scholarly journals Genome sequences of the five Sitopsis species of Aegilops and the origin of polyploid wheat B-subgenome

2021 ◽  
Author(s):  
Linfeng Li ◽  
Zhibin Zhang ◽  
Zhenhui Wang ◽  
Ning Li ◽  
Yan Sha ◽  
...  

Bread wheat (Triticum aestivum L., BBAADD) is a major staple food crop worldwide. The diploid progenitors of the A- and D-subgenomes have been unequivocally identified, that of B however remains ambiguous and controversial but is suspected to be related to species of Aegilops, section Sitopsis. Here, we report the assembly of chromosome-level genome sequences of all five Sitopsis species, namely Ae. bicornis, Ae. longissima, Ae. searsii, Ae. sharonensis, and Ae. speltoides, as well as partial assembly of Ae. mutica genome for phylogenetic analysis. Our results support that the donor of bread wheat B-subgenome is a distinct, probably extinct, diploid species that diverged from an ancestral progenitor of the B-lineage similar to Ae. mutica and Ae. speltoides. The five Sitopsis species have variable genome sizes (4.11-5.89 Gb) with high proportions of repetitive sequences (85.99-89.81%); nonetheless, they retain high collinearity with other wheat genomes. Differences in genome size are primarily due to independent post-speciation amplification of transposons rather than to inter-specific genetic introgression. We also identified a set of Sitopsis genes pertinent to important agronomic traits that can be harnessed for wheat breeding. These resources provide a new roadmap for evolutionary and genetic studies of the wheat group.

Genetics ◽  
2003 ◽  
Vol 164 (2) ◽  
pp. 655-664 ◽  
Author(s):  
Li Huang ◽  
Steven A Brooks ◽  
Wanlong Li ◽  
John P Fellers ◽  
Harold N Trick ◽  
...  

Abstract We report the map-based cloning of the leaf rust resistance gene Lr21, previously mapped to a generich region at the distal end of chromosome arm 1DS of bread wheat (Triticum aestivum L.). Molecular cloning of Lr21 was facilitated by diploid/polyploid shuttle mapping strategy. Cloning of Lr21 was confirmed by genetic transformation and by a stably inherited resistance phenotype in transgenic plants. Lr21 spans 4318 bp and encodes a 1080-amino-acid protein containing a conserved nucleotide-binding site (NBS) domain, 13 imperfect leucine-rich repeats (LRRs), and a unique 151-amino-acid sequence missing from known NBS-LRR proteins at the N terminus. Fine-structure genetic analysis at the Lr21 locus detected a noncrossover (recombination without exchange of flanking markers) within a 1415-bp region resulting from either a gene conversion tract of at least 191 bp or a double crossover. The successful map-based cloning approach as demonstrated here now opens the door for cloning of many crop-specific agronomic traits located in the gene-rich regions of bread wheat.


2020 ◽  
Vol 10 (5) ◽  
pp. 253-258
Author(s):  
S.O. Kovalchuk ◽  
S.I. Voloschuk ◽  
N.A. Kozub

The aim of work was the estimation of valuable traits of bread wheat breeding lines, obtained from interspecies crosses with wild Aegilops and Triticum species growing in a condition of the Forest-Steppe of Ukraine. We used the seed proteins electrophoresis in PAAG for confirmation of the presence of rye seed storage components in the wheat parental lines genomes. The biochemical compositions of seeds had determined by the infrared spectroscopy method. As a result of researching from the set of 600 breeding lines were selected best lines with increased grain yield from 1 m2, with high protein content in grain, disease resistance, and winter hardiness significantly exceeded the standard variety Polesskaya-90. All lines have high and moderate resistance against diseases: Powdery Mildew, Brown Rust, Septoria Blotch. Based on obtained data had selected breeding lines, which were promising sources of single and complex agronomically valuable traits for bread wheat breeding and genetic researches.


2014 ◽  
Vol 69 (1) ◽  
pp. 44-54
Author(s):  
NASER SABAGHNIA ◽  
MOHSEN JANMOHAMMADI ◽  
ADEL BASHIRI ◽  
REZA ASGHARI-SHIRGHAN

The genetic diversity among 56 bread wheat (Triticum aestivum L.) genotypes was evaluated by 18 agronomical traits in the experimental field at Maragheh, Iran. Significant differences among bread wheat genotypes in all of the measured traits i.e. stem diameter, plant height, leaf number, leaf length, leaf width, tiller number, internode length, peduncle length, spike length, floret number, spikelet number, grain number, length of awn, grain diameter, grain length, the number of days to flowering, thousand seed weight and grain yield. The coefficient of variation (CV) was high for grain yield (25.61%), number of tillers per plant (22.06%) and number of grains per spike (21.45). The other remaining traits recorded moderate to low CV estimates from 14.30% in grain number per spike to 4.81% in days to flowering. The largest thousand seed weight was 45.93 g, the lowest thousand seed weight was 26.16 g and the mean thousand seed weight was 37.85 g. The mean performance of grain yield was 5031.2 kg ha-1, the minimum grain yield was 2835.0 kg ha-1 and the maximum grain yield was 7125.3 kg ha-1. Ward’s minimum variance cluster analysis based on squared Euclidian distance on the raw data of 18 agronomic traits clearly separated five clusters. In general, cluster analysis of the 56 genotypes based on the selected agronomic traits was consistent with known information. Our plant materials could be important germplasm resources for enriching the genetic background of commercial cultivars. Such genetic differences of bread wheat traits studied in this investigation can be applied as a new source of variation in other breeding programs and crossing nurseries in breeding program


2020 ◽  
Author(s):  
N.S. LYSENKO ◽  
◽  
V.A. LOSEVA ◽  

This publication presents the results of a field assessment of 225 winter bread wheat accessions from the VIR collection for their winter hardiness in the environments of the Northwestern (Town of Pushkin, 2007/2008, 2008/2009 and 2013/2014) and Central Black Earth (Yekaterinino Settlem., 2007/2008 and 2008/2009) Regions of the Russian Federation. The tested accessions included landraces and old improved varieties, earlier identified as sources of winter hardiness, as well as modern improved cultivars and lines, added to the VIR collection from 1990 through 2006. For reference purposes, along with the wintering data, information on biological and agronomic traits is given for the tested accessions. The presented data will be of interest to plant breeders and other experts working with winter bread wheat.


Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 653
Author(s):  
Oscar Carey-Fung ◽  
Jesse T. Beasley ◽  
Alexander A. T. Johnson

Effective maintenance of plant iron (Fe) homoeostasis relies on a network of transcription factors (TFs) that respond to environmental conditions and regulate Fe uptake, translocation, and storage. The iron-related transcription factor 3 (IRO3), as well as haemerythrin motif-containing really interesting new gene (RING) protein and zinc finger protein (HRZ), are major regulators of Fe homeostasis in diploid species like Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa L.), but remain uncharacterised in hexaploid bread wheat (Triticum aestivum L.). In this study, we have identified, annotated, and characterised three TaIRO3 homoeologs and six TaHRZ1 and TaHRZ2 homoeologs in the bread wheat genome. Protein analysis revealed that TaIRO3 and TaHRZ proteins contain functionally conserved domains for DNA-binding, dimerisation, Fe binding, or polyubiquitination, and phylogenetic analysis revealed clustering of TaIRO3 and TaHRZ proteins with other monocot IRO3 and HRZ proteins, respectively. Quantitative reverse-transcription PCR analysis revealed that all TaIRO3 and TaHRZ homoeologs have unique tissue expression profiles and are upregulated in shoot tissues in response to Fe deficiency. After 24 h of Fe deficiency, the expression of TaHRZ homoeologs was upregulated, while the expression of TaIRO3 homoeologs was unchanged, suggesting that TaHRZ functions upstream of TaIRO3 in the wheat Fe homeostasis TF network.


2021 ◽  
Vol 273 ◽  
pp. 01027
Author(s):  
Оlesya Nekrasova ◽  
Nina Kravchenko ◽  
Dmitry Marchenko ◽  
Evgeny Nekrasov

The purpose of the study was to estimate the effect of sunflower and pea on the amount of productivity, protein and gluten percentage in grain. The objects of the study were 13 winter bread wheat varieties (Triticum aestivum L.) developed by the Agricultural Research Center “Donskoy”. The study was carried out in 2018-2020 on the fields of the department of winter wheat breeding and seed production. The forecrops were peas and sunflower. The study results showed that the varieties ‘Volny Don’ (6.1 t / ha), ‘Krasa Dona’ (6.1 t / ha) and ‘Lidiya’ (6.0 t / ha), when sown after peas, gave the largest yields. The varieties ‘Volny Don’ (4.9 t / ha) and ‘Polina’ (4.8 t / ha) which were sown after sunflower, showed the best productivity. The analysis of qualitative indicators established that the maximum percentage of protein and gluten in grain was identified in the varieties ‘Podarok Krymu’ (16.3%; 28.3%) and ‘Volnitsa’ (16.1%; 28.5%), which were sown after peas; and the same varieties showed good results (‘Podarok Krymu’ (16.2%; 27.4%) and ‘Volnitsa’ (15.7%; 27.8%)), when sown after sunflower.


Genome ◽  
1995 ◽  
Vol 38 (3) ◽  
pp. 516-524 ◽  
Author(s):  
James C. Nelson ◽  
Allen E. Van Deynze ◽  
Mark E. Sorrells ◽  
Enrique Autrique ◽  
Yun Hai Lu ◽  
...  

A molecular-marker map of bread wheat having many markers in common with other grasses in the Gramineae family is a prerequisite for molecular level genetic studies and breeding in this crop species. We have constructed restriction fragment length polymorphism maps of the A-, B-, and D-genome chromosomes of homoeologous group 2 of hexaploid wheat (Triticum aestivum L. em. Thell) using 114 F7 lines from a synthetic × bread wheat cross and clones from 11 libraries. Chromosomes 2A, 2B, and 2D comprise 57, 60, and 56 markers and each spans about 200 cM. Comparisons between chromosomes are facilitated by 26 sets of homoeoloci. Genes mapped include a heterologous abscisic acid responsive locus cloned as pBS128, the epidermal waxiness inhibitor W21, and two presumed leaf rust and stem rust resistance genes. Anomalies suggesting ancestral rearrangements in chromosome 2B are pointed out and features of wheat group 2 chromosomes that are common to barley (Hordeum vulgare L.), rice (Oryza spp.), and T. tauschii are discussed.Key words: RFLP, wheat, waxy, rust.


2021 ◽  
Vol 181 (4) ◽  
pp. 71-82
Author(s):  
I. D. Fadeeva ◽  
I. N. Gazizov ◽  
A. G. Khakimov ◽  
O. P. Mitrofanova

Background. Bread wheat (Triticum aestivum L.), due to significant progress in breeding, has high potential of biological productivity, but its implementation is quite low. To change the situation for the better, it is necessary to increase the resistance of developed cultivars to unfavorable abiotic and biotic factors in the regions of its cultivation. To solve this problem, source material is required. The purpose of this research was to evaluate a set of winter wheat accessions from the VIR collection, and first of all, the newly introduced accessions, and the accessions from the working collection of Kazan Scientific Center of the Russian Academy of Sciences for variability of agronomic traits and stability under the conditions of the north of the Middle Volga region, and to identify sources promising for inclusion in the crossing programs.Materials and methods. A three-year field study of 166 winter bread wheat accessions was carried out. All accessions were assessed for their overwintering and plant and ear productivity traits using the methods developed by VIR and the State Variety Trials. The best accessions, or sources, were selected by comparing them with the reference cv. ‘Kazan 560’, taking into account the quantitative values of such indicators as “general adaptability” (ОАСi ), variance of “specific adaptability” (σ2САСi ) and “relative stability” (Sgi) for each accession according to A. V. Kilchevsky and L. V. Khotyleva.Results and conclusion. Descriptions of winter bread wheat accessions are presented in the context of their agronomic traits. Groups and subgroups of accessions with different trait variability levels were identified. Some accessions with stable levels of trait manifestation exceeded the reference in ear productivity. All of them are promising for wheat breeding programs. It is shown that the group of accessions “weakly changing” over the years of study differs from the group of “moderately/strongly changing” accessions in values of correlations between traits and the number of significant correlations. 


Author(s):  
Ankica Kondic-Spika ◽  
Srbislav Dencic ◽  
Novica Mladenov ◽  
Dragana Trkulja ◽  
Sanja Mikic ◽  
...  

This study analysed polymorphism of 15 microsatellite loci in the col?lection comprising of 40 genotypes of bread wheat (Triticum aestivum L.), 32 genotypes belonging to other species within Triticum genus and 3 genotypes from Aegilops genus. The results showed significant differences in the variability of the tested loci in bread wheat and related species. In the collection of bread wheat genotypes, 119 alleles were detected with the average number of 7.9 alleles per locus. In wild and cultivated related species 157 alleles were identified, with the average of 10.5 alleles per locus. All analysed parameters of micro?satellite loci variability (PIC value, gene diversity, heterozygosity, etc.) indicated higher level of polymorphism in wild relatives than in the cultivated bread wheat. Analyses of individual genomes indicated that in the bread wheat genetic diversity of the B and D genomes was significantly reduced in relation to the A genome, while the differences in polymorphism between genomes in the wild relatives were significantly lower. The results showed that wild related species can be used as sources for new variability in wheat breeding.


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