Analysis of pollen fertility in aneuploid hybrids with substitutions for specific chromosomes or their arms in cotton G.hirsutum L.

Biomics ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 376-379
Author(s):  
M.F. Sanamyan ◽  
Sh.U. Bobokhujaev
Keyword(s):  
Pollen Fertility ◽  
Chromosome 7 ◽  
F1 Hybrids ◽  
Chromosome 6 ◽  
Chromosome 2 ◽  
Chromosome 4 ◽  
Strong Decrease ◽  
Cotton Genome ◽  
Hybrid Plants

Analysis of pollen fertility in interspecific aneuploid F1 hybrids with substitutions of specific chromosomes (2, 4, 6, 7, 18) and chromosome arms (telo 6, telo11) of the cotton genome G. hirsutum L. revealed a decrease in fertility in all hybrid plants. It was shown that hybrid monosomics for chromosome 2 were characterized by a slight decrease in pollen fertility; hybrid monosomics of different families with substitution on chromosome 4 and on chromosome 6 - a significant decrease; hybrid monosomics with substitution on chromosome 7 and 18, as well as monotelodisome hybrid plants with substitution of an individual arm of chromosome 6 or 11 - a strong decrease, which indicated the existence of specific differences in pollen fertility in hybrid monosomic plants with substitution of specific chromosomes of the cotton genome due to the formation of partially unbalanced haplo-deficient gametes.

Interspecific Hybridisation Between Trifolium repens and T. uniflorum

1987 ◽  
Vol 35 (2) ◽  
pp. 171 ◽  
Author(s):  
KK Pandey ◽  
JE Grant ◽  
EG Williams
Keyword(s):  
Pollen Fertility ◽  
Morphological Characteristics ◽  
F1 Hybrids ◽  
Interspecific Hybridisation ◽  
Parent Species ◽  
F1 Hybrid ◽  
Hybrid Plants ◽  
F2 Hybrids ◽  
Fertile Hybrids

Several partially fertile hybrids (2n = 32) were produced by embryo culture from crosses of the type T. repens (2n = 32) female × T. uniflorum (2n = 32) male . The reciprocal crosses, although giving better seed development in vivo, were less successful in producing viable hybrid plants. Backcrosses to both parent species and F2 hybrids were also produced. Hybrid materials were variable with respect to morphological characteristics but broadly within the expected intermediate range. Their root systems were generally coarser and deeper than that of T. repens, offering the prospect of improved resistance to beetle larvae and drought. One F1 hybrid proved to be highly self-compatible, although derived from self-incompatible parent species. Pollen fertility ranged from 0 to 58% for F1 hybrids, 0 to 13% for F2 hybrids, 0 to 84% for backcrosses to T. repens and 0 to 26% for backcrosses to T. uniflorum. Marked seasonal variations in pollen fertility were also observed. Up to two quadrivalent chromosome associations per pollen mother cell were observed at meiosis in F1 hybrids, indicating some intragenomic pairing of T. repens chromosomes. Quadrivalent associations were also observed in an F2 hybrid and three backcrosses to T. repens.

scholarly journals Identification of univalent chromosomes in monosomic lines of cotton (Gossypium hirsutum L.) by means of cytogenetic markers

2019 ◽  
Vol 23 (7) ◽  
pp. 836-845
Author(s):  
M. F. Sanamyan ◽  
Sh. U. Bobokhujayev
Keyword(s):  
Morphological Characters ◽  
F1 Hybrids ◽  
Index Number ◽  
Chromosome 2 ◽  
Chromosome 4 ◽  
Gossypium Hirsutum L ◽  
Homologous Chromosomes ◽  
National University ◽  
Complete Set ◽  
Unconventional Method

The lack of clear morphological markers of cotton chromosomes contributed to the development of an unconventional method for marking chromosomes using translocations. Today, tester translocation cotton lines represent the most complete set of cytological markers. The results of cytogenetic analysis of F1 hybrids obtained from crosses of monosomic cotton lines with translocation lines with identified chromosomes are presented. Cytogenetic identification and numbering of univalent chromosomes in 25 monosomic lines of the cytogenetic collection of the National University of Uzbekistan allowed us to establish the following univalent occurrences: chromosome 2 in four monosomic lines, chromosome 4 in 15 lines, chromosome 6 in four lines, chromosome 7 of the At-subgenome in one line and chromosome 18 of the Dt-subgenome in one line. The remaining 21 lines were duplicates of three non-homologous chromosomes. All monosomic lines identified were characterized by differences in univalent sizes, meiotic index, number of tetrads with micronuclei, pollen fertility, frequency of monosomy in the progeny, and a complex of morphological characters associated with the monosomy of the chromosome identified. Despite differences in the genotypic environment and methods for producing monosomics in the two cotton collections, there is a surprising coincidence of data suggesting a higher frequency of chromosomes 2, 4 and 6 occurring as monosomics, while the other chromosomes of the set occur as monosomics at a much lower frequency, and eight nonhomologous chromosomes (5, 8, 13 of the At-subgenome and 14, 15, 19, 22 and 24 of the Dt-subgenome of cotton) never do.

scholarly journals Recombinant inbred strain and interspecific backcross analysis of molecular markers flanking the murine agouti coat color locus.

Genetics ◽  
1989 ◽  
Vol 122 (3) ◽  
pp. 669-679
Author(s):  
L D Siracusa ◽  
A M Buchberg ◽  
N G Copeland ◽  
N A Jenkins
Keyword(s):  
Molecular Markers ◽  
Inbred Strain ◽  
Mouse Chromosome ◽  
Recombinant Inbred ◽  
Recombinant Inbred Strain ◽  
Interspecific Backcross ◽  
Chromosome 2 ◽  
Chromosome 4 ◽  
Agouti Locus ◽  
Mouse Chromosome 2

Abstract Recombinant inbred strain and interspecific backcross mice were used to create a molecular genetic linkage map of the distal portion of mouse chromosome 2. The orientation and distance of the Ada, Emv-13, Emv-15, Hck-1, Il-1a, Pck-1, Psp, Src-1 and Svp-1 loci from the beta 2-microglobulin locus and the agouti locus were established. Our mapping results have provided the identification of molecular markers both proximal and distal to the agouti locus. The recombinants obtained provide valuable resources for determining the direction of chromosome walking experiments designed to clone sequences at the agouti locus. Comparisons between the mouse and human genome maps suggest that the human homolog of the agouti locus resides on human chromosome 20q. Three loci not present on mouse chromosome 2 were also identified and were provisionally named Psp-2, Hck-2 and Hck-3. The Psp-2 locus maps to mouse chromosome 14. The Hck-2 locus maps near the centromere of mouse chromosome 4 and may identify the Lyn locus. The Hck-3 locus maps near the distal end of mouse chromosome 4 and may identify the Lck locus.

Cytoplasmic male sterility in Desmodium

1969 ◽  
Vol 20 (2) ◽  
pp. 227 ◽  
Author(s):  
KS McWhirter
Keyword(s):  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Interspecific Hybrid ◽  
Pollen Fertility ◽  
Pollen Sterility ◽  
Hybrid Origin ◽  
F1 Hybrids ◽  
Male Sterile ◽  
Genetic Stocks

A type of male sterility found in two Desmodium plants of probably interspecific hybrid origin was cytoplasmically inherited. The cytoplasmic male-sterile character was incorporated in the tropical legume Desmodium sandwicense by backcrossing. In this genetic background pollen sterility was complete. The male-sterile character was not graft-transmissible, and it produced no detectable pleiotropic effects on growth and development. Desmodium intortum gave restoration of pollen fertility in Fl hybrids with male-sterile lines of D. sandwicense. Restored F1 hybrids produced apparently normal pollen, but tests of functional ability of the pollen disclosed that pollen fertility was less than that of Fl hybrids with normal cytoplasm. Incomplete restoration of fertility was not due to heterozygosity of fertility-restoring genes with gametophytic expression, since fertility-restoring genes were shown to act sporophytically. The results established the occurrence in the legume Desmodium of a system of determination of the male-sterile, fertility-restored phenotypes that is similar to the cytoplasmic male sterility systems described in many other angiosperm plants. A scheme utilizing the genetic stocks produced in this study for commercial production of the interspecific hybrid D. sandwicense x D. intortum as a cultivar is presented.

NULLISOMIC ANALYSIS OF NUCLEOLAR FORMATION IN ZEA MAYS

1978 ◽  
Vol 20 (1) ◽  
pp. 97-100 ◽  
Author(s):  
David F. Weber
Keyword(s):  
Zea Mays ◽  
Chromosome Number ◽  
Zea Mays L ◽  
Diploid Species ◽  
5S Rrna ◽  
Chromosome 6 ◽  
Chromosome 2 ◽  
Nucleolar Organizing Region

When a monosomic plant of a diploid species undergoes meiosis, two haploid and two nullisomic cells are produced. Zea mays L. microspore quartet cells nullisomic for chromosome number 1, 2, 4, 6, 7, 8, 9, or 10 produced by monosomics were analyzed. Cells nullisomic for chromosome 6, as expected, do not contain a nucleolus because chromosome 6 bears the nucleolar organizing region. Cells nullisomic for chromosome 2 contain nucleoli; therefore, the 5S rRNA template on chromosome 2 is not necessary for nucleolar formation. Cells nullisomic for chromosomes 1, 4, 7, 8, 9, or 10 also contain nucleoli; thus, no factors located on these chromosomes are necessary for nulceolar formation at the quartet stage.

scholarly journals MAMMALIAN CHROMOSOMES IN VITRO

1964 ◽  
Vol 23 (1) ◽  
pp. 53-62 ◽  
Author(s):  
T. C. Hsu
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Sex Chromosomes ◽  
Chinese Hamster ◽  
Distal Portion ◽  
S Phase ◽  
Chromosome 1 ◽  
Chromosome 6 ◽  
Chromosome 2

The complete DNA replication sequence of the entire complement of chromosomes in the Chinese hamster may be studied by using the method of continuous H3-thymidine labeling and the method of 5-fluorodeoxyuridine block with H3-thymidine pulse labeling as relief. Many chromosomes start DNA synthesis simultaneously at multiple sites, but the sex chromosomes (the Y and the long arm of the X) begin DNA replication approximately 4.5 hours later and are the last members of the complement to finish replication. Generally, chromosomes or segments of chromosomes that begin replication early complete it early, and those which begin late, complete it late. Many chromosomes bear characteristically late replicating regions. During the last hour of the S phase, the entire Y, the long arm of the X, and chromosomes 10 and 11 are heavily labeled. The short arm of chromosome 1, long arm of chromosome 2, distal portion of chromosome 6, and short arms of chromosomes 7, 8, and 9 are moderately labeled. The long arm of chromosome 1 and the short arm of chromosome 2 also have late replicating zones or bands. The centromeres of chromosomes 4 and 5, and occasionally a band on the short arm of the X are lightly labeled.

Localization of the 68 000-Da human neurofilament gene (NF68) using a murine cDNA probe

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 499-500 ◽  
Author(s):  
Martin J. Somerville ◽  
Donald R. McLachlan ◽  
Maire E. Percy
Keyword(s):  
Centromeric Region ◽  
Human Gene ◽  
Cdna Probe ◽  
Chromosome 8 ◽  
Chromosome 7 ◽  
Gene Localization ◽  
Chromosome 2 ◽  
Genomic Probe ◽  
Human Genomic

A recent investigation, using a human genomic probe, has indicated that the 68 000 dalton neurofilament gene (NF68) is on the short arm of chromosome 8. We have used a murine cDNA probe on 65 metaphase spreads in situ to localize the human NF68 gene to 8p21 (20/370 grains; p < 0.0001). In addition, we have found secondary hybridization sites at the centromeric region of chromosome 2 and the long arm of chromosome 7, which are putative loci for other intermediate filaments.Key words: neurofilament, human, gene localization, murine cDNA.

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