A Comparative Analysis of Chromosome Pairing at Metaphase I in Interspecific Hybrids between Durum Wheat (Triticum turgidum L.) and the Most Widespread Aegilops Species

2010 ◽  
Vol 129 (1-3) ◽  
pp. 124-132 ◽  
Author(s):  
M. Cifuentes ◽  
V. Garcia-Agüero ◽  
E. Benavente
Keyword(s):  
Comparative Analysis ◽  
Durum Wheat ◽  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
Triticum Turgidum ◽  
Metaphase I

Pairing affinities of the B- and G-genome chromosomes of polyploid wheats with those of Aegilops speltoides

Genome ◽  
2000 ◽  
Vol 43 (5) ◽  
pp. 814-819 ◽  
Author(s):  
S Rodríguez ◽  
B Maestra ◽  
E Perera ◽  
M Díez ◽  
T Naranjo
Keyword(s):  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
Triticum Turgidum ◽  
Aegilops Speltoides ◽  
Meiotic Pairing ◽  
Triticum Timopheevii ◽  
C Banding ◽  
Tetraploid Wheats ◽  
B Genome ◽  
Metaphase I

Chromosome pairing at metaphase I was studied in different interspecific hybrids involving Aegilops speltoides (SS) and polyploid wheats Triticum timopheevii (AtAtGG), T. turgidum (AABB), and T. aestivum (AABBDD) to study the relationships between the S, G, and B genomes. Individual chromosomes and their arms were identified by means of C-banding. Pairing between chromosomes of the G and S genomes in T. timopheevii × Ae. speltoides (AtGS) hybrids reached a frequency much higher than pairing between chromosomes of the B and S genomes in T. turgidum × Ae. speltoides (ABS) hybrids and T. aestivum × Ae. speltoides (ABDS) hybrids, and pairing between B- and G-genome chromosomes in T. turgidum × T. timopheevii (AAtBG) hybrids or T. aestivum × T. timopheevii (AAtBGD) hybrids. These results support a higher degree of closeness of the G and S genomes to each other than to the B genome. Such relationships are consistent with independent origins of tetraploid wheats T. turgidum and T. timopheevii and with a more recent formation of the timopheevi lineage.Key words: Triticum turgidum, Triticum timopheevii, Aegilops speltoides, meiotic pairing, evolution, C-banding.

CHROMOSOME PAIRING IN TWO INTERSPECIFIC HYBRIDS OF TRIFOLIUM

1970 ◽  
Vol 12 (4) ◽  
pp. 790-794 ◽  
Author(s):  
Chi-Chang Chen ◽  
Pryce B. Gibson
Keyword(s):  
Phylogenetic Relationship ◽  
Chromosome Pairing ◽  
Trifolium Repens ◽  
Interspecific Hybrids ◽  
Triploid Hybrid ◽  
Close Phylogenetic Relationship ◽  
Metaphase I

Both Trifolium repens (2n = 32) and T. nigrescens (2n = 16) formed bivalents during meiosis. However, their triploid hybrid showed an average of 4.27 trivalents per microsporocyte at metaphase I. The frequency of trivalents in the hybrid between T. nigrescens and autotetraploid T. occidentale (2n = 32) was 5.69. The data are interpreted to indicate: (1) a possible autotetraploid origin of T. repens; and (2) a close phylogenetic relationship among T. repens, T. nigrescens and T. occidentale.

Genome constitution of the Australian hexaploid grass Elymus scabrus (Poaceae: Triticeae)

Genome ◽  
1993 ◽  
Vol 36 (1) ◽  
pp. 147-151 ◽  
Author(s):  
J. Torabinejad ◽  
R. J. Mueller
Keyword(s):  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
Intergeneric Hybrid ◽  
Meiotic Pairing ◽  
Genome Constitution ◽  
Psathyrostachys Juncea ◽  
Hybrid Plants ◽  
Thinopyrum Bessarabicum ◽  
Mother Cells ◽  
Metaphase I

Eight intergeneric hybrid plants were obtained between Elymus scabrus (2n = 6x = 42, SSYY??) and Australopyrum pectinatum ssp. retrofractum (2n = 2x = 14, WW). The hybrids were vegetatively vigorous but reproductively sterile. Examination of pollen mother cells at metaphase I revealed an average of 16.63 I, 5.29 II, 0.19 III, and 0.05 IV per cell for the eight hybrids. The average chiasma frequency of 6.77 per cell in the above hybrids strongly supports the presence of a W genome from A. pectinatum ssp. retrofractum in E. scabrus. Meiotic pairing data of some other interspecific hybrids suggest the existence of the SY genomes in E. scabrus. Therefore, the genome constitution of E. scabrus should be written as SSYYWW. Two other hybrid plants resulted from Elymus yezoensis (2n = 4x = 28, SSYY) crosses with A. pectinatum ssp. pectinatum (2n = 2x = 14, WW). Both were weak and sterile. An average of 0.45 bivalents per cell were observed at metaphase I. This clearly indicates a lack of pairing between W genome of Australopyrum and S or Y genomes of E. yezoensis. In addition, six hybrid plants of E. scabrus with Psathyrostachys juncea (2n = 2x = 14, NN) and one with Thinopyrum bessarabicum (2n = 2x = 14, JJ) were also obtained. The average bivalents per cell formed in both combinations were 2.84 and 0.70, respectively. The results of the latter two combinations showed that there is no N or J genome in E. scabrus.Key words: wide hybridization, chromosome pairing, genome analysis, Australopyrum, Elymus.

CHROMOSOME PAIRING IN HEXAPLOID HYBRIDS FROM BROMUS ERECTUS (2n = 28) × B. INERMIS (2n = 56)

1973 ◽  
Vol 15 (3) ◽  
pp. 427-436 ◽  
Author(s):  
K. C. Armstrong
Keyword(s):  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
Meiotic Chromosome ◽  
The Other ◽  
Meiotic Chromosome Pairing ◽  
Hybrid Plants ◽  
Quadrivalent Frequency ◽  
Bromus Erectus ◽  
Metaphase I

Meiotic chromosome pairing was studied at metaphase I of B. erectus (2n = 28), B. inermis (2n = 56) and interspecific hybrids from B. erectus × B. inermis (2n = 42). The B. erectus material averaged 2.08 IV + 0.11 III + 9.51 II + 0.35 I and B. inermis 0.05 VIII + 0.06 VI + 0.02 V + 2.25 IV + 0.11 III + 22.95 II + 0.25 I. The hybrid plants (2n = 42) averaged 0.18 VI + 1.90 IV + 0.19 III + 16.10 II + 0.39 I and one hybrid with 2n = 41 averaged 0.08 VI + 0.02 V + 0.95 IV + 0.50 III + 17.42 II + 0.72 I. Karyotype evidence supported the conclusion that B. erectus was an autotetraploid. The karyotype contains four large satellites and four subterminal chromosomes but the other four groups of four are median, with one group possibly a submedian. Since chromosome pairing in the hybrids was complete and the quadrivalent frequency in the parents and hybrids was similar, it was concluded that the genomic formula of B. erectus, B. inermis, and the hybrid was AAAA, AAAABBBB, and AAAABB, respectively.

Alien chromosome addition in durum wheat. II. Advanced progeny

Genome ◽  
1988 ◽  
Vol 30 (3) ◽  
pp. 303-306 ◽  
Author(s):  
J. Schulz-Schaeffer ◽  
S. E. Haller
Keyword(s):  
Durum Wheat ◽  
Chromosome Pairing ◽  
Triticum Turgidum ◽  
Alien Chromosome ◽  
Group Of Seven ◽  
Chromosome Addition ◽  
Agropyron Intermedium ◽  
Alien Chromosome Addition ◽  
Wheat Parent ◽  
Intermedium Chromosome

Alien chromosome addition in durum wheat was accomplished by backcrossing and selling an amphiploid derivative F10 strain of Triticum turgidum L. var. durum × Agropyron intermedium (Host) Beauv. The number of chromosome pairs increased from an average of 10.4 bivalents in the B1F1 to 18.5 bivalents in the B1F7 generation. Stabilization of chromosome pairing was improved as expressed in the range of bivalents (0–21 in the B1F1 and 16–21 in the B1F7 generation). Backcrossing to the durum wheat parent resulted in the elimination of some Agropyron chromosomes and in others becoming pairs. A hexaploid Agrotriticum with the constitution AABBII resulted. The I genome consists of a group of seven chromosome pairs from A. intermedium.Key words: Agrotriticum, Agropyron intermedium, chromosome pairing.

The C-band pattern of a Ph− mutant of durum wheat

1984 ◽  
Vol 26 (3) ◽  
pp. 360-363 ◽  
Author(s):  
J. Dvořák ◽  
Kuey-Chu Chen ◽  
B. Giorgi
Keyword(s):  
Durum Wheat ◽  
Chromosome Pairing ◽  
Tandem Duplication ◽  
Triticum Turgidum ◽  
Chromosome Region ◽  
Homologous Chromosomes ◽  
Sister Chromatids ◽  
Approximate Location ◽  
Parental Cultivar ◽  
Interband Region

A mutation of the Ph gene which normally suppresses heterogenetic chromosome pairing was obtained in cultivar 'Cappelli' of Triticum turgidum L. em Morris et Sears var. durum. The chromosomes of 'Cappelli,' the Ph− mutant, and another 'Cappelli' line suspected to have a duplication of part of arm 5Bq (5BL) were C-banded. Compared with arm 5Bq of the parental cultivar, the 5Bq arm of the Ph− mutant was shorter owing to a deletion of one of two interband regions in the middle of the arm. In the line suspected to have a duplication, the 5Bq arm was longer than in 'Cappelli' and the interband region that was absent in Ph− was twice as long. An interchange between sister chromatids or homologous chromosomes is suggested to be responsible for the deletion and tandem duplication of the chromosome region. The C-band patterns are used to infer the approximate location of the Ph gene in the 5Bq arm.Key words: wheat, C-band, deletion, duplication, Triticum, 5B chromosome.

Development of Triticum turgidum subsp. durum – Aegilops longissima amphiploids with high iron and zinc content through unreduced gamete formation in F1 hybrids

Genome ◽  
2008 ◽  
Vol 51 (9) ◽  
pp. 757-766 ◽  
Author(s):  
Vijay K. Tiwari ◽  
Nidhi Rawat ◽  
Kumari Neelam ◽  
Gursharn S. Randhawa ◽  
Kuldeep Singh ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Chromosome Pairing ◽  
Triticum Turgidum ◽  
Zinc Content ◽  
F1 Hybrids ◽  
Unreduced Gamete ◽  
Wheat Cultivars ◽  
Aegilops Longissima ◽  
Gamete Formation ◽  
Iron And Zinc

Four different interspecific hybrids involving three different accessions of Aegilops longissima Schweinf. & Muschl. with high grain iron and zinc content and three Triticum turgidum L. subsp. durum (Desf.) Husn. cultivars with low micronutrient content were made for durum wheat biofortification and investigated for chromosome pairing, fertility, putative amphiploidy, and micronutrient content. The chromosome pairing in the 21-chromosome F1 hybrids (ABSl) consisted of 0–6 rod bivalents and occasionally 1 trivalent. All the F1 hybrids, however, unexpectedly showed partial but variable fertility. The detailed meiotic investigation indicated the simultaneous occurrence of two types of aberrant meiotic divisions, namely first-division restitution and single-division meiosis, leading to regular dyads and unreduced gamete formation and fertility. The F2 seeds, being putative amphiploids (AABBSlSl), had nearly double the chromosome number (40–42) and regular meiosis and fertility. The F1 hybrids were intermediate between the two parents for different morphological traits. The putative amphiploids with bold seed size had higher grain ash content and ash iron and zinc content than durum wheat cultivars, suggesting that Ae. longissima possesses a better genetic system(s) for uptake and seed sequestration of iron and zinc, which could be transferred to elite durum and bread wheat cultivars and exploited.

The chromosomal location of a gene (msg) affecting megasporogenesis in durum wheat

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 578-581 ◽  
Author(s):  
L. R. Joppa ◽  
N. D. Williams ◽  
S. S. Maan
Keyword(s):  
Durum Wheat ◽  
Key Words ◽  
Chromosomal Location ◽  
Triticum Turgidum ◽  
Wheat Line ◽  
Pollen Mother Cells ◽  
Chromosome Arm ◽  
Pollen Nucleus ◽  
Mother Cells ◽  
Metaphase I

An aneuploid durum wheat line (Triticum turgidum L. var. durum) having 13 chromosome pairs and 2 unpaired chromosomes at metaphase I of meiosis in pollen mother cells (i.e., monosomic for chromosomes 7A and 7D) was observed to produce some progeny plants with 2n = 40 chromosomes. These aneuploid (triploid) plants were usually weak and sterile. Triploid plants also occurred in the progeny of durum plants monosomic for chromosome 7A, or in progeny of plants that were mono-telodisomic or ditelomonotelosomic for chromosome 7Aq (13 II + 1 t II or 13 II + t II + t I) but not in the progeny of plants ditelomonotelosomic for chromosome 7Ap (13 II + t II + t 1). Therefore, there is a gene(s) on chromosome arm 7Ap that prevents the production of diploid (2n) egg cells in wheat. In the absence of 7Ap, a portion of the egg cells have 26 chromosomes, which when fertilized with a pollen nucleus with 14 chromosomes, produces progeny plants with 2n = 40 chromosomes. The data also indicated that chromosome arm 7Dp probably contains a second gene that is capable of preventing the production of triploid plants. Key words: Triticum turgidum L. var. durum, polyploidy, aneuploid, triploid, monosomic.

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