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 of plants. To develop an efficient in vitro regenerated system without hyperdydricity, we demonstrated the effect of different disinfected agents (mercuric chlorite and hypochlorite), growth regulators, their concentrations and combinations, Agar, pH, ammonium nitrate (NH₄NO₃) and number of subcultures. Mercuric chlorite at 0.07% 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 multiplication with symptoms of hyperhydricity than those induced by Kinetin alone or in combination with NAA. Hyperhydricity was also reduced by increasing the concentration of agar, pH and elimination of NH₄NO₃ from the macroelements of Murashig and Skoog (MS) medium. Repeated subcultures affected both multiplication and hyperhydricity. The multiplication of shoots increased from parental culture up to 5th subculture and thereafter declined in 6th subculture. Although shoot hyperhydricity were observed from 1st subculture (19%) and then increased up to 85% in 6th subculture. This increased in hyperhydricity could be due to the remaining influence of hormones. In shoots of 5th subculture the content of chlorophyll (dark green) were higher than shoots of 6th subculture.