Exploitation of Tolerance of Wheat Kernel Weight and Shape-Related Traits from Aegilops tauschii under Heat and Combined Heat-Drought Stresses

Kernel weight and shape-related traits are inherited stably and increase wheat yield. Narrow genetic diversity limits the progress of wheat breeding. Here, we evaluated kernel weight and shape-related traits and applied genome-wide association analysis to a panel of wheat multiple synthetic derivative (MSD) lines. The MSD lines harbored genomic fragments from Aegilops tauschii. These materials were grown under optimum conditions in Japan, as well as under heat and combined heat–drought conditions in Sudan. We aimed to explore useful QTLs for kernel weight and shape-related traits under stress conditions. These can be useful for enhancing yield under stress conditions. MSD lines possessed remarkable genetic variation for all traits under all conditions, and some lines showed better performance than the background parent Norin 61. We identified 82 marker trait associations (MTAs) under the three conditions; most of them originated from the D genome. All of the favorable alleles originated from Ae. tauschii. For the first time, we identified markers on chromosome 5D associated with a candidate gene encoding a RING-type E3 ubiquitin–protein ligase and expected to have a role in regulating wheat seed size. Our study provides important knowledge for the improvement of wheat yield under optimum and stress conditions. The results emphasize the importance of Ae. tauschii as a gene reservoir for wheat breeding.

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Novel Loci for Kernel Hardness Appeared as a Response to Heat and Combined Heat-Drought Conditions in Wheat Harboring Aegilops tauschii Diversity

Agronomy ◽

10.3390/agronomy11061061 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1061

Author(s):

Gamila Mohamed Idris Elhadi ◽

Nasrein Mohamed Kamal ◽

Yasir Serag Alnor Gorafi ◽

Yuji Yamasaki ◽

Yusuke Ban ◽

...

Keyword(s):

Stress Tolerance ◽

Aegilops Tauschii ◽

Kernel Weight ◽

Stress Conditions ◽

High Yield ◽

Kernel Hardness ◽

D Genome ◽

Yield And Quality ◽

First Time ◽

Synthetic Derivatives

Kernel hardness influences the milling and baking quality of wheat. Stress environments such as heat and combined heat-drought can produce harder kernels, thereby affecting the overall wheat quality. Beside puroindoline genes that are known to determine hardness, other QTLs contribute to the hardness. These QTLs, especially under stress conditions, need extensive research. Moreover, understanding the modification or stabilization of hardness under stress condition and the relationship with stress tolerance will facilitate the selection of superior lines that maintain both high yield and quality even under the stress environment. Therefore, in the current work, we aimed to identify the genetic loci and marker trait associations (MTAs) that contributes for hardness under optimum conditions in Japan, and heat and combined heat-drought (HD) conditions in Sudan. We used a panel of multiple synthetic derivatives (MSD) having diverse Aegilops tauschii genome segments and investigated the association between hardness stabilization and stress tolerance. Under stress conditions, we observed that less reduction of kernel weight is associated with either low change or stable kernel hardness. We identified 47 markers associated with hardness under all conditions; the D genome was the main contributor. For the first time, we found a significant association with hardness under stress conditions on chromosome 4D. We dissected several candidate genes associated with the change of hardness under stress conditions. Our results will improve the understanding of the genetic factors that affect wheat hardness stability.

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A 1BL/1RS translocation contributing to kernel length increase in three wheat recombinant inbred line populations

Czech Journal of Genetics and Plant Breeding ◽

10.17221/79/2019-cjgpb ◽

2020 ◽

Vol 56 (No. 2) ◽

pp. 43-51

Author(s):

Shui Qin Li ◽

Hua Ping Tang ◽

Han Zhang ◽

Yang Mu ◽

Xiu Jin Lan ◽

...

Keyword(s):

In Situ Hybridization ◽

Inbred Line ◽

Recombinant Inbred Line ◽

Recombinant Inbred ◽

Wheat Yield ◽

Kernel Weight ◽

Translocation Line ◽

Wheat Kernel ◽

Kernel Length

The 1BL/1RS wheat-rye translocation has been widely utilized in wheat genetic improvement and breeding programs. Our understanding on the effects of the 1BL/1RS translocation on wheat kernel size (e.g. length and width) is limited despite of numerous studies reporting about the effects on kernel weight. Here, we identified a wheat 1BL/1RS translocation line 88-1643 with higher kernel length (KL) using fluorescence in situ hybridization (FISH), genomic in situ hybridization (GISH) and molecular markers. To detect the possible role of the 1BL/1RS translocation in KL, kernel width (KW), and thousand-kernel weight (TKW), three recombinant inbred line (RIL) populations were constructed by crossing 88-1643 and three other wheat lines. As expected, the results showed that the values of KL in lines carrying 1RS were significantly higher than those carrying 1BS in three RIL populations at multiple environments, indicating that a major and stably expressed allele or gene responsible for increasing KL is most likely located on 1RS from 88-1643. Additionally, in one RIL population, the increased KL contributed significantly to the increase in TKW. Collectively, the 1BL/1RS translocation reported here is of interest to reveal molecular mechanism of the gene controlling KL and will be useful for improving wheat yield.

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Genome-wide Survey of the Dehydrin Genes in Bread Wheat (Triticum Aestivum L.) and its Relatives: Identification, Evolution and Expression Profiling Under Various Abiotic Stresses

10.21203/rs.3.rs-709007/v1 ◽

2021 ◽

Author(s):

Yongchao Hao ◽

Ming Hao ◽

Hongwei Wang

Keyword(s):

Triticum Aestivum ◽

Bread Wheat ◽

Abiotic Stresses ◽

Aegilops Tauschii ◽

Protein Structures ◽

Interaction Network ◽

Wheat Breeding ◽

Functional Study ◽

Genome Wide ◽

A Genome

Abstract Background: Bread wheat (Triticum aestivum) is an important and fundamental cereal worldwide. With increasingly severe environmental stress, it is very important to mine stress-resistant genes for wheat breeding. Dehydrin (DHN) genes are primary candidates because they are involved in the response to many stressors. Results: Here, a genome-wide analysis of this gene family was performed on the genomes of wheat and its three relatives. A total of 55 DHN genes in Triticum aestivum, 31 in Triticum dicoccoides, 15 in Triticum urartu, and 16 in Aegilops tauschii were identified. The phylogenetic, synteny, sequence and protein structure analyses showed that the DHN genes were divided into five groups, Genes in the same group share similar conserved motifs, protein structures, and potential functions. The tandem TaDHN genes responded strongly to drought, cold and high salinity stresses, while the non-tandem genes were responded weakly to all stress conditions. Further, multiple DHN proteins cooperation maybe an important way to prevent plants from abiotic stress according to the interaction network analysis. Conclusions: Conserved, duplicated DHN genes may have played an important role in the adaptation of wheat to a variety of conditions, hence, contributing to the distribution of bread wheat as a global staple food. This research illuminates the contributions of DHN genes to abiotic stresses in Triticeae species and offers helpful information for further functional study of DHN genes in these crops.

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Uncovering candidate genes involved in photosynthetic capacity using unexplored genetic variation in Spring Wheat

10.1101/2020.06.15.151928 ◽

2020 ◽

Cited By ~ 1

Author(s):

Ryan Joynson ◽

Gemma Molero ◽

Benedict Coombes ◽

Laura-Jayne Gardiner ◽

Carolina Rivera-Amado ◽

...

Keyword(s):

Genetic Variation ◽

Candidate Genes ◽

Complex Traits ◽

Photosynthetic Capacity ◽

Wheat Breeding ◽

Donor Genome ◽

D Genome ◽

Strategic Integration ◽

Breeding Populations ◽

Synthetic Derivative

AbstractTo feed an ever-increasing population we must leverage advances in genomics and phenotyping to harness the variation in wheat breeding populations for traits like photosynthetic capacity which remains unoptimized. Here we survey a diverse set of wheat germplasm containing elite, introgression and synthetic derivative lines uncovering previously uncharacterised variation. We demonstrate how strategic integration of exotic material alleviates the D genome genetic bottleneck in wheat, increasing SNP rate by 62% largely due to Ae. tauschii synthetic wheat donors. Across the panel, 67% of the Ae. tauschii donor genome is represented as introgressions in elite backgrounds. We show how observed genetic variation together with hyperspectral reflectance data can be used to identify candidate genes for traits relating to photosynthetic capacity using association analysis. This demonstrates the value of genomic methods in uncovering hidden variation in wheat and how that variation can assist breeding efforts and increase our understanding of complex traits.

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High molecular weight glutenin gene diversity in Aegilops tauschii demonstrates unique origin of superior wheat quality

10.21203/rs.3.rs-230727/v1 ◽

2021 ◽

Cited By ~ 1

Author(s):

Emily Delorean ◽

LiangLiang Gao ◽

Jose Fausto Cervantes Lopez ◽

The Open Wild Wheat Consortium ◽

Brande Wulff ◽

...

Keyword(s):

Gene Diversity ◽

Aegilops Tauschii ◽

Tetraploid Wheat ◽

Wheat Breeding ◽

D Genome ◽

Breeding Programs ◽

Lineage 2 ◽

End Use ◽

Genomic Resource ◽

New Alleles

Abstract Central to the diversity of wheat products was the origin of hexaploid bread wheat, which added the D-genome of Aegilops tauschii to tetraploid wheat giving rise to superior dough properties in leavened breads. The polyploidization, however, imposed a genetic bottleneck, with only limited diversity introduced in the wheat D-subgenome. To understand genetic variants for quality, we sequenced 273 accessions spanning the known diversity of Ae. tauschii. We discovered 45 haplotypes in Glu-D1, a major determinant of quality, relative to the two predominant haplotypes in wheat. The wheat allele 2+12 was found in Ae. tauschii Lineage 2, the donor of the wheat D-subgenome. Conversely, the superior quality wheat allele 5+10 allele originated in Lineage 3, a recently characterized lineage of Ae. tauschii, showing a unique origin of this important allele. These two wheat alleles were also quite similar relative to the total observed molecular diversity in Ae. tauschii at Glu-D1. Ae. tauschii is thus a reservoir for unique Glu-D1 alleles and provides the genomic resource to begin utilizing new alleles for end-use quality improvement in wheat breeding programs.

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Effects of Rht dwarfing alleles on wheat seed vigour after controlled deterioration

Crop and Pasture Science ◽

10.1071/cp13041 ◽

2013 ◽

Vol 64 (9) ◽

pp. 857 ◽

Cited By ~ 5

Author(s):

Manuela Nagel ◽

Anne-Kathrin Behrens ◽

Andreas Börner

Keyword(s):

Green Revolution ◽

General Pattern ◽

Wheat Yield ◽

Wheat Breeding ◽

Kernel Weight ◽

Wild Type ◽

Seed Vigour ◽

Yield Increase ◽

Reduced Height ◽

Controlled Deterioration

Reduced height (Rht) alleles, commonly known as the ‘Green Revolution’ genes, have facilitated wheat breeding programs and achieved globally a more than 10% wheat yield increase. However, studies in barley indicate that shorter plant habits are associated with reduced seed vigour and longevity. Therefore, wheat seeds of six near-isogenic lines (NIL) carrying the dwarfing alleles Rht-B1b, Rht-D1b, Rht-B1c, Rht-B1b+-D1b, Rht-B1c+-D1b and the wild-type allele Rht-B1a+-D1a, each in four background cultivars, were stressed by controlled deterioration. Seed vigour expressed as root and shoot lengths, time to 50% (T50) and time between 16 and 84% (T16-84) germination showed significant changes after treatment. However, after controlled deterioration only a combination of Rht alleles highly affected T16-84 and T50, which followed the general pattern Rht-B1c+-D1b followed by > Rht-B1c > Rht-B1b+-D1b > Rht-B1b > Rht D1b = Rht-B1a+-D1a (wild type). Interestingly, only under control conditions seed vigour correlated positively with thousand-kernel weight, which decreased with severity of Rht type. Further, the seed length was not affected by the different NIL. In conclusion, NIL carrying combinations of Rht alleles tend to influence seed vigour, which could influence seed longevity. Therefore, plant breeders but especially genebank managers should consider that the genetic background of genotypes may affect seed deterioration processes, which could be an economically important aspect in future.

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Genomic analysis for heat and combined heat–drought resilience in bread wheat under field conditions

Theoretical and Applied Genetics ◽

10.1007/s00122-021-03969-x ◽

2021 ◽

Author(s):

Michael O. Itam ◽

Ryosuke Mega ◽

Yasir S. A. Gorafi ◽

Yuji Yamasaki ◽

Izzat S. A. Tahir ◽

...

Keyword(s):

Bread Wheat ◽

Vegetation Index ◽

Isotope Composition ◽

Association Studies ◽

Canopy Temperature ◽

Kernel Weight ◽

Field Conditions ◽

Genome Wide Association Studies ◽

D Genome ◽

Genome Wide

Abstract Key message GWAS on a bread wheat panel with high D genome diversity identified novel alleles and QTLs associated with resilience to combined heat and drought stress under natural field conditions. Abstract As heat (H) and drought stresses occur concurrently under field conditions, studying them separately offers limited opportunities for wheat improvement. Here, a wheat diversity panel containing Aegilops tauschii introgressions was evaluated under H and combined heat–drought (HD) stresses to identify quantitative trait loci (QTLs) associated with resilience to the stresses, and to assess the practicability of harnessing Ae. tauschii diversity for breeding for combined stress resilience. Using genome-wide analysis, we identified alleles and QTLs on chromosomes 3D, 5D, and 7A controlling grain yield (GY), kernel number per spike, and thousand-kernel weight, and on 3D (521–549 Mbp) controlling GY alone. A strong marker–trait association (MTA) for GY stability on chromosome 3D (508.3 Mbp) explained 20.3% of the variation. Leaf traits—canopy temperature, vegetation index, and carbon isotope composition—were controlled by five QTLs on 2D (23–96, 511–554, and 606–614 Mbp), 3D (155–171 Mbp), and 5D (407–413 Mbp); some of them were pleiotropic for GY and yield-related traits. Further analysis revealed candidate genes, including GA20ox, regulating GY stability, and CaaX prenyl protease 2, regulating canopy temperature at the flowering stage, under H and HD stresses. As genome-wide association studies under HD in field conditions are scarce, our results provide genomic landmarks for wheat breeding to improve adaptation to H and HD conditions under climate change.

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High molecular weight glutenin gene diversity in Aegilops tauschii demonstrates unique origin of superior wheat quality

Communications Biology ◽

10.1038/s42003-021-02563-7 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Emily Delorean ◽

Liangliang Gao ◽

Jose Fausto Cervantes Lopez ◽

Ali Mehrabi ◽

Alison Bentley ◽

...

Keyword(s):

Gene Diversity ◽

Aegilops Tauschii ◽

Tetraploid Wheat ◽

Wheat Breeding ◽

D Genome ◽

Breeding Programs ◽

Lineage 2 ◽

End Use ◽

Genomic Resource ◽

New Alleles

AbstractCentral to the diversity of wheat products was the origin of hexaploid bread wheat, which added the D-genome of Aegilops tauschii to tetraploid wheat giving rise to superior dough properties in leavened breads. The polyploidization, however, imposed a genetic bottleneck, with only limited diversity introduced in the wheat D-subgenome. To understand genetic variants for quality, we sequenced 273 accessions spanning the known diversity of Ae. tauschii. We discovered 45 haplotypes in Glu-D1, a major determinant of quality, relative to the two predominant haplotypes in wheat. The wheat allele 2 + 12 was found in Ae. tauschii Lineage 2, the donor of the wheat D-subgenome. Conversely, the superior quality wheat allele 5 + 10 allele originated in Lineage 3, a recently characterized lineage of Ae. tauschii, showing a unique origin of this important allele. These two wheat alleles were also quite similar relative to the total observed molecular diversity in Ae. tauschii at Glu-D1. Ae. tauschii is thus a reservoir for unique Glu-D1 alleles and provides the genomic resource to begin utilizing new alleles for end-use quality improvement in wheat breeding programs.

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Resistance to root-lesion nematode (Pratylenchus thornei) in Aegilops tauschii Coss., the D-genome donor to wheat

Australian Journal of Agricultural Research ◽

10.1071/a96167 ◽

1997 ◽

Vol 48 (5) ◽

pp. 553 ◽

Cited By ~ 25

Author(s):

J. P. Thompson ◽

M. I. Haak

Keyword(s):

Aegilops Tauschii ◽

Wheat Breeding ◽

Heterodera Avenae ◽

Root Lesion Nematode ◽

Sources Of Resistance ◽

D Genome ◽

Nematode Reproduction ◽

Pratylenchus Thornei ◽

Eastern Australia ◽

Lesion Nematode

Root-lesion nematode (Pratylenchus thornei Sher and Allen) causes substantial loss in yield of wheat in eastern Australia. Central Asian accessions of Aegilops tauschii Coss. were tested to find new sources of resistance to P. thornei for use in wheat-breeding programs. Ae. tauschii (2n = 14, DD genome) is one of the wild progenitors of wheat, Triticum aestivum L. (2n = 42, AABBDD genomes). Resistance was determined by nematode reproduction in the plant roots during 16 weeks of growth in pots in a glasshouse. Thirty-nine of 244 accessions of Ae. tauschii tested in 2 replicated experiments had lower numbers of nematodes than GS50a, a partially resistant line of wheat used as a resistance standard. Resistance to P. thornei was present in accessions of most taxonomic groups within Ae. tauschii, i.e. Ae. tauschii subsp. strangulata (Eig) Tzvel., and Ae. tauschii subsp. tauschii var. typica L. and var. meyeri (Griseb.) Tzvel. Resistance was most common in subsp. strangulata with 20 out of 40 strangulata accessions in the resistant group and none in a highly susceptible group of 43 accessions. Accessions of var. meyeri with the Cre3 gene for effective resistance to cereal cyst nematode (Heterodera avenae Woll.) were also resistant to P. thornei. The results indicate that several resistances to P. thornei are present in Ae. tauschii subspecies and varieties, which could be introgressed into cultivated wheat to help control P. thornei and increase farm profits.

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Identification of QTLs and a Candidate Gene for Reducing Pre-Harvest Sprouting in Aegilops tauschii–Triticum aestivum Chromosome Segment Substitution Lines

International Journal of Molecular Sciences ◽

10.3390/ijms22073729 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3729

Author(s):

Jie He ◽

Dale Zhang ◽

Xian Chen ◽

Yuge Li ◽

Minjie Hu ◽

...

Keyword(s):

Amino Acid ◽

Aegilops Tauschii ◽

Wheat Yield ◽

Wheat Breeding ◽

Chromosome Segment ◽

Pcr Analysis ◽

Nucleotide Polymorphisms ◽

Substitution Lines ◽

Chromosome Segment Substitution Lines ◽

Segment Substitution

Wheat pre-harvest sprouting (PHS) causes serious losses in wheat yield. In this study, precise mapping was carried out in the chromosome segment substitution lines (CSSL) F2 population generated by a direct cross of Zhoumai 18 (PHS-sensitive) and Aegilops tauschii accession T093 (highly PHS-resistant). Three Ae. tauschii-derived quantitative trait loci (QTLs), QDor.3D.1, QDor.3D.2, and QDor.3D.3, were detected on chromosome 3DL using four simple sequence repeats (SSR) markers and 10 developed Kompetitive allele-specific PCR (KASP) markers. Alongside these QTL results, the RNA-Seq and qRT-PCR analysis revealed expression levels of TraesCS3D01G466100 in the QDor.3D.2 region that were significantly higher in CSSLs 495 than in Zhoumai 18 during the seed imbibition treatment. The cDNA sequencing results of TraesCS3D01G466100 showed two single nucleotide polymorphisms (SNPs), resulting in two changed amino acid substitutions between Zhoumai 18 and line 495, and the 148 nt amino acid substitution of TraesCS3D01G466100, derived from Ae. tauschii T093, which may play an important role in the functioning of ubiquitin ligase enzymes 3 (E3) according to the homology protein analysis, which could lead to differential PHS-resistance phenotypes. Taken together, our results may foster a better understanding of the mechanism of PHS resistance and are potentially valuable for marker-assisted selection in practical wheat breeding efforts.

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