KARYOTYPE ANALYSIS AND NEW CHROMOSOME NUMBERS OF SOME SPECIES OF EUPHORBIA L. (EUPHORBIACEAE) IN IRAN

The somatic chromosome numbers and karyotype features of 15 species of Euphorbia (Euphorbiaceae) from Iran were analyzed. The chromosome counts of four species including E. inderiensis (2n=18), E. polycaulis (2n=18), E. phymatosperma (2n=16) and E. gypsicola (2n=54) are reported for the first time, while the chromosome number of 11 more studied species are confirmed. We also confirm the occurrence of two different cytotypes in E. microsciadia: one diploid (2n=18) and the other tetraploid (2n=36). The karyotypes are often symmetrical composing mainly of metacentric and submetacentric chromosomes. The results also confirm the presence of different basic chromosome numbers including x= 7, 8, 9 and 10 within the genus, indicating the potential evolutionary importance of such data in the genus.