Impact of Slight Change in Water Potential of Culture Media on In vitro Shoot Multiplication and Esterase and Protein Patterns of Simmondsia chinensis L.

Abstract

Amplification of DNA on ten jojoba shrubs using 7 RAPD primers indicated that seed propagation of jojoba results in high genetic variation. To produce true to type clones, micropropagation technique was applied. Medium (MS) containing relatively low concentrations of BAP (1 or 2 mg/l) did not stimulate shoot formation on nodal explants of jojoba. The best shoot cloning on nodal explant was established on MS medium containing 3 mg/l BAP and 0.1 mg/l NAA. Shoot formation was more sensitive than growth of the formed shoots to change in water potential of culture medium. Decrease in water potential (Ψ) of medium by the addition of 0.5 mg/l of mannitol slightly increased the number of formed shoots, further decrease in the medium Ψ by increase the concentration of NaCl or mannitol resulted in retardation of shoot formation. Data indicated that shoot formation was more sensitive than shoot growth to change the Ψ of the medium. Callus weight was decreased by decrease of medium Ψ less than – 435.014 MPa using 1 g/l of NaCl, while application of mannitol to decrease Ψ of the medium up to 435.054 MPa (4 g/l) significantly increased callus fresh weights. Jojoba calli clearly expressed the effect of decrease in Ψ of MS medium on esterase and protein pattens.