scholarly journals Telomeres and Subtelomeres Dynamics in the Context of Early Chromosome Interactions During Meiosis and Their Implications in Plant Breeding

2021 ◽  
Vol 12 ◽  
Author(s):  
Miguel Aguilar ◽  
Pilar Prieto
Keyword(s):  
Plant Breeding ◽  
Agronomic Traits ◽  
Specific Chromosome ◽  
Chromatin Dynamics ◽  
Homologous Chromosomes ◽  
Chromosome Manipulation ◽  
Chromosome Recombination ◽  
Chromosome Associations ◽  
Chromosome Regions ◽  
Donor Species

Genomic architecture facilitates chromosome recognition, pairing, and recombination. Telomeres and subtelomeres play an important role at the beginning of meiosis in specific chromosome recognition and pairing, which are critical processes that allow chromosome recombination between homologs (equivalent chromosomes in the same genome) in later stages. In plant polyploids, these terminal regions are even more important in terms of homologous chromosome recognition, due to the presence of homoeologs (equivalent chromosomes from related genomes). Although telomeres interaction seems to assist homologous pairing and consequently, the progression of meiosis, other chromosome regions, such as subtelomeres, need to be considered, because the DNA sequence of telomeres is not chromosome-specific. In addition, recombination operates at subtelomeres and, as it happens in rye and wheat, homologous recognition and pairing is more often correlated with recombining regions than with crossover-poor regions. In a plant breeding context, the knowledge of how homologous chromosomes initiate pairing at the beginning of meiosis can contribute to chromosome manipulation in hybrids or interspecific genetic crosses. Thus, recombination in interspecific chromosome associations could be promoted with the aim of transferring desirable agronomic traits from related genetic donor species into crops. In this review, we summarize the importance of telomeres and subtelomeres on chromatin dynamics during early meiosis stages and their implications in recombination in a plant breeding framework.

scholarly journals Chromosome Manipulation for Plant Breeding Purposes

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1695
Author(s):  
Pilar Prieto
Keyword(s):  
Plant Breeding ◽  
Plant Material ◽  
Special Issue ◽  
Breeding Programs ◽  
Chromosome Manipulation ◽  
Chromosome Associations ◽  
Breeding Techniques ◽  
Donor Species ◽  
Traditional Breeding

The transfer of genetic variability from related species into crops has been a main objective for decades in breeding programs. Breeders have used interspecific genetic crosses and alien introgression lines to achieve this goal, but the success is always dependent on the interspecific chromosome associations between the alien chromosomes and those from the crop during early meiosis. In this Special Issue, the strength of chromosome manipulation in a breeding framework is revealed through research and review papers that combine molecular markers, cytogenetics tools and other traditional breeding techniques. The papers and reviews included in this Special Issue “Chromosome manipulation for plant breeding purposes” describe the development and/or characterization of new plant material carrying desirable traits and the study of chromosome associations and recombination during meiosis. New tools to facilitate the transfer of desired traits from a donor species into a crop can be developed by expanding the knowledge of chromosome associations during meiosis.

scholarly journals Pemilihan Karakter Agronomi untuk Seleksi pada Galur-galur Padi Dihaploid Hasil Kultur Antera

2017 ◽  
Vol 45 (1) ◽  
pp. 1-8
Author(s):  
Gerland Akhmadi ◽  
Bambang Sapta Purwoko ◽  
Iswari Saraswati Dewi ◽  
Dan Desta Wirnas
Keyword(s):  
Plant Breeding ◽  
Anther Culture ◽  
Plant Height ◽  
Plant Material ◽  
Agronomic Traits ◽  
Culture Technique ◽  
Genotypic Correlation ◽  
Agronomic Characters ◽  
Selection Of ◽  
Panicle Weight

Anther culture technique is able to accelerate plant breeding activities. The objectives of this research was to determine the agronomic traits that could be used for selection of the dihaploid rice line population through the calculation of heritability, genotypic correlation, path analysis and selecting dihaploid rice lines. The plant material used was 65 dihaploid rice lines DH 1 of F1 anther culture plants and Ciherang and Inpari 13 as check varieties. Agronomic characters that could be used as selection character are generative plant height, number of filled grain per panicle, the total number of grains per panicle, weight of 1,000 grains, and grain per hill. Twenty three dihaploid lines were selected based good agronomic characters with criteria generative plant height between 80-120 cm, number of filled grains per panicle > 100, number of grains per panicle > 120, weight of 1,000 grains > 20 g, and grain per hill > 25 g.Keywords: anther culture, heritability, agronomic characters

New and novel genetic tools for improving crops.

2021 ◽  
Vol 16 (028) ◽  
Author(s):  
Penna Suprasanna
Keyword(s):  
Plant Breeding ◽  
Agronomic Traits ◽  
Plant Traits ◽  
Crop Improvement ◽  
Genetically Modified Crops ◽  
Climate Resilience ◽  
Crop Varieties ◽  
New Novel ◽  
High Throughput Phenotyping ◽  
Sequencing Platforms

Abstract The basic tenet of crop improvement is the novel genetic variability that is achieved through selection, hybridization, mutation and recombination. The new technological innovations of plant breeding offer scope for transforming crop improvement with more precision and resolution. Advances in genomic-based tools and high-throughput phenotyping have enabled the analysis of genetic variation and identification of molecular signatures of agronomic traits. Molecular markers and molecular-marker-assisted breeding have facilitated the speedy selection of new, novel genetic combinations in breeding for high-yielding, stress-tolerant and nutritionally enriched crops. Transgenic methods have revolutionized modification for stress tolerance and higher productivity, and several genetically modified crops are under cultivation. Availability of genome sequencing platforms and genomic resources has significantly contributed to accessing novel genes and validating their functions. Genome-editing tools and recent advances of prime editing are now accessible for precise genetic alteration of plant traits. The new plant breeding tools will certainly foster development of highly productive, improved crop varieties for achieving food security and climate resilience.

scholarly journals New Plant Breeding Techniques in Citrus for the Improvement of Important Agronomic Traits. A Review

2020 ◽  
Vol 11 ◽  
Author(s):  
Fabrizio Salonia ◽  
Angelo Ciacciulli ◽  
Lara Poles ◽  
Helena Domenica Pappalardo ◽  
Stefano La Malfa ◽  
...  
Keyword(s):  
Plant Breeding ◽  
Agronomic Traits ◽  
Breeding Techniques ◽  
New Plant Breeding Techniques

Quinacrine fluorescence of specific chromosome regions

Chromosoma ◽  
1972 ◽  
Vol 36 (4) ◽  
pp. 375-390 ◽  
Author(s):  
J. R. Ellison ◽  
H. J. Barr
Keyword(s):  
Specific Chromosome ◽  
Quinacrine Fluorescence ◽  
Chromosome Regions

Interspecific Hybridization in Sunflowers: an Illustration of the Importance of Wild Genetic Resources in Plant Breeding

1986 ◽  
Vol 15 (3) ◽  
pp. 104-109 ◽  
Author(s):  
Joseph E. Laferrière
Keyword(s):  
Chemical Composition ◽  
Plant Breeding ◽  
Genetic Resources ◽  
Helianthus Annuus ◽  
Drought Resistance ◽  
Interspecific Hybrids ◽  
Agronomic Traits ◽  
Hybrid Seed Production ◽  
Male Sterile ◽  
Future Potential

This article reviews past successes and future potential of the use of interspecific hybrids in the breeding of cultivated Helianthus annuus, with emphasis on the necessity for conservation of non-cultivated germplasm. The topics discussed include resistance to diseases and other pests; the development of male-sterile lines for hybrid seed production; introduction of genes for various agronomic traits, such as drought resistance and cold tolerance; and attempts to change the chemical composition of the harvested crop.

Cytogenetics of decaploid Agropyron elongatum (Elytrigia elongata) (2n = 70). I. Frequency of decavalent formation

Genome ◽  
1990 ◽  
Vol 33 (6) ◽  
pp. 811-817 ◽  
Author(s):  
Mikio Muramatsu
Keyword(s):  
High Frequency ◽  
Chromosome Association ◽  
Agropyron Elongatum ◽  
Homologous Chromosomes ◽  
Ring Shape ◽  
Meiotic Configuration ◽  
Multivalent Formation ◽  
A Cell ◽  
Chromosome Associations ◽  
Metaphase I

The multivalents that appeared in the decaploid strain of Agropyron elongatum (2n = 10x = 70), a relative of wheat, ranged from trivalent to decavalent. Few univalents occurred. The metaphase I chromosome association in 12 cells where all configurations could clearly be identified averaged 0.42 ring X + 0.17 chain X + 0.42 ring VIII + 0.17 branched VIII + 0.25 chain VIII + 0.17 chain VII + 1.17 ring VI + 0.33 branched VI + 0.5 chain VI + 1.67 ring IV + 0.42 branched IV + 0.58 chain IV + 0.08 branched III + 0.17 chain III + 12.58 ring II + 3.75 open II + 0.25 I. The occurrence of decavalents, up to two in one cell, and of a cell with five multivalents, each of which involved more than five chromosomes, and many multivalents of ring shape indicated that the strain is autodecaploid.The chromosome associations of each cell can be interpreted as seven groups of 10 homologous chromosomes. The high frequency of bivalents indicated a tendency toward reduced multivalent formation, for which an explanation is suggested.Key words: Agropyron elongatum, meiotic configuration, decaploid, multivalent.

Dosage effects on morphological and quantitative traits in maize aneuploids

Genome ◽  
1996 ◽  
Vol 39 (5) ◽  
pp. 898-908 ◽  
Author(s):  
E. A. Lee ◽  
L. L. Darrah ◽  
E. H. Coe
Keyword(s):  
Zea Mays ◽  
Quantitative Traits ◽  
Zea Mays L ◽  
Genetic Relationships ◽  
Specific Chromosome ◽  
Phenotypic Changes ◽  
Dosage Effects ◽  
Quantitative Characters ◽  
Chromosome Arm ◽  
Chromosome Regions

Dosage effects generated by either loss or gain of a chromosome segment were used to identify chromosome regions associated with morphological and quantitative characters in maize (Zea mays L.). Using B–A translocation stocks introgressed into a B73Ht background, a chromosome arm dosage series in a Mo17Ht × B73Ht F1 hybrid background was created for 18 of the 20 chromosome arms. The dosage series was then evaluated for 12 quantitatively inherited characters to associate specific phenotypic changes in a trait with a specific chromosome arm. Not only did our results show the familiar aneuploid syndrome phenomenon, but differential dosage effects among particular chromosome arms were demonstrated. All the quantitative traits measured and all the chromosome arms examined in this study were responsive to changes in chromosome arm dosage. The possible bases behind those differences and their utility in identifying quantitative trait loci, as well as the genetic relationships among the group of quantitatively inherited characters studied, are considered. Key words : corn, chromosome arm, B–A translocations, dosage analysis.

scholarly journals Functional Markers for Precision Plant Breeding

2020 ◽  
Vol 21 (13) ◽  
pp. 4792
Author(s):  
Romesh K. Salgotra ◽  
C. Neal Stewart
Keyword(s):  
Abiotic Stress ◽  
Plant Breeding ◽  
Stress Resistance ◽  
High Throughput Sequencing ◽  
Agronomic Traits ◽  
Direct Selection ◽  
Phenotypic Traits ◽  
Functional Markers ◽  
Grand Challenge ◽  
Biotic And Abiotic Stress

Advances in molecular biology including genomics, high-throughput sequencing, and genome editing enable increasingly faster and more precise cultivar development. Identifying genes and functional markers (FMs) that are highly associated with plant phenotypic variation is a grand challenge. Functional genomics approaches such as transcriptomics, targeting induced local lesions in genomes (TILLING), homologous recombinant (HR), association mapping, and allele mining are all strategies to identify FMs for breeding goals, such as agronomic traits and biotic and abiotic stress resistance. The advantage of FMs over other markers used in plant breeding is the close genomic association of an FM with a phenotype. Thereby, FMs may facilitate the direct selection of genes associated with phenotypic traits, which serves to increase selection efficiencies to develop varieties. Herein, we review the latest methods in FM development and how FMs are being used in precision breeding for agronomic and quality traits as well as in breeding for biotic and abiotic stress resistance using marker assisted selection (MAS) methods. In summary, this article describes the use of FMs in breeding for development of elite crop cultivars to enhance global food security goals.

scholarly journals Expanding the CRISPR Toolbox in P. patens Using SpCas9-NG Variant and Application for Gene and Base Editing in Solanaceae Crops

2020 ◽  
Vol 21 (3) ◽  
pp. 1024 ◽  
Author(s):  
Florian Veillet ◽  
Laura Perrot ◽  
Anouchka Guyon-Debast ◽  
Marie-Paule Kermarrec ◽  
Laura Chauvin ◽  
...  
Keyword(s):  
Plant Breeding ◽  
Genome Editing ◽  
Gene Function ◽  
Physcomitrella Patens ◽  
Agronomic Traits ◽  
Function Analysis ◽  
Single Amino Acid ◽  
Base Substitution ◽  
Base Editing ◽  
Gene Function Analysis

Genome editing has become a major tool for both functional studies and plant breeding in several species. Besides generating knockouts through the classical CRISPR-Cas9 system, recent development of CRISPR base editing holds great and exciting opportunities for the production of gain-of-function mutants. The PAM requirement is a strong limitation for CRISPR technologies such as base editing, because the base substitution mainly occurs in a small edition window. As precise single amino-acid substitution can be responsible for functions associated to some domains or agronomic traits, development of Cas9 variants with relaxed PAM recognition is of upmost importance for gene function analysis and plant breeding. Recently, the SpCas9-NG variant that recognizes the NGN PAM has been successfully tested in plants, mainly in monocotyledon species. In this work, we studied the efficiency of SpCas9-NG in the model moss Physcomitrella patens and two Solanaceae crops (Solanum lycopersicum and Solanum tuberosum) for both classical CRISPR-generated gene knock-out and cytosine base editing. We showed that the SpCas9-NG greatly expands the scope of genome editing by allowing the targeting of non-canonical NGT and NGA PAMs. The CRISPR toolbox developed in our study opens up new gene function analysis and plant breeding perspectives for model and crop plants.

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