In vitro acclimatization of <i>Curcuma longa</i> under controlled <i>iso</i>-osmotic conditions

Abstract

In vitro acclimatization has been validated as the successful key to harden the plantlets before transplanting to ex vitro conditions. In the present study, we investigated the potential of different sugar types (glucose, fructose, galactose, sucrose) in regulating morphological, physiological and biochemical strategies, survival percentage and growth performance, and rhizome traits of turmeric under iso-osmotic potential. Leaf greenness (SPAD value) in acclimatized plantlets (4% glucose; −1.355 MPa osmotic potential) of 'ST018' was retained and greater than in 'PB009' by 1.69-fold, leading to maintain high F v /F m (maximum quantum yield of PSII), Φ PSII (photon yield of PSII) and P n (net photosynthetic rate) levels, and retained shoot height, leaf length, leaf width, shoot fresh weight and shoot dry weight after one month upon transplanting to ex vitro conditions. In addition, P n , C i (intracellular CO 2), g s (stomatal conductance) and E (transpiration rate) in acclimatized plantlets (6% sucrose; −1.355 MPa osmotic potential) of 'PB009' were stabilized as physiological adapted strategies, regulating the shoot and root growth and fresh and dry weights of mini-rhizome. Interestingly, the accumulation of total curcuminoids in mini-rhizome derived from 6% sucrose acclimatized plantlets of 'ST018' was greater than in 'PB009' by 3.76-fold. The study concludes that in vitro acclimation of turmeric 'PB009' and 'ST018' using 6% sucrose and 4% glucose, respectively, promoted percent survival, physiological adaptations, and overall growth performances under greenhouse conditions.

Response to the application of Pectimorf® and Viyoya® to coffee tree seedlings regenerated from germplasm conserved in vitro during the acclimatization phase

“…Generally, when in vitro plants are transferred to greenhouse conditions, they exhibit rapid wilting, so it is not only important to maintain a high relative humidity in the new environment, but also to be able to induce a certain level of tolerance to drought in the seedlings to preserve the mechanisms that regulate the water volume (Chintakovid et al, 2021) and this was achieved in this research with the application of AMF to the coffee plants. The AHM are important for the plants, since they improve the growth of the host increasing nutrient and water intake from the soil, they also protect plants from salinity, pathogens and some toxic compounds (Vaast et al, 2004).…”