Electrophoresis of proteins, especially seed proteins, and karyological studies are
useful techniques for determining species and solving the problems of modern
taxonomy. The present study was carried out on two species of the Apocynaceae
family, Rhazya stricta Decasine and Nerium 01eancder.L. Seed samples of these two genera were taken from the south-east of Iran and SDS-PAGE analysis of their
proteins showed 35-88% and 40-80% similarities between different populations of
each species respectively. In the protein groups from a selected population of each one of these two species and Vinca rosea L., another species of the Apocynaceae family, 47-55% similarity was observed. However, for identification of these genera, the possession of 2-5 protein groups which were present in excessive quantities could be used. Studies on mitotic and meiotic chromosomes in the various populations of
Rhazya and Nerium showed that the basic chromosome number in both species was
1 1, (2n= 2x=22) but the small size of the chromosomes madekaryotyping problematic. In spite of this difficulty, the relatively larger chromosomes of one of the Nertum populations were prepared.