Abstract
The karyotypes of three forms of Oryza perennis i.e. barthii, balunga and a collection from Assam were investigated by pachytene analysis. The three karyotypes are comparable in the relative lengths of the chromosomes but differ in the arm ratios. This species exhibits the most symmetric karyotypes in the genus, balunga being included in the group 2b and other two varieties in the group 1b of Stebbins' (1958) classification.
