Further reports of cytological and genetic investigations of Rumex acetosa L.

I. New chromosome and chromosome-fragments

Abstract

1. Six chromosomal formulas of the intersexual plants of Rumex acetosa L. were determined as follows,
Chromosome-number Chromosomal formula
15 13a+X+Y
15 11a+X+2Y+y
15 12a+X+Y+y
15+1f 12a+X+2Y+1f
15+4f 12a+X+2Y+4f
22 18a+2X+2Y
(f=fragment)
2. The y-chromosome which is sometimes discovered in the intersexual plants seems to be the chromosome formed as the result of fusion of the two bifurcate unequal arms of the Y-chromosome. This conclusion was drawn from various reasons, especially from the result of quantitative considerations.
3. The y-chromosome and the chromosome-fragments are considered to have a relation to or an influence on the expression of the sexual characters.