Direct somatic embryogenesis of Malaxis densiflora (A. Rich.) Kuntze

Abstract

A protocol for induction of direct somatic embryogenesis and subsequent plant regeneration for the medicinally important and endangered plant of Malaxis densiflora has been developed for the first time. In the present study, in vitro seed derived protocorm explants were cultured on half strength Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D), Picloram and Dicamba individually and in combination with cytokinins BAP, TDZ and Kn for its effectiveness to induce the differentiation of somatic embryos. The best response was observed in protocorms cultured half strength MS medium supplemented with 2,4-D at 3.39 μM and TDZ at 6.80 μM. Both epidermal and sub epidermal cells were involved in the formation of embryos. The proembryos developed into globular stage and subsequently developed into protocoms. Complete plantlets were formed after 60 days of culture. The plantlets were acclimatized in plastic pots containing sterilized vermiculite. The survival rate was 76%.

Keywords

• Malaxis densiflora
• Somatic embryogenesis
• Histological analysis
• Plant growth regulators
• Plantlet regeneration
• Scanning electron microscopy