Genome-wide association mapping and genomic prediction of stalk rot in two mid-altitude tropical maize populations

Maize stalk rot reduces grain yield and quality.Information about the genetics of resistance to maize stalk rot could help breeders design effective breeding strategies for the trait.Genomic prediction may be a more effective breeding strategy for stalk-rot resistance than marker-assisted selection.We performed a genome-wide association study(GWAS)and genomic prediction of resistance in testcross hybrids of 677 inbred lines from the Tuxpe?o and non-Tuxpe?o heterotic pools grown in three environments and genotyped with 200,681 single-nucleotide polymorphisms(SNPs).Eighteen SNPs associated with stalk rot shared genomic regions with gene families previously associated with plant biotic and abiotic responses.More favorable SNP haplotypes traced to tropical than to temperate progenitors of the inbred lines.Incorporating genotype-by-environment(G×E)interaction increased genomic prediction accuracy.

Identification of powdery mildew resistance loci in wheat by integrating genome-wide association study(GWAS) and linkage mapping

Wheat powdery mildew(Blumeria graminis f.sp.tritici, Bgt) is a disease of increasing importance globally due to the adoption of high yielding varieties and modern sustainable farming technologies.Growing resistant cultivars is a preferred approach to managing this disease, and novel powdery mildew resistance genes are urgently needed for new cultivar development.A genome-wide association study was performed on a panel of 1292 wheat landraces and historical cultivars using 5011 single nucleotide polymorphism(SNP)markers.The association panel was evaluated for reactions to three Bgt inoculants, OKS(14)-B-3-1, OKS(14)-C-2-1, and Bgt15.Linkage disequilibrum(LD) analysis indicated that genome-wide LD decayed to 0.1 at 23 Mb, and population structure analysis revealed seven subgroups in the panel.Association analysis using a mixed linear model(MLM) identified three loci for powdery mildew resistance on chromosome 2 B, designated QPm.stars-2BL1,QPm.stars-2BL2, and QPm.stars-2BL3.To evaluate the efficacy of GWAS in gene discovery,QPm.stars-2BL2 was validated using F2 and F2:3 populations derived from PI420646 × OK1059060-126135-3.Linkage analysis delimited the powdery mildew resistance gene in PI 420646 to an interval where QPm.stars-2BL2 was located, lending credence to the GWAS results.QPm.stars-2BL1 and QPm.stars-2BL3, which were associated with four SNPs located at 457.7–461.7 Mb and two SNPs located at 696.6–715.9 Mb in the Chinese Spring reference IWGSC RefSeq v1.0, respectively, are likely novel loci for powdery mildew resistance and can be used in wheat breeding to improve powdery mildew resistance.

Genome-wide and candidate gene association studies identify BnPAP17 as conferring the utilization of organic phosphorus in oilseed rape

Phosphorus(P)is essential for living plants,and P deficiency is one of the key factors limiting the yield in rapeseed production worldwide.As the most important organ for plants,root morphology traits(RMTs)play a key role in P absorption.To investigate the genetic variability of RMT under low P availability,we dissected the genetic structure of RMTs by genome-wide association studies(GWAS),linkage mapping and candidate gene association studies(CGAS).A total of 52 suggestive loci were associated with RMTs under P stress conditions in 405 oilseed rape accessions.The purple acid phosphatase gene BnPAP17 was found to control the lateral root number(LRN)and root dry weight(RDW)under low P stress.The expression of BnPAP17 was increased in shoot tissue in P-efficient cultivars compared to root tissue and P-inefficient cultivars in response to low P stress.Moreover,the haplotype of BnPAP17^(Hap3)was detected for the selective breeding of P efficiency in oilseed rape.Over-expression of the BnPAP17^(Hap3)could promote the shoot and root growth with enhanced tolerance to low P stress and organic phosphorus(Po)utilization in oilseed rape.Collectively,these findings increase our understanding of the mechanisms underlying BnPAP17-mediated low P stress tolerance in oilseed rape.

Integrated linkage mapping and genome-wide association study to dissect the genetic basis of zinc deficiency tolerance in maize at seedling stage

Zinc(Zn)deficiency is the most widespread micronutrient deficiency,affecting yield and quality of crops worldwide.Identifying genes associated with Zn-deficiency tolerance in maize is a basis for elucidating its genetic mechanism.A K22×CI7 recombinant inbred population consisting of 210 lines and an association panel of 508 lines were used to identify genetic loci influencing Zn-deficiency tolerance.Under-Zn and-Zn/CK conditions,15 quantitative trait loci(QTL)were detected,each explaining 5.7%-12.6%of phenotypic variation.Sixty-one significant single-nucleotide polymorphisms(SNPs)were identified at P<10^(-5)by genome-wide association study(GWAS),accounting for 5%-14%of phenotypic variation.Among respectively 198 and 183 candidate genes identified within the QTL regions and the 100-kb regions flanking these significant SNPs,12 were associated with Zn-deficiency tolerance.Among these candidate genes,four genes associated with hormone signaling in response to Zn-deficiency stress were co-localized with QTL or SNPs,including the genes involved in the auxin(ZmARF7),and ethylene(ZmETR5,ZmESR14,and ZmEIN2)signaling pathways.Three candidate genes were identified as being responsible for Zn transport,including ZmNAS3 detected by GWAS,ZmVIT and ZmYSL11 detected by QTL mapping.Expression of ZmYSL11 was up-regulated in Zn-deficient shoots.Four candidate genes that displayed different expression patterns in response to Zn deficiency were detected in the regions overlapping peak GWAS signals,and the haplotypes for each candidate gene were further analyzed.

Genome-wide association study for starch content and constitution in sorghum(Sorghum bicolor(L.) Moench)

Starch is the most important component in endosperm of sorghum grain.Usually,two types of starch are present:amylose(AM)and amylopectin(AP).The levels of AM and AP contents play a significant role in the appearance,structure,and quality of sorghum grains and in marketing applications.In the present study,a panel of 634 sorghum(Sorghum bicolor(L.)Moench)accessions were evaluated for starch,AM,and AP contents of grain,which included a mini core collection of 242 accessions from the International Crops Research Institute for the Semi-Arid Tropics(ICRISAT)in India,and 252 landraces and 140 cultivars from China.The average starch content was 67.64%and the average AM and AP contents were 20.19 and 79.81%,respectively.We developed a total of 260000 high-confidence single nucleotide polymorphism(SNP)markers in the panel of 634 accessions of S.bicolor using specific locus amplified fragment sequencing(SLAF-seq).We performed genome-wide association studies(GWAS)of starch,AM,and AM/AP of grain and SNP markers based on a mixed linear model(MLM).In total,70 significant association signals were detected for starch,AM,and AM/AP ratio of grain with P<4.452×10^-7,of which 10 SNPs were identified with significant starch,51 SNPs were associated with AM,and nine SNPs were associated with the AM/AP ratio.The Gene Ontology(GO)analysis identified 12 candidate genes at five QTLs associated with starch metabolism within the 200-kb intervals,located on chromosomes 1,5,6,and 9.Of these genes,Sobic.006G036500.1 encodes peptidyl-prolyl cis-trans-isomerase CYP38 responsible for hexose monophosphate shunt(HMS)and Sobic.009G071800 encodes 6-phospho-fructokinase(PFK),which is involved in the embden-meyerhof pathway(EMP).Kompetitive allele specific PCR(KASP)markers were developed to validate the GWAS results.The C allele is correlated with a high starch content,while the T allele is linked with a low level of starch content,and provides reliable haplotypes for MAS in sorghum quality improvement.

Genome-Wide Association Study for Certain Carcass Traits and Organ Weights in a Large White×Minzhu Intercross Porcine Population

Porcine carcass traits and organ weights have important economic roles in the swine industry. A total of 576 animals from a Large White×Minzhu intercross population were genotyped using the Illumina PorcineSNP60K Beadchip and were phenotyped for 10 traits, speciifcally, backfat thickness （6-7 libs）, carcass length, carcass weight, foot weight, head weight, heart weight, leaf fat weight, liver weight, lung weight and slaughter body weight. The genome-wide association study （GWAS） was assessed by Genome Wide Rapid Association using the mixed model and regression-genomic control approach. A total of 31 single nucleotide polymorphisms （SNPs） （with the most signiifcant SNP being MARC0033464, P value=6.80×10-13） were located in a 9.76-Mb （31.24-41.00 Mb） region on SSC7 and were found to be signiifcantly associated with one or more carcass traits and organ weights. High percentage of phenotypic variance explanation was observed for each trait ranging from 31.21 to 67.42%. Linkage analysis revealed one haplotype block of 495 kb, in which the most signiifcant SNP being MARC0033464 was contained, on SSC7 at complete linkage disequilibrium. Annotation of the pig reference genome suggested 6 genes （GRM4, HMGA1, NUDT3, RPS10, SPDEF and PACSIN1） in this candidate linkage disequilibrium （LD） interval. Functional analysis indicated that the HMGA1 gene presents the prime biological candidate for carcass traits and organ weights in pig, with potential application in breeding programs.

Genetic dissection of hexanol content in soybean seed through genome-wide association analysis

Hexanol is a major compound contributing to the off-flavors(the bean-like odor)of soybean derived soymilk.The most effective way to reduce the off-flavors of soymilk is the screening and utilization of soybean cultivars with improved hexanol content.However,no genome-wide genetic analysis for this particular trait has been conducted to date.The objective of the present study was to dissect the genetic basis of hexanol content in soybean seed through genome-wide association analysis(GWAS).A total of 105 soybean accessions were analyzed for hexanol content in a three-year experiments and genotyped by sequencing using the specific locus amplified fragment sequencing(SLAF-seq)approach.A total of 25 724 single nucleotide polymorphisms(SNPs)were obtained with minor allele frequencies(MAF)>5%.GWAS showed that 25 quantitative trait nucleotides(QTNs)were significantly associated with the hexanol concentration in soybean seed.These identified QTNs distributed on different genomic regions of the 15 chromosomes.A total of 91 genes were predicted as candidate genes underlying the seed hexanol level and six candidates were predicted possibly underlying the seed hexanol by gene based association.In this study,GWAS has been proven to be an effective way to dissect the genetic basis of the hexanol concentration in multiple genetic backgrounds.The identified beneficial alleles and candidate genes might be valuable for the improvement of marker-assisted breeding efficiency for low hexanol level and help to explore possible molecular mechanisms underlying hexanol content in soybean seed.

Evaluation of maize root growth and genome-wide association studies of root traits in response to low nitrogen supply at seedling emergence

Nitrogen(N) deficiency is one of the main factors limiting maize(Zea mays L.) productivity. Genetic improvement of root traits could improve nitrogen use efficiency. An association panel of 461 maize inbred lines was assayed for root growth at seedling emergence under high-nitrate(HN, 5 mmol L^(-1))and low-nitrate(LN, 0.05 mmol L^(-1)) conditions. Twenty-one root traits and three shoot traits were measured. Under LN conditions, the root-to-shoot ratio, root dry weight, total root length, axial root length,and lateral root length on the primary root were all increased. Under LN conditions, the heritability of the plant traits ranged from 0.43 to 0.82, a range much wider than that of 0.27 to 0.55 observed under HN conditions. The panel was genotyped with 542,796 high-density single-nucleotide polymorphism(SNP) markers. Totally 328 significant SNP markers were identified using either mixed linear model(MLM) or general linear model analysis, with 34 detected by both methods. In the 100-kb intervals flanking these SNP markers, four candidate genes were identified. Under LN conditions, the protoporphyrinogen IX oxidase 2 gene was associated with total root surface area and the DELLA protein-encoding gene was associated with the length of the visible lateral root zone of the primary root. Under HN conditions, a histone deacetylase gene was associated with plant height. Under both LN and HN conditions, the gene encoding MA3 domain-containing protein was associated with the first whorl crown root number. The phenotypic and genetic information from this study may be exploited for genetic improvement of root traits aimed at increasing NUE in maize.

Genetic architecture of maize yield traits dissected by QTL mapping and GWAS in maize

The study of yield traits can reveal the genetic architecture of grain yield for improving maize production.In this study, an association panel comprising 362 inbred lines and a recombinant inbred line population derived from X178 × 9782 were used to identify candidate genes for nine yield traits. High-priority overlap(HPO) genes, which are genes prioritized in a genome-wide association study(GWAS), were investigated using coexpression networks. The GWAS identified 51 environmentally stable SNPs in two environments and 36 pleiotropic SNPs, including three SNPs with both attributes. Seven hotspots containing 41 trait-associated SNPs were identified on six chromosomes by permutation. Pyramiding of superior alleles showed a highly positive effect on all traits, and the phenotypic values of ear diameter and ear weight consistently corresponded with the number of superior alleles in tropical and temperate germplasm. A total of 61 HPO genes were detected after trait-associated SNPs were combined with the coexpression networks. Linkage mapping identified 16 environmentally stable and 16 pleiotropic QTL.Seven SNPs that were located in QTL intervals were assigned as consensus SNPs for the yield traits.Among the candidate genes predicted by our study, some genes were confirmed to function in seed development. The gene Zm00001 d016656 encoding a serine/threonine protein kinase was associated with five different traits across multiple environments. Some genes were uniquely expressed in specific tissues and at certain stages of seed development. These findings will provide genetic information and resources for molecular breeding of maize grain yield.

Association Mapping of Quantitative Trait Loci for Grain Size in Introgression Line Derived from Oryza rufipogon

Grain size is one of the critical agronomic traits governing grain yield and quality in rice.However,the underlying genetic mechanisms that control grain size in rice are poorly understood.We used an introgression line derived from Zhonghui 8015 and Oryza rufipogon Griff.This introgression line was evaluated under two different environmental conditions to dissect the quantitative trait loci controlling grain size.Genome-wide association study(GWAS)was performed using 28193 SNPs through a general linear model,and 56 significant SNPs on different loci associated with the 4 grain size traits were detected.Cloned genes including GS3 and q GL3 showed substantial effects on grain length and size.Seven new stable loci were identified with pleiotropic effects on grain size.Haplotype,gene expression analyses,combined gene-based associations,and functional annotations permitted the shortlisting of important dominant genes including GS3 and q GL3.

Genome-wide Association Analysis of Maize Flowering Traits

Flowering regulation is important for maize to adapt to a variety of environments as well as associated with high yield.In this study,the genetic mechanism of three flowering traits of 310 maize inbred lines with rich genetic background was investigated in three years at three different environments such as days to tasseling(DTT),days to silking(DTS)and days to pollen shedding(DTP).Based on mean performance,the longest flowering time was observed in Zhanyi(2018),whereas the shortest in Shizong(2019).The coefficient of variance depicted the range from 3.62%to 9.06%for three flowering traits under all environments.Therefore,we have integrated these flowering traits corresponding to SNP molecular markers for genome-wide association study(GWAS).Results showed that 22 SNPs markers were significantly associated with DTT according to physical position and average linkage disequilibrium(LD)decay distance,and a total of 234 candidate genes were identified near these significantly associated SNP markers.Moreover,KEGG and GO analysis showed that these genes were enriched in the regulation of the physiological pathways for flowering.In more details,16 genes involved in development of floral organs are more worthy of our attention in future studies.

Genome-Wide Association Study in Thai Tsunami Survivors Identified Risk Alleles for Posttraumatic Stress Disorder

Posttraumatic stress disorder (PTSD) is a psychiatric disorder found in individuals afflicted by a traumatic event. Multiple environmental and genetic factors can contribute to PTSD susceptibility. Since it is rare to find members of the same family afflicted by the same catastrophic event, it is not practical to determine PTSD susceptibility genes by a gene linkage analysis. A natural disaster, such as the 2004 Tsunami, provided us with a rare chance for a genetic analysis of PTSD. To identify SNPs associated with PTSD susceptibility, we conducted a genome-association study (GWAS) in Thai-Tsunami survivors. Initial phase of the study with 396 chronic PTSD patients and 457 controls, we identified top ninety SNPs (P -4), which were further assessed in the second phase with 395 chronic PTSD patients and 798 controls. Two SNPs (rs267950 and rs954406), were identified in the second phase, and subjected to fine mapping using a data set from both phases. SNP rs267943 showed the strongest association with PTSD susceptibility and was in complete linkage disequilibrium with SNP rs267950 with P = 6.15 × 10-8, OR = 1.46 and 95% CI = 1.19 - 1.79, reaching genome-wide significance. SNP rs267943 is located on chromosome 5 in the intron of the death-associated protein 1 (DAP1) gene and, when linked to a synthetic promoter, could regulate transcription. To our knowledge, this is the first GWAS for PTSD susceptibility in an Asian population which could provide an important insight into the genetic contribution of PTSD and may lead to new treatment strategies for PTSD.

Genome-wide association study (GWAS) of leaf wax components of apple

The wax layer of apple leaves plays an important role in improving stress resistance,but relatively little is known about the mechanisms of wax synthesis and transport in apple leaves.In this study,17 wax components,including alcohols,alkanes,fatty acids and terpenes,were analyzed by gas chromatography-tandem mass spectrometry(GCMS)from the leaves of 123 apple germplasms.Whole-genome sequencing of these apple accessions yielded 5.9 million high-quality single nucleotide polymorphisms(SNPs).We performed a genome-wide association study(GWAS)on 17 wax components and identified several genes related to wax synthesis and transport,including MdSHN1(SHINE1),MdLTP4(LIPID TRANSFER PROTEIN4),MdWSD1(WAX ESTER SYNTHASE/ACYL-COA DIAC-YLGLYCEROL ACYLTRANSFERASE1),MdRDR1(RNA-DEPENDENT RNA POLYMERASE1),MdACBP6(ACYL-COA-BINDING PROTEIN6),MdNLE(NOTCHLESS)and MdABCG21(ATP-BINDING CASSETTE G21).Moreover,we identified some prominent SNPs that may affect gene expression and protein function.These results provide insights into mechanisms of wax synthesis and transport in apple leaves and broaden the genetic resources and basis for facilitating resistance breeding.

Genome-wide markers for seed yield and disease resistance in perennial ryegrass

The market success of perennial ryegrass(Lolium perenne L.) cultivars depends on sufficient seed production, as they are propagated by seed. However, breeding for high quality forage production reduces seed yield, and breaking the negative correlation would help to overcome the problem. The foliar disease crown rust is another factor affecting reproductive capacity and thereby seed yield. We evaluated seed yield-related traits and resistance to crown rust in a collection of commercial cultivars and ecotypes of perennial ryegrass and identified genome-wide markers associated with the traits. The study revealed high variation between the ecotype and cultivar groups as well as between years. A genome-wide association study identified 17 DNA single-nucleotide polymorphisms(SNPs) of which eight were associated with crown rust and nine with flag-leaf length. The SNP markers were located within or near predicted genes functioning in defense against pathogens. The identified genes are strong candidates for a further in-depth functional study to continue unravel determination of leaf architecture and crown rust resistance in perennial ryegrass.

A genome-wide association study on growth traits in orangespotted grouper(Epinephelus coioides) with RAD-seq genotyping

The orange-spotted grouper, Epinephelus coioides, is one of the most popular fish in China and Southeast Asian countries because of its important economic value. However, molecular mechanism underlying the growth of orange-spotted grouper has never been fully understood. Herein, we performed a genome-wide association study （GWAS） on a natural population of 198 individuals aiming to screen the whole genome of orange-spotted grouper for identification of growth-related loci by restriction-site associated DNA sequencing. In this research, 261,366 single nucleotide polymorphisms （SNPs） were developed, in which 110 SNPs were identified to be correlated with growth and 20 SNPs were further confirmed to be associated with both body weight and total length. From these identified SNPs, we annotated a total of 34 genes, including adgrb2, csnkzal, cers5, co122al, creb5, dndl, dzankl, dnail, npy2r, fat3, lrrk2, lrp5, map3k9, and so on. Among these candidate genes, npy2r （neuropeptide Y receptor Y2） was reported to play a critical role in growth of the orange-spotted grouper. In addition, population structure, principal component analysis, kinship matrix and linkage disequilibrium were examined to verify the accuracy and reliability of our GWAS results. Our data will also provide a valuable genetic resource for further marker-assisted selection program to improve growth quality in groupers.

Genome-wide association studies:inherent limitations and future challenges

Genome-wide association studies(GWAS)have achieved great success in identifying genetic variants related to complex human diseases such as cancer and have provided valuable insights into their genetic architecture.Recently,GWAS is quite the fashion in China.However,there are issues related to its nature.Enormous work needs to be done in the post-GWAS era.Deep sequencing followed by functional studies will be needed to elucidate the underpinning biological mechanisms and further translate GWAS findings into medical practice.Along with pharmacogenomics,the success of GWAS in identifying genetic risk factors and genetic differences in drug response has been gradually enabling personalized medicine.In this article,we used hepatocellular carcinoma(HCC)as an example to demonstrate some of the inherent limitations and summarized future challenges of GWAS.

Resequencing and genome-wide association studies of autotetraploid potato

Potato is the fourth most important food crop in the world.Although with a long history for breeding approaches,genomic information and association between genes and agronomic traits remain largely unknown particularly in autotetraploid potato cultivars,which limit the molecular breeding progression.By resequencing the genome of 108 main cultivar potato accessions with rich genetic diversity and population structure from International Potato Center,with approximate 20-fold coverage,we revealed more than 27 million Single Nucleotide Polymorphisms and~3 million Insertion and Deletions with high quality and accuracy.Domestication analysis and genome-wide association studies(GWAS)identified candidate loci related to photoperiodic flowering time and temperature sensitivity as well as disease resistance,providing informative insights into the selection and domestication of cultivar potato.In addition,GWAS with GWASploy for 25 agronomic traits identified candidate loci by association signals,especially those related to tuber size,small-sized tuber weight and tuber thickness that was also validated by transcriptome analysis.Our study provides a valuable resource that facilitates the elucidation of domestication process as well as the genetic studies and agronomic improvement of autotetraploid potato.

Dissecting the genetic architecture of glucosinolate compounds for quality improvement in flowering stalk tissues of Brassica napus

Glucosinolates(GSLs) and their hydrolytic products contribute to the quality traits of rapeseed flowering stalk tissues, such as taste, flavor and anticarcinogenic properties(Glucoraphanin). However, little is known about the genetic mechanisms of GSL accumulation in rapeseed flowering stalks. In this study, the variation and genetic architecture of GSL metabolites in flowering stalk tissues were investigated for the first time among a panel of 107 accessions. All GSL compounds exhibited continuous and wide variations in the present population. Progoitrin,glucobrassicanapin and gluconapin were the most abundant GSL compounds. Five quantitative trait loci(QTL) significantly associated with three GSL compounds were identified by genome-wide association study. GRA_C04 was under selected during modern breeding, in which the ratio of lower GSL haplotype(HAP2) in the accessions bred before 1990(52.56%) was significantly lower than that after 1990(78.95%). Four candidate genes, BnaA01. SOT16, BnaA06. SOT17, Bna A06. MYB51a, and Bna A06. MYB51b, were identified in the GTL_A01 and 4OH_A06 regions.These findings provide new insights into GSL biosynthesis in flowering stalk tissues and facilitate quality improvement in rapeseed flowering stalks.

Exome-wide variation in a diverse barley panel reveals genetic associations with ten agronomic traits in Eastern landraces

Barley(Hordeum vulgare ssp.vulgare)is one of the first crops to be domesticated and is adapted to a wide range of environments.Worldwide barley germplasm collections possess valuable allelic variations that could further improve barley productivity.Although barley genomics has offered a global picture of allelic variation among varieties and its association with various agronomic traits,polymorphisms from East Asian varieties remain scarce.In this study,we analyze exome polymorphisms in a panel of 274 barley varieties collected worldwide,including 137 varieties from East Asian countries and Ethiopia.We reveal the underlying population structure and conduct genome-wide association studies for 10 agronomic traits.Moreover,we examin genome-wide associations for traits related to grain size such as awn length and glume length.Our results demonstrate the value of diverse barley germplasm panels containing Eastern varieties,highlighting their distinct genomic signatures relative to Western subpopulations.

小麦茎秆断裂强度相关性状QTL的连锁和关联分析

小麦茎秆断裂强度与倒伏特性关系密切,并对产量有很大影响。本研究旨在解析茎秆断裂强度的遗传机制,开发与该性状紧密连锁/关联的分子标记。利用山农01-35′藁城9411重组自交系(RIL)群体(含173个F8:9株系)和由205个品种(系)构成的自然群体,借助90 k小麦SNP基因芯片、DArT芯片及传统分子标记技术,在2个环境中对两群体的茎秆断裂强度相关性状进行连锁分析和全基因组关联分析。利用已构建的高密度连锁图谱,在4B染色体的TDURUM_CONTIG63670_287–IACX557和EX_C101685–RAC875_C27536等区段上,检测到9个控制小麦茎秆断裂强度、株高、茎秆第2节间充实度、茎秆第2节壁厚相关性状的加性QTL,可解释表型变异9.40%~36.30%。同时,利用包含24 355个SNP位点的复合遗传图谱,在自然群体中检测到37个与茎秆断裂强度相关性状(P<0.0001)的标记,分别位于1A、1B、2B、2D、3A、3B、4A、4B、5A、5B、5D、6B、7A、7B和7D染色体,可解释表型变异7.76%~36.36%。在4B染色体上,以连锁分析检测到控制茎秆断裂强度的RAC875_C27536与关联分析检测到的Tdurum_contig4974_355标记,在复合遗传图谱上的距离为6.7 cM,说明该区段存在控制小麦茎秆断裂强度的重要基因。