Chromosome Studies in Cyperaceae

II. Scirpus lacustris L

Abstract

In the present work, three types of Scirpus lacustris L., i.e. normal self-colored typicus and two variegated forms pictus and zebrinus have been studied.
The chromosome numbers of these three forms are determined as follows: (1) normal form typiczts, n=19, 2n=38, ineluding one large chromosome in the polten mother cells and two in the somatic cells; (2) variegated form pictus, 2n=40, ineluding one large chromosome in the somatic cells; (3) variegated form zebrinus, 2n=42, ineluding no such large element as found in the other two forms.
Assuming that the two variegated forms were derived from the normal green form, the relation between the chromosome numbers of the three forms, especially the existence of the so-called “Sammelchromosom”, has been discussed from the point of segmentation, and the correlation between the chromosomal conditions and variegation has also been considered.
The writer wishes to record his cordial thanks to Dr. Honda for his kindness in verifying the plants used in the present work. Thanks are also due to Dr. Sinotô under whose direction the work has been carried out.