐producing state that is severely impacted by this insect. The most effective control in these areas is an integrated pest management program, including resistant varieties of wheat. Hessian fly populations are genetically diverse and can rapidly become virulent to specific resistance genes once they are widely deployed in a region. Knowing the current virulence status of regional fly populations is important for wheat breeders and producers. In this study, a virulence analysis was conducted on populations sampled in the northeastern and central Texas regions. This analysis showed that resistance genes H12, H13, H20, H22, H25, H26, H28, H29, H32, H33, H34, and Hdic are still highly effective in these regions. However, it is also evident that Texas fly populations have become more virulent to existing genes in the past 10 years, with very high levels of virulence to resistance genes H3, H5, vH6, H7/H8, H9, H10, H14, H15, H23, H24, H31, and H35/H36.

Genome-Wide Association Study of Host Resistance to Hessian Fly in Barley.

The Hessian fly (HF), Mayetiola destructor (Diptera: Cecidomyiidae), is one of the most devastating insect pests of cereals including wheat, barley, and rye. Although wheat is the preferred host for HF, this continuously evolving pest has been emerging as a threat to barley production. However, characterization and identification of genetic resistance to HF has not been conducted in barley. In the present study, we used a genome-wide association study (GWAS) to identify barley resistance loci to HF using a geographically diverse set of 234 barley accessions. The results showed that around 90% of barley lines were highly susceptible, indicating a significant vulnerability to HF in barley, and a total of 29 accessions were resistant, serving as potential resistance resources. GWAS with a mixed linear model revealed two marker-trait associations, both on chromosome 4H. The resistance loci and associated markers will facilitate barley improvement and development for breeders. In addition, our results are fundamental for genetic studies to understand the HF resistance mechanism in barley.

The Hessian fly resistance gene HvRHF1 is localized in an NBS-LRR gene cluster in barley.

Hessian fly (Mayetiola destructor Say) is a significant pest in cereal crops, causing substantial yield losses worldwide. While host resistance is the most efficient method for pest control, research on genetic characterization of Hessian fly resistance in barley (Hordeum vulgare L.) has been limited, and the underlying resistance mechanism remains largely unknown. In this study, we conducted fine mapping of a crucial Hessian fly resistance locus, known as HvRHF1, using a biparental population. Assisted with genetic markers and robust phenotyping assay, we pinpointed the HvRHF1 gene to an ~ 82kb region on chromosome 4H. Gene prediction and annotation revealed that the HvRHF1 locus comprises three complete NBS-LRR genes, which are characteristic of disease resistance genes. As a result, our study not only provides valuable resources for resistance in barley and genetic tools for breeding, but also identifies candidate genes that lay the foundation for cloning HvRHF1. This endeavor will significantly contribute to our understanding of the molecular mechanisms underlying cereal resistance to Hessian fly.

Tetraploid wheat (Triticum turgidum) lines from the United States as a source of Hessian fly (Mayetiola destructor) resistance

AbstractDeploying resistant wheat cultivars is the most economical and environment‐friendly strategy to manage the devastating effects of the dipteran pest, Hessian fly (Hf; Mayetiola destructor). Currently, 37 Hf resistance genes have been identified to combat the 18 Hf genotypes documented so far. However, the Hf populations adapt rapidly to overcome the newly deployed resistance genes within a few years of release resulting in development of virulent Hf biotypes and breakdown of plant resistance. Identification of new and novel sources of resistance offers breeders additional resources that can be included in the breeding programmes to develop elite Hf‐resistant cultivars. In the current study, we screened 374 wheat (tetraploid and hexaploid) accessions originating from different regions of the United States and identified three tetraploid (Triticum turgidum) pasta wheat lines, one originating from North Dakota (PI 639869) and two from Minnesota (PI 352398 and CItr 15710) exhibiting ≥95% resistance to Hf biotype L at 20°C. Further, the wheat cultivar PI 352398 showed 100% resistance to six additional Hf genotypes including biotypes B, C, D, O, GP and vH13. The lines PI 639869 and CItr 15710 also showed >70% resistance with most biotypes, except against biotype GP with the former and biotype B with the latter. Interestingly, a few plants from these two cultivars exhibited putative tolerance to these biotypes where the plants showed normal growth but harboured white, live larvae and showed cell permeability that was intermediate in levels between Hf‐infested resistant and susceptible wheat. Additionally, since the increase in environmental temperatures to 25–30°C also negatively impacts Hf resistance, the three T. turgidum (PI 639869, PI 352398 and CItr 15710) cultivars were evaluated for Hf resistance at 30°C. None of the wheat cultivars were resistant to Hf biotype L at 30°C indicating a temperature‐dependent breakdown of resistance and are therefore not suitable for geographical regions with higher environmental temperatures. Taken together, these three wheat lines represent additional sources of Hf resistance that can be leveraged by breeders for developing durable elite lines.

Genetic dissection of Hessian fly resistance in bread wheat (Triticum aestivum L.) using genome-wide association study in Morocco

Hessian fly (HF), Mayetiola destructor (Say), is an important wheat insect pest that annually results in significant production losses. In Morocco, this insect reduces wheat yields by 32–36 % during drought years. The purpose of the current study is to identify the genomic region, marker-trait associations (MTAs), and putative genes associated with the trait of hessian fly resistance in 210 bread wheat (Triticum aestivum L.) genotypes from the International Center for Agricultural Research in Dry Areas (ICARDA). The screening was carried out in the growth chamber using the Hessian fly Mayetiola destructor (Say) populations collected from the Chaouia Ouardigha region in Morocco. The 210 genotypes tested showed various degrees of resistance to the Hessian fly, with eighty-six accessions showing high levels of resistance. The HF severity ranged from 0 to 100 %, whereas the coefficient of variance (CV) was recorded at 84.15 %. Genome-wide association studies (GWAS) using a mixed linear model (MLM) identified 20 significant MTAs at P < 0.001 associated with Hessian fly resistance. The highest number of MTA (10) was recorded in the A sub-genome, followed by 9 MTAs in the B genome. The highest significant marker is AX-95143016 which is located on chromosome 3B with a -Log10(p) of 10.23. After mapping the 20 significant markers associated with Hessian fly resistance, there were 12 potential candidate genes found. This study identified highly resistant genotypes and significant markers that could be used in future wheat breeding programs.

Hessian fly (Diptera: Cecidomyiidae) virulence in Louisiana: assessment of field populations from 2023 to efficacy of 27 Hessian fly resistance genes in wheat.

The Hessian fly, Mayetiola destructor (Say), is one of the most important insect pest plaguing wheat (Triticum aestivum, L) producers across the United States and around the world. Genetic resistance is the stalwart for control of Hessian fly. However, new genotypes (biotypes) arise in deployment of wheat containing resistance genes, so field populations must be evaluated periodically to provide information on the efficacy of those deployed genes. Louisiana (LA), with its diverse agricultural landscape, is not exempt from the challenges posed by this destructive pest. We previously documented the resistance response of wheat lines harboring Hessian fly resistance (H) genes against field populations collected in 2008 from across the southeastern United States, including Iberville Parish, LA. In the spring of 2023, we reevaluated the resistance response of 27 H genes from the field populations collected from Iberville Parish, LA, and compared the results with those observed in 2008. Sixteen H genes showed comparable resistance to the field populations from both years. While 3 of the H genes, H11, H23, and H24, showed a significant decrease in resistance, 2 genes, H16 and H31, had marked increase in resistance. Furthermore, 6 additional H genes were evaluated in 2023, with 4 showing >70% resistance. Our results clearly identify a total of 20 H genes that are moderate to highly effective against the 2023 Hessian fly population from Iberville Parish, LA. The resistance response documented in this study offers valuable information to wheat breeders in the region for effective management of this insect pest.

LONG-TERM (2005-2020) WINTER WHEAT PEST POPULATION DYNAMICS IN UKRAINE IN RESPONSE TO EFFECTS OF ACREAGE TREATED WITH INSECTICIDES AND CLIMATE CHANGE

We studied the long-term population dynamic`s (2005-2020) of six main insect pests of winter wheat (late wheat shoot fly, hessian fly, frit flies, cereal beetles, corn ground beetle and sun pest) in three climatic zones of Ukraine under conditions of increasing areas of application pesticides and global warming. The aim of the research was to investigate how these factors influence pest population dynamics. Comparison of sums of effective temperatures (SET) with standard values for different zones indicates significant climate warming over the past 15 years. Correlation analysis with two variables showed a general decrease in the numbers of most populations, especially in the steppe and forest-steppe zones.

Understanding and improving resistance to Hessian fly (Mayetiola destructor) in US wheat using genetic mapping and molecular techniques

AbstractHessian fly (Mayetiola destructor) is a worldwide pest of wheat (Triticum spp.) causing significant yield losses. Utilizing resistant varieties of wheat is the most effective method of control, particularly in mild climates. The effectiveness of resistance genes is lost over time due to genetic diversity within fly populations, and most cultivars have only one resistance gene making them vulnerable to this loss of resistance. Thirty‐seven resistance genes have been mapped along with four Hessian fly response genes and 11 novel quantitative trait loci (QTL). The majority of these exhibit antibiotic resistance, but new research suggests two or more novel QTL are associated with a valuable tolerant response. Studies suggest that fitness costs associated with resistance can be overcome after the initial infestation, but this may not hold true with repeated fly attacks and should be considered when pyramiding genes. Several of these genes do show temperature sensitivity, which should also be considered during breeding. Resistance mechanisms include increased levels of salicylic acid, upregulation of oxo‐phytodienoic acid reductase genes and genes responsible for lipid and protein mobilization, and increased synthesis of polyphenols, among others. These mechanisms are part of an effector‐triggered response. Resistant genes and QTL with KASP markers for use in creating gene pyramids include QHf.hwwg‐6BS, Qhara.icd‐6B, h4, H7, H32, H33, H34, H35, and H36. GWAS has been used to screen large numbers of elite breeding lines for resistance to Hessian fly. Marker trait associations discovered through GWAS can potentially be used in creating gene pyramids with multiple pest and pathogen resistance genes.

Untapped Sources of Dual Resistance to Hessian Fly and Greenbug in Synthetic Hexaploid Wheats.

The Hessian fly (Hf) and greenbugs (Gb) are major pests of wheat, causing severe economic losses globally. Deploying resistant wheat is the most effective strategy for managing these destructive insects. However, the resistance is not effective against all Hf or Gb biotypes and can impose selection pressure on insects, resulting in the development of virulent biotypes. These challenges must be met through the discovery of new and novel sources of resistance to these pests. Synthetic Hexaploid Wheat (SHW)-developed cultivars are a rich source of resistance against a diverse array of pathogens and pests. In this study, 80 SHW lines were evaluated for their resistance to Hf and Gb under controlled environmental conditions. Of these, a total of 36 SHW lines showed resistance independently to Hf biotype L and Gb biotype E, while 27 lines showed combined resistance to both Hf and Gb. Further, a subset of 10 SHW lines showed resistance to additional Hf biotypes, Great Plains and vH13. The identification of SHW lines resistant to multiple insects and biotypes offers an invaluable resource to breeders who are looking to stack resistance traits to develop elite cultivars as a strategy to alleviate economic impacts upon global wheat production.

Development, results and prospects of the spring durum wheat breeding in Russia (post-Soviet states).

The article outlines a brief historical background on the introduction to cultivation, distribution and breeding of spring durum wheat in the steppe and forest-steppe regions of Eurasia (the countries of the former USSR: Russia, Ukraine, and Kazakhstan). The approaches and methodology for improving durum wheat during certain scientific selection periods are given. The features of the selection program implementation and the breeding scale expansion during the creation of breeding stations at the beginning of the XX century, after the end of the Great Patriotic War, in the second half of the XX century, and at present are considered. A characteristic according to the main features and properties of varieties created in different periods is given. The achievements of the classical breeding method by comparing old and new varieties are analyzed. The efficiency and rate of wheat selection by periods in different regions of Russia is estimated. The results and methods of breeding for yield, resistance to drought, leaf diseases (Stagonospora nodorum Berk., Septoria tritici (Roeb. et Desm.), Bipolaris sorokiniana (Sacc.) Shoemaker, Pyrenophora tritici repentis (Died.) Drechs., Fusarium sp., Puccinia titicina Eriks., Puccinia graminis Pers. f. sp. tritici Eriks., Blumeria graminis (DC.) f. sp. tritici Em. Marchal), grain pathogens Ustilago tritici (Pers.) Rostr.) and pathogens causing darkening of the corcule and endosperm (Bipolaris sorokiniana (Sacc.) Shoemaker, Alternaria tenuis (Nees et Fr.), Аlternaria triticina (Prasada & Prabhu)), pests (Cephus pygmeus Lens, Osinosoma frit L., Mayetiola destructor (Say)), grain quality (protein content, amount of yellow pigments, dough rheology, sprouting resistance) and end products are presented. The prospects for the molecular marker application for a number of traits in breeding in the near future are given.

Comparison of Agro-Phenological and Technological Traits in Advanced Durum Wheat Lines Differing in Reaction to Hessian Fly Infestation

The aim of this study was to compare agro-phenological and technological traits in advanced durum wheat lines differing in responses to Hessian fly larval attacks. A field experiment was carried out during the 2014/2015 cropping season at the main research stations of Marchouch and Tassaoute in a randomized completed block design. Twenty-two durum wheat genotypes comprising twenty advanced lines from the INRA breeding program and two commercial varieties were used in this study. Agro-phenological and grain quality determinations were concerned with plant height, grain yield, days to heading, protein content, wet gluten content, gluten strength, and yellow pigment content. The analysis of variance revealed significant environment, genotype, and genotype-by-environment (G × E) effects for the majority of the measured traits. A high level of heritability was also observed for grain yield (94.9%), followed by gluten strength (90.7%), yellow pigment content (79.3%), wet gluten content (77.79%), plant height (71.5), and protein content (70.02%); moderate levels of heritability were recorded for days to heading (65.8%). The data for Hessian fly resistance in both the field and infested greenhouse demonstrated three distinct group of genotypes: “resistant” with 4 genotypes, “susceptible without field escape to Hessian fly attack” with 16 genotypes, and “susceptible with field escape to Hessian fly attack” with 2 genotypes. The ANOVA analysis indicated the existence of significant differences between groups of genotypes for grain yield, days to heading, protein content, yellow pigment content, and gluten strength at the Tassaoute station, while at the Marchouch site, the differences were significant only for plant height and gluten strength. Protein content and wet gluten content revealed highly significant positive correlations, indicating the possibility of effective selection of the two traits simultaneously. Biplot analysis indicated that the first two Principal Components (PCs) accounted for 56.04% and 56.34% of the relationships between the genotypes and all of the attributes at the Marchouch and Tassaoute sites, respectively. The results of principal component analysis and Cluster based on agro-phenological and grain quality traits categorized the genotypes into three separate groups for the Marchouch site and four groups for the Tassaoute site. Individuals within each group are characterized by well-defined precocity, productivity, and technological criteria. The different behaviors of the lines studied in the present work are of great interest and can be exploited in breeding programs in order to improve agro-phenological and technological traits in durum wheat.

Quantitative Trait Locus Analysis of Hessian Fly Resistance in Soft Red Winter Wheat.

The Hessian fly (HF) is an invasive insect that has caused millions of dollars in yield losses to southeastern US wheat farms. Genetic resistance is the most sustainable solution to control HF. However, emerging biotypes are quickly overcoming resistance genes in the southeast; therefore, identifying novel sources of resistance is critical. The resistant line "UGA 111729" and susceptible variety "AGS 2038" were crossbred to generate a population of 225 recombinant inbred lines. This population was phenotyped in the growth chamber (GC) during 2019 and 2021 and in field (F) trials in Georgia during the 2021-2022 growing seasons. Visual scoring was utilized in GC studies. The percentage of infested tillers and number of pupae/larvae per tiller, and infested tiller per sample were measured in studies from 2021 to 2022. Averaging across all traits, a major QTL on chromosome 3D explained 42.27% (GC) and 10.43% (F) phenotypic variance within 9.86 centimorgans (cM). SNP marker IWB65911 was associated with the quantitative trait locus (QTL) peak with logarithm of odds (LOD) values of 14.98 (F) and 62.22 (GC). IWB65911 colocalized with resistance gene H32. KASP marker validation verified that UGA 111729 and KS89WGRC06 express H32. IWB65911 may be used for marker-assisted selection.