In vitro regeneration of peanut (Arachis hypogaea L.) plantlets from embryo axes and cotyledon segments

Abstract

Peanut (Arachis hypogaea L.) plants were regenerated from embryo axes on four basal media: Murashige and Skoog (MS), Gamborg (B5), Potato Extract (PE) and Linsmaier and Skoog (LS). MS basal medium was found superior to others in supporting the development of a high frequency of plantlets and in increasing the number of roots per plantlet. Plants were also regenerated from cotyledon segments on MS medium supplemented with α-naphthalenacetic acid (NAA) and/or 6-benzyladenine (BA). On MS medium, 1 mg/l of NAA induced the maximum frequency of rooting compared to any other level of NAA tested. Shoot induction was greater when the medium was supplemented with 2 mg of BA/l. These shoots on transfer to MS basal medium developed roots. Further experimentation using 1 mg NAA/l in combination with varying levels of BA resulted in regeneration of whole plants. However, the rate of regeneration was lower compared with the regeneration frequency on medium containing BA alone. Shoot induction was predominantly from the cotyledon segments proximal to the embryo axes.