Dilemma of genome relationship in the diploid species Thinopyrum bessarabicum and Thinopyrum elongatum (Triticeae: Poaceae)

Genome ◽  
1990 ◽  
Vol 33 (6) ◽  
pp. 944-946 ◽  
Author(s):  
Prem P. Jauhar
Keyword(s):  
Chromosome Pairing ◽  
Constitutive Heterochromatin ◽  
Diploid Species ◽  
Total Content ◽  
Ploidy Levels ◽  
5S Dna ◽  
Thinopyrum Bessarabicum ◽  
Thinopyrum Elongatum ◽  
Relationship Of ◽  
The Relationship

Evidence on the relationship of the J genome of diploid Thinopyrum bessarabicum and the E genome of diploid Thinopyrum elongatum (= Lophopyrum elongatum) is discussed. Low chromosome pairing between J and E at different ploidy levels, suppression of J–E pairing by the Ph1 pairing regulator that inhibits homoeologous pairing, complete sterility of the diploid hybrids (JE), karyotypic differentiation of the two genomes and differences in their biochemical organization as reflected in total content and distribution of constitutive heterochromatin, and marked differences in isozymes, 5S DNA, and rDNA indicate that J and E are distinct genomes. These genomes are homoeologous and not homologous. There is no justification for the merger of J and E genomes.Key words: chromosome pairing, Ph1 pairing regulator, C-banding, isozymes, 5S DNA, rDNA.

Differential transferability of EST-SSR primers developed from the diploid species Pseudoroegneria spicata, Thinopyrum bessarabicum, and Thinopyrum elongatum

Genome ◽  
2017 ◽  
Vol 60 (6) ◽  
pp. 530-536 ◽  
Author(s):  
Richard R.-C. Wang ◽  
Steve R. Larson ◽  
Kevin B. Jensen
Keyword(s):  
Expressed Sequence Tag ◽  
Genome Mapping ◽  
Diploid Species ◽  
Genetic Maps ◽  
Pseudoroegneria Spicata ◽  
Ssr Primers ◽  
Polymorphic Species ◽  
Thinopyrum Bessarabicum ◽  
Species Specific ◽  
Thinopyrum Elongatum

Simple sequence repeat technology based on expressed sequence tag (EST-SSR) is a useful genomic tool for genome mapping, characterizing plant species relationships, elucidating genome evolution, and tracing genes on alien chromosome segments. EST-SSR primers developed from three perennial diploid species of Triticeae, Pseudoroegneria spicata (Pursh) Á. Löve (having St genome), Thinopyrum bessarabicum (Savul. & Rayss) Á. Löve (Jb = Eb = J), and Thinopyrum elongatum (Host) D.R. Dewey (Je = Ee = E), were used to produce amplicons in these three species to (i) assess relative transferability, (ii) identify polymorphic species-specific markers, and (iii) determine genome relationships among the three species. Because of the close relationship between Jb and Je genomes, EST-SSR primers derived from Th. bessarabicum and Th. elongatum had greater transferability to each other than those derived from the St-genome P. spicata. A large number of polymorphic species- and genome-specific EST-SSR amplicons were identified that will be used for construction of genetic maps of these diploid species, and tracing economically useful genes in breeding or gene transfer programs in various species of Triticeae.

Genome evolution of intermediate wheatgrass as revealed by EST-SSR markers developed from its three progenitor diploid species

Genome ◽  
2015 ◽  
Vol 58 (2) ◽  
pp. 63-70 ◽  
Author(s):  
Richard R.-C. Wang ◽  
Steve R. Larson ◽  
Kevin B. Jensen ◽  
B. Shaun Bushman ◽  
Lee R. DeHaan ◽  
...  
Keyword(s):  
Scientific Literature ◽  
Diploid Species ◽  
Triticum Aestivum L ◽  
Thinopyrum Intermedium ◽  
Forage Crop ◽  
Intermediate Wheatgrass ◽  
Ssr Primers ◽  
Thinopyrum Bessarabicum ◽  
Thinopyrum Elongatum ◽  
Available Information

Intermediate wheatgrass (Thinopyrum intermedium (Host) Barkworth & D.R. Dewey), a segmental autoallohexaploid (2n = 6x = 42), is not only an important forage crop but also a valuable gene reservoir for wheat (Triticum aestivum L.) improvement. Throughout the scientific literature, there continues to be disagreement as to the origin of the different genomes in intermediate wheatgrass. Genotypic data obtained from newly developed EST-SSR primers derived from the putative progenitor diploid species Pseudoroegneria spicata (Pursh) Á. Löve (St genome), Thinopyrum bessarabicum (Savul. & Rayss) Á. Löve (J = Jb = Eb), and Thinopyrum elongatum (Host) D. Dewey (E = Je = Ee) indicate that the V genome of Dasypyrum (Coss. & Durieu) T. Durand is not one of the three genomes in intermediate wheatgrass. Based on all available information in the literature and findings in this study, the genomic designation of intermediate wheatgrass should be changed to JvsJrSt, where Jvs and Jr represent ancestral genomes of present-day Jb of Th. bessarabicum and Je of Th. elongatum, with Jvs being more ancient. Furthermore, the information suggests that the St genome in intermediate wheatgrass is most similar to the present-day St found in diploid species of Pseudoroegneria from Eurasia.

Cytological relationship between Paspalum dilatatum and diploid cytotypes of P. brunneum and P. rufum

Genome ◽  
1992 ◽  
Vol 35 (2) ◽  
pp. 332-336 ◽  
Author(s):  
Byron L. Burson ◽  
Camilo L. Quarín
Keyword(s):  
Interspecific Hybrids ◽  
Meiotic Chromosome ◽  
Diploid Species ◽  
Paspalum Dilatatum ◽  
Probable Source ◽  
Chromosome Associations ◽  
The Mean ◽  
Relationship Of ◽  
The Relationship ◽  
Very High

Tetraploid Paspalum dilatatum Poir. (2n = 4x = 40, genome formula IIJJ) was crossed with diploid cytotypes of P. brunneum Mez (2n = 2x = 20) and P. rufum Nees (2n = 2x = 20), both of which have the genome formula II. The objectives of this investigation were to determine the relationship of these two diploid species to P. dilatatum and to ascertain if they are more closely related to P. dilatatum than diploid P. intermedium Munro. ex Morong, which also has the genome formula II. Crossability for both crosses was in excess of 11%, which is very high for this genus. Twelve P. dilatatum × P. brunneum and 15 P. dilatatum × P. rufum hybrids studied cytologically had 30 chromosomes. The mean meiotic chromosome associations were 14.061, 7.91 II, and 0.04 III for the P. dilatatum × P. brunneum hybrids and 15.81 I, 7.04 II, and 0.03 III for the P. dilatatum × P. rufum hybrids. These data indicate that both P. brunneum and P. rufum are related to P. dilatatum, but the I genome in P. dilatatum differs from the I genome in these species. Thus, P. intermedium is more closely related to P. dilatatum than either P. brunneum or P. rufum and remains the most probable source for the I genome in P. dilatatum.Key words: meiosis, genomes, interspecific hybrids, chromosome pairing, dallisgrass.

FUSION OF CHROMOCENTERS IN PREMEIOTIC INTERPHASE OF SECALE CEREALE AND ITS POSSIBLE RELATIONSHIP TO CHROMOSOME PAIRING

1977 ◽  
Vol 19 (2) ◽  
pp. 313-321 ◽  
Author(s):  
J. G. Bowman ◽  
Tibor Rajhathy
Keyword(s):  
Chromosome Pairing ◽  
Secale Cereale ◽  
Disruptive Effect ◽  
Immature Inflorescence ◽  
Multivalent Formation ◽  
Relationship Of ◽  
The Relationship ◽  
Metaphase I

The premeiotic interphase of rye has been found to exhibit a synchronized fusion of chromocenters. This results in a solid knot of heterochromatin localized to one side of the nucleus. Colchicine injected into the immature inflorescence of diploid rye has been found to induce univalent and multivalent formation at metaphase I. The early premeiotic interphase was the phase of development most sensitive to colchicine. Colchicine was also found to have a similar disruptive effect on fusion of chromocenters in the premeiotic interphase. The relationship of these observations to chromosome pairing is discussed.

scholarly journals Structural Identification and Conversion Analysis of Malonyl Isoflavonoid Glycosides in Astragali Radix by HPLC Coupled with ESI-Q TOF/MS

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3929 ◽  
Author(s):  
Yunfeng Zheng ◽  
Weiping Duan ◽  
Jie Sun ◽  
Chenguang Zhao ◽  
Qizhen Cheng ◽  
...  
Keyword(s):  
Total Content ◽  
Astragali Radix ◽  
Fragment Ions ◽  
Long Duration ◽  
Diagnostic Fragment ◽  
Positive Mode ◽  
Relationship Of ◽  
The Relationship ◽  
Tof Ms

In this study, four malonyl isoflavonoid glycosides (MIGs), a type of isoflavonoid with poor structural stability, were efficiently isolated and purified from Astragali Radix by a medium pressure ODS C18 column chromatography. The structures of the four compounds were determined on the basis of NMR and literature analysis. Their major diagnostic fragment ions and fragmentation pathways were proposed in ESI/Q-TOF/MS positive mode. Using a target precursor ions scan, a total of 26 isoflavonoid compounds, including eleven malonyl isoflavonoid glycosides coupled with eight related isoflavonoid glycosides and seven aglycones were characterized from the methanolic extract of Astragali Radix. To clarify the relationship of MIGs and the ratio of transformation in Astragali Radix under different extraction conditions, two MIGs (calycosin-7-O-glycoside-6″-O-malonate and formononetin-7-O-glycoside-6″-O-malonate) coupled with related glycosides (calycosin-7-O-glycoside and formononetin-7-O-glycoside) and aglycones (calycosin and formononetin) were detected by a comprehensive HPLC-UV method. Results showed that MIGs could convert into related glycosides under elevated temperature conditions, which was further confirmed by the conversion experiment of MIGs reference compounds. Moreover, the total contents of MIGs and related glycosides displayed no obvious change during the long-duration extraction. These findings indicated that the quality of Astragali Radix could be evaluated efficiently and accurately by using the total content of MIGs and related glycosides as the quality index.

scholarly journals LATENT NONSTRUCTURAL DIFFERENTIATION AMONG HOMOLOGOUS CHROMOSOMES AT THE DIPLOID LEVEL: CHROMOSOME 6Be OF AEGILOPS LONGISSIMA

Genetics ◽  
1986 ◽  
Vol 114 (2) ◽  
pp. 579-592
Author(s):  
Rama S Kota ◽  
Patrick E McGuire ◽  
Jan Dvořák
Keyword(s):  
Chromosome Pairing ◽  
Chinese Spring ◽  
Constitutive Heterochromatin ◽  
Diploid Species ◽  
Triticum Aestivum L ◽  
Homologous Chromosomes ◽  
B Genome ◽  
Aegilops Longissima ◽  
Chinese Spring Wheat ◽  
Diploid Level

ABSTRACT Previous work has shown that chromosome pairing at metaphase I (MI) of wheat homologous chromosomes from different inbred lines (heterohomologous chromosomes) is reduced relative to that between homologous chromosomes within an inbred line (euhomologous chromosomes). In order to determine if a potential for this phenomenon exists in diploid species closely related to the wheat B genome, MI chromosome pairing was investigated between euhomologous and heterohomologous 6Be (=6Se) chromosomes, each from a different population of Aegilops longissima Schweinf. et Muschl. (2n = 2x = 14) substituted for chromosome 6B of Chinese Spring wheat (Triticum aestivum L., 2n = 6x = 42). Euhomologous and heterohomologous monotelodisomics, i.e., plants with one complete chromosome 6Be and a telosome of either 6Bep or 6Beq, were constructed in the isogenic background of Chinese Spring. Pairing at MI of the Ae. longissima chromosomes was reduced in heterohomologous monotelodisomics compared to that in the corresponding euhomologous monotelodisomics. The remaining 20 pairs of Chinese Spring chromosomes paired equally well in the euhomologous and heterohomologous monotelodisomics. Thus, the cause of the reduced pairing must reside specifically in the Ae. longissima heterohomologues. In the hybrids between the Ae. longissima lines that contributed the substituted chromosomes, pairing between the heterohomologous chromosomes was normal and did not differ from that of the euhomologous chromosomes. These data provide evidence that a potential for reduced pairing between the heterohomologues is present in the diploid species, but is expressed only in the polyploid wheat genetic background. The reduction in heterohomologous chromosome pairing was greater in the p arm than in the q arm, exactly as in chromosome 6B of wheat. It is concluded that the reduced pairing between Ae. longissima heterohomologues has little to do with constitutive heterochromatin. The value of chromosome pairing as an unequivocal means of determining the origin of genomes in polyploid plants is questioned.

GENOME RELATIONS BETWEEN PASPALUM CONSPERSUM AND TWO DIPLOID PASPALUM SPECIES

1978 ◽  
Vol 20 (3) ◽  
pp. 365-372 ◽  
Author(s):  
Byron L. Burson
Keyword(s):  
Chromosome Number ◽  
Chromosome Pairing ◽  
Mean Frequency ◽  
Hybrid Plants ◽  
The Mean ◽  
The Cross ◽  
Relationship Of ◽  
The Relationship

Paspalum conspersum Schrad. ex Schult., 2n = 4x = 40, was crossed with P. intermedium Munro ex Morong, 2n = 2x = 20, and P. jurgensii Hackel, 2n = 2x = 20, and the hybrids were studied cytologically to determine the relationship between these species. Thirteen P. intermedium × P. conspersum hybrid plants were produced; however, only eight survived. They had a chromosome number of 2n = 3x = 30. Meiosis was irregular with a chromosome pairing relationship of 19.87 univalents, 5.03 bivalents, and 0.03 trivalents per cell. These findings suggested that the two species have a partially homologous genome. The two hybrids obtained from the cross between P. jurgensii and P. conspersum had a chromosome number of 2n = 3x = 30. The mean chromosome pairing in these hybrids was 10.12 univalents. 9.86 bivalents, 0.08 trivalents, and 0.004 quadrivalents. The close bivalent pairing and a mean frequency of 9.86 bivalents suggested that the P. jurgensii genome was homologous to one genome of P. conspersum. Limited autosyndetic pairing of the P. conspersum chromosomes was also detected in both groups of hybrids. A standardization of genome formulas for the genus was proposed in which P. intermedium, P. jurgensii, and P. conspersum were represented by genome formulas of II, JJ, and I2I2 JJ, respectively. The genome relationships and formulas were discussed for other related Paspalum species.

The genomic relationship of the diploid Bromus variegatus to Bromus inermis

1984 ◽  
Vol 26 (4) ◽  
pp. 469-474 ◽  
Author(s):  
K. C. Armstrong
Keyword(s):  
Chromosome Pairing ◽  
Diploid Species ◽  
Bromus Inermis ◽  
Genomic Relationship ◽  
Diploid Genome ◽  
B Genome ◽  
Hybrid Plants ◽  
Relationship Of ◽  
Genomic Model

The diploid species Bromus variegatus Bieb. was crossed to Bromus inermis Leyss (4x, 8x). Chromosome pairing in each of the six F1 hybrid plants of B. variegatus × B. inermis (4x) fit a 2:1 genomic model of chromosome pairing, which indicated that the B. variegatus genome was more closely related to the A or B genome of B. inermis than A and B were related to each other. A breakdown of microsporocytes was observed in the B. variegatus × B. inermis (8x) hybrid. However, chromosome pairing suggested that the B. variegatus genome was differentiated from the A and B genomes of octoploid B. inermis.Key words: Bromus, diploid, genome, affinity.

scholarly journals Heterochromatin Dynamics in Response to Environmental Stress in Amazonian Fish

2021 ◽  
Author(s):  
Daniele Aparecida Matoso ◽  
Maelin da Silva ◽  
Hallana Cristina Menezes da Silva ◽  
Eliana Feldberg ◽  
Roberto Ferreira Artoni
Keyword(s):  
Transposable Elements ◽  
Environmental Stress ◽  
Genomic Dna ◽  
Constitutive Heterochromatin ◽  
Amazonian Fish ◽  
Architectural Proteins ◽  
And Function ◽  
Genomic Regions ◽  
Relationship Of ◽  
The Relationship

Transcriptionally inactive portions of genomic DNA, condensed with histones and architectural proteins, are known as heterochromatic regions, often positive C band. The advent of epigenetics and new methodological approaches, showed that these regions are extremely dynamic and responsive to different types of environmental stress. The relationship of the constitutive heterochromatin with the transposable elements inactivation, especially from the Rex family, seems to be a frequent condition in fish. In this manuscript we review the existing knowledge of the nature and function of these genomic regions, based on species-based studies, with a focus on species of fish from the Amazon region.

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