Bi-directional in vitro propagation of Arachis hypogaea L. Var. ICGS 44 through different explants
Sharmistha Maity
Department of Botany, Krishnagar Government College, Krishnagar, Nadia-741101 (India) E-mail address: Sharmistha_maity@ rediffmail.com; Mobile No. - 9832223933
ABSTRACT
In vitro propagation using different explants viz. shoot apex, cotyledonary nodes, de-embryonated cotyledons from axenic plants, has been attempted in Arachis hypogaea L. var. ICGS 44. The explants were cultured in Murashige and Skoog’s basal medium supplemented with various concentrations (1-50 mg l-1) of benzylaminopurine (BAP). Multiple shoots were induced both from shoot apices as well as from cotyledonary nodes. De-embryonated cotyledons showed swelling near proximal notch and infrequent shoot multiplication. Shoot multiplication rate in the cotyledonary node explants was higher than shoot apical explants. However, with increasing concentrations of benzylaminopurine in the medium, both cotyledonary nodes and shoot apices exhibited multiple shoot bud formation and these tiny buds could be subsequently developed into leafy shoots by culturing in plant growth regulator free media or in presence of either low level of kinetin (5mg l-1) or benzylaminopurine (5mg l-1) with or without auxin supplementation (napthalene acetic acid 1mg l-1). Shoots of 2-3 cm size could be quickly rooted in presence of either 2, 4 dichlrophenoxy acetic acid or napthalene acetic acid. Well grown rooted plantlets were successfully transferred to soil and after hardening established finally in the field. Abbreviations: ANOVA- analysis of variance; BAP- N6– benzylaminopurine; DMRT- Duncan’s Multiple Range Test; Kn- Kinetin; MS- Murashige and Skoog’s medium; NAA- -naphthaleneacetic acid; PGR- Plant growth regulator; 2.4-D- 2,4-dichlorophenoxyacetic acid;