J. Patnaik et Bk. Debata, REGENERATION OF PLANTLETS FROM NACL TOLERANT CALLUS LINES OF CYMBOPOGON MARTINII (ROXB) WATS, PLANT SCI, 128(1), 1997, pp. 67-74
Plantlets were regenerated successfully through somatic embryogenesis
of NaCl stressed (up to 350 mM) and subsequently selected, tolerant (u
p to 300 mM) callus lines of the aromatic grass Cymbopogon martinii (R
oxb.) Wats. The NaCl tolerant callus lines were isolated, characterize
d and selected on the basis of their growth behaviour as well as physi
ological parameters (K+/Na+ ratio and proline contents) and compared w
ith those of the wild type (control) callus lines. The regeneration po
tential of the NaCl tolerant callus ranged from 81.6 to 0% against 80.
4 to 0% in the control lines with the NaCl level varying between 0-300
mM and 0-200 mM respectively in the medium. The embryogenic potential
of NaCl tolerant callus selected even at 300 mM could be improved sig
nificantly by the incorporation of gibberellic acid (GA(3)) and abscis
ic acid (ABA) in the medium where, with 2 mg/l of GA(3) and 1 mg/l of
ABA the highest rates of embryogenesis (44.5, 28.8 and 18.6%) were ach
ieved against 17.5, 8.2 and 1.8% on medium devoid of GA(3), and ABA at
50, 150 and 250 mM of NaCl respectively. Complete tissue browning and
subsequent death were observed at 300 mM NaCl in the differentiation
medium. Plantlets regenerated from NaCl tolerant callus were transferr
ed to soil and grown under green house conditions with about 70% trans
plantation success. (C) 1997 Elsevier Science Ireland Ltd.