Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-25T16:39:21.040Z Has data issue: false hasContentIssue false
  • English
  • Français

The position of a locus on chromosome 5B of Triticum aestivum affecting homoeologous meiotic pairing

Published online by Cambridge University Press:  14 April 2009

A. M. Wall ,
Ralph Riley  and
M. D. Gale
A. M. Wall
Affiliation:
Plant Breeding Institute, Cambridge
Ralph Riley
Affiliation:
Plant Breeding Institute, Cambridge
M. D. Gale
Affiliation:
Plant Breeding Institute, Cambridge
Rights & Permissions [Opens in a new window]

Summary

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

An investigation was made of the chromosomal position of the mutant locus, in Mutant 10/13 of Triticum aestivum (2n = 6x = 42), affecting homoeologous chromosome pairing at meiosis. In hybrids between Mutant 10/13 and rye (Secale cereale 2n = 14), homoeologous chromosomes frequently pair at meiosis although normally, in wheat-rye hybrids, this happens infrequently.

The association of the mutant condition with chromosome 5B was determined by (i) the absence of segregation in hybrids obtained when Mutant 10/13 monosomic 5B was pollinated by rye; (ii) the occurrence of trisomie segregation for pairing behaviour in 28-chromosome wheat-rye hybrids, obtained from SB trisomie wheat parents with two 5B chromosome from a non-mutant and one from a mutant parent; (iii) the absence of segregation for pairing behaviour in the 29-chromosome wheat-rye hybrids obtained from the same trisomie wheat parents.

The alternative pairing behaviours segregated independently of the centromere when wheat plants that were simultaneously heteromorphic, 5BL telocentric/5B complete, and heterozygous for the Mutant 10/13 state, were pollinated by rye. The alternative chromosome-pairing patterns segregated to give a ratio not different from 1:1, so that the association of homoeologous pairing with Mutant 10/13 probably derived from the occurrence of mutation at a single locus on 5BL. In the disomic heteromorphic state, 5BL was 91 map units in length.

Trisomie wheats with two complete 5B chromosomes and one 5BL telocentric, that were also heterozygous for the Mutant 10/13 condition, were pollinated by rye. Among the resulting 28-chromosome hybrids there was a 2:1 segregation of hybrids with low pairing: high (homoeologous) pairing and also of hybrids with complete 5B: telocentric 5BL. However, there was no evidence of linkage in this trisomie segregation. All the 29-chromosome hybrids from this cross had low pairing and it could be concluded that the single mutant allele, in Mutant 10/13, was recessive. In the trisomie condition, relative to a simplex situation, 5BL was 33·05 map units in length.

The critical locus on 5BL was designated Pairing homoeologous. The normal dominant allele was symbolized Ph and the recessive allele, in Mutant 10/13, ph.

The prevention of homoeologous pairing by the activity of a single locus makes the evolution of the regular meiotic behaviour of T. aestivum more readily comprehensible.

Type
Research Article
Information
Genetics Research , Volume 18 , Issue 3 , December 1971 , pp. 329 - 339
Copyright
Copyright © Cambridge University Press 1971

References

REFERENCES

Law, C. N. (1966). The location of genetic factors affecting a quantitative character in wheat. Genetics 53, 487–498.CrossRefGoogle ScholarPubMed
Okamoto, M. (1966). Studies of the 5B effects in wheat. Proceedings 2nd International Wheat Genetics Symposium. Hereditas, suppl. 2, pp. 409–417.Google Scholar
Riley, R. (1960). The diploidisation of polyploid wheat. Heredity 15, 407–429.CrossRefGoogle Scholar
Riley, R. & Chapman, V. (1958). Genetic control of the cytologically diploid behaviour of hexaploid wheat. Nature 182, 713–715.CrossRefGoogle Scholar
Riley, R. & Chapman, V. (1967). Effect of SBs in suppressing the expression of altered dosage of 5BL on meiotic pairing in Triticum aestivum. Nature 216, 60–c62.CrossRefGoogle Scholar
Riley, R., Chapman, V. & Belifield, A. M. (1966). Induced mutation affecting the control of meiotic chromosome pairing in Triticum aestivum. Nature 211, 368–369.CrossRefGoogle Scholar
Riley, R., Kimber, G. & Chapman, V. (1961). The origin of genetic control of diploid-like behaviour of polyploid wheat. Journal of Heredity 52, 22–25.CrossRefGoogle Scholar
Riley, R. & Law, C. N. (1965). Genetic variation in chromosome pairing. Advances in Genetics 13, 57–114.CrossRefGoogle Scholar
Sears, E. R. (1966). Chromosome mapping with the aid of telocentrics. Proceedings 2nd International Wheat Genetics Symposium. Hereditas, suppl. 2, pp. 370–380.Google Scholar
Wall, A. M., Riley, R. & Chapman, V. (1971). Wheat mutants permitting homoeologous meiotic chromosome pairing. Genetical Research 18, 311–28.CrossRefGoogle Scholar