Nucleolus-Chromosome Relationship in Paris verticillata MB., with Special Reference to the Presence and Absence of a Satellite

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A diploid karyotype heterozygous for three chromosome pairs is newly described (Karyotype 2n-V). Nucleolar conditions were investigated in five diploid and in two triploid karyotypes. D-type chromosomes are nucleolar, developing a nucleolus interstitially at the region of satellite stalk in the case provided with a satellite (chromosome D and D-₁) and terminally at the naked distal end of the short arm in chromosome D-which is deprived of its whole satellite. In accord with the number of nucleolar chromosomes contained the maximum number of nucleoli in the root-tip nuclei is two in diploids and three in triploids irrespective of the karyotypic alterations.
The writer wishes to acknowledge his sincere gratitude to Professor H. Matsuura for his valuable suggestion and criticism and for his kindness in taking the photomicrographs reproduced in the present paper. The expence of carrying out the present study was partly defrayed out of a grant from the Science Research Fund of the Department of Education to which his thanks are also due.