EFFICIENT in vitro PROPAGATION OF Amaranthus viridis L. USING NODE EXPLANTS

Hyperhydricity is a frequently problem in plants during in vitro culture and affected micropropagation ofplants. To develop an efficient in vitro regenerated system without hyperdydricity, we demonstrated the effectof different disinfected agents (mercuric chlorite and hypochlorite), growth regulators, their concentrationsand combinations, Agar, pH, ammonium nitrate (NH4NO3) and number of subcultures. Mercuric chlorite at0.07% and exposing time (9–10 min) was appropriate for hygienic culture. The shoots induced by Benzyladnine(BA) alone or in combination with α-Naphthaleneacetic acid (NAA) exhibited maximum multiplicationwith symptoms of hyperhydricity than those induced by Kinetin alone or in combination with NAA. Hyperhydricitywas also reduced by increasing the concentration of agar, pH and elimination of NH4NO3 from themacroelements of Murashig and Skoog (MS) medium. Repeated subcultures affected both multiplication andhyperhydricity. The multiplication of shoots increased from parental culture up to 5th subculture and thereafterdeclined in 6th subculture. Although shoot hyperhydricity were observed from 1st subculture (19%) andthen increased up to 85% in 6th subculture. This increased in hyperhydricity could be due to the remaininginfluence of hormones. In shoots of 5th subculture the content of chlorophyll (dark green) were higher thanshoots of 6th subculture.