IN VITRO SELECTION OF SALT RESISTANT DUONG MANDARIN (CITRUS RETICULATA BLANCO) CALLUS LINES

Abstract

Duong mandarin (Citrus retieulata Blanco) was a fruit tree cultivated popularly in Mekong Delta. Duong mandarin plant was not resistant to salt (NaCl) inspite of low concentrations. In vitro selection technique can overcome these salt obstacles. The objectives of this study were to evaluate salt resistance of callus lines from nucellar calli. Two techniques of in vitro selection applied in this study were solid and shaken liquid selective media. Concentrations of salt used in this study were 0; 0.5; I; 2 and 4 g/l. Results showed that the second technique gave a more serious selection pressure. There were almost the same numbers of surviving calli obtained by two techniques at concentrations of NaCI from 0 to 2 g/l. But, at higher salt concentration of salt (4 g/l), there were no surviving calli. The growth of selected calli was subcultured three' times to determine the stability of·the selected calli. Four selected callus lines of duong mandarin grew normally on salt selective media at 0; 0,5; I and 2 g/l NaCl. Plantlet regeneration of selected calli through embryogenesis obtained at MS medium supplemted galactose 20 g/l.