Cytomorphological Comparison in Natural Intraspecific Cytotypes (2<i>x</i>, 4<i>x</i>) in <i>Brachyactis pubescens</i> from Northwest Himalayas, India

Abstract

Intraspecific euploid cytotypes (2n=18, 36) were found in the wild plants of Brachyactis pubescens in North West Himalayas from the hills of Ladakh division of Jammu and Kashmir and Solang Valley, Kullu district, Himachal Pradesh. The plants with each ploidy level showed regular bivalent formation, equal segregation of chromosomes during anaphases and normal sporads. The 2x plants were found growing at higher elevations in the Kashmir Himalayas and adjoining hills of Afghanistan while the 4x plants grow at lower elevations in the Solang Valley, Himachal Pradesh. The 4x and 2x plants could be differentiated in various morphometric parameters. The 4x plants were noticed to be robust and much taller and show gigantism in leaf and floral characters besides depicting the increase in the size of trichomes, stomata and pollen grains. Analysis of meiotic chromosome pairing in the tetraploid taxa indicates towards its allopolyploid nature.