Effect of phytohormones on plant regeneration from callus ofGladiolus cultivar “Jenny Lee”

Abstract

Callus capable of plant regeneration was initiated at a higher frequency from the basal leaves of in vitro plants (70% explants) as compared to cormel slices (30% explants) when cultured on medium containing various concentrations of auxin. The greatest number of plants were regenerated from 4-mo.-old callus (112 plants/g fresh weight callus) cultured on medium containing 10 mg/liter (53.8µM) 1-napthaleneacetic acid. The addition of 2 mg/liter (9.3µM) kinetin to a Murashige and Skoog’s basal salts regeneration medium resulted in an average two- to three-fold increase in the number of plants regenerated compared to regeneration on medium without hormones. Ten months after callus initiation, all callus maintained on auxin-supplemented media showed a drastic reduction in its capacity to regenerate plants. Ten-month-old callus maintained on dicamba regenerated the greatest number of plants (14 to 23 plants regenerated per gram fresh weight callus) as compared to callus maintained 10 mo. on medium containing 1-napthaleneacetic acid or 2,4-dichlorophenoxyacetic acid. Cormel slices cultured on cytokinin-supplemented media formed small amounts of callus which regenerated up to 19 plants per cormel slice within 1 to 2 mo. after the cormel slice had been placed on either 10 mg/liter (49.2µM) N6-2-isopentenyladenosine or 1 mg/liter (4.4µM) 6-benzylaminopurine.