Self-incompatibility in Beta vulgaris L.
I. Four gametophytic, complementary S-loci in sugar beet
Article first published online: 12 FEB 2009
© 1977 Mendelian Society of Lund
Volume 85, Issue 2, pages 227–248, June 1977
How to Cite
LARSEN, K. (1977), Self-incompatibility in Beta vulgaris L. Hereditas, 85: 227–248. doi: 10.1111/j.1601-5223.1977.tb00971.x
- Issue published online: 12 FEB 2009
- Article first published online: 12 FEB 2009
As early as 1942, a rather complex self-incompatibility mechanism in sugar beet was discovered by Owen, but his two-locus interpretation appeared to be insufficient.
Observations presented in this paper, including F1, F2, F3, F4 and F2 × F3 families, all favoured a model involving four gametophytic S-loci with complementary interaction. It is pointed out that more than the four S-loci so far identified may exist in a hidden state of homozygosity.
This complementary S-mechanism is in principle identical with the two-locus system in the monocotyledonous family Gramineae. Caryophyllales, the taxonomic order of Beta, is generally considered a rather close derivative of those early dicotyledones that also gave rise to the monocotyledones. Hence it is suggested that these early dicots possessed several co-operating S-loci, and that multi-S-locus systems may still exist in many species, even among those hitherto considered to carry only one S-locus. Apparently, many researchers did not seriously realize the possibility of multi-locus systems, and therefore worked with too limited materials, methods and hypotheses.