Studies on the Genome Constitution of Triticum timopheevi Zhuk. II. The T. timopheevi Complex and Its Origin

Evolution ◽  
1966 ◽  
Vol 20 (2) ◽  
pp. 150 ◽  
Author(s):  
E. B. Wagenaar
Keyword(s):  
Genome Constitution ◽  
Triticum Timopheevi

STUDIES ON THE GENOME CONSTITUTION OF TRITICUM TIMOPHEEVI ZHUK: III. SEGREGATION OF MEIOTIC CHROMOSOME BEHAVIOUR IN BACKCROSS GENERATIONS

1970 ◽  
Vol 12 (2) ◽  
pp. 347-355 ◽  
Author(s):  
E. B. Wagenaar
Keyword(s):  
Cytogenetic Analysis ◽  
Triticum Turgidum ◽  
Meiotic Chromosome ◽  
Successive Generation ◽  
Meiotic Behaviour ◽  
Chromosome Behaviour ◽  
Genome Constitution ◽  
Triticum Timopheevi ◽  
Meiotic Irregularities

Cytogenetic analysis of three backcross generations of the hybrid Triticum turgidum × T. timopheevi (2n = 28) showed segregation of meiotic behaviour in each successive generation. The segregation was continuous and was possibly under control of polygenes. These results indicate that the meiotic irregularities commonly found in F1 hybrids between T. turgidum and T. timopheevi are primarly genetically induced.

scholarly journals Molecular variation in chloroplast DNA regions in ancestral species of wheat.

Genetics ◽  
1994 ◽  
Vol 137 (3) ◽  
pp. 883-889 ◽  
Author(s):  
N T Miyashita ◽  
N Mori ◽  
K Tsunewaki
Keyword(s):  
Chloroplast Dna ◽  
Restriction Enzymes ◽  
Triticum Dicoccoides ◽  
The Other ◽  
Major Type ◽  
Aegilops Speltoides ◽  
Triticum Timopheevi ◽  
Restriction Sites ◽  
D Values ◽  
Chloroplast Dna Regions

Abstract Restriction map variation in two 5-6-kb chloroplast DNA regions of five diploid Aegilops species in the section Sitopsis and two wild tetraploid wheats, Triticum dicoccoides and Triticum araraticum, was investigated with a battery of four-cutter restriction enzymes. A single accession each of Triticum durum, Triticum timopheevi and Triticum aestivum was included as a reference. More than 250 restriction sites were scored, of which only seven sites were found polymorphic in Aegilops speltoides. No restriction site polymorphisms were detected in all of the other diploid and tetraploid species. In addition, six insertion/deletion polymorphisms were detected, but they were mostly unique or species-specific. Estimated nucleotide diversity was 0.0006 for A. speltoides, and 0.0000 for all the other investigated species. In A. speltoides, none of Tajima's D values was significant, indicating no clear deviation from the neutrality of molecular polymorphisms. Significant non-random association was detected for three combinations out of 10 possible pairs between polymorphic restriction sites in A. speltoides. Phylogenetic relationship among all the plastotypes (plastid genotype) suggested the diphyletic origin of T. dicoccoides and T. araraticum. A plastotype of one A. speltoides accession was identical to the major type of T. araraticum (T. timopheevi inclusively). Three of the plastotypes found in the Sitopsis species are very similar, but not identical, to that of T. dicoccoides, T. durum and T. aestivum.

CYTOLOGICAL STUDIES OF THE DEVELOPMENT OF METAPHASE I IN HYBRIDS BETWEEN TRITICUM TIMOPHEEVI ZHUK. AND T. DURUM DESF.

1961 ◽  
Vol 39 (1) ◽  
pp. 81-108 ◽  
Author(s):  
E. B. Wagenaar
Keyword(s):  
Late Stage ◽  
Developmental Stages ◽  
Progressive Increase ◽  
Cell Populations ◽  
Equatorial Plate ◽  
Triticum Timopheevi ◽  
Late Stages ◽  
I Cells ◽  
Metaphase I

In two hybrids between Triticum timopheevi Zhuk. and T. durum Desf., which have irregular meioses, metaphase I was subdivided into four developmental stages, early, medium, late, and very late. This subdivision was based on the presence in the anthers of other stages that occurred together with metaphase I. It was then discovered that in metaphase I cell populations there was a progressive increase of univalents from the early and medium stages to the very late stage. This phenomenon can be explained on the assumption that metaphase I is of shorter duration in the less irregular cells which pass into anaphase I earlier than the more irregular cells. As a consequence of this developmental phenomenon at metaphase I, the anaphase I and telophase I cells in the late anthers contained fewer lagging chromosomes than the anaphase I and telophase I cells in the very late anthers. Despite these numerical differences, the degrees of lagging were remarkably similar in both stages; approximately 70% of these univalents lagged at late and very late stages in both hybrids.During metaphase I many univalents of the irregular cells moved towards the equatorial plate, became oriented, and lagged at anaphase I and telophase I. It was found that the univalents of the least irregular cells accumulated somewhat faster at the plates than those of the more irregular cells.Considering the relationships between all of the available data, the hypothesis is advanced that when a certain number of univalents have accumulated at the equatorial plate a state of equilibrium is established and anaphase I is initiated. On the basis of this hypothesis an explanation of the trends observed at metaphase I is given.

scholarly journals Microsatellite markers for the Triticum timopheevi-derived leaf rust resistance gene Lr18 on wheat 5BL chromosome

2017 ◽  
Vol 67 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Ali Aliakbari Sadeghabad ◽  
Ali Dadkhodaie ◽  
Bahram Heidari ◽  
Hooman Razi ◽  
Reza Mostowfizadeh-Ghalamfarsa
Keyword(s):  
Microsatellite Markers ◽  
Leaf Rust ◽  
Resistance Gene ◽  
Rust Resistance ◽  
Leaf Rust Resistance ◽  
Rust Resistance Gene ◽  
Leaf Rust Resistance Gene ◽  
Triticum Timopheevi

Evidence on the origin of the G genome in wheat: cytology and fertility of a T. timopheevi-like mutant

1983 ◽  
Vol 25 (6) ◽  
pp. 651-661 ◽  
Author(s):  
U. Kushnir ◽  
G. M. Halloran
Keyword(s):  
Triticum Turgidum ◽  
Chromosome Rearrangement ◽  
Plant Morphology ◽  
Triticum Timopheevi ◽  
Somatic Mutant ◽  
Normal Pairing

A spontaneous somatic mutant with Triticum timopheevi Zhuk. plant morphology was found in late tillers of a Triticum turgidum L. var. dicoccoides (Bowden) plant. Hybrids of the timopheevi-like mutant with T. turgidum L. var. dicocooides (Bowden), T. timopheevi Zhuk., and T. araraticum Jakubz. exhibited irregular pairing at meiosis and sterility, almost normal pairing and fertility, and relatively high pairing and sterility, respectively. This evidence plus that of karyotype changes in the somatic mutant indicated that it was differentiated from T. turgidum dicoccoides through chromosome interchanges. This mutation, believed to arise through chromosome rearrangement, is discussed in relation to the origin of the G genome of T. timopheevi.

Genomic constitution and phylogenetic position of several New Zealand Triticeae species revealed by two single copy nuclear genes

2011 ◽  
Vol 59 (1) ◽  
pp. 1 ◽  
Author(s):  
Aimee G. Oliver ◽  
Kara Harnish ◽  
Genlou Sun
Keyword(s):  
New Zealand ◽  
North American ◽  
Diploid Species ◽  
Single Copy ◽  
Nuclear Genes ◽  
Phylogenetic Position ◽  
Genome Constitution ◽  
Elymus Species ◽  
New Zealand Flora ◽  
Hordeum Species

Three genera of Triticeae, Elymus, Stenostachys and Australopyrum, are described in the New Zealand flora. Cytological analyses suggested that five basic genomes (St, H, Y, P and W) donated by different diploid species in different combinations exist in the genera Elymus and Stenostachys, whereas Australopyrum species contain the W genome only. Morphological and cytogenetic data suggested that the genome constitution for both E. apricus and E. multiflorus is StYW. Chloroplast DNA and ITS data supported the genome constitution of these Elymus species, but the HW genome constitution was assigned to the Stenostachys species. In this study, sequences of two single copy nuclear genes, RPB2 and DMC1, were used to confirm or refute the genome constitutions of the two Stenostachys species and the two Elymus species from New Zealand, and to analyse their phylogenetic relationships with other Elymus species. Our RPB2 and DMC1 data confirmed that the genome constitution of hexaploid E. apricus is StWY, and tetraploid S. gracilis is HW. The presence of the StW genome in hexaploid E. multiflorus, and the W genome in tetraploid S. laevis is also confirmed. No obvious St genome differentiation between New Zealand and non-New Zealand species is observed. The H genomes in the S. gracilis and S. laevis are closely related to the H genome from North American species, indicating that the H genomes in these two New Zealand species might originate from North American Hordeum species.

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