Cytotaxonomical Studies of South Indian Urticaceae

Abstract

Cytotaxonomical studies have been made in 17 species coming under 7 genera of South Indian Urticaceae. First record of chromosome number has been made in 1. Laportea terminalis, 2. Elatostemma lineolatum, 3. E. surculosum, 4. Pilea trinervia, 5. P. microphylla, 6. P. involucrata, 7. Pellionia repens, 8. Pouzolzia auriculata, 9. P. cymosa, 10. P. wightii, 11. P. bennettiana, 12. P. zeylanica, 13. Drougetia diffusa, and 14. Villebrunea integrifolia.
The somatic chromosome number ranges from 18 to 50 among the species studied. n=10 may be the primary basic chromosome number and n=12 derived basic chromosome number. All the other numbers might have been produced by means of euploidy and aneuploidy. The karyotype analyses show that each and every species has a distinct karyotype. Therefore, karyotype alteration of chromosomes play important role in speciation along with aneuploidy and euploidy already discussed.