Gamete composition and chromosome variation in pollen-derived plants from octoploid triticale x common wheat hybrids

1993 ◽  
Vol 85-85 (6-7) ◽  
pp. 681-687 ◽  
Author(s):  
Wang Yibing ◽  
Hu Han
Keyword(s):  
Common Wheat ◽  
Chromosome Variation ◽  
Wheat Hybrids ◽  
Octoploid Triticale

scholarly journals Chromosome Stability of Synthetic-Natural Wheat Hybrids

2021 ◽  
Vol 12 ◽  
Author(s):  
Laibin Zhao ◽  
Die Xie ◽  
Chaolan Fan ◽  
Shujie Zhang ◽  
Lei Huang ◽  
...  
Keyword(s):  
Common Wheat ◽  
De Novo ◽  
Recombinant Inbred Lines ◽  
Chromosome Instability ◽  
Wheat Variety ◽  
Chromosome Variation ◽  
Synthetic Wheat ◽  
Species Evolution ◽  
Wheat Hybrids

Primary allopolyploids are not only ideal materials to study species evolution, but also important bridges in incorporating genetic diversity of wild species into crops. Primary allopolyploids typically exhibit chromosome instability that a disadvantage trait in crop breeding. Newly synthesized hexaploid wheat has been widely used in wheat genetics and breeding studies. To better understand the cytological and genetic basis of chromosome instability, this study investigated the chromosomes of a large number of seeds derived from the synthetic wheat SHW-L1 and its hybrids with natural wheat. SHW-L1 exhibited persistent chromosome instability since we observed a high frequent chromosome variation de novo generated from euploid SHW-L1 plants at the 14th generation of selfing (F14). High frequent chromosome variations were also observed in the F2 hybrids and most of the analyzed recombinant inbred lines (RILs) at F14, derived from the cross of SHW-L1 with common wheat variety Chuanmai 32. Chromosome instability was associated with frequent univalency during meiotic metaphase I. The experiment on reciprocal crosses between SHW-L1 and Chuanmai 32 indicated that cytoplasm has not obvious effects on chromosome instability. An analysis on 48 F14 RILs revealed chromosome variation frequency was not associated with the Ph1 alleles from either SHW-L1 or Chuanmai 32, rejecting the hypothesis that chromosome instability was due to the Ph1 role of synthetic wheat. In the analyzed RILs, chromosome instability influences the phenotype uniformity, showing as obvious trait differences among plants within a RIL. However, the analyzed commercial varieties only containing ∼12.5% genomic components of synthetic wheat were chromosomally stable, indicating that chromosome instability caused by synthetic wheat can be effectively overcome by increasing the genetic background of common wheat.

CHROMOSOME CONDITIONS IN THE SECOND AND THIRD GENERATIONS OF PENTAPLOID WHEAT HYBRIDS

1930 ◽  
Vol 2 (2) ◽  
pp. 162-170 ◽  
Author(s):  
J. A. Jenkins ◽  
W. P. Thompson
Keyword(s):  
Common Wheat ◽  
Germ Cells ◽  
Chromosome Numbers ◽  
Wheat Hybrids

The numbers and mating capabilities of the chromosomes were determined in a good many F2 plants and their offspring in two crosses between common (42-chromosome) wheat and emmer (28-chromosome) types. In general the results confirmed those of Kihara and supported his conclusions. Chromosome numbers were much nearer those of the parental types than was to be expected if all germ cells were capable of functioning and all zygotes of developing. A large number of expected chromosome types did not appear at all. A high percentage of F2 had only 14 bivalent chromosomes and zero to seven univalents. These tended to revert rapidly to the 14-bivalent condition of emmers. F3 in this group did not have more than 14 bivalents nor more univalents than their F2 parents. A chromosome formula for all of the group of F2 with more than 14 bivalents may be written (14+x) bivalents +(7−x) univalents. Thesetended to revert to the 21-bivalent condition of common wheat. F3 in this group did not have fewer bivalents nor more univalents than their F2 parents. Occasional plants were exceptions to these rules.

Effect of different doses of group-2 chromosomes on homoeologous pairing in intergeneric wheat hybrids

1986 ◽  
Vol 28 (2) ◽  
pp. 240-246 ◽  
Author(s):  
C. Ceoloni ◽  
I. Strauss ◽  
M. Feldman
Keyword(s):  
Common Wheat ◽  
Chinese Spring ◽  
Intergeneric Hybrid ◽  
Homoeologous Pairing ◽  
Aegilops Variabilis ◽  
Group 2 ◽  
Wheat Hybrids ◽  
A Minor ◽  
Homoeologous Chromosomes ◽  
Different Doses

While an extra dose of chromosome 2A of common wheat, previously reported to carry a pairing promoter on its short arm, did not increase pairing between homoeologous chromosomes in F1 hybrids between common wheat cv. Chinese Spring (CS) and Aegilops variabilis, two doses of chromosome 2D or 2B caused a significant increase in homoeologous pairing. Evidently, chromosomes 2D and 2B carry a pairing promoter(s). Studies of F1 hybrids between aneuploids of CS, either deficient for chromosome 2D or having it in an extra dose, and Ae. variabilis, Ae. longissima, and Secale cereale supported the finding that this chromosome carries a pairing promoter. Using ditelosomic lines, the promoter was found to be located on the short arm of 2D (2DS). It was deduced that the promoter of 2B is also located on the homoeologous short arm, i.e., on 2BS. Evidence was obtained that the long arm of 2D may carry a suppressor(s) of pairing. Thus, the short arm of 2A, 2D, and 2B carries a pairing promoter(s), while the long arm of 2D and possibly of 2A and 2B carry a minor suppressor(s). The promoters are more potent than the suppressors and the overall effect of group-2 chromosomes is pairing promotion.Key words: wheat, homoeologous pairing, pairing promoter, pairing suppressor, intergeneric hybrid, meiosis.

The effect of different Agropyron elongatum chromosomes on pairing in Agropyron – common wheat hybrids

Genome ◽  
1988 ◽  
Vol 30 (6) ◽  
pp. 978-983 ◽  
Author(s):  
A. Charpentier ◽  
M. Feldman ◽  
Y. Cauderon
Keyword(s):  
Common Wheat ◽  
Chromosome Pairing ◽  
Chinese Spring ◽  
Chromosomal Location ◽  
Wheat Cultivar ◽  
Agropyron Elongatum ◽  
The Common ◽  
Disomic Addition Lines ◽  
Wheat Hybrids ◽  
Tetraploid Cytotypes

Chromosome pairing at first meiotic metaphase was studied in hybrids between the common wheat cultivar Chinese Spring (CS) and an induced autotetraploid line derived from diploid Agropyron elongatum. The latter was found to carry genes for homoeologous pairing. To determine the chromosomal location of these and other genes that control pairing, disomic addition lines of A. elongatum in the cv. Chinese Spring were crossed with tetraploid cytotypes of A. elongatum, and pairing was then compared in the resulting hybrids and in hybrids between cv. Chinese Spring and tetraploid A. elongatum. The elongatum chromosomes were classified into those that suppress (6E), promote (5E, 3E, and possibly 1E), or have no effect on pairing (4E). The effect of chromosomes 2E and 7E was not studied. Chromosomes 5E and 3E differed in their effect on the degree and pattern of chromosome pairing. These findings are compared with the available data on the control of pairing in A. elongatum and in other Triticinae species.Key words: chromosome pairing, pairing promoter, Triticum, common wheat, Agropyron.

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