Chromosomal behavior of same rice varieties (Oriza sativa L.)

Abstract

The author studied the chromosomic behaviour of eighteen varieties of rice and observed the following: a) they all have a set of n=12 and 2n=24 chromosomes; b) the length of their chromosomes varies between 2.2 and 1.0 micra; c) the number of nucleoli varies between 1 and 2 in the meiosis, and from 2 to 4 during mitosis; d) due to the chromosomic sets presented by the varieties of rice studied, it is suggested that they must have their origin in a hybridization between a tetraploid of 5 as a basic number, and a related species of a small number of chromosomes.