First report of intraspecific polyploidy (2x, 4x) in Physochlaina praealta (Decne.) Miers. (family: Solanaceae)

Abstract

Physochlaina praealta (family: Solanaceae), a widely distributed species of Indian cold deserts, is studied for male meiotic studies. We here report for the first time the existence of intraspecific polyploidy (2x, 4x) in the species. Both the 2x and 4x individuals show perfectly normal meiotic behavior and nearly 100% fertile pollen grains. The 4x plants show allopolyploid like meiotic behavior characterized by normal chromosome pairing and regular segregation of chromosomes. The 2x and 4x plants grow under similar type of habitats but the 4x individuals were noticed to be more pubescent. The 4x plants can also be differentiated from the 2x on the basis of micro-characters like trichome (size, density), stomata (size and frequency) and pollen grain size which increases with ploidy.