The pattern of homoeologous recombination in triploid hybrids of Lolium multiflorum with Festuca pratensis

Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 720-726 ◽  
Author(s):  
Z Zwierzykowski ◽  
A J Lukaszewski ◽  
B Naganowska ◽  
A Lesniewska
Keyword(s):  
Parental Species ◽  
Lolium Multiflorum ◽  
Festuca Pratensis ◽  
Meiotic Pairing ◽  
Homoeologous Recombination ◽  
Translocation Breakpoints ◽  
Zygotic Selection ◽  
Homoeologous Chromosomes ◽  
Pairing Initiation

Homoeologous chromosomes of Lolium-Festuca hybrids are capable of frequent meiotic pairing and recombination. The frequency and distribution of recombination was studied by genomic in situ hybridization in backcross progenies of reciprocal triploid hybrids of Lolium multiflorum with Festuca pratensis. Significant differences in the male transmission of the parental and translocated chromosomes were observed depending on the cytoplasm of the F1 hybrids and the ploidy level of the female test cross partner. The frequency of intergeneric translocations in the progeny indicated that, on average, there must have been at least 4.5 homoeologous arms paired in the F1 hybrids; the actual frequency might have been higher because of pre- or post-zygotic selection against the F. pratensis chromatin, which probably eliminated certain gametes with Festuca-Lolium translocations. Both parental species are known for localized distal chiasmata, but the intergeneric translocation breakpoints were distributed along the entire lengths of the chromosome arms. The change in the distribution of homoeologous recombination might have been related to different pairing initiation of homologues and homoeologues. It probably resulted from allocation of additional chiasmata to chromosome arms and produced a net increase in recombination.Key words: homoeologous exchanges, Lolium-Festuca, translocations, recombination.

scholarly journals Direct evidence for crossover and chromatid interference in meiosis of two plant hybrids (Lolium multiflorum×Festuca pratensis and Allium cepa×A. roylei)

2020 ◽  
Author(s):  
Marco Tulio Mendes Ferreira ◽  
Marek Glombik ◽  
Kateřina Perničková ◽  
Martin Duchoslav ◽  
Olga Scholten ◽  
...  
Keyword(s):  
Allium Cepa ◽  
Direct Evidence ◽  
Lolium Multiflorum ◽  
Crossing Over ◽  
Festuca Pratensis ◽  
Physical Measure ◽  
Crossover Interference ◽  
Chromosome Arm ◽  
Double Crossovers

Abstract Crossing over, in addition to its strictly genetic role, also performs a critical mechanical function, by bonding homologues in meiosis. Hence, it is responsible for an orderly reduction of the chromosome number. As such, it is strictly controlled in frequency and distribution. The well-known crossover control is positive crossover interference which reduces the probability of a crossover in the vicinity of an already formed crossover. A poorly studied aspect of the control is chromatid interference. Such analyses are possible in very few organisms as they require observation of all four products of a single meiosis. Here, we provide direct evidence of chromatid interference. Using in situ probing in two interspecific plant hybrids (Lolium multiflorum×Festuca pratensis and Allium cepa×A. roylei) during anaphase I, we demonstrate that the involvement of four chromatids in double crossovers is significantly more frequent than expected (64% versus 25%). We also provide a physical measure of the crossover interference distance, covering ~30–40% of the relative chromosome arm length, and show that the centromere acts as a barrier for crossover interference. The two arms of a chromosome appear to act as independent units in the process of crossing over. Chromatid interference has to be seriously addressed in genetic mapping approaches and further studies.

Cytogenetics of two interspecific synthetic hybrids of the grasshopper genus Euchorthippus

Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 909-912 ◽  
Author(s):  
J. L. Santos ◽  
P. Arana ◽  
N. Henriques-Gil
Keyword(s):  
Parental Species ◽  
The Other ◽  
Meiotic Pairing ◽  
Banding Patterns ◽  
Hybrid Individual ◽  
C Banding ◽  
Isolating Mechanisms ◽  
Synthetic Hybrids ◽  
The Cross ◽  
Homoeologous Chromosomes

The spermatogenesis of two synthetic hybrid individuals of the grasshopper genus Euchorthippus was studied by C-banding methods. One resulted from the cross Euchorthippus pulvinatus ♂ × Euchorthippus chopardi ♀ (p/c), whereas the other one was produced in the cross E. chopardi ♂ × E. pulvinatus ♀ (c/p). The two parental sets of chromosomes were always recognized according to their different C-banding patterns. Chiasma frequency was decreased in both hybrids when compared with the parental species, this decrease being more accentuated in the hybrid individual c/p, where univalents at metaphase I were frequent. Chiasmata were formed between homoeologous chromosomes, and only two multivalent associations were observed. Polyploid spermatids and some micronuclei were a common feature in both hybrids. It is suggested that C-heterochromatin differences do not play any important role in the speciation process: genie differences between parental genomes are probably more important.Key words: synthetic hybrid, Euchorthippus, C-heterochromatin, meiotic pairing, reproductive isolating mechanisms.

Physical Distribution of Homoeologous Recombination in Individual Chromosomes of Festuca pratensis in Lolium multiflorum

2010 ◽  
Vol 129 (1-3) ◽  
pp. 162-172 ◽  
Author(s):  
D. Kopecký ◽  
M. Havránková ◽  
J. Loureiro ◽  
S. Castro ◽  
A.J. Lukaszewski ◽  
...  
Keyword(s):  
Lolium Multiflorum ◽  
Festuca Pratensis ◽  
Homoeologous Recombination ◽  
Physical Distribution

A Demonstration of a 1:1 Correspondence Between Chiasma Frequency and Recombination Using a Lolium perenne/Festuca pratensis Substitution

Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 307-314 ◽  
Author(s):  
J King ◽  
L A Roberts ◽  
M J Kearsey ◽  
H M Thomas ◽  
R N Jones ◽  
...  
Keyword(s):  
Lolium Perenne ◽  
Chiasma Frequency ◽  
Chiasma Formation ◽  
Grass Species ◽  
Festuca Pratensis ◽  
Single Chromosome ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms ◽  
Frequency Counts

Abstract A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line (2n = 2x = 14). The chromatin of F. pratensis and L. perenne can be distinguished by genomic in situ hybridization (GISH), and it is therefore possible to visualize the substituted F. pratensis chromosome in the L. perenne background and to study chiasma formation in a single marked bivalent. Recombination occurs freely in the F. pratensis/L. perenne bivalent, and chiasma frequency counts give a predicted map length for this bivalent of 76 cM. The substituted F. pratensis chromosome was also mapped with 104 EcoRI/Tru91 and HindIII/Tru91 amplified fragment length polymorphisms (AFLPs), generating a marker map of 81 cM. This map length is almost identical to the map length of 76 cM predicted from the chiasma frequency data. The work demonstrates a 1:1 correspondence between chiasma frequency and recombination and, in addition, the absence of chromatid interference across the Festuca and Lolium centromeres.

Intergeneric hybrids between Thinopyrum and Psathyrostachys (Triticeae)

Genome ◽  
1990 ◽  
Vol 33 (6) ◽  
pp. 845-849 ◽  
Author(s):  
Richard R.-C. Wang
Keyword(s):  
Genome Analysis ◽  
Parental Species ◽  
Intergeneric Hybrids ◽  
Meiotic Pairing ◽  
Green Leaves ◽  
Psathyrostachys Juncea ◽  
Basic Genome ◽  
Chromosome Associations ◽  
Thinopyrum Elongatum ◽  
First Time

Intergeneric hybrids were synthesized for the first time from the diploid crosses Thinopyrum elongatum (JeJe) × Psathyrostachys juncea (NjNj), T. elongatum × P. fragilis (NfNf), T. bessarabicum (JbJb) × P. huashanica (NhNh), and T. bessarabicum × P. juncea, as well as from a cross between the amphidiploid of T. bessarabicum × T. elongatum (JbJbJeJe) and P. juncea. Spikes of these hybrids are morphologically intermediate between those of the parental species. Double spikelets occurred occasionally at central nodes of the spikes. Glaucous blue leaves appeared in the F1 only in the cross T. bessarabicum × P. huashanica, suggesting that the gene(s) for glaucous blue leaves in T. bessarabicum is (are) recessive to a gene(s) for green leaves in P. juncea but is (are) dominant to that for yellowish green leaves in P. huashanica. Meiotic pairing at metaphase I in these diploid (JN) and triploid (JJN) hybrids revealed a very low level of homology between the basic J and N genome. Therefore, the J and N genomes are nonhomologous and justifiably represented by different genome symbols. The triploid hybrids exhibited a pattern of chromosome associations that substantiated the earlier conclusion that the genomes in T. bessarabicum and T. elongatum are two versions of a basic genome (J). These hybrids will be useful in genome analysis, forming new Leymus species with the J and N genomes and broadening the diversity in the genus Pascopyrum with the SHJN genomes.Key words: hybrid, Thinopyrum, Psathyrostachys, genome.

The Effect of Homoeologous Meiotic Pairing in Tetraploid Hordeum bulbosum L. × H. vulgare L. Hybrids on Alien Introgressions in Offspring

2016 ◽  
Vol 150 (2) ◽  
pp. 139-149 ◽  
Author(s):  
Margret Scholz ◽  
Galina Pendinen
Keyword(s):  
Interspecific Hybrids ◽  
In Situ Hybridisation ◽  
Basic Material ◽  
Meiotic Pairing ◽  
Hordeum Bulbosum ◽  
Homoeologous Pairing ◽  
Introgression Breeding ◽  
The Individual ◽  
Pairing Behaviour

The pairing behaviour of the individual chromosome arms of Hordeum vulgare (Hv) with their homoeologous arms of H. bulbosum (Hb) at metaphase I of meiosis in tetraploid Hb × Hv hybrids and the frequencies of recombined Hv chromosome arms in selfed offspring were studied on differentially visualized chromosomes after fluorescent in situ hybridisation. The frequencies of paired Hv-Hb arms in the F2 and F3 hybrids were correlated with the frequencies of recombined Hv chromosomes in progenies. Self-generation of hybrids, the number of Hv and Hb chromosomes, and the number of recombined Hv chromosomes of the hybrids strongly influenced the Hv-Hb pairing frequency in meiosis. Within the offspring of F2 and F3 hybrids both Hv plants and hybrids were detected. In contrast, all progenies of the F4 hybrid were hybrids which exhibited centromere misdivisions. The highest frequencies of homoeologous pairing in hybrids and most recombinants were obtained for the barley chromosome 1HL. Recombinants for 4HL, 5HS, 6HS, and 7HS were rarely found. Meiotic pairing and recombinants involving chromosome 1HS were never observed. The results of this study demonstrate that fertile tetraploid interspecific hybrids with a high intergenomic pairing at meiosis are valuable basic material for introgression breeding in barley.

Synaptonemal complex spreading in Allium ursinum: pericentric asynapsis and axial thickenings

1987 ◽  
Vol 87 (3) ◽  
pp. 439-448
Author(s):  
J. Loidl
Keyword(s):  
Synaptonemal Complex ◽  
Inhibitory Effect ◽  
Proximal Region ◽  
High Rate ◽  
Meiotic Pairing ◽  
Loop Formation ◽  
Allium Ursinum ◽  
High Incidence ◽  
Pairing Initiation ◽  
Inversion Loop

In Allium ursinum meiotic pairing of homologues is always incomplete; a proximal region on each bivalent remains regularly unsynapsed even in late pachytene. The spatial correlation of the unsynapsed region with the kinetochore suggests that the kinetochore itself exerts an inhibitory effect on synapsis in its vicinity. This can be interpreted as the cytological basis of the ‘centromere effect’ on recombination in this species. Moreover, the high incidence of a pericentric inversion loop in a heterozygous chromosome pair shows that proximal pairing initiation is possible and that its failure cannot be responsible for pericentric asynapsis. The formation of the inversion loop is complicated by the need for two independent pairing initiation sites because synapsis cannot proceed across the pericentric region. It is proposed that the meiotic bouquet polarization helps in establishing the presynaptic alignment of the homologous sites within the inverted regions and hence to achieve a high rate of inversion loop formation. Thickenings of the axial/lateral elements are not distributed equally along the synaptonemal complex. They are underrepresented in unpaired axes but strikingly abundant at the borders with synapsed regions, suggesting their origin in the pairing forks during the process of synapsis. They are virtually always present at nucleolus-organizing regions and often they appear at corresponding sites on opposite lateral elements. Besides the thickenings several other kinds of axial deformities are present in unpaired axes.

Inflorescence development and seed production in Lolium spp. × Festuca pratensis tetraploid hybrids

1975 ◽  
Vol 85 (2) ◽  
pp. 301-307 ◽  
Author(s):  
P. Cremades ◽  
E. W. Bean
Keyword(s):  
Seed Production ◽  
Lolium Perenne ◽  
Lolium Multiflorum ◽  
Pollen Viability ◽  
Festuca Pratensis ◽  
Inflorescence Development ◽  
Tetraploid Hybrid ◽  
Pollen Release ◽  
Sufficient Variation ◽  
Reproductive Characters

SUMMARYThe reproductive development and seed production characters of a Lolium multiflorum × Festuca pratensis tetraploid hybrid and a Lolium perenne × Festuca pratensis tetraploid hybrid were compared with those of their tetraploid parental cultivars. Experiments were carried out under glasshouse and natural conditions; single plants were studied as only small quantities of seed were available from the breeder. The lowtemperature/short-day requirements for inflorescence induction of the two hybrids were in between those of the corresponding parental species. The variance of the date at which vegetative primordia changed to the reproductive condition was greater in the hybrids than in the parental cultivars, but the variance of the dates of inflorescence emergence were similar for the hybrids and parental cultivars. Inflorescences ranged from the Lolium type with only sessile spikelets to the Festuca type with primary branches. Inner glumes, which are absent in the Lolium parents but present in Festuca pratensis, were found in the hybrids, though not in all spikelets. In the Lolium perenne × Festuca pratensis hybrid pollen release, potential pollen viability and floret fertility were low, but the Lolium multiflorum × Festuca pratensis hybrid produced large amounts of pollen with a higher potential viability and had floret fertilities similar to those of its two parental cultivars. There was sufficient variation in reproductive characters for further selection, particularly in the Lolium perenne × Festuca pratensis hybrid.

scholarly journals Comparison of agronomic characters of Festulolium, Festuca pratensis Huds. and Lolium multiflorum Lam. genotypes under high elevation conditions in Turkey

1970 ◽  
Vol 37 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Ilknur Akgun ◽  
Metin Tosun ◽  
Suleyman Sengul
Keyword(s):  
Seed Yield ◽  
Crude Protein ◽  
Dry Matter ◽  
Lolium Multiflorum ◽  
High Elevation ◽  
Ash Content ◽  
Festuca Pratensis ◽  
Higher Plant ◽  
Green Matter ◽  
Significant Difference

Prior {Lolium perenne × Festuca pratensis) and Elmet (Lolium multiflorum × Festuca pratensis) cultivars were compared with Festuca pratensis Huds. and Lolium multiflorum Lam. genotypes for some agronomical characteristics (green and dry matter yields, crude protein, seed yield, crude ash content) under Erzurum ecological conditions. Analysis of variance and mean separation were performed using the SPSS 11.0 computer program. There was a significant difference among genotypes in every character tested except for green and dry matter yield and crude ash content. Hybrid genotypes had higher plant height, dry and green matter yield, seed yield per plant and crude protein yield except 1000-seed weight. Elmet performed better than Prior except for seed yield per plant.   Key words: Festulolium, Lolium, Festuca, Yield, Crude protein, Crude ash doi:10.3329/bjb.v37i1.1556 Bangladesh J. Bot. 37(1): 1-6, 2008 (June)

Sign in / Sign up

Export Citation Format

Share Document