Accumulation of secondary products in tomato callus (Lycopersicon esculentum Mill) under drought stress conditions

Abstract

Callus which initiated from shoot tips of tomato local variety (Lycopersicon esculentum. Mill) were exposed to Polyethylene glycol at levels of (-0.15, -0.29, -0.44, -0.59 MPa ) to induce drought stress. Callus fresh and dry weight, amino acid proline, carotene and lycopene pigments were evaluated under drought stress condition In Vitro. Results revealed different response toward these indicators. Callus fresh weight recorded gradually increase started from levels of (-0.15, -0.29 up to -0.44 MPa) and remarkable reduction at level of (-0.59 MPa), unlike callus dry weight which gave positive response at (-0.44 and -0.59 MPa) levels. Proline and photosynthetic pigment (carotene, lycopene) also influence significantly by the drought. However, all physiological parameters recorded significantly higher accumulation at high level of drought stress.