Abstract
Callus was initiated from hypocotyl and cotyledon explants of seven of commercial Kazakh cotton cultivars on MS medium supplemented with 0,1 mg L-1 2,4-D and 0,5 mg L-1 kinetin. The percentage of callus formation ranged from 64,0 to 91,0% for cotyledons and from 72 to 90% for hypocotyls. Study of morphological heterogeneity peculiarities of metamorphosis and histological structure of calli of cotton allowed to identifying seven tissues types and selecting the morphologically stable and perspective callus type for embryogenesis. Significant differences between the calli types of cotton were found by histological and morphological comparative analysis.