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The present meiotic study was carried out in two varieties of Catharanthus roseus (L.) i.e. Pink flower and white flower. They showed regular formation of 8 bivalents (n=8). The course of meiosis has been found to be normal in both the varieties of C. roseus. The number of bivalents were constant and comparatively small in size. It was found that bivalents were in ring and rod shape in both varieties in late diakinesis and metaphase. In the present work ring bivalents occurred in high frequency and were the outcome of maximum homogeneity of homologous chromosomes. There was negative correlation between bivalents in relation to inter chromosomal distribution of chiasmata. The correlation coefficient was —0.01 in both varieties. The chiasma frequency in pink flower and white flower was recorded as 1.67 and 1.70 respectively and they do not differ very much. The difference in variance ratio of the varieties investigated clearly suggested that there are variation in size, nature and over all Karyotype of bivalents in same pollen mother cell.

Key words: Catharanthus roseus, Meiosis, Negative correlation.