Somatic embryogenesis in four tree legumes.

Premananda Das

doi:10.4061/2011/737636

Abstract

Somatic embryogenesis was achieved in four leguminous tree species, that is, Acacia catechu, Acacia arabica, Hardwickia binata, and Dalbergia sissoo using immature zygotic embryos as explants on Murashige and Skoog (MS) medium supplemented with 0.25–1.0 mg/l Kn (kinetin) and 2.0–3.0 mg/l 2,4-D (2,4-dichlorophenoxyacetic acid) or NAA (1-napthaleneacetic acid) and 3% sucrose. MS medium containing 2.0 mg/l 2,4-D and 1.0–1.5 mg/l Kn was noted to be most effective in inducing friable embryogenic callus (FEC); the number of somatic embryos per culture varied in MS medium supplemented with 1.0–2.0 mg/l 2,4-D or NAA and 0.25–1.5 mg/l kinetin. The maximum number of somatic embryos was obtained in MS medium containing 1.5–2.0 mg/l 2,4-D or NAA and 1.0–1.5 mg/l kinetin; proliferation of embryogenic calli was enhanced in cultures having 1.0–2.0 mg/l 2,4-D, 1.0–1.5 mg/l kinetin, and 400–600 mg/l L-Proline. The somatic embryos in various shapes and sizes after the first subculture on MS medium supplemented with 0.1 mg/l IAA and 0.25 mg/l BA; developed shoots and rooted in 1/2 strength MS medium supplemented with 0.1 mg/l IBA or IAA. The somatic embryo-derived plantlets were transferred to the field after being hardened in the climate-controlled hardening chamber.

Highlights

Tree legumes, once established, grow faster than other tree species even under poorly managed plantation-forestry systems as they fix atmospheric nitrogen for sustenance and growth
Acacia arabica (Babul), a leguminous tree of tropical and sub-Saharan Africa is naturalized in many parts of peninsular India; as an economically valued timber, it is used for crafting of agricultural implements, building materials, furniture, and fuel wood as well while the leaves and pods are used for fodder; gum arabica has many industrial applications
Immature green pods of Acacia arabica, Acacia catechu, Hardwickia binata, and Dalbergia sissoo (60 days after flowering) were collected from elite trees growing in dry deciduous forests

Summary

Introduction

Once established, grow faster than other tree species even under poorly managed plantation-forestry systems as they fix atmospheric nitrogen for sustenance and growth. Acacia arabica (Babul), a leguminous tree of tropical and sub-Saharan Africa is naturalized in many parts of peninsular India; as an economically valued timber, it is used for crafting of agricultural implements, building materials, furniture, and fuel wood as well while the leaves and pods are used for fodder; gum arabica has many industrial applications. This species has great ecological value in controlling erosion and improving soil fertility. It was thought that plants must coordinate the growth of root and shoot meristems to maintain an appropriate balance of root and shoot organs, respond and adapt to various environmental conditions to achieve an intermeristems coordination of growth and development involving the interplay of several long-range signals [5, 6]

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Results