In-Vitro Acclimatization of Curcuma Zedoaria Under Iso-Osmotic Treatments, Ex-Vitro Adaptation and Agronomic Traits in Greenhouse Conditions

Abstract

Low survival rate, poor adaptation to ex-vitro environments, and time required for hardening the plants to cope with fluctuated environments of field trial are identified as major barriers in this technology. In present study, iso-osmotic adjustment in the culture medium using sucrose and/or mannitol was applied to the in-vitro cloning of Curcuma zedoaria (white turmeric) plants, which were transferred to ex-vitro conditions and subsequently cultivated in the greenhouse conditions prior to harvest after 9 months. During both in-vitro and ex-vitro development of plant, growth and physiological traits under 3% sucrose (Suc) + 2.5% mannitol (Man) were lower than those in control (3% Suc; conventional tissue culture). Interestingly, pseudostem height and root length in acclimatized plantlets under 3% Suc + 2.5% Man were sharply dropped by 60.13% and 92.37% over control, respectively, resulting in a decrease in the ex-vitro adaptation by 56.27% and 33.33% over the control. A positive relationship between reduction of net photosynthetic rate (Pn) and sucrose concentration in the leaf tissues was evidently observed. Remarkably, the morphological and physiological traits of aboveground and underground parameters of acclimatized plantlets under 3% Suc + 2.5% Man were maximized over control, leading to high yield of curcuminoids (229.4 mg plant− 1) in the dry rhizome (31 g plant− 1) when cultivated under greenhouse microenvironments for 9 months. Based on this investigation, we propose that plantlets of C. zedoaria micropropagated using 3% Suc + 2.5% Man can readily acclimatize under ex-vitro conditions and subsequently develop as healthy plants with compact and uniform size.