The bay scallop and Peruvian scallop are economically important species.Interspecific hybrids of these two scallops outperformed both of their parent species in multiple growth traits but exhibited decreased fertility...The bay scallop and Peruvian scallop are economically important species.Interspecific hybrids of these two scallops outperformed both of their parent species in multiple growth traits but exhibited decreased fertility,which provides good models for the study of heterosis and species divergence.Genetic mapping serves as a chromosomal-level framework to investigate the molecular mechanisms of hybridization and introgression.In this study,high-resolution linkage maps were constructed for the bay and Peruvian scallops with an interspecific hybrid family.The linkage map of the bay scallop covered over 98.9% of the whole genome with 2994 mapped markers and the average marker interval of 0.32 cM.For the Peruvian scallop,1585 markers were mapped with the average maker interval of 0.51 cM,covering 97.7% of the genome.Both the two linkage maps have 16 linkage groups,corresponding to the haploid chromosome number of the two species.Approximately,54.5% of markers exhibited significant deviation from the expected Mendelian ratio of segregation,lending in sights into the intrinsic incompatibility between the two species.QTLs related to growth and shell coloration were detected,which could explain 13.1%and 74.9% of the phenotypic variance,respectively.This represents important information for further evaluation.These findings are an important addition to the genomic resources for scallop genetic studies,and are especially useful for investigations on genomic incompatibility for hybridization,genome evolution of closely related species,and genetic enhancement programs in aquaculture.展开更多
In this paper,we propose generalized fiducial methods and construct four generalized p-values to test the existence of quantitative trait locus effects under phenotype distributions from a location-scale family.Compar...In this paper,we propose generalized fiducial methods and construct four generalized p-values to test the existence of quantitative trait locus effects under phenotype distributions from a location-scale family.Compared with the likelihood ratio test based on simulation studies,our methods perform better at controlling type I errors while retaining comparable power in cases with small or moderate sample sizes.The four generalized fiducial methods support varied sce-narios:two of them are more aggressive and powerful,whereas the other two appear more conservative and robust.A real data example involving mouse blood pressure is used to illustrate our proposed methods.展开更多
High temperature stress (HTS), an increasingly important problem in rice production, significantly reduces rice yield by reducing pollen fertility and seed setting rate. Breeding rice varieties with tolerance to HTS a...High temperature stress (HTS), an increasingly important problem in rice production, significantly reduces rice yield by reducing pollen fertility and seed setting rate. Breeding rice varieties with tolerance to HTS at the flowering stage is therefore essential for maintaining rice production as the climate continues to become warm. In this study, two quantitative trait loci (QTLs) underlying tolerance to HTS were identified using recombinant inbred lines derived from a cross between an HTS-tolerant rice cultivar 996 and a sensitive cultivar 4628. Pollen fertility was used as a heat-tolerance indicator for the lines subjected to HTS at the flowering stage in field experiments. Two QTLs that affected pollen fertility, qPF4 and qPF6, were detected between RM5687 and RM471 on chromosome 4, and between RM190 and RM225 on chromosome 6, by using the composite interval mapping (CIM) analysis. The two QTLs explained 15.1% and 9.31% of the total phenotypic variation in pollen fertility, and increased the pollen fertility of the plants subjected to HTS by 7.15% and 5.25%, respectively. The positive additive effects of the two QTLs were derived from the 996 alleles. The two major QTLs identified would be useful for further fine mapping and cloning of these genes and for molecular marker-assistant breeding of heat-tolerant rice varieties.展开更多
QTLs for heading date located in the regions of Hd3a and Hd1 were detected using an F2:3 population developed from a residual heterozygous line(RHL) identified from the recombinant inbred lines of the indica rice cros...QTLs for heading date located in the regions of Hd3a and Hd1 were detected using an F2:3 population developed from a residual heterozygous line(RHL) identified from the recombinant inbred lines of the indica rice cross Zhenshan 97B /Milyang 46.Linkage in coupling phase between the QTLs for heading date and yield traits detected in a previous study was found.Four more F2:3 populations were each developed from an RHL that was homozygous at Hd3a and Hd1 but heterozygous in a portion of the intervals flanked by Hd3a and Hd1.QTLs for grain yield per plant,number of panicles per plant,number of grains per panicle and 1000-grain weight were detected in the heterozygous region.Five sets of near-isogenic lines(NILs) with overlapping heterogenous segments covering the interval RM6119-RM6779 were developed and used to validate and delimitate the QTLs.A QTL conferring a consistent effect for the number of grains per panicle was located within the interval RM19615-RM19652 that corresponded to a 514.4-kb region on chromosome 6.The same region might have pleiotropic effects on the other three yield-related traits analyzed,but the effects varied greatly among different populations and across different environments.This study suggests that it is possible to develop a population with little variation on heading date and to identify QTLs for yield traits that might not be associated with heading date by using the information of physical positions of DNA markers and cloned genes.展开更多
Rice kernel shape affects kernel quality(appearance) and yield(1000-kernel weight) and therefore is an important agronomic trait, but its inheritance is complicated. We identified a long-kernel rice chromosome segment...Rice kernel shape affects kernel quality(appearance) and yield(1000-kernel weight) and therefore is an important agronomic trait, but its inheritance is complicated. We identified a long-kernel rice chromosome segment substitution line(CSSL), Z741, derived from Nipponbare as a recipient and Xihui 18 as a donor parent. Z741 has six substitution segments distributed on rice chromosomes 3, 6, 7, 8 and 12 with an average replacement length of 5.82 Mb. Analysis of a secondary F2 population from a cross between Nipponbare and Z741 identified 20 QTLs for important agronomic traits. The kernel length of Z741 is controlled by a major QTL(qKL3) and a minor QTL(qKL7). Candidate gene prediction and sequencing indicated that qKL3 may be an allele of OsPPKL1, which encodes a protein phosphatase implicated in brassinosteroid signaling, and qKL7 is an unreported QTL. Finally, we validated eight QTLs(qKL3, qKL7, qRLW3-1, qRLW7, qPH3-1, qKWT3, qKWT7 and qNPB6) using three selected singlesegment substitution lines(SSSLs), S1, S2 and S3. Also, we detected five QTLs(qKL6, qKW3, qKW7, qKW6 and qRLW6) in S1, S2 and S3, which were not found in the Nipponbare/Z741 F2 population. However, qNPB3, qNPB7 and qPL3 QTLs were not validated by the three SSSLs in 2019, suggesting that minor QTLs are susceptible to environmental factors. These results lay the foundation for studying the biodiversity of kernal length and molecular breeding of different kernel types.展开更多
Drought is one of the most critical abiotic stresses influencing maize yield. Improving maize cultivars with drought tolerance using marker-assisted selection requires a better understanding of its genetic basis. In t...Drought is one of the most critical abiotic stresses influencing maize yield. Improving maize cultivars with drought tolerance using marker-assisted selection requires a better understanding of its genetic basis. In this study, a doubled haploid(DH) population consisting of 217 lines was created by crossing the inbred lines Han 21(drought-tolerant) and Ye 478(drought-sensitive). The population was genotyped with a 6 K SNP assay and 756 SNP(single nucleotide polymorphism) markers were used to construct a linkage map with a length of 1344 c M. Grain yield(GY), ear setting percentage(ESP), and anthesis–silking interval(ASI) were recorded in seven environments under well-watered(WW) and water-stressed(WS) regimes. High phenotypic variation was observed for all traits under both water regimes. Using the LSMEAN(least-squares mean) values from all environments for each trait, 18 QTL were detected, with 9 associated with the WW and 9 with the WS regime. Four chromosome regions,Chr. 3: 219.8–223.7 Mb, Chr. 5: 191.5–194.7 Mb, Chr. 7: 132.2–135.6 Mb, and Chr. 10: 88.2–89.4 Mb, harbored at least 2 QTL in each region, and QTL co-located in a region inherited favorable alleles from the same parent. A set of 64 drought-tolerant BC_3F_6 lines showed preferential accumulation of the favorable alleles in these four regions, supporting an association between the four regions and maize drought tolerance. QTL-by-environment interaction analysis revealed 28 ed QTL(environment-dependent QTL) associated with the WS regime and 22 associated with the WW regime for GY, ESP, and ASI. All WS QTL and55.6% of WW QTL were located in the ed QTL regions. The hotspot genomic regions identified in this work will support further fine mapping and marker-assisted breeding of drought-tolerant maize.展开更多
Advanced backcross QTL analysis was used to identify QTLs for seven yield and yield-related traits in a BC2F2 population from the cross between a popular Oryza sativa cv Swarna and O. nivara IRGC81848. Transgressive s...Advanced backcross QTL analysis was used to identify QTLs for seven yield and yield-related traits in a BC2F2 population from the cross between a popular Oryza sativa cv Swarna and O. nivara IRGC81848. Transgressive segregants with more than 15% increased effect over Swarna were observed for all the traits except days to heading and days to 50% flowering. Thirty QTLs were detected for seven yield and yield-related traits using interval and composite interval mapping. Enhancing alleles at 13 (45%) of these QTLs were derived from O. nivara, and enhancing alleles at all the QTLs for stem diameter and rachis diameter were derived from O. nivara. Three stem diameter QTLs, two rachis diameter QTLs and one number of secondary branches QTL identified by both Interval and composite interval mapping contributed more than 15% of the total phenotypic variance. The QTL epistasis was significant for stem diameter and plot yield. The most significant QTLs qSD7.2, qSD8.1 and qSD9.1 for stem diameter, qRD9.1 for rachis diameter and qNSB1.1 for number of secondary branches are good targets to evaluate their use in marker-assisted selection. O. nivara is a good source of novel alleles for yield related traits and reveals major effect QTLs suitable for marker-assisted selection.展开更多
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 deri...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.展开更多
Plant height in cucumber is not only an important trait for breeding,but also one of the model traits suitable for the study of developmental biology.Amplified fragment length polymorphism(AFLP)and simple sequence rep...Plant height in cucumber is not only an important trait for breeding,but also one of the model traits suitable for the study of developmental biology.Amplified fragment length polymorphism(AFLP)and simple sequence repeat(SSR)markers techniques were applied for the construction of genetic linkage maps in cucumber.To understand the dwarf trait genetic basis in cucumber,the quantitative trait loci(QTL)were identified using F_6 recombinant inbred line populations(RILs)comprising 336 lines from the cross between the two cultivars D0462(the dwarf)and DN129(the vine).In total,six SSR markers and 15 AFLP markers were detected on the five linkage groups covering 152.8 cM with a mean marker interval of 7.28 cM.Only one QTL was found to be linked with plant height and the dwarf trait locus remained in the fourth linkage group.The contributory percentage of the single QTL to plant height was 11.39%.展开更多
The source-sink relationship determines the ultimate grain yield.We investigated the genetic basis of the relationship between source and sink and yield potential in rice.In two environments,we identified quantitative...The source-sink relationship determines the ultimate grain yield.We investigated the genetic basis of the relationship between source and sink and yield potential in rice.In two environments,we identified quantitative trait loci(QTL)associated with sink capacity(total spikelet number per panicle and thousand-grain weight),source leaf(flag leaf length,flag leaf width and flag leaf area),source-sink relationship(total spikelet number to flag leaf area ratio)and yield-related traits(filled grain number per panicle,panicle number per plant,grain yield per plant,biomass per plant,and harvest index)by genome-wide association analysis using 272 Xian(indica)accessions.The panel showed substantial variation for all traits in the two environments and revealed complex phenotypic correlations.A total of 70 QTL influencing the 11 traits were identified using 469,377 high-quality SNP markers.Five QTL were detected consistently in four chromosomal regions in both environments.Five QTL clusters simultaneously affected source,sink,source–sink relationship,and grain yield traits,probably explaining the genetic basis of significant correlations of grain yield with source and sink traits.We selected 24 candidate genes in the four consistent QTL regions by identifying linkage disequilibrium(LD)blocks associated with significant SNPs and performing haplotype analysis.The genes included one cloned gene(NOG1)and three newly identified QTL(qHI6,qTGW7,and qFLA8).These results provide a theoretical basis for high-yield rice breeding by increasing and balancing source–sink relationships using marker-assisted selection.展开更多
The foundation parents play key roles in the genetic improvement of both yield potential and end-use quality in wheat.Characterizing the genetic basis that underlies certain beneficial traits in the foundation parents...The foundation parents play key roles in the genetic improvement of both yield potential and end-use quality in wheat.Characterizing the genetic basis that underlies certain beneficial traits in the foundation parents will provide theoretical reference for molecular breeding by a design approach.‘Kenong 9204’(KN9204)is a candidate foundation parent characterized by ideotype,high yield potential,and particularly high nitrogen fertilizer utilization.To better understand the genetic basis of its high yield potential,high throughput whole-genome re-sequencing(10×)was performed on KN9204,its parental lines and its derivatives.A high-resolution genetic composition map of KN9204 was constructed,which showed the parental origin of the favorable genomic segments based on the identification of excellent yield-related quantitative trait loci(QTL)from a bi-parental mapping population.Xiaoyan 693(XY693),a wheat–Thinopyrum ponticum partial amphidiploid,contributed a great deal to the high yield potential of KN9204,and three major stable QTLs from XY693 were fine mapped.The transmissibility of key genomic segments from KN9204 to its derivatives were delineated,indicating that haplotype blocks containing beneficial gene combinations were conserved along with directional selection by breeders.Evidence for selection sweeps in the breeding programs was identified.This study provides a theoretical reference for the breeding of high-yield wheat varieties by a molecular design approach.展开更多
The nutritional quality of rice is a major concern,along with the need to enhance productivity to feed the continuously growing population.Therefore,there is a requirement to breed high-yielding rice varieties with im...The nutritional quality of rice is a major concern,along with the need to enhance productivity to feed the continuously growing population.Therefore,there is a requirement to breed high-yielding rice varieties with improved nutritional quality that can help combat malnutrition,a global health issue.Undoubtedly,breeding approaches have played a significant role in increasing rice yield while enhancing its nutritional content.In addition to traditional breeding techniques,other recent approaches,such as genetic engineering,gene editing,omics methods,and agronomic practices,must also be employed to meet the nutritional needs of the current population.In this review,we offered detailed information on the development of nutritionally improved rice varieties through the enhancement of protein content,microand macronutrients,vitamins,and oil quality using genetic engineering approaches.We also identified QTLs associated with amino acids,proteins,and micronutrients in rice.Furthermore,omics approaches provide a range of tools and techniques for effectively exploring resources and understanding the molecular mechanisms involved in trait development.Omics branches,including transcriptomics,proteomics,ionomics,and metabolomics,are efficiently utilized for improving rice nutrition.Therefore,by utilizing the information obtained from these techniques and incorporating all of these recent approaches,we can effectively modify the rice genome,directly enhancing the nutritional value of rice varieties.This will help address the challenges of malnutrition in the years to come.展开更多
Peanut pod shape is a heritable trait which affects the market acceptance of in-shell peanut products.In order to determine the genetic control of pod shape,six component traits of pod shape(pod length,pod width,pod l...Peanut pod shape is a heritable trait which affects the market acceptance of in-shell peanut products.In order to determine the genetic control of pod shape,six component traits of pod shape(pod length,pod width,pod length/width ratio,pod roundness,beak degree and constriction degree)were measured using an image-based phenotyping method.A recombinant inbred line(RIL)population consisting of 181 lines was phenotyped across three environments.Continuous distributions and transgressive segregations were demonstrated in all measured traits and environments.Significant correlations were found among most component traits with broad-sense heritability ranging from 0.87 to 0.95.Quantitative trait locus(QTL)analysis yielded 26 additive QTLs explaining 3.79 to 52.37%phenotypic variations.A novel,stable and major QTL region conditioning multiple shape features was detected on chromosome 2,which spans a 10.81-Mb genomic region with 543 putative genes.Bioinformatics analysis revealed several candidate genes in this region.In addition,73 pairs of epistatic interactions involving 92 loci were identified for six component traits explaining 0.94–6.45%phenotypic variations.These results provide new genetic loci to facilitate genomics-assisted breeding of peanut pod shape.展开更多
Germplasm resource innovation is a crucial factor for cultivar development,particularly within the context of hybrid rice breeding based on the three-line system.Quan 9311A,a cytoplasmic male sterile(CMS)line,has been...Germplasm resource innovation is a crucial factor for cultivar development,particularly within the context of hybrid rice breeding based on the three-line system.Quan 9311A,a cytoplasmic male sterile(CMS)line,has been successfully cultivated using rice restoration materials and extensively employed as a female parent in hybrid breeding program in China.This line was developed by crossing the CMS line Zhong 9A with a two-line restorer line 93-11,with the intention of eliminating the restoring ability of 93-11 while retaining the sterility gene WA352c from Zhong 9A.Quan 9311A effectively amalgamates the most favorable agronomic traits from both parental lines.In this study,the relationship between phenotypic characteristics and the known functional genes of Quan 9311A were analyzed using the rice genome navigation technology based on whole-genome sequencing.The findings revealed that Quan 9311A harbors multiple superior alleles from both 93-11 and Zhong 9A,providing exceptional agronomic traits that are unavailable in earlier CMS lines.Despite the removal of the fertility restorer gene Rf3 from 93-11,numerous chromosomal segments from 93-11 persist in the Quan 9311A genome.Furthermore,the hybrid rice Quanyousimiao(QYSM)and the restorer line Wushansimiao(WSSM)were used as examples to illustrate the important role of Quan 9311A as the female parent in heterosis.It was found that QYSM carries a great number of superior alleles,which accounts for its high grain yield and wide adaptability.These insights not only advanced the utilization of hybrid rice pairing groups but also provided guidance for future breeding endeavors.The study introduced innovative concepts to further integrate genomics with traditional breeding techniques.Ultimately,Quan 9311A signified a significant milestone in rice breeding technology,opening up novel avenues for hybrid rice development.展开更多
Bacterial leaf streak (BLS) is one of the important limiting factors to rice production in southern China and other tropicaland sub-tropical areas in Asia. Resistance to BLS was found to be a quantitative trait and no...Bacterial leaf streak (BLS) is one of the important limiting factors to rice production in southern China and other tropicaland sub-tropical areas in Asia. Resistance to BLS was found to be a quantitative trait and no major resistant gene waslocated in rice until date. In the present study, a new major quantitative trait locus (QTL) conferring resistance to BLS wasidentified from a highly resistant variety Dular by the employment of Dular/Balilla (DB) and Dular/IR24 (DI) segregationpopulations and was designated qBLSR-11-1. This QTL was located between the simple sequence repeat (SSR) markersRM120 and RM441 on chromosome 11 and could account for 18.1-21.7% and 36.3% of the variance in DB and DIpopulations, respectively. The genetic pattern of rice resistance to BLS was discussed.展开更多
Seed storability(SS) is an important trait for agronomic production and germplasm preservation in rice(Oryza sativa L.). Quantitative trait locus(QTL) for seed storability in three storage periods was identified using...Seed storability(SS) is an important trait for agronomic production and germplasm preservation in rice(Oryza sativa L.). Quantitative trait locus(QTL) for seed storability in three storage periods was identified using two sets of recombinant inbred lines(RILs) derived from the crosses with a common female parent Shennong 265(SN265). Ten QTLs for seed storability were detected on chromosomes 1, 2, 3, 4, 6, 8, and 12 in SL-RILs(SN265/Lijiangxingtuanheigui(LTH)), and a total of 12 QTLs were identified on chromosomes 2, 3, 4, 6, 9, and 10 in SH-RILs(SN265/Luhui 99(LH99)) in different storage periods. Among these QTLs, five major QTLs were identified in more than one storage period. The qSS3-1, qSS3-2, qSS12-1, and qSS12-2 were detected in SL-RILs. Similarly, qSS2-2, qSS2-3, qSS6-2, qSS6-3, qSS6-4, qSS9-1, and qSS9-2 were detected in SH-RILs. In addition, the maximum phenotypic variation was derived from the qSS6-1 and qSS9-2, explaining 53.58 and 29.09%, respectively, while qSS6-1 was a new stable QTL for seed storability. These results provide an opportunity for pyramiding and map-based cloning major QTLs for seed storability in rice.展开更多
Appearance and cooked rice elongation are key quality traits of rice. Although some QTL for these traits have been identified, understanding of the genetic relationship between them remains limited. In the present stu...Appearance and cooked rice elongation are key quality traits of rice. Although some QTL for these traits have been identified, understanding of the genetic relationship between them remains limited. In the present study, large phenotypic variation was observed in 760 accessions from the 3 K Rice Genomes Project for both appearance quality and cooked rice elongation. Most component traits of appearance quality and cooked rice elongation showed significant pairwise correlations, but a low correlation was found between appearance quality and cooked rice elongation. A genome-wide association study identified 74 QTL distributed on all 12 chromosomes for grain length, grain width, length to width ratio, degree of endosperm with chalkiness, rice elongation difference, and elongation index. Thirteen regions containing QTL stably expressed in multiple environments and/or exerting pleiotropic effects on multiple traits were detected. By gene-based association analysis and haplotype analysis, 46 candidate genes, including five cloned genes, and 49 favorable alleles were identified for these 13 QTL. The effect of the candidate gene Wx on rice elongation difference was validated by a transgenic strategy. These results shed light on the genetic bases of appearance quality and cooked rice elongation and provide gene resources for improving rice quality by molecular breeding.展开更多
Grain number per spikelet (GNS) is a key determinant of grain yield in wheat.A recombinant inbred line population comprising 300 lines was developed from a cross between a high GNS variety H461 and Chinese Spring from...Grain number per spikelet (GNS) is a key determinant of grain yield in wheat.A recombinant inbred line population comprising 300 lines was developed from a cross between a high GNS variety H461 and Chinese Spring from which the reference genome assembly of bread wheat was obtained.Both parents and the recombinant inbred lines were genotyped using the wheat 55K single nucleotide polymorphism(SNP) array.A high-density genetic map containing 21,197 SNPs was obtained.These markers covered each of the 21 chromosomes with a total linkage distance of 3792.71 c M.Locations of these markers in this linkage map were highly consistent with their physical locations in the genome assembly of Chinese Spring.The two parents and the whole RIL population were assessed for GNS in two consecutive years at two different locations.Based on multi-environment phenotype data and best liner unbiased prediction values,three quantitative trait loci (QTL) for GNS were identified.One of them located on chromosomes 2B and the other two on 2D.Phenotypic variation explained by these loci varied from 3.07%to26.57%.One of these QTL,QGns.sicau-2D-2,was identified in each of all trials conducted.Based on the best linear unbiased prediction values,this locus explained 19.59%–26.57%of phenotypic variation.A KASP(Kompetitive Allele-Specific PCR) marker closely linked with this locus was generated and used to validate the effects of this locus in three different genetic backgrounds.The identified QTL and the KASP marker developed for it will be highly valuable in fine-mapping the locus and in exploiting it for markerassisted selection in wheat breeding programs.展开更多
基金the Grant support from National Natural Science Foundation of China(U1706203,31172404 and 31572618)Taishan Scholar Project Fund of Shandong Province of China,and Youth Talent Program Supported by Laboratory for Marine Fisheries Science and Food Production Processes,Pilot National Laboratory for Marine Science and Technology(Qingdao)(2018-MFS-T07).
文摘The bay scallop and Peruvian scallop are economically important species.Interspecific hybrids of these two scallops outperformed both of their parent species in multiple growth traits but exhibited decreased fertility,which provides good models for the study of heterosis and species divergence.Genetic mapping serves as a chromosomal-level framework to investigate the molecular mechanisms of hybridization and introgression.In this study,high-resolution linkage maps were constructed for the bay and Peruvian scallops with an interspecific hybrid family.The linkage map of the bay scallop covered over 98.9% of the whole genome with 2994 mapped markers and the average marker interval of 0.32 cM.For the Peruvian scallop,1585 markers were mapped with the average maker interval of 0.51 cM,covering 97.7% of the genome.Both the two linkage maps have 16 linkage groups,corresponding to the haploid chromosome number of the two species.Approximately,54.5% of markers exhibited significant deviation from the expected Mendelian ratio of segregation,lending in sights into the intrinsic incompatibility between the two species.QTLs related to growth and shell coloration were detected,which could explain 13.1%and 74.9% of the phenotypic variance,respectively.This represents important information for further evaluation.These findings are an important addition to the genomic resources for scallop genetic studies,and are especially useful for investigations on genomic incompatibility for hybridization,genome evolution of closely related species,and genetic enhancement programs in aquaculture.
基金This work was supported by the China Scholarship Council[Grant Number 201906140047]National Natural Science Foundation of China[Grant Numbers 11801210,11801359 and 11771145].
文摘In this paper,we propose generalized fiducial methods and construct four generalized p-values to test the existence of quantitative trait locus effects under phenotype distributions from a location-scale family.Compared with the likelihood ratio test based on simulation studies,our methods perform better at controlling type I errors while retaining comparable power in cases with small or moderate sample sizes.The four generalized fiducial methods support varied sce-narios:two of them are more aggressive and powerful,whereas the other two appear more conservative and robust.A real data example involving mouse blood pressure is used to illustrate our proposed methods.
基金supported by the National Natural Science Foundation of China (Grant Nos. 30971745 and 30900874)the Natural Science Foundation of Hunan Province, China (Grant No. 08JJ1003)+1 种基金the Ph.D. Programs Foundation of Ministry of Education of China (Grant No. 20070537006)the Scientific Research Fund of Hunan Provincial Education Department, China (Grant No. 06B042)
文摘High temperature stress (HTS), an increasingly important problem in rice production, significantly reduces rice yield by reducing pollen fertility and seed setting rate. Breeding rice varieties with tolerance to HTS at the flowering stage is therefore essential for maintaining rice production as the climate continues to become warm. In this study, two quantitative trait loci (QTLs) underlying tolerance to HTS were identified using recombinant inbred lines derived from a cross between an HTS-tolerant rice cultivar 996 and a sensitive cultivar 4628. Pollen fertility was used as a heat-tolerance indicator for the lines subjected to HTS at the flowering stage in field experiments. Two QTLs that affected pollen fertility, qPF4 and qPF6, were detected between RM5687 and RM471 on chromosome 4, and between RM190 and RM225 on chromosome 6, by using the composite interval mapping (CIM) analysis. The two QTLs explained 15.1% and 9.31% of the total phenotypic variation in pollen fertility, and increased the pollen fertility of the plants subjected to HTS by 7.15% and 5.25%, respectively. The positive additive effects of the two QTLs were derived from the 996 alleles. The two major QTLs identified would be useful for further fine mapping and cloning of these genes and for molecular marker-assistant breeding of heat-tolerant rice varieties.
基金supported by the Chinese Super Rice Breeding Program(Grant No.200906)the National High Technology Research and Development Program(Grant No.2009AA101101)the Research Funding of the China National RiceResearch Institute(Grant No.2009RG002)
文摘QTLs for heading date located in the regions of Hd3a and Hd1 were detected using an F2:3 population developed from a residual heterozygous line(RHL) identified from the recombinant inbred lines of the indica rice cross Zhenshan 97B /Milyang 46.Linkage in coupling phase between the QTLs for heading date and yield traits detected in a previous study was found.Four more F2:3 populations were each developed from an RHL that was homozygous at Hd3a and Hd1 but heterozygous in a portion of the intervals flanked by Hd3a and Hd1.QTLs for grain yield per plant,number of panicles per plant,number of grains per panicle and 1000-grain weight were detected in the heterozygous region.Five sets of near-isogenic lines(NILs) with overlapping heterogenous segments covering the interval RM6119-RM6779 were developed and used to validate and delimitate the QTLs.A QTL conferring a consistent effect for the number of grains per panicle was located within the interval RM19615-RM19652 that corresponded to a 514.4-kb region on chromosome 6.The same region might have pleiotropic effects on the other three yield-related traits analyzed,but the effects varied greatly among different populations and across different environments.This study suggests that it is possible to develop a population with little variation on heading date and to identify QTLs for yield traits that might not be associated with heading date by using the information of physical positions of DNA markers and cloned genes.
基金supported by the National Key Research Plan Project of China(Grant No.2017YFD0101107)Chongqing Technical Innovation and Application Development Project(Grant No.cstc2019jscx-msxmX0392)。
文摘Rice kernel shape affects kernel quality(appearance) and yield(1000-kernel weight) and therefore is an important agronomic trait, but its inheritance is complicated. We identified a long-kernel rice chromosome segment substitution line(CSSL), Z741, derived from Nipponbare as a recipient and Xihui 18 as a donor parent. Z741 has six substitution segments distributed on rice chromosomes 3, 6, 7, 8 and 12 with an average replacement length of 5.82 Mb. Analysis of a secondary F2 population from a cross between Nipponbare and Z741 identified 20 QTLs for important agronomic traits. The kernel length of Z741 is controlled by a major QTL(qKL3) and a minor QTL(qKL7). Candidate gene prediction and sequencing indicated that qKL3 may be an allele of OsPPKL1, which encodes a protein phosphatase implicated in brassinosteroid signaling, and qKL7 is an unreported QTL. Finally, we validated eight QTLs(qKL3, qKL7, qRLW3-1, qRLW7, qPH3-1, qKWT3, qKWT7 and qNPB6) using three selected singlesegment substitution lines(SSSLs), S1, S2 and S3. Also, we detected five QTLs(qKL6, qKW3, qKW7, qKW6 and qRLW6) in S1, S2 and S3, which were not found in the Nipponbare/Z741 F2 population. However, qNPB3, qNPB7 and qPL3 QTLs were not validated by the three SSSLs in 2019, suggesting that minor QTLs are susceptible to environmental factors. These results lay the foundation for studying the biodiversity of kernal length and molecular breeding of different kernel types.
基金supported by the National Key Research and Development Program of China(2016YFD0101803)the Key Transgenic Breeding Program of the Ministry of Agriculture of China(2016ZX08003-002)the China Agriculture Research System(CARS-02-10)。
文摘Drought is one of the most critical abiotic stresses influencing maize yield. Improving maize cultivars with drought tolerance using marker-assisted selection requires a better understanding of its genetic basis. In this study, a doubled haploid(DH) population consisting of 217 lines was created by crossing the inbred lines Han 21(drought-tolerant) and Ye 478(drought-sensitive). The population was genotyped with a 6 K SNP assay and 756 SNP(single nucleotide polymorphism) markers were used to construct a linkage map with a length of 1344 c M. Grain yield(GY), ear setting percentage(ESP), and anthesis–silking interval(ASI) were recorded in seven environments under well-watered(WW) and water-stressed(WS) regimes. High phenotypic variation was observed for all traits under both water regimes. Using the LSMEAN(least-squares mean) values from all environments for each trait, 18 QTL were detected, with 9 associated with the WW and 9 with the WS regime. Four chromosome regions,Chr. 3: 219.8–223.7 Mb, Chr. 5: 191.5–194.7 Mb, Chr. 7: 132.2–135.6 Mb, and Chr. 10: 88.2–89.4 Mb, harbored at least 2 QTL in each region, and QTL co-located in a region inherited favorable alleles from the same parent. A set of 64 drought-tolerant BC_3F_6 lines showed preferential accumulation of the favorable alleles in these four regions, supporting an association between the four regions and maize drought tolerance. QTL-by-environment interaction analysis revealed 28 ed QTL(environment-dependent QTL) associated with the WS regime and 22 associated with the WW regime for GY, ESP, and ASI. All WS QTL and55.6% of WW QTL were located in the ed QTL regions. The hotspot genomic regions identified in this work will support further fine mapping and marker-assisted breeding of drought-tolerant maize.
基金the Department of Biotechnology, Government of India for financial support to the Network Project on Functional Genomics of rice at the Directorate of Rice Research, Andhra Pradesh, India
文摘Advanced backcross QTL analysis was used to identify QTLs for seven yield and yield-related traits in a BC2F2 population from the cross between a popular Oryza sativa cv Swarna and O. nivara IRGC81848. Transgressive segregants with more than 15% increased effect over Swarna were observed for all the traits except days to heading and days to 50% flowering. Thirty QTLs were detected for seven yield and yield-related traits using interval and composite interval mapping. Enhancing alleles at 13 (45%) of these QTLs were derived from O. nivara, and enhancing alleles at all the QTLs for stem diameter and rachis diameter were derived from O. nivara. Three stem diameter QTLs, two rachis diameter QTLs and one number of secondary branches QTL identified by both Interval and composite interval mapping contributed more than 15% of the total phenotypic variance. The QTL epistasis was significant for stem diameter and plot yield. The most significant QTLs qSD7.2, qSD8.1 and qSD9.1 for stem diameter, qRD9.1 for rachis diameter and qNSB1.1 for number of secondary branches are good targets to evaluate their use in marker-assisted selection. O. nivara is a good source of novel alleles for yield related traits and reveals major effect QTLs suitable for marker-assisted selection.
基金funded and supported by China Agriculture Research System of MOF and MARA,Sichuan Science and Technology Support Project(2021YFYZ0020,2021YFYZ0027,2021YFFZ0017)National Natural Science Foundation of China(31971955)Sichuan Science and Technology Program(2019YJ0418,2020YJ0138)。
文摘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.
基金Supported by the"Academic Backbone"Project of Northeast Agricultural University(18XG06)Supporting Certificate of Heilongjiang Postdoctoral Scientific Research Developmental Fund(LBH-Q16021)the Natural Science Foundation of Heilongjiang Province,China(LH2019C033)。
文摘Plant height in cucumber is not only an important trait for breeding,but also one of the model traits suitable for the study of developmental biology.Amplified fragment length polymorphism(AFLP)and simple sequence repeat(SSR)markers techniques were applied for the construction of genetic linkage maps in cucumber.To understand the dwarf trait genetic basis in cucumber,the quantitative trait loci(QTL)were identified using F_6 recombinant inbred line populations(RILs)comprising 336 lines from the cross between the two cultivars D0462(the dwarf)and DN129(the vine).In total,six SSR markers and 15 AFLP markers were detected on the five linkage groups covering 152.8 cM with a mean marker interval of 7.28 cM.Only one QTL was found to be linked with plant height and the dwarf trait locus remained in the fourth linkage group.The contributory percentage of the single QTL to plant height was 11.39%.
基金funded by the National Key Research and Development Program of China(2016YFD0100301)the National Natural Science Foundation of China(31671602)the Agricultural Science and Technology Innovation Program and the Cooperation and Innovation Mission(CAASZDXT2018001)
文摘The source-sink relationship determines the ultimate grain yield.We investigated the genetic basis of the relationship between source and sink and yield potential in rice.In two environments,we identified quantitative trait loci(QTL)associated with sink capacity(total spikelet number per panicle and thousand-grain weight),source leaf(flag leaf length,flag leaf width and flag leaf area),source-sink relationship(total spikelet number to flag leaf area ratio)and yield-related traits(filled grain number per panicle,panicle number per plant,grain yield per plant,biomass per plant,and harvest index)by genome-wide association analysis using 272 Xian(indica)accessions.The panel showed substantial variation for all traits in the two environments and revealed complex phenotypic correlations.A total of 70 QTL influencing the 11 traits were identified using 469,377 high-quality SNP markers.Five QTL were detected consistently in four chromosomal regions in both environments.Five QTL clusters simultaneously affected source,sink,source–sink relationship,and grain yield traits,probably explaining the genetic basis of significant correlations of grain yield with source and sink traits.We selected 24 candidate genes in the four consistent QTL regions by identifying linkage disequilibrium(LD)blocks associated with significant SNPs and performing haplotype analysis.The genes included one cloned gene(NOG1)and three newly identified QTL(qHI6,qTGW7,and qFLA8).These results provide a theoretical basis for high-yield rice breeding by increasing and balancing source–sink relationships using marker-assisted selection.
基金supported by the grants from the Shandong Major Basic Research Project of Natural Science Foundation,China(ZR2019ZD16)the Shandong Provincial Key Research and Development Program,China(2019GNC106126 and 2021LZGC009)+3 种基金the Natural Science Foundation of Hebei Province,China(C2021205013)the Hebei Scientific and Technological Innovation Team of Modern Wheat Seed Industry,China(21326318D)the National Natural Science Foundation of China(31871612,31901535,and 32101726)the China Agriculture Research System of MOF and MARA(CARS-03).
文摘The foundation parents play key roles in the genetic improvement of both yield potential and end-use quality in wheat.Characterizing the genetic basis that underlies certain beneficial traits in the foundation parents will provide theoretical reference for molecular breeding by a design approach.‘Kenong 9204’(KN9204)is a candidate foundation parent characterized by ideotype,high yield potential,and particularly high nitrogen fertilizer utilization.To better understand the genetic basis of its high yield potential,high throughput whole-genome re-sequencing(10×)was performed on KN9204,its parental lines and its derivatives.A high-resolution genetic composition map of KN9204 was constructed,which showed the parental origin of the favorable genomic segments based on the identification of excellent yield-related quantitative trait loci(QTL)from a bi-parental mapping population.Xiaoyan 693(XY693),a wheat–Thinopyrum ponticum partial amphidiploid,contributed a great deal to the high yield potential of KN9204,and three major stable QTLs from XY693 were fine mapped.The transmissibility of key genomic segments from KN9204 to its derivatives were delineated,indicating that haplotype blocks containing beneficial gene combinations were conserved along with directional selection by breeders.Evidence for selection sweeps in the breeding programs was identified.This study provides a theoretical reference for the breeding of high-yield wheat varieties by a molecular design approach.
基金This study was funded by the Hainan Yazhou Bay Seed Lab Project,China(Grant No.B21HJ0216)the Key Research and Development Project of Hainan Province,China(Grant No.ZDYF2021XDNY128)the Agricultural Science and Technology Innovation Program and the Cooperation and Innovation Mission,China(Grant No.CAAS-ZDXT202001).
文摘The nutritional quality of rice is a major concern,along with the need to enhance productivity to feed the continuously growing population.Therefore,there is a requirement to breed high-yielding rice varieties with improved nutritional quality that can help combat malnutrition,a global health issue.Undoubtedly,breeding approaches have played a significant role in increasing rice yield while enhancing its nutritional content.In addition to traditional breeding techniques,other recent approaches,such as genetic engineering,gene editing,omics methods,and agronomic practices,must also be employed to meet the nutritional needs of the current population.In this review,we offered detailed information on the development of nutritionally improved rice varieties through the enhancement of protein content,microand macronutrients,vitamins,and oil quality using genetic engineering approaches.We also identified QTLs associated with amino acids,proteins,and micronutrients in rice.Furthermore,omics approaches provide a range of tools and techniques for effectively exploring resources and understanding the molecular mechanisms involved in trait development.Omics branches,including transcriptomics,proteomics,ionomics,and metabolomics,are efficiently utilized for improving rice nutrition.Therefore,by utilizing the information obtained from these techniques and incorporating all of these recent approaches,we can effectively modify the rice genome,directly enhancing the nutritional value of rice varieties.This will help address the challenges of malnutrition in the years to come.
基金supported by the National Natural Science Foundation of China(32001584)the Natural Science Foundation of Shandong Province,China(ZR202111290099)+2 种基金the Breeding Project from Department Science&Technology of Shandong Province,China(2020LZGC001)the Agricultural Scientific and the Technological Innovation Project of Shandong Academy of Agricultural Sciences,China(CXGC2022A21,CXGC2022A03,and CXGC2023A06(A39 and A46))the Qingdao People’s Livelihood Science and Technology Program,China(20-3-4-26-nsh)。
文摘Peanut pod shape is a heritable trait which affects the market acceptance of in-shell peanut products.In order to determine the genetic control of pod shape,six component traits of pod shape(pod length,pod width,pod length/width ratio,pod roundness,beak degree and constriction degree)were measured using an image-based phenotyping method.A recombinant inbred line(RIL)population consisting of 181 lines was phenotyped across three environments.Continuous distributions and transgressive segregations were demonstrated in all measured traits and environments.Significant correlations were found among most component traits with broad-sense heritability ranging from 0.87 to 0.95.Quantitative trait locus(QTL)analysis yielded 26 additive QTLs explaining 3.79 to 52.37%phenotypic variations.A novel,stable and major QTL region conditioning multiple shape features was detected on chromosome 2,which spans a 10.81-Mb genomic region with 543 putative genes.Bioinformatics analysis revealed several candidate genes in this region.In addition,73 pairs of epistatic interactions involving 92 loci were identified for six component traits explaining 0.94–6.45%phenotypic variations.These results provide new genetic loci to facilitate genomics-assisted breeding of peanut pod shape.
基金This study was funded by the National Natural Science Foundation of China(Grant No.32001516)Shanghai Agriculture Applied Technology Development Program,China(Grant No.X20190103)Rice Industry of China Agriculture Research System(Grant No.CARS-01-03).
文摘Germplasm resource innovation is a crucial factor for cultivar development,particularly within the context of hybrid rice breeding based on the three-line system.Quan 9311A,a cytoplasmic male sterile(CMS)line,has been successfully cultivated using rice restoration materials and extensively employed as a female parent in hybrid breeding program in China.This line was developed by crossing the CMS line Zhong 9A with a two-line restorer line 93-11,with the intention of eliminating the restoring ability of 93-11 while retaining the sterility gene WA352c from Zhong 9A.Quan 9311A effectively amalgamates the most favorable agronomic traits from both parental lines.In this study,the relationship between phenotypic characteristics and the known functional genes of Quan 9311A were analyzed using the rice genome navigation technology based on whole-genome sequencing.The findings revealed that Quan 9311A harbors multiple superior alleles from both 93-11 and Zhong 9A,providing exceptional agronomic traits that are unavailable in earlier CMS lines.Despite the removal of the fertility restorer gene Rf3 from 93-11,numerous chromosomal segments from 93-11 persist in the Quan 9311A genome.Furthermore,the hybrid rice Quanyousimiao(QYSM)and the restorer line Wushansimiao(WSSM)were used as examples to illustrate the important role of Quan 9311A as the female parent in heterosis.It was found that QYSM carries a great number of superior alleles,which accounts for its high grain yield and wide adaptability.These insights not only advanced the utilization of hybrid rice pairing groups but also provided guidance for future breeding endeavors.The study introduced innovative concepts to further integrate genomics with traditional breeding techniques.Ultimately,Quan 9311A signified a significant milestone in rice breeding technology,opening up novel avenues for hybrid rice development.
文摘Bacterial leaf streak (BLS) is one of the important limiting factors to rice production in southern China and other tropicaland sub-tropical areas in Asia. Resistance to BLS was found to be a quantitative trait and no major resistant gene waslocated in rice until date. In the present study, a new major quantitative trait locus (QTL) conferring resistance to BLS wasidentified from a highly resistant variety Dular by the employment of Dular/Balilla (DB) and Dular/IR24 (DI) segregationpopulations and was designated qBLSR-11-1. This QTL was located between the simple sequence repeat (SSR) markersRM120 and RM441 on chromosome 11 and could account for 18.1-21.7% and 36.3% of the variance in DB and DIpopulations, respectively. The genetic pattern of rice resistance to BLS was discussed.
基金supported by the Major Project of Education Department in Liaoning,China(LSNZD201604)
文摘Seed storability(SS) is an important trait for agronomic production and germplasm preservation in rice(Oryza sativa L.). Quantitative trait locus(QTL) for seed storability in three storage periods was identified using two sets of recombinant inbred lines(RILs) derived from the crosses with a common female parent Shennong 265(SN265). Ten QTLs for seed storability were detected on chromosomes 1, 2, 3, 4, 6, 8, and 12 in SL-RILs(SN265/Lijiangxingtuanheigui(LTH)), and a total of 12 QTLs were identified on chromosomes 2, 3, 4, 6, 9, and 10 in SH-RILs(SN265/Luhui 99(LH99)) in different storage periods. Among these QTLs, five major QTLs were identified in more than one storage period. The qSS3-1, qSS3-2, qSS12-1, and qSS12-2 were detected in SL-RILs. Similarly, qSS2-2, qSS2-3, qSS6-2, qSS6-3, qSS6-4, qSS9-1, and qSS9-2 were detected in SH-RILs. In addition, the maximum phenotypic variation was derived from the qSS6-1 and qSS9-2, explaining 53.58 and 29.09%, respectively, while qSS6-1 was a new stable QTL for seed storability. These results provide an opportunity for pyramiding and map-based cloning major QTLs for seed storability in rice.
基金funded by the National Key Research and Development Program of China (2016YFD0100301)Project for Cultivating New Transgenic Varieties (2016ZX08009003-004)+2 种基金the Agricultural Science and Technology Innovation Program and the Cooperation and Innovation Mission (CAAS-ZDXT202001)Open Fund of Hubei Collaborative Innovation Center for Grain Industry (HCICGI2020-06)the National Natural Science Foundation of China (U19A2025 and 31870229)。
文摘Appearance and cooked rice elongation are key quality traits of rice. Although some QTL for these traits have been identified, understanding of the genetic relationship between them remains limited. In the present study, large phenotypic variation was observed in 760 accessions from the 3 K Rice Genomes Project for both appearance quality and cooked rice elongation. Most component traits of appearance quality and cooked rice elongation showed significant pairwise correlations, but a low correlation was found between appearance quality and cooked rice elongation. A genome-wide association study identified 74 QTL distributed on all 12 chromosomes for grain length, grain width, length to width ratio, degree of endosperm with chalkiness, rice elongation difference, and elongation index. Thirteen regions containing QTL stably expressed in multiple environments and/or exerting pleiotropic effects on multiple traits were detected. By gene-based association analysis and haplotype analysis, 46 candidate genes, including five cloned genes, and 49 favorable alleles were identified for these 13 QTL. The effect of the candidate gene Wx on rice elongation difference was validated by a transgenic strategy. These results shed light on the genetic bases of appearance quality and cooked rice elongation and provide gene resources for improving rice quality by molecular breeding.
基金supported by the National Natural Science Foundation of China (31771794)the National Key Research and Development Program of China (2016YFD0101004 and 2017YFD0100900)the International Science & Technology Cooperation Program of the Bureau of Science and Technology of Chengdu China (2015DFA306002015-GH03-00008-HZ)。
文摘Grain number per spikelet (GNS) is a key determinant of grain yield in wheat.A recombinant inbred line population comprising 300 lines was developed from a cross between a high GNS variety H461 and Chinese Spring from which the reference genome assembly of bread wheat was obtained.Both parents and the recombinant inbred lines were genotyped using the wheat 55K single nucleotide polymorphism(SNP) array.A high-density genetic map containing 21,197 SNPs was obtained.These markers covered each of the 21 chromosomes with a total linkage distance of 3792.71 c M.Locations of these markers in this linkage map were highly consistent with their physical locations in the genome assembly of Chinese Spring.The two parents and the whole RIL population were assessed for GNS in two consecutive years at two different locations.Based on multi-environment phenotype data and best liner unbiased prediction values,three quantitative trait loci (QTL) for GNS were identified.One of them located on chromosomes 2B and the other two on 2D.Phenotypic variation explained by these loci varied from 3.07%to26.57%.One of these QTL,QGns.sicau-2D-2,was identified in each of all trials conducted.Based on the best linear unbiased prediction values,this locus explained 19.59%–26.57%of phenotypic variation.A KASP(Kompetitive Allele-Specific PCR) marker closely linked with this locus was generated and used to validate the effects of this locus in three different genetic backgrounds.The identified QTL and the KASP marker developed for it will be highly valuable in fine-mapping the locus and in exploiting it for markerassisted selection in wheat breeding programs.
