Abstract
Hybrids between Papavr somniferum and P. setigerum had mean pairing as 10.7II+11.6I at metaphase I. Rarely one trivalent was also observed. Late stages of meiosis indicated abnormalities e.g. laggardism, precociously dividing chromosomes etc. In the F2, plants with 2n=23-34 chromosomes were obtained.
i. The presence 12II in the triploid hybrids indicated homologies between somniferum and setigerum genomes. In addition autosyndesis between some of the chromosomes of second setigerum genomes also occurred.
ii. The amphiploids, raised following colchicine treatment, had mean pairing of .65IV+.65III+26.9II+7.65I at metaphase I. There was low frequency of multivalents. The bivalent pairing is attributed to strong differential affinity be-tween chromosomes of the same origin in the amphiploid. The occurrence of a genetic system promoting bivalent formation in the setigerum species is envisaged.
iii. The possible role of other species e.g. P. glaucum, P. orientale and P. aculeatum in the origin of P. somniferum and P. setigerum is discussed.
iv. In addition F2, backcrosses have also been cytogenetically analysed and their data are used in interpreting the genome relationships of somniferum and setigerum species.
