EFFECTS OF PLANT GROWTH REGULATOR ON IN VITRO CALLOGENESIS OF GARDEN CRESS (LEPIDIUM SATIVUM L.)

Abstract

Three explants (seeds, shoot and root) of Garden cress (Lepidium sativum L.) were used for the standardization of
previously reported protocol of callus initiation from seed and shoot explants under in-vitro conditions. The
various combination of different concentration (0.0, 2.0, 4.0 and 6.0 mg/L) of plant growth regulators {á-
naphthalene acetic acid (NAA), 2, 4-Dichlorophenoxyacetic acid (2, 4-D) and Kinetin (Kin)} were used in
Murashige and Skoog (1962) medium (MS medium), to analyze the effect on explants of Garden cress for callus
initiation. Plant growth regulators, 2, 4-D (4.0 and 6.0 mg/L) and Kin (2.0 mg/L) were found to be the most
efficient combinations for calli formation (50 % and 20 % callus initiation from seeds and shoots inoculation,
respectively). Globular and pale yellow callus was formed in the MS-medium containing 2, 4-D (4.00 to 6.00 mg/
L). Similar trends were also obtained for callus formation from shoot explants using MS-medium containing 2, 4-
D (4.00 to 6.00 mg/L) and Kinetin (2.0 mg/L). However, higher concentrations of Kinetin i.e., more than 2.0 mg/
L did not show any improvement on callusing and also reduced the callus induction frequency from both
explants. Highest amount/ number of callus formation (50 % callus initiation) were observed in culturing of seed
in MS medium than the culturing of shoot and root explants. This study may be useful for rapid micropropagation
or callus regeneration of Garden cress in in-vitro condition in future Lepidium improvement programme.