Crop Science Grow Your Career with CSSA
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Published in Crop Sci 8:740-743 (1968)
© 1968 Crop Science Society of America
677 S. Segoe Rd., Madison, WI 53711 USA
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Urich, M. A.
Right arrow Articles by Heyne, E. G.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Urich, M. A.
Right arrow Articles by Heyne, E. G.
Agricola
Right arrow Articles by Urich, M. A.
Right arrow Articles by Heyne, E. G.

Genetic Instability of Ottawa Wheat (Triticum aestivum L.)1

Max A. Urich and E. G. Heyne2

Spontaneously occurring off-type plants susceptible to leaf rust race 9 were found at a high rate (2.61 per 1,000 seedlings tested) in the progeny of self-pollinated (bagged) spikes of ‘Ottawa’ wheat. They appeared to originate from three different events in a normal, disomic Ottawa population: (1) mutation of the gene for leaf rust race 9 resistance, (2) breakage and loss of a terminal portion of chromosome 6B, which included the gene for resistance, and (3) nonpairing of the two 6B homologues, which resulted in mono-6B and mono-6B telo-6BS aneuploids. A relatively high rate of 6B aneuploids occurred after one generation of self-pollination (1.58 per 1,000 seedlings) and after two generations of self-pollination (2.97 per 1,000 seedlings).

Spontaneously occurring white-glumed spikes ere found at the rate of 1.8 and 2.4 per 10,000 spikes in foundation and registered Ottawa, respectively. Those off-types had either a ditelo or di-iso constitution, indicating loss of an arm of chromosome lB. They probably originated from nonpairing of an 1B bivalent and subsequent misdivision and recombination of an 1B univalent.

Nonhomology did not appear to cause nonpairing which was not random but affected chromosomes 1B and 6B more frequently than other chromosomes. This study suggests that Ottawa has some type of genetic malfunction that prevents chromosomes 1B and 6B from pairing in all meiotic cells.

Key Words: Aneuploid • Chromosome • Genetic Variability • Leaf Rust • Meiosis

1 Contribution No. 1038, Department of Agronomy and Kansas Agricultural Experiment Station, Kansas State University, Manhattan, in cooperation with the Crops Research Division, Agricultural Research Service, U. S. Department of Agriculture. Part of a dissertation submitted by the senior author to Kansas State University in partial fulfillment of the requirements for the Ph.D. degree.

2 Research Assistant, Kansas State University (now Research Agronomist, W. R. Grace and Co., Hutchinson, Kansas), and Professor of Agronomy, Manhattan 66502, respectively.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
The SCI Journals Agronomy Journal Vadose Zone Journal
Journal of Natural Resources
and Life Sciences Education		 Soil Science Society of America Journal
Journal of Plant Registrations Journal of
Environmental Quality		 The Plant Genome
Copyright © 1968 by the Crop Science Society of America.