A fertile amphiploid between diploid wheat (Triticum tauschii) and crested wheatgrass (Agropyron cristatum)

Genome ◽  
1999 ◽  
Vol 42 (3) ◽  
pp. 519-524 ◽  
Author(s):  
A Martín ◽  
A Cabrera ◽  
E Esteban ◽  
P Hernández ◽  
M C Ramírez ◽  
...  
Keyword(s):  
Intergeneric Hybrids ◽  
Agropyron Cristatum ◽  
Evolutionary Mechanisms ◽  
Triticum Tauschii ◽  
New Crops ◽  
Breeding Programmes ◽  
Diploid Level ◽  
Mother Cells ◽  
Tetraploid Parent

Alloploidy, one of the most efficient evolutionary mechanisms in nature, has not been extensively exploited in plant breeding programmes. Many genomic combinations remain to be created by plant breeders, to be used directly as new crops or indirectly to widen the genetic basis of crops. The Triticeae tribe, to which wheat belongs, is among the botanical groups in which this strategy has been successfully explored. However, there remain valuable genomic combinations that have not been obtained at the diploid level. The Agropyron complex (wheat-grasses) has recently been the focus of attention for interspecific hybridization, but intergeneric hybrids or amphiploids with wheat have not been reported at the diploid level. Here we report synthesis of a tetraploid amphiploid between Triticum tauschii and Agropyron cristatum by crossing two tetraploid accessions. Using total genome in situ hybridization (GISH) staining on metaphase I pollen mother cells, data on allosyndetic and autosyndetic chromosome pairing have been obtained. These data support the view that the A. cristatum tetraploid parent used in the synthesis of the amphiploid has a segmental alloploidy nature.

Alteration of chromosome behavior and synchronization of parental chromosomes after successive generations in Brassica napus × Orychophragmus violaceus hybrids

Genome ◽  
2007 ◽  
Vol 50 (2) ◽  
pp. 226-233 ◽  
Author(s):  
Zhigang Zhao ◽  
Ni Ma ◽  
Zaiyun Li
Keyword(s):  
Brassica Napus ◽  
Meiotic Division ◽  
Morphological Characteristics ◽  
Intergeneric Hybrids ◽  
Orychophragmus Violaceus ◽  
Genome Separation ◽  
Cytogenetic Evidence ◽  
Successive Generations ◽  
Mother Cells

In an earlier study, the progenies of intergeneric hybrids Brassica napus (2n = 38) × Orychophragmus violaceus (2n = 24) were investigated in successive generations (F1–F4) for the cytological phenomenon of parental genome separation during mitotic and meiotic division. In the present study, inbred lines (F5–F8) derived from 1 such hybrid were characterized for morphology, chromosome pairing behaviour, and genome composition. One F5 plant (2n = 31) with slightly yellow petals and 12:19 and 15:16 segregation ratios in its pollen mother cells (PMCs) produced F6 plants with distinct morphological characteristics and wide variations in fertility and chromosome numbers (2n = 25–38). F7 and F8 lines with distinctive morphology and wide ranges in chromsome numbers were established. In PMCs of F7 plants from 4 F6 plants, 0–12 labelled chromosomes from O. violaceus, which predominantly appeared as bivalents, were identified by genomic in situ hybridization. They behaved synchronously with B. napus chromosomes during meiotic division. The results provide molecular cytogenetic evidence of the inclusion of O. violaceus chromosomes in the original hybrids and the cytology in the hybrids documented earlier. They also show that chromosome behaviour was altered and the parental chromosomes became synchronized after successive generations.

C-banding and fluorescence in situ hybridization studies of the wheat–alien hybrid 'Agrotana'

Genome ◽  
1994 ◽  
Vol 37 (3) ◽  
pp. 477-481 ◽  
Author(s):  
Jie Xu ◽  
R. L. Conner ◽  
A. Laroche
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Genomic Dna ◽  
Chromosome Engineering ◽  
C Banding ◽  
Chinese Spring Wheat ◽  
Mother Cells ◽  
Alien Chromatin ◽  
Chromosome Segments

'Agrotana', a wheat-alien hybrid (2n = 56), is a potential source of resistance to common root rot, stem rust, wheat streak mosaic virus, and the wheat curl mite. However, the origin of 'Agrotana', reported to be durum wheat × Agropyron trichophorum (pubescent wheatgrass), is uncertain. The objective of this investigation was to determine the chromosome constitution of 'Agrotana' using C-banding and fluorescence in situ hybridization techniques. The F1 hybrid of 'Agrotana' × 'Chinese Spring' wheat showed 7 I + 21 II in 14.9% of the pollen mother cells, evidence of the presence of the A, B, and D genomes in 'Agrotana'. The hybrid had 16 heavily C-banded chromosomes, namely 4A, and 1-7B of wheat, and a translocation that probably involved wheat chromosomes 2A and 2D. In situ hybridization using biotinylated genomic DNA of Ag. trichophorum cv. Greenleaf blocked with CS DNA failed to identify the alien chromosomes in 'Agrotana', indicating that the alien chromosomes were not likely derived from pubescent wheatgrass. In situ hybridization using labelled wheat genomic DNA blocked with 'Agrotana' DNA revealed that 'Agrotana' had 40 wheat, 14 alien, and 2 (a pair) wheat–alien translocated chromosomes. There was no homology between wheat and the alien chromosomes or chromosome segments involved in the wheat–alien recombinant. Two of the seven pairs of alien chromosomes were homoeologous to each other. The ability to identify alien chromatin in wheat using labelled wheat DNA instead of labelled alien DNA will be particularly useful in chromosome engineering of wheat germplasms having alien chromatin of unknown origin.Key words: wheat–alien hybrid, C-banding, fluorescence in situ hybridization, labelled wheat DNA as probe.

scholarly journals Development and Characterization of Wheat-Agropyron cristatum Introgression Lines Induced by Gametocidal Genes and Wheat ph1b Mutant

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 277
Author(s):  
Alejandro Copete-Parada ◽  
Carmen Palomino ◽  
Adoración Cabrera
Keyword(s):  
Genetic Resources ◽  
Agropyron Cristatum ◽  
Homologous Gene ◽  
Aegilops Cylindrica ◽  
Induction Frequency ◽  
Structural Aberrations ◽  
Translocation Lines ◽  
New Germplasm

The P genome of Agropyron cristatum Gaertn. contains many desirable genes that can be utilized as genetic resources to improve wheat. In this research, we used both the gametocidal chromosome 2Cc and the pairing homologous gene (Ph1b) mutant to induce structural aberrations and translocations between wheat and the 4P, 5P, and 6P genome chromosomes. By using the two approaches, a total of 19 wheat-A. cristatum translocations have been identified, in which 13 were induced by the Triticum aestivum cv. Chinese Spring (CS) ph1b mutant (CS ph1b) and six were induced by gametocidal chromosome 2Cc from Aegilops cylindrica Host. The wheat-4P, -5P and -6P A. cristatum translocations were characterized by in situ hybridization and by a set of conserved orthologous set (COS) molecular markers. The aberrations included centromeric translocations, terminal translocations, dicentric translocations, and deletions. The average induction frequency of chromosome structural aberrations was 10.9% using gametocidal 2Cc chromosome and 8.8% using ph1b mutant. The highest frequency obtained was for chromosome 4P using both approaches. All the wheat-A. cristatum translocation lines obtained were valuable for identifying A. cristatum chromosome 4P, 5P, and 6P related genes. In addition, these lines provided genetic resources and new germplasm accessions for the genetic improvement of wheat.

scholarly journals The Drosophila couch potato gene: an essential gene required for normal adult behavior.

Genetics ◽  
1992 ◽  
Vol 131 (2) ◽  
pp. 365-375 ◽  
Author(s):  
H J Bellen ◽  
H Vaessin ◽  
E Bier ◽  
A Kolodkin ◽  
D D'Evelyn ◽  
...  
Keyword(s):  
Nervous System ◽  
Essential Gene ◽  
Flight Behavior ◽  
Regulatory Sequences ◽  
Adult Behavior ◽  
The Central Nervous System ◽  
Enhancer Detection ◽  
Dna Fragment ◽  
Mother Cells

Abstract Through enhancer detection screens we have isolated 14 insertions in an essential gene that is expressed in embryonic sensory mother cells (SMC), in most cells of the mature embryonic peripheral nervous system (PNS), and in glial cells of the PNS and the central nervous system (CNS). Embryos homozygote for amorphic alleles die, but show no obvious defects in their cuticle, PNS or CNS. The gene has been named couch potato (cpo) because several insertional alleles alter adult behavior. Homozygous hypomorphic cpo flies recover slowly from ether anaesthesia, show aberrant flight behavior, fail to move toward light and do not exhibit normal negative behavior. However, the flies are able to groom and walk, and some are able to fly when prodded, indicating that not all processes required for behavior are severely affected. A molecular analysis shows that the 14 insertions are confined to a few hundred nucleotides which probably contain key regulatory sequences of the gene. The orientation of these insertions and their position within this DNA fragment play an important role in the couch potato phenotype. In situ hybridization to whole mount embryos suggest that some insertions affect the levels of transcription of cpo in most cells in which it is expressed.

Coenocytism, ameiosis, and chromosome diminution in intergeneric hybrids in the perennial Triticeae

Genome ◽  
1988 ◽  
Vol 30 (5) ◽  
pp. 766-775 ◽  
Author(s):  
Richard R.-C. Wang
Keyword(s):  
Intergeneric Hybrid ◽  
Chromosome Elimination ◽  
Intergeneric Hybrids ◽  
Pollen Grain ◽  
Unreduced Gamete ◽  
Pollen Mother Cells ◽  
Psathyrostachys Juncea ◽  
Hybrid Plants ◽  
Mother Cells ◽  
Pollen Grain Wall

Three different pathways of ameiotic microsporogenesis were observed in some intergeneric hybrids of the perennial Triticeae grasses. In one of the hybrids between Pseudoroegneria spicata ssp. inermis and Psathyrostachys juncea, pollen mother cells remained as premeiotic interphase cells when the pollen grain wall started to form. The microspores in such an ameiotic plant are presumably unreduced. Coenocyte formation coupled with ameiosis occurred in two hybrid plants of Psathyrostachys huashanica × Secale montanum. Less than 10% of the pollen mother cells had one nucleus. An average of 4.44 nuclei, ranging from 1 to 25 per pollen mother cell, was observed. The nuclei in coenocytes remained unfused when the pollen grain wall was formed. Nucleus splitting followed by cytoplasmic budding or cleavage, possibly a process of chromosome diminution or elimination, replaced meiotic divisions in most of the pollen mother cells in one plant of Leymus angustus × Hordeum bulbosum and two plants of Thinopyrum elongatum × Psathyrostachys juncea. It is evident that these meiotic abnormalities are under genetic control. Probable locations for these genes controlling these phenomena are suggested.Key words: coenocyte, ameiosis, chromosome diminution, chromosome elimination, microsporogenesis, unreduced gamete, polyploidy, intergeneric hybrid.

Molecular cytogenetic analysis of wheat-alien hybrids and derivatives

2002 ◽  
Vol 50 (3) ◽  
pp. 303-311 ◽  
Author(s):  
M. Molnár-Láng ◽  
G Linc ◽  
E. D. Nagy ◽  
Keyword(s):  
Ssr Markers ◽  
Molecular Genetic ◽  
Colchicine Treatment ◽  
Translocation Chromosome ◽  
Chromosome Polymorphism ◽  
Translocation Breakpoints ◽  
Mother Cells ◽  
High Degree

New wheat × barley, wheat × Aegilops biuncialis and wheat × rye hybrids were produced with the aim of alien gene transfer from these species into wheat. Amphiploids were produced with the help of colchicine treatment from the last two combinations. The new wheat × barley hybrids were multiplied in tissue culture because of the high degree of sterility and then pollinated with wheat to obtain backcross progenies. Wheat-barley chromosome pairing was detected using genomic in situ hybridization (GISH) in two combinations (Mv9 kr1 × Igri, Asakazekomugi × Manas). In vitro conditions caused an increase in chromosome arm association frequency in both combinations and in fertility in some regenerants. Five wheat-barley translocations were produced in a wheat background and characterized through the combination of cytogenetic and molecular genetic approaches (GISH, FISH and SSR markers). The following translocations were identified: 2DS.2DL-1HS, 3HS.3BL, 6BS.6BL-4HL, 4D-5HS and 7DL.7DS-5HS. Physical mapping of the SSR markers on chromosomes 1H and 5H was carried out using the intragenomic and interspecific translocation breakpoints and the centromere as physical landmarks.  Disomic wheat-Aegilops biuncialis additions were produced after backcrossing the wheat-Ae. biuncialis amphiploids. Fluorescence in situ hybridization (FISH) was carried out using two repetitive DNA clones (pSc119.2 and pAs1) on Ae. biuncialis and its two diploid progenitor species to detect chromosome polymorphism. The 7M and 3M disomic chromosome additions were selected and five more lines still need to be characterized.  The octoploid triticale (Mv9 kr1 × Lovászpatonai) produced in Martonvásár was crossed with a 1RS.1BL wheat cultivar Matador. GISH analysis detected pairing between the 1RS arm of the translocation chromosome and that of Lovászpatonai rye in 32 % of the pollen mother cells, making it possible to select recombinants from this combination. The new recombinants between the 1RS of Petkus and the 1RS of Lovászpatonai rye cultivars are being analysed with the help of microsatellite markers.

Mitotic and meiotic irregularities in somatic hybrids of Lycopersicon esculentum and Solanum tuberosum

Genome ◽  
1994 ◽  
Vol 37 (5) ◽  
pp. 726-735 ◽  
Author(s):  
A. M. A. Wolters ◽  
H. C. H. Schoenmakers ◽  
S. Kamstra ◽  
J. van Eden ◽  
M. Koornneef ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
High Frequency ◽  
Somatic Hybrids ◽  
Unreduced Gametes ◽  
Root Tip ◽  
Root Tips ◽  
Tetrad Stage ◽  
Chromosome Arm ◽  
Mother Cells

Chromosome numbers were determined in metaphase complements of root-tip meristems of 107 tomato (+) potato somatic hybrids, obtained from five different combinations of parental genotypes. Of these hybrids 79% were aneuploid, lacking one or two chromosomes in most cases. All four hybrids that were studied at mitotic anaphase of root tips showed laggards and bridges, the three aneuploids in a higher frequency than the single euploid. Hybrid K2H2-1C, which showed the highest percentage of aberrant anaphases, possessed 46 chromosomes. Fluorescence in situ hybridization with total genomic DNA showed that this hybrid contained 23 tomato, 22 potato, and 1 recombinant chromosome consisting of a tomato chromosome arm and a potato chromosome arm. The potato parent of K2H2-1C was aneusomatic in its root tips with a high frequency of monosomic and trisomic cells and a relatively high frequency of cells with one fragment or telosome. Meiotic analyses of three tomato (+) potato somatic hybrids revealed laggards, which occurred most frequently in the triploid hybrids, and bridges, which were frequently present in pollen mother cells (PMCs) at anaphase I of hypotetraploid K2H2-1C. We observed putative trivalents in PMCs at diakinesis and metaphase I of eutriploid A7-82A and quadrivalents in part of the PMCs of hypotetraploid K2H2-1C, suggesting that homoeologous recombination between tomato and potato chromosomes occurred in these hybrids. All three hybrids showed a high percentage of first division restitution, giving rise to unreduced gametes. However, shortly after the tetrad stage all microspores completely degenerated, resulting in exclusively sterile pollen.Key words: tomato, potato, symmetric somatic hybrids, chromosomal irregularities, genomic in situ hybridization.

The genome composition of hexaploid Psammopyrum athericum and octoploid Psammopyrum pungens (Poaceae: Triticeae)

Genome ◽  
2003 ◽  
Vol 46 (1) ◽  
pp. 164-169 ◽  
Author(s):  
Pernilla Ellneskog-Staam ◽  
Björn Salomon ◽  
Roland von Bothmer ◽  
Kesara Anamthawat-Jónsson
Keyword(s):  
In Situ Hybridization ◽  
Genome Analysis ◽  
Genomic In Situ Hybridization ◽  
Agropyron Cristatum ◽  
Genome Composition ◽  
Genomic Constitution ◽  
Hybridization Pattern ◽  
Genomic Probe

The genomic constitution of two species in the genus Psammopyrum, i.e., Ps. athericum (2n = 6x = 42) and Ps. pungens (2n = 8x = 56), was studied by genomic in situ hybridization (GISH). In Ps. athericum, one diploid chromosome set hybridized to a genomic probe from Pseudoroegneria ferganensis (St genome), one diploid set to a probe from Agropyron cristatum (P genome), and one diploid set to a probe from Thinopyrum junceiforme (EbEe genomes) or Th. bessarabicum (Eb genome). Substituting the St-genome probe with an L-genome probe from Festucopsis serpentinii resulted in exactly the same hybridization pattern, suggesting a genomic constitution of EStP or ELP for Ps. athericum. The same probes used on Ps. pungens showed two diploid sets of chromosomes hybridizing to the St-genome probe, one diploid set hybridizing to the P-genome probe, and one diploid set hybridizing to the EbEe-genome probe. The L-genome probe hybridized to approximately 14 of the chromosomes that were labeled by the St-genome probe. Hence the genomic constitution for Ps. pungens is proposed to be EStStP or EStLP.Key Words: Psammopyrum athericum, Psammopyrum pungens, in situ hybridization, Elytrigia pycnantha, Elytrigia pungens, genome analysis.

Meiotic chromosome pairing in intergeneric hybrids of colchicaceous ornamentals revealed by genomic in situ hybridization (GISH)

Euphytica ◽  
2014 ◽  
Vol 200 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Tomonari Kishimoto ◽  
Miki Yamakawa ◽  
Daisuke Nakazawa ◽  
Junji Amano ◽  
Sachiko Kuwayama ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Chromosome Pairing ◽  
Meiotic Chromosome ◽  
Intergeneric Hybrids ◽  
Genomic In Situ Hybridization ◽  
Meiotic Chromosome Pairing
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