Chromosome variations in interspecific hybrids between F. esculentum (2n=2x=16) and F. homotropicum (2n=2x=32)

Yingjie Wang¹, Rachael Scarth² and Clayton Campbell¹.

¹ Kade Research Ltd., Morden, Manitoba, Canada R6M 1E9 ² Department of Plant Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2

Yingjie Wang, Rachael Scarth and Clayton Campbell. 2001. Chromosome variations in interspecific hybrids between F. esculentum (2n=2x=16) and F. homotropicum (2n=2x=32). Eighth International Symposium on Buckwheat, Chunchon, Korea, Kangwon University Press. pp. 301-307.

Abstract: Interspecific hybrids between F. esculentum (2n=16) and tetraploid F. homotropicum (2n=32) were obtained through ovule rescue. The F₁ hybrids were found to be triploid (2n=24) and sterile. However, 2 out of 41 plants set one seed each and another 2 plants set several seeds after approximately 2 years growth maintained through cuttings. Fertility was also recovered by colchicine treatment which normally produces chromosome doubling. The resulting plants were found to be hexaploid (2n=48), diploid (2n=16) and anueplid (2n=less or more than 48). The progenies of the hexaploid plants had unstable chromosome numbers, that were either higher or lower than 48, indicating that the hexaploid plants possibly were alloautohexaploid. In the diploid plants, 8 chromosomes of the F₁ hybrids were eliminated. These diploid plants showed recombinant morphological characters fom both F. esculentum and F. homotropicum, suggesting that the plants might contain chromosomes or chromosome fragments from both parents. In addition, a plant with 17 chromosomes that could be a trisomic or an addition line was found in this study. This plant will be useful material for future genetic studies.

Key words: Buckwheat, F. esculentum, F. homotropicum, tissue culture, embryo rescue, chromosome elimination