Green Global
Foundation Journal
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Papers
IN VITRO MICROPROPAGATION AND MICROGRAFTING OF GUM ARABIC TREE [Acacia senegal (L.) Wild] (Pages : 19 - 27)
M. M. KHALAFALLA AND H. M. DAFFALLAIn order to find a reproducible method for in vitro multiplication of gum Arabic tree (Acacia senegal (L.) Wild). A protocol for in vitro micropropagatin and micrografting was developed at the laboratory of plant tissue culture, Commission for Biotechnology and Genetic Engineering, Khartoum, Sudan, during the period of October 2006 to October 2007 Multiple shoots were regenerated from cotyledonary node derived from 7-days- old in vitro raised seedlings and nodal segment derived from 12-months-old plant growing in a greenhouse. Explants were cultured on Murashige and Skoog (MS) medium supplemented with 0.5–5.0 mgL-1 of either benzyladenine (BA) or kinetin (Kn) alone or in combination with 0.5 mgL-1 ?-naphthalene acetic acid (NAA). The maximum number of shoots per cotyledonary node (8.3 ±0.3) and nodal segment (5.3 ±0.7) explants were obtained on MS medium supplemented with 1.0 mg/l BA after 4 weeks of culture. In vitro regenerated shoots were either rooted in vitro on MS medium supplemented with auxins or micrografted on in vitro induced rootstock. Only 25% of the shoots formed roots after being transferred to MS medium containing 1.0 mgL- 1 indole-3-butyric acid (IBA) after 28 days of culture under dark condition.The rate of successfully grafted shoots was influenced by both scion length and rootstock age. 100% successful graft was obtained with scion length of 3.0 cm and rootstock of 14-days-age. In vitro rooted shoots and successful grafts were transplanted to plastic pots containing autoclaved garden soil and sand (3:1), then hardened off and transferred to greenhouse where grown to maturity with 100% success. The success of the micrografting was independent of the nature and concentration of growth regulator used in shoot initiation medium and the time period for induction of shoots. This efficient plant regeneration system provides a solid basis for large scale reforestation and genetic improvement of this important multipurpose leguminouDownload