Analysis of chromosomal structural polymorphisms in the St, P, and Y genomes of Triticeae (Poaceae)

Genome ◽  
2010 ◽  
Vol 53 (3) ◽  
pp. 241-249 ◽  
Author(s):  
Qiuxia Wang ◽  
Jishan Xiang ◽  
Ainong Gao ◽  
Xinming Yang ◽  
Weihua Liu ◽  
...  
Keyword(s):  
Wild Species ◽  
Centromeric Region ◽  
Perennial Species ◽  
Origin And Evolution ◽  
Fish Method ◽  
The Individual ◽  
Evolution Of Genomes ◽  
Tribe Triticeae

The St, P, and Y genomes are three important genomes in the tribe Triticeae, which includes many perennial species. To study polymorphisms within the chromosomes of the St, P, and Y genomes, a GISH–FISH method was developed that allowed them to be clearly distinguished. The karyotypes of five individuals from population Z1925 of Kengyilia grandiglumis (Keng) J.L. Yang et al. (2n = 6x = 42, StStPPYY) were analyzed. The results showed that there were structural polymorphisms in all of the chromosomes from the three individual genomes. The polymorphisms were found mainly in the terminal regions of chromosomes and infrequently near the centromeric region. Of all the chromosomes, 1P, 1St, 1Y, 2Y, 3St, and 3Y showed the most polymorphisms. The polymorphisms within the individual chromosomes suggested that more extensive and scientific conclusions regarding the origin and evolution of genomes in wild species of Triticeae would be achieved by studying a population as a sampling and analysis unit.

scholarly journals Comets (Existing Populations)

1994 ◽  
Vol 160 ◽  
pp. 77-94
Author(s):  
Ľ. Kresák
Keyword(s):  
Kuiper Belt ◽  
Dynamical Evolution ◽  
Oort Cloud ◽  
Survival Times ◽  
Evolutionary Time ◽  
Origin And Evolution ◽  
History Of ◽  
The Individual ◽  
Evolutionary Paths

The definition, population, extent, origin and evolution of the individual subsystems of comets and transitions between them are discussed, together with presentation of the relevant statistical data and their changes with time. The largest outer subsystems are unobservable, but their existence is documented by the necessity of progressive replenishment of the observable populations, with limited survival times. There is persuasive evidence for two different evolutionary paths, one from the Oort cloud and another from the Kuiper belt. While the extent and accuracy of the data available is increasing rapidly, the Jupiter family of comets is the only one for which the evolutionary time scales do not exceed by many orders of magnitude the history of astronomical observations. The individual comet populations differ from one another not only by the distribution of orbits, but also by the size distribution and aging rate of their members. Their dynamical evolution is coupled with disintegration processes, which make it questionable whether the present state can be interpreted as a long-term average.

scholarly journals RECAS9: Recombining wild species introgression via mitotic gene editing in barley

2020 ◽  
Author(s):  
Shelly Lazar ◽  
Manas Ranjan Prusty ◽  
Khaled Bishara ◽  
Amir Sherman ◽  
Eyal Fridman
Keyword(s):  
Wild Species ◽  
Association Studies ◽  
Digital Pcr ◽  
Crop Wild Relatives ◽  
Linkage Drag ◽  
Genome Wide Association Studies ◽  
Starting Point ◽  
Rnp Complex ◽  
Causal Genes ◽  
The Individual

AbstractGenetic loci underlying variation in traits with agronomic importance or genetic risk factors in human diseases have been identified by linkage analysis and genome-wide association studies. However, narrowing down the mapping to the individual causal genes and variations within these is much more challenging, and so is the ability to break linkage drag between beneficial and unfavourable loci in crop breeding. We developed RECAS9 as a transgene-free approach for precisely targeting recombination events by delivering CRISPR/Cas9 ribonucleotide protein (RNP) complex into heterozygous mitotic cells for the barley (Hordeum vulgare) Heat3.1 locus. A wild species (H. spontaneum) introgression in this region carries the agronomical unfavourable tough rachis phenotype (non-brittle) allele linked with a circadian clock accelerating QTL near GIGANTEA gene. We delivered RNP, which was targeted between two single nucleotide polymorphism (SNPs), to mitotic calli cells by particle bombardment. We estimated recombination events by next generation sequencing (NGS) and droplet digital PCR (ddPCR). While NGS analysis grieved from confounding effects of PCR recombination, ddPCR analysis allowed us to associate RNP treatment on heterozygous individuals with significant increase of homologous directed repair (HDR) between cultivated and wild alleles, with recombination rate ranging between zero to 57%. These results show for the first time in plants a directed and transgene free mitotic recombination driven by Cas9 RNP, and provide a starting point for precise breeding and fine scale mapping of beneficial alleles from crop wild relatives.

scholarly journals Supernova Remnants Resembling the Crab Nebula

1983 ◽  
Vol 101 ◽  
pp. 299-320 ◽  
Author(s):  
K. W. Weiler
Keyword(s):  
Large Class ◽  
Supernova Remnants ◽  
Crab Nebula ◽  
Origin And Evolution ◽  
Class C ◽  
The Individual ◽  
The Crab Nebula

While reviewing and systematizing the properties of the class of supernova remnants resembling the Crab Nebula it has been found that supernova remnants can be split into three morphological groups – Class S (shells), Class P (plerions), and Class C (combinations) – where the Class C objects appear to represent a new and especially interesting classification. In this overview, the identifying properties of all three classes are defined. Because the large Class S has been studied in detail many times previously, it is not discussed further here. For the smaller Classes P and C, the individual members and suspected members are presented and their properties reviewed. Finally, an origin and evolution for each class is suggested.

scholarly journals The Origin and Evolution of Birds, 2nd Edition

The Auk ◽  
2000 ◽  
Vol 117 (4) ◽  
pp. 1084-1085
Author(s):  
Walter J. Bock
Keyword(s):  
Origin And Evolution ◽  
Subjective Assessments ◽  
Official Policy ◽  
Evolution Of Birds ◽  
The Individual

Abstract The following critiques express the opinions of the individual evaluators regarding the strengths, weaknesses, and value of the books they review. As such, the appraisals are subjective assessments and do not necessarily reflect the opinions of the editors or any official policy of the American Ornithologists' Union.

Tandem repetitive Afa-family sequences from Leymus racemosus and Psathyrostachys juncea (Poaceae)

Genome ◽  
1999 ◽  
Vol 42 (6) ◽  
pp. 1258-1260 ◽  
Author(s):  
Kiyotaka Nagaki ◽  
Masahiro Kishii ◽  
Hisashi Tsujimoto ◽  
Tetsuo Sasakuma
Keyword(s):  
In Situ Hybridization ◽  
Phylogenetic Tree ◽  
Tandem Repeat ◽  
Related Species ◽  
Perennial Species ◽  
Elymus Trachycaulus ◽  
Psathyrostachys Juncea ◽  
Leymus Racemosus ◽  
Tribe Triticeae

Tandem repetitive Afa-family sequences of 340 bp are known to occur in wheat and related species of tribe Triticeae. We isolated six and three Afa-family sequences from Leymus racemosus and Psathyrostachys juncea, respectively, both of which are perennial species. The sequences account for 0.5% and 0.2% of L. racemosus and P. juncea genomes, respectively, and using in situ hybridization were located in subtelomeric and interstitial regions of L. racemosus chromosomes. These sequences are clustered with those of Elymus trachycaulus in the phylogenetic tree. Our findings indicate that the Afa-family sequences have been amplified at least twice in the lineage of L. racemosus, P. juncea, and E. trachycaulus.Key words: Triticeae, Leymus, Psathyrostachys, tandem repeat, Afa-family sequences.

HORDEIN VARIATION IN WILD (HORDEUM SPONTANEUM) AND CULTIVATED (H. VULGARE) BARLEY

1979 ◽  
Vol 21 (3) ◽  
pp. 391-404 ◽  
Author(s):  
Hans Doll ◽  
A. H. D. Brown
Keyword(s):  
Linkage Disequilibrium ◽  
Wild Species ◽  
Storage Protein ◽  
Natural Populations ◽  
Hordeum Spontaneum ◽  
Allele Frequencies ◽  
Evolutionary Processes ◽  
Highly Correlated ◽  
The Individual ◽  
Allozyme Loci

The storage protein hordein contains two major groups of polypeptides which are highly polymorphic in barley, and in its evolutionary progenitor Hordeum spontaneum Koch. Crosses between the two species showed that the complex electrophoretic phenotypes within the two groups of polypeptides are governed by codominant alleles at two corresponding loci, Hor-1 and Hor-2, which are moderately linked (11% ± 2). In natural populations of the wild species, the two complex hordein loci were much more polymorphic than the allozyme loci. Furthermore, the variation at these two loci was highly correlated so that individuals differ from one another at both loci much more frequently than expected from the allele frequencies at the individual loci. Considerable hordein variation was also present in Composite Cross XXI, and there was evidence of reassortment of patterns by the seventeenth generation. Thus the complex hordein loci, with their extreme diversity and linkage disequilibrium, are ideal markers for monitoring evolutionary processes in both natural, or composite cross populations.

The Principles of the Origin and Evolution of Genomes

1996 ◽  
pp. 201-240
Author(s):  
Vadim A. Ratner ◽  
Andrey A. Zharkikh ◽  
Nikolay Kolchanov ◽  
Sergey N. Rodin ◽  
Viktor V. Solovyov ◽  
...  
Keyword(s):  
Origin And Evolution ◽  
Evolution Of Genomes

Chloroplast DNA diversity reveals the contribution of two wild species to the origin and evolution of diploid safflower (Carthamus tinctorius L.)

Genome ◽  
2008 ◽  
Vol 51 (8) ◽  
pp. 638-643 ◽  
Author(s):  
Deepmala Sehgal ◽  
Vijay Rani Rajpal ◽  
Soom Nath Raina
Keyword(s):  
Chloroplast Dna ◽  
Wild Species ◽  
Rare Event ◽  
Carthamus Tinctorius ◽  
Oilseed Crop ◽  
Crop Species ◽  
Origin And Evolution ◽  
Nucleotide Sequence Level ◽  
Dna Diversity ◽  
Chloroplast Genomes

The identity of the wild progenitor of one of the most important oil crop species, Carthamus tinctorius (2n = 2x = 24), commonly known as safflower, has been the subject of numerous studies at morphological, biochemical, cytogenetic, and biosystematic levels, but no definitive conclusions have been made. The nuclear, mitochondrial, and chloroplast genomes of the two botanical varieties of C. tinctorius, C. tinctorius var. tinctorius and C. tinctorius var. inermis, and two wild species, C. palaestinus and C. oxyacantha , were assayed at the nucleotide sequence level and by DNA markers. The nuclear and mitochondrial DNA assays were not helpful in conclusively identifying the diploid ancestor of C. tinctorius. The chloroplast DNA diversity, on the other hand, unambiguously provided new and novel evidence that C. palaestinus and C. oxyacantha contributed their plastomes to the evolution of C. tinctorius var. inermis and C. tinctorius var. tinctorius, respectively. This study, therefore, affirms a startling revelation of a rare event of two wild species contributing to the origin and evolution of safflower, a major world oilseed crop about whose genetics very little is known.

Occurrence and mechanisms of 2n egg formation in 2x potato

Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 975-982 ◽  
Author(s):  
Joanna E. Werner ◽  
Stanley J. Peloquin
Keyword(s):  
Wild Species ◽  
Seed Set ◽  
2N Gametes ◽  
Origin And Evolution ◽  
First Division Restitution ◽  
Egg Formation ◽  
Second Division Restitution ◽  
2N Eggs ◽  
Haploid Species ◽  
Species Hybrids

The occurrence of 2n eggs in 381 haploids from six tetraploid parents and in 127 plants representing five diploid wild species was detected using 2x × 4x crosses. Sixty-two percent of the haploids and 24% of the wild-species plants produced 2n eggs. Twenty-six haploids and 17 species plants that gave high seed set in 2x × 4x crosses were examined cytologically to determine the frequency and mechanisms of 2n egg formation. There was significant variation in the frequency of 2n eggs among haploids (7–57%) and among species plants (4.9–57.3%). Five mechanisms of 2n egg formation were identified: synaptic variant (genetically first division restitution); delayed meiotic division (first division restitution and second division restitution); omission of the second division (the prevalent mechanism, second division restitution); irregular anaphase II (second division restitution); and failure of second cytokinesis (second division restitution). 2n eggs can be formed by more than one mechanism within a clone. The occurrence of 2n eggs in wild species and the higher frequency of 2n eggs in haploids than in wild species indicate that sexual polyploidization has been involved in the origin and evolution of polyploid series in potato. The high frequency of 2n eggs in both haploids and diploid wild species allows generation of haploid-species hybrids that produce 2n eggs. These hybrids can then be used in the 2x × 4x and 2x × 2x breeding schemes.Key words: haploids, wild species, 2n gametes, first division restitution, second division restitution.

Identification of resistance sources in wild species of rice against two recently evolved pathotypes ofXanthomonas oryzaepvoryzae

2016 ◽  
Vol 15 (6) ◽  
pp. 558-562 ◽  
Author(s):  
Kumari Neelam ◽  
Jagjeet Singh Lore ◽  
Karminderbir Kaur ◽  
Shivali Pathania ◽  
Kishor Kumar ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Wild Species ◽  
Partial Resistance ◽  
Bacterial Blight ◽  
Immune Reaction ◽  
Rice Production ◽  
Xanthomonas Oryzae ◽  
Oryza Glaberrima ◽  
A Genome ◽  
The Individual

AbstractBacterial blight (BB) of rice caused byXanthomonas oryzaepv.oryzae(Xoo) is a major biotic constraint of rice production in all the major irrigated/lowland rice growing regions of Asia, including Punjab and its adjoining states in India. None of the individual BB resistantXa/xagenes is effective against Punjab pathotypes. In the present study, we have screened 1176 accessions, comprising 1007 accessions of A genome speciesOryza glaberrima, O. barthii, O. nivara, O. rufipogon, O. longistaminata, O. meridionalis, O. glumaepatulaand 169 accessions from ten other wild species having CC, FF, EE, BBCC and CCDD genomes against two most recently evolvedXoopathotypes viz. PbXo-10 and PbXo-8 in Punjab state of India, for two constitutive years 2014 and 2015. Based on 2 years of data, four accessions ofO. glaberrima(IRGC102206, IRGC1022445, IRGC102512 and IRGC102520) and two of theO. longistaminataaccessions (IRGC92624 and IRGC101754) were identified with immune reaction against PbXo-8. For PbXo-10,O. longistaminatashowed large number of accessions with complete to partial resistance followed byO. rufipogon(8),O. nivara(2),O. punctata(2) andO. officinalis(1). Two of theO. longistaminataaccessions IRGC92624 and IRGC92644 from Mali were found to have resistance against both theXoopathotypes indicating presence of BB resistance gene other thanXa21. These can be transferred to elite cultivars ofO. sativafor better management of BB.

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