scholarly journals FISH landmarks reflecting meiotic recombination and structural alterations of chromosomes in wheat (Triticum aestivum L.)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yang Zou ◽  
Linrong Wan ◽  
Jie Luo ◽  
Zongxiang Tang ◽  
Shulan Fu
Keyword(s):  
Triticum Aestivum ◽  
Meiotic Recombination ◽  
Tandem Repeats ◽  
Single Copy ◽  
Triticum Aestivum L ◽  
Wheat Breeding ◽  
Structural Variations ◽  
Factors Affecting ◽  
Sequence Composition ◽  
Double Recombination

Abstract Background DNA sequence composition affects meiotic recombination. However, the correlation between tandem repeat composition and meiotic recombination in common wheat (Triticum aestivum L.) is unclear. Results Non-denaturing fluorescent in situ hybridization (ND-FISH) with oligonucleotide (oligo) probes derived from tandem repeats and single-copy FISH were used to investigate recombination in three kinds of the long arm of wheat 5A chromosome (5AL). 5AL535–18/275 arm carries the tandem repeats pTa-535, Oligo-18, and pTa-275, 5AL119.2–18/275 arm carries the tandem repeats pSc119.2, Oligo-18 and pTa-275, and 5AL119.2 arm carries the tandem repeats pSc119.2. In the progeny of 5AL535–18/275 × 5AL119.2, double recombination occurred between pSc119.2 and pTa-535 clusters (119–535 interval), and between pTa-535 and Oligo-18/pTa-275 clusters (535–18 interval). The recombination rate in the 119–535 interval in the progeny of 5AL535–18/275 × 5AL119.2–18/275 was higher than that in the progeny of 5AL535–18/275 × 5AL119.2. Recombination in the 119–535 interval produced 5AL119 + 535 segments with pTa-535 and pSc119.2 tandem repeats and 5ALNo segments without these repeats. The 5AL119 + 535 and 5ALNo segments were localized between the signal sites of the single-copy probes SC5A-479 and SC5A-527. The segment between SC5A-479 and SC5A-527 in the metaphase 5ALNo was significantly longer than that in the metaphase 5AL119 + 535. Conclusion The structural variations caused by tandem repeats might be one of the factors affecting meiotic recombination in wheat. Meiotic recombination aggregated two kinds of tandemly repeated clusters into the same chromosome, making the metaphase chromosome more condensed. To conclude, our study provides a robust tool to measure meiotic recombination and select parents for wheat breeding programs.

Competitive ability of wheat in conventional and organic management systems: A review of the literature

2006 ◽  
Vol 86 (2) ◽  
pp. 333-343 ◽  
Author(s):  
H. E. Mason ◽  
D. Spaner
Keyword(s):  
Triticum Aestivum ◽  
Leaf Area ◽  
Organic Agriculture ◽  
Competitive Ability ◽  
Triticum Aestivum L ◽  
Wheat Breeding ◽  
Management Systems ◽  
Wheat Varieties ◽  
Early Season ◽  
Low Input

Wheat (Triticum aestivum L.) is the world’s most widely grown crop, cultivated in over 115 nations. Organic agriculture, a production system based on reducing external inputs in order to promote ecosystem health, can be defined as a system that prohibits the use of synthetic fertilizers, chemical pesticides and genetically modified organisms. Organic agriculture is increasing in popularity, with a 60% increase in the global acreage of organically managed land from the year 2000 to 2004. Constraints that may be associated with organic grain production include reduced yields due to soil nutrient deficiencies and competition from weeds. Global wheat breeding efforts over the past 50 yr have concentrated on improving yield and quality parameters; in Canada, disease resistance and grain quality have been major foci. Wheat varieties selected before the advent of chemical fertilizers and pesticides may perform differently in organic, low-input management systems than in conventional, high-input systems. Height, early-season growth, tillering capacity, and leaf area are plant traits that may confer competitive ability in wheat grown in organic systems. Wheat root characteristics may also affect competitive ability, especially in low-input systems, and more research in this area is needed. The identification of a competitive crop ideotype may assist wheat breeders inthe development of competitive wheat varieties. Wheat varieties with superior performance in low-input systems, and/or increased competitive ability against weeds, could assist organic producers in overcoming some of the constraints associated with organic wheat production. Key words: Triticum aestivum L., wheat breeding, low-input agriculture, plant height, early-season growth, tillering capacity, leaf area index

scholarly journals Population structure of Nepali spring wheat (Triticum aestivum L.) germplasm

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Kamal Khadka ◽  
Davoud Torkamaneh ◽  
Mina Kaviani ◽  
Francois Belzile ◽  
Manish N. Raizada ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Triticum Aestivum ◽  
Population Structure ◽  
Food Security ◽  
Spring Wheat ◽  
Principal Component ◽  
Genotyping By Sequencing ◽  
Triticum Aestivum L ◽  
Wheat Breeding ◽  
Exotic Germplasm

Abstract Background Appropriate information about genetic diversity and population structure of germplasm improves the efficiency of plant breeding. The low productivity of Nepali bread wheat (Triticum aestivum L.) is a major concern particularly since Nepal is ranked the 4th most vulnerable nation globally to climate change. The genetic diversity and population structure of Nepali spring wheat have not been reported. This study aims to improve the exploitation of more diverse and under-utilized genetic resources to contribute to current and future breeding efforts for global food security. Results We used genotyping-by-sequencing (GBS) to characterize a panel of 318 spring wheat accessions from Nepal including 166 landraces, 115 CIMMYT advanced lines, and 34 Nepali released varieties. We identified 95 K high-quality SNPs. The greatest genetic diversity was observed among the landraces, followed by CIMMYT lines, and released varieties. Though we expected only 3 groupings corresponding to these 3 seed origins, the population structure revealed two large, distinct subpopulations along with two smaller and scattered subpopulations in between, with significant admixture. This result was confirmed by principal component analysis (PCA) and UPGMA distance-based clustering. The pattern of LD decay differed between subpopulations, ranging from 60 to 150 Kb. We discuss the possibility that germplasm explorations during the 1970s–1990s may have mistakenly collected exotic germplasm instead of local landraces and/or collected materials that had already cross-hybridized since exotic germplasm was introduced starting in the 1950s. Conclusion We suggest that only a subset of wheat “landraces” in Nepal are authentic which this study has identified. Targeting these authentic landraces may accelerate local breeding programs to improve the food security of this climate-vulnerable nation. Overall, this study provides a novel understanding of the genetic diversity of wheat in Nepal and this may contribute to global wheat breeding initiatives.

Analysis of induced homoeologous pairing in hybrids between 6x triticale ph1 mutant and Triticum aestivum L.

1986 ◽  
Vol 28 (5) ◽  
pp. 696-700 ◽  
Author(s):  
Nicolás Jouve ◽  
Benito Giorgi
Keyword(s):  
Triticum Aestivum ◽  
Triticum Aestivum L ◽  
Wheat Breeding ◽  
Hexaploid Triticale ◽  
D Genome ◽  
Level Of Involvement ◽  
Mother Cells ◽  
Homoeologous Chromosomes ◽  
Different Doses ◽  
Induced Homoeologous Pairing

The meiotic behaviour of three hexaploid triticale × Triticum aestivum L. hybrids having different doses of ph1 mutant alleles was investigated using C-band staining of pollen mother cells at first metaphase. D-genome chromosomes that were clearly distinguished by their small size and unbanded response to Giemsa staining were increasingly promoted to pair with the homoeologous chromosomes of the A and B genomes in the absence of Ph1 genes. However, the wheat–rye associations were not enhanced when one or two ph1 alleles were present. The distribution of meiotic configurations was significantly different for each chromosome in the ph1/ph1 hybrid. Thus, 1B did not form multivalents in this hybrid, and the remaining identified chromosomes differed significantly in the level of involvement in tri-, quadri-, or quinque-valents. The hybrids should be of value for hexaploid and wheat breeding programs.Key words: Triticale, Triticum aestivum, C-banding, ph1 mutants.

scholarly journals Genome-Wide Identification and Expression Profiles of Late Embryogenesis-Abundant (LEA) Genes during Grain Maturation in Wheat (Triticum aestivum L.)

Genes ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 696
Author(s):  
Datong Liu ◽  
Jing Sun ◽  
Dongmei Zhu ◽  
Guofeng Lyu ◽  
Chunmei Zhang ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Expression Profiles ◽  
Triticum Aestivum L ◽  
Late Embryogenesis Abundant ◽  
Wheat Breeding ◽  
Pcr Analysis ◽  
Lea Genes ◽  
Cellular Dehydration ◽  
Genome Wide ◽  
Late Embryogenesis

Late embryogenesis-abundant (LEA) genes play important roles in plant growth and development, especially the cellular dehydration tolerance during seed maturation. In order to comprehensively understand the roles of LEA family members in wheat, we carried out a series of analyses based on the latest genome sequence of the bread wheat Chinese Spring. 121 Triticum aestivum L. LEA (TaLEA) genes, classified as 8 groups, were identified and characterized. TaLEA genes are distributed in all chromosomes, most of them with a low number of introns (≤3). Expression profiles showed that most TaLEA genes expressed specifically in grains. By qRT-PCR analysis, we confirmed that 12 genes among them showed high expression levels during late stage grain maturation in two spring wheat cultivars, Yangmai16 and Yangmai15. For most genes, the peak of expression appeared earlier in Yangmai16. Statistical analysis indicated that expression level of 8 genes in Yangmai 16 were significantly higher than Yangmai 15 at 25 days after anthesis. Taken together, our results provide more knowledge for future functional analysis and potential utilization of TaLEA genes in wheat breeding.

scholarly journals Exome association analysis sheds light onto leaf rust ( Puccinia triticina ) resistance genes currently used in wheat breeding ( Triticum aestivum L.)

2019 ◽  
Vol 18 (6) ◽  
pp. 1396-1408 ◽  
Author(s):  
Fang Liu ◽  
Yusheng Zhao ◽  
Sebastian Beier ◽  
Yong Jiang ◽  
Patrick Thorwarth ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Leaf Rust ◽  
Association Analysis ◽  
Resistance Genes ◽  
Puccinia Triticina ◽  
Triticum Aestivum L ◽  
Wheat Breeding

scholarly journals Estimation of grain productivity and biochemical indicators of the winter bread wheat varieties depending on the forecrop

2021 ◽  
Vol 273 ◽  
pp. 01027
Author(s):  
Оlesya Nekrasova ◽  
Nina Kravchenko ◽  
Dmitry Marchenko ◽  
Evgeny Nekrasov
Keyword(s):  
Triticum Aestivum ◽  
Bread Wheat ◽  
Agricultural Research ◽  
Triticum Aestivum L ◽  
Wheat Breeding ◽  
Wheat Varieties ◽  
Biochemical Indicators ◽  
Winter Bread Wheat ◽  
Grain Productivity ◽  
Study Results

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.

An application of multivariate analysis to selection for quality characters in wheat

1976 ◽  
Vol 27 (1) ◽  
pp. 11 ◽  
Author(s):  
GM Bhatt
Keyword(s):  
Triticum Aestivum ◽  
Multivariate Analysis ◽  
Triticum Aestivum L ◽  
Wheat Breeding ◽  
Environmental Stability ◽  
Quality Performance ◽  
Wheat Breeding Program ◽  
Selection For ◽  
The Stability ◽  
Clustering Pattern

A set of 12 genotypes of bread wheat (Triticum aestivum L.) was grown in four different environments involving sites and years. Multivariate analysis according to the D2 technique was performed on six quality characters measured on material harvested from each environment and on the data pooled over four environments. The analysis offered meaningful grouping criteria with regard to quality performance. The clustering pattern was stable in different environments. This environmental stability was found to be independent of the stability of six individual characters. The application of multivariate analysis to selection for quality characters in a wheat breeding program is discussed.

Frequencies and sequence characteristics of di-, tri-, and tetra-nucleotide microsatellites in wheat

Genome ◽  
1996 ◽  
Vol 39 (1) ◽  
pp. 123-130 ◽  
Author(s):  
Z. Q. Ma ◽  
M. Röder ◽  
M. E. Sorrells
Keyword(s):  
Triticum Aestivum ◽  
Tandem Repeats ◽  
Size Range ◽  
Triticum Aestivum L ◽  
Small Sample ◽  
Genomic Libraries ◽  
Key Words Wheat ◽  
Expected Size Range ◽  
Sequence Characteristics ◽  
Eukaryotic Genomes

Microsatellites have emerged as an important source of genetic markers for eukaryotic genomes. In this report, two wheat (Triticum aestivum L.) genomic libraries were screened for several di-, tri-, and tetra-nucleotide tandem repeats. Clones containing (AC)n, (AG)n, (TCT)n, and (TTG)n repeats were isolated and sequenced. On average, there was one (AC)n microsatellite every 292 kbp and one (AG)n microsatellite every 212 kbp. The trinucleotide tandem repeats (TCT)n and (TTG)n were about 10 times less common than the two dinucleotide tandem repeats tested and tetranucleotide tandem repeats were rare. Many of the microsatellites had more than 10 repeats. The maximum repeat number found for (AC)n was 36 and for (TCT)n was more than 50. The prevailing category of (AG)n microsatellites from (AG)n isolates was perfect repeats. About half of the (AC)n microsatellites were compound repeats, while most of the (TCT)n microsatellites were imperfect repeats. In a small sample, (TTG)n microsatellites consisted mainly of compound repeats. The most frequently associated repeats were (AC)n with (AG)n, (TCT)n with (TCC)n, and (TTG)n with (TGG)n. Among 32 pairs of microsatellite primers surveyed, seven produced polymorphic products in the expected size range and these loci were mapped using a hexaploid wheat mapping population or aneuploid stocks. Key words : wheat, Triticum aestivum L., microsatellites, polymorphism, sequence characteristics.

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