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

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.

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

2021 ◽  
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.

scholarly journals Genomic Selection for End-Use Quality and Processing Traits in Soft White Winter Wheat Breeding Program with Machine and Deep Learning Models

2021 ◽  
Author(s):  
Karansher S Sandhu ◽  
Meriem Aoun ◽  
Craig Morris ◽  
Arron H Carter
Keyword(s):  
Deep Learning ◽  
Grain Yield ◽  
Cross Validation ◽  
Wheat Breeding ◽  
Breeding Program ◽  
Quality Traits ◽  
Learning Models ◽  
Breeding Programs ◽  
Wheat Breeding Program ◽  
End Use

Breeding for grain yield, biotic and abiotic stress resistance, and end-use quality are important goals of wheat breeding programs. Screening for end-use quality traits is usually secondary to grain yield due to high labor needs, cost of testing, and large seed requirements for phenotyping. Hence, testing is delayed until later stages in the breeding program. Delayed phenotyping results in advancement of inferior end-use quality lines into the program. Genomic selection provides an alternative to predict performance using genome-wide markers. Due to large datasets in breeding programs, we explored the potential of the machine and deep learning models to predict fourteen end-use quality traits in a winter wheat breeding program. The population used consisted of 666 wheat genotypes screened for five years (2015-19) at two locations (Pullman and Lind, WA, USA). Nine different models, including two machine learning (random forest and support vector machine) and two deep learning models (convolutional neural network and multilayer perceptron), were explored for cross-validation, forward, and across locations predictions. The prediction accuracies for different traits varied from 0.45-0.81, 0.29-0.55, and 0.27-0.50 under cross-validation, forward, and across location predictions. In general, forward prediction accuracies kept increasing over time due to increments in training data size and was more evident for machine and deep learning models. Deep learning models performed superior over the traditional ridge regression best linear unbiased prediction (RRBLUP) and Bayesian models under all prediction scenarios. The high accuracy observed for end-use quality traits in this study support predicting them in early generations, leading to the advancement of superior genotypes to more extensive grain yield trailing. Furthermore, the superior performance of machine and deep learning models strengthen the idea to include them in large scale breeding programs for predicting complex traits.

scholarly journals Late-maturity α-amylase (LMA): exploring the underlying mechanisms and end-use quality effects in wheat

Planta ◽  
2021 ◽  
Vol 255 (1) ◽  
Author(s):  
Ashley E. Cannon ◽  
Elliott J. Marston ◽  
Alecia M. Kiszonas ◽  
Amber L. Hauvermale ◽  
Deven R. See
Keyword(s):  
Wheat Breeding ◽  
Protein Accumulation ◽  
Comprehensive Overview ◽  
Breeding Programs ◽  
Future Directions ◽  
Open Questions ◽  
Late Maturity ◽  
End Use ◽  
Molecular Aspects ◽  
Underlying Mechanisms

Abstract Main conclusion A comprehensive understanding of LMA from the underlying molecular aspects to the end-use quality effects will greatly benefit the global wheat industry and those whose livelihoods depend upon it. Abstract Late-maturity α-amylase (LMA) leads to the expression and protein accumulation of high pI α-amylases during late grain development. This α-amylase is maintained through harvest and leads to an unacceptable low falling number (FN), the wheat industry’s standard measure for predicting end-use quality. Unfortunately, low FN leads to significant financial losses for growers. As a result, wheat researchers are working to understand and eliminate LMA from wheat breeding programs, with research aims that include unraveling the genetic, biochemical, and physiological mechanisms that lead to LMA expression. In addition, cereal chemists and quality scientists are working to determine if and how LMA-affected grain impacts end-use quality. This review is a comprehensive overview of studies focused on LMA and includes open questions and future directions.

scholarly journals Genetic control of seed dormancy and pre-harvest sprouting in wheat

2006 ◽  
Vol 63 (6) ◽  
pp. 564-566 ◽  
Author(s):  
Claudinei Andreoli ◽  
Manoel Carlos Bassoi ◽  
Dionisio Brunetta
Keyword(s):  
Seed Dormancy ◽  
Bimodal Distribution ◽  
Wheat Breeding ◽  
Breeding Programs ◽  
Control Seed ◽  
Grain Color ◽  
The Mean ◽  
The Cross ◽  
End Use ◽  
Financial Losses

Pre-harvest sprouting (PHS) damage leads to occasional massive losses in all wheat producing areas, causing downgrading of grain quality, that severely limits end-use applications and results in substantial financial losses to farmers and food processors. Red grain color is a traditional marker for resistance to sprouting in wheat breeding programs, however red-grained genotype alone does not always guarantee effective resistance. The objective of this work was to find genes for resistance to PHS and investigate its inheritance in Brazilian wheat cultivars. Genetic variation for dormancy was investigated in the parents, F1 and 300 F2 lines derived from the cross Frontana × OR1 and its reciprocal. The germination/dormancy sprouted grains was evaluated on fifty seeds per replication, germinated in paper towel rolls at 20ºC for 5 days. A bimodal distribution for dormancy occurred in the Frontana/OR1 and OR1/Frontana derived F2 populations. The mean ratio of dormant and non-dormant seeds of the cross and its reciprocal was 85:1115, fitting a digenic model of 1:15 (P < 0.05). In fact, all non after-ripened F1 seeds germinated. The F2 distribution indicates that two major genes, here called A,a and B,b, control seed dormancy, which it appears to be recessive to dormancy. Only the homozygous aabb is dormant. As expected, there was no effect of maternal tissues.

scholarly journals Polyploidization enhancing genetic recombination of the ancestral diploid genome in the evolution of hexaploid wheat

2020 ◽  
Author(s):  
Hongshen Wan ◽  
Jun Li ◽  
Shengwei Ma ◽  
Qin Wang ◽  
Xinguo Zhu ◽  
...  
Keyword(s):  
Hexaploid Wheat ◽  
Genetic Recombination ◽  
Aegilops Tauschii ◽  
Tetraploid Wheat ◽  
Synthetic Hexaploid Wheat ◽  
Evolutionary Potential ◽  
D Genome ◽  
Diploid Genome ◽  
Synthetic Hexaploid ◽  
The Impact

AbstractAllopolyploidy increases its evolutionary potential by fixing heterosis and the advantage of gene redundancy. Allelic combinations generated from genetic recombination potentially provide many variations to the selection pools for evolution. May there be any relationship between allopolyploidization and genetic recombination? To study the impact of polyploidy on genetic recombination, we selected wheat as a model and simulated its evolution pathway of allopolyploidy by developing synthetic hexaploid wheat. The change of homologous chromosome recombination were investigated on their diploid DD and tetraploid AABB genomes after their allohexaploidization, respectively. The genetic recombination of the ancestral diploid genome of Aegilops tauschii was enhanced significantly more than 2 folds after their hexaploidization. Hexaploidization enhancing genetic recombination of the ancestral diploid D genome was firstly reported to be a new way to increase evolutionary potential of wheat, which is beneficial for wheat to conquer their narrow origination of D genome, quickly spread and make it a major crop of the world. Finally, re-synthetizing hexaploid wheat using diverse Ae. tauschii species with tetraploid wheat can be considered as a pleiotropic strategy to speed adaptive evolution of bread wheat in breeding processes by increasing both gene allele types and genetic recombination variations.

scholarly journals Targeted sequencing of the short arm of chromosome 6V of a wheat relative Haynaldia villosa for marker development and gene mining

2020 ◽  
Author(s):  
Jin Xiao ◽  
Wentao Wan ◽  
Mengli Li ◽  
Zhongyu Yu ◽  
Xu Zhang ◽  
...  
Keyword(s):  
Aegilops Tauschii ◽  
Wheat Breeding ◽  
Linkage Drag ◽  
Addition Line ◽  
Sequencing Data ◽  
Haynaldia Villosa ◽  
Breeding Programs ◽  
Homologous Genes ◽  
Flow Cytometric ◽  
Flow Cytometric Sorting

Abstract Background: Short arm of chromosome 6V (6VS) of Haynaldia villosa has been used in wheat breeding programs to introduce Pm21 resistance gene against powdery mildew and some other genes. Results: In this work, 6VS was isolated from a wheat ( Triticum aestivum ) - 6VS telosome addition line by flow cytometric sorting and sequenced by illumina technology. The assembly length was 230.39 Mb with contig N50 of 9,788 bp. The sequence annotation identified 3,276 high confidence genes supported by RNA sequencing data, representing about 2.3% of the chromosome arm sequence; repetitive elements accounted for 74.91% of the arm sequence. Sequences homologous to 6VS genes were identified on short arms of chromosomes 6A of T. urartu , 6D of Aegilops tauschii , 6A and 6B of T. dicoccoides , 6A, 6B and 6D of T. aestivum and 6H of Hordeum vulgare , revealing synteny relationships among these chromosome arms. Based on differences in intron size between the homologous genes on 6VS and 6AS/6BS/6DS of T. aestivum , 222 primer pairs were designed. Out of them, 120 amplified 6VS-specific products and are suitable as intron-target (IT) markers to trace the 6VS chromatin introduced into wheat. Conclusions: The results obtained and markers developed in this work will facilitate introduction of important genes to common wheat from its wild relative, while reducing the presence of unfavorable genes due to linkage drag.

scholarly journals Targeted sequencing of the short arm of chromosome 6V of a wheat relative Haynaldia villosa for marker development and gene mining

2020 ◽  
Author(s):  
Jin Xiao ◽  
Wentao Wan ◽  
Mengli Li ◽  
Zhongyu Yu ◽  
Xu Zhang ◽  
...  
Keyword(s):  
Aegilops Tauschii ◽  
Wheat Breeding ◽  
Linkage Drag ◽  
Addition Line ◽  
Sequencing Data ◽  
Haynaldia Villosa ◽  
Breeding Programs ◽  
Homologous Genes ◽  
Flow Cytometric ◽  
Flow Cytometric Sorting

Abstract Background: Short arm of chromosome 6V (6VS) of Haynaldia villosa has been used in wheat breeding programs to introduce Pm21 resistance gene against powdery mildew and some other genes. Results: In this work, 6VS was isolated from a wheat ( Triticum aestivum ) - 6VS telosome addition line by flow cytometric sorting and sequenced by illumina technology. The assembly length was 230.39 Mb with contig N50 of 9,788 bp. The sequence annotation identified 3,276 high confidence genes supported by RNA sequencing data, representing about 2.3% of the chromosome arm sequence; repetitive elements accounted for 74.91% of the arm sequence. Sequences homologous to 6VS genes were identified on short arms of chromosomes 6A of T. urartu , 6D of Aegilops tauschii , 6A and 6B of T. dicoccoides , 6A, 6B and 6D of T. aestivum and 6H of Hordeum vulgare , revealing synteny relationships among these chromosome arms. Based on differences in intron size between the homologous genes on 6VS and 6AS/6BS/6DS of T. aestivum , 222 primer pairs were designed. Out of them, 120 amplified 6VS-specific products and are suitable as intron-target (IT) markers to trace the 6VS chromatin introduced into wheat. Conclusions: The results obtained and markers developed in this work will facilitate introduction of important genes to common wheat from its wild relative, while reducing the presence of unfavorable genes due to linkage drag.

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

1997 ◽  
Vol 48 (5) ◽  
pp. 553 ◽  
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.

scholarly journals Genetic stability in synthetic wheat accessions: cytogenetic evaluation as a support in breeding programs

2017 ◽  
Vol 47 (4) ◽  
Author(s):  
Patrícia Frizon ◽  
◽  
Sandra Patussi Brammer ◽  
Maria Imaculada Pontes Moreira Lima ◽  
Ricardo Lima de Castro ◽  
...  
Keyword(s):  
Genetic Stability ◽  
Triticum Turgidum ◽  
Aegilops Tauschii ◽  
Diploid Species ◽  
Optical Microscope ◽  
Wheat Breeding ◽  
Germplasm Bank ◽  
Synthetic Wheat ◽  
Breeding Programs ◽  
Abiotic Stressors

ABSTRACT: Synthetic wheat is developed by crossing tetraploid species ( Triticum turgidum , AABB) with a diploid species ( Aegilops tauschii , DD), followed by chromosome duplication through the use of colchicine to restore the resultant sterile hybrid to a fertile hexaploid plant. The main importance of producing synthetically improved wheat is to increase their genetic variability and to incorporate genes that code for resistance to biotic and abiotic stressors. This study aimed to evaluate the presence of micronuclei (MN) and the meiotic index (MI) in the tetrad phase in synthetic wheat accessions and cultivars ( Triticum aestivum ) stored at the Germplasm Bank of Embrapa Trigo (Brazil), in order to identify and select genetically stable accessions for plant improvement. Five plants were collected by genotype, prior to anthesis, and the tissues were fixed in Carnoy solution. Cytological slides were prepared by the smash method, and the cells were dyed with 1% acetocarmine and observed under an optical microscope. Presence of MN was observed in all genotypes analyzed, and variability of genetic stability was reported in the two years of analysis. In 2014, the highest MI of synthetic wheat accessions was 96.86% and the lowest was 46.32%. In 2015, the highest MI was 96.60% and the lowest was 47.96%. Based on the results, some genotypes were considered meiotically stable and suitable for use in wheat breeding programs.

Sign in / Sign up

Export Citation Format

Share Document