Hostname: page-component-cd9895bd7-fscjk Total loading time: 0 Render date: 2024-12-25T06:31:09.683Z Has data issue: false hasContentIssue false

Meiotic irregularities in hexaploid oats: II. A cytological survey of the variety Picton

Published online by Cambridge University Press:  27 March 2009

H. W. Howard
Affiliation:
Plant Breeding Institute, School of Agriculture, University of Cambridge

Summary

1. Picton, a winter-hardy variety of oats selected from the cross Argentine x Grey Winter, contains plants which have irregular meiotic divisions.

2. Two types of irregularities were observed: first, univalents and the products of their division; and secondly, bridges and fragments at both first and second divisions.

3. Plants selected for a low frequency of irregularities produced offspring with a low frequency of irregular divisions. On the other hand, plants with regular divisions were also obtained from parents which had a high frequency of irregularities.

4. It is pointed out that the genetical effects of bridge chromatid formation and breakage is the production of gametes deficient for chromosome segments. There is some evidence that chlorotic plants are produced when such deficiencies become homozygous.

5. It is suggested that the meiotic irregularities produce a certain degree of heterozygosity which may make Picton more adaptable, and at the same time give it a certain degree of hybrid vigour.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1948

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Darlington, C. D. (1937). Recent Advances in Cytology, 2nd ed. London: J. and A. Churchill, Ltd.Google Scholar
Darlington, C. D. & La Cour, L. F. (1942). The Handling of Chromosomes. London: George Allen and Unwin, Ltd.Google Scholar
Gustaffson, A. (1946). Hereditas, Lund, 33, 573.Google Scholar
Hollingshead, L. (1932). Cytologia, Tokyo, 3, 119.CrossRefGoogle Scholar
Howard, H. W. (1947 a). J. Agric. Sci. 37, 139.Google Scholar
Howard, H. W. (1947 b). J. Minist. Agric. 54, 298.Google Scholar
Hunter, H. (1935). J. Agric. Sci., 25, 419.Google Scholar
Jones, D. F. (1945). Genetics, 30, 527.Google Scholar
Love, R. M. (1939). Proc. 1th Int. Gen. Congress, J. Genet (1941), p. 197.Google Scholar
Love, R. M. (1941). Canad. J. Res. 19, 351.CrossRefGoogle Scholar
McClintock, B. (1938). Bull. Mo. Agric. Exp. Std. 290.Google Scholar
Philp, J. (1935). J. Genet. 30, 267.Google Scholar
Powers, L. (1932). J. Agric. Res. 44, 797.Google Scholar
Richardson, M. M. (1936). J. Genet. 32, 411.CrossRefGoogle Scholar
Sementuk, W. (1947). Sci. Agric. 27, 7.Google Scholar
Thompson, W. P. & Robertson, H. T. (1930). Cytologia, Tokyo, 1, 252.Google Scholar