International Journal of Conservation Science (Jun 2012)
A Micropropagation Protocol for a Critically Endangered Mangrove Excoecaria Agallocha L
Abstract
Excoecaria agallocha L. is a critically endangered mangrove tree from the Pichavaram mangrove reserve forest, the Tamil Nadu Coastal area. It is distributed on the seashore and the edge-mangrove. In order to reduce the decrease in number of these Mediterranean mixed stand, unsupervised forest management practices have drastically been reduced. In addition, the deforestation of the mangrove area, along with a low seed germination rate further endanger this species. In this study we developed a protocol for the micropropagation of adult Excoecaria agallocha. Microcuttings were obtained from lateral and apical twigs of mature plants and used as explants. Microcuttings with axillary buds were grown on different media, plant growth regulators and phenolic exudation substances. The axillary shoots produced on uncontaminated explants were excised, segmented and recultured in the same medium, to increase the stock of shoot cultures. The Modified Murashige and Skoog (MMS) medium, augmented with different concentrations of N6 – benzyl adenine (BAP) and Naphthalene acetic acid (NAA), either alone, or in combinations, as a potential medium for shoot multiplication by nodal segments, was tested. In the following experiment, equal molar concentrations of four cytokonins [BAP, Kinetin and 2- isopenthenyladenine (2iP)] in combination with equal molar concentrations of three auxins [ NAA, Indole acetic acid (IAA) and indole-3- butyric ]were used to test the rate of axillary shoot proliferation, induced on MMS agar medium supplemented with 3.9 µM BAP and 1.34 µM NAA after 6 weeks in culture. Different auxins (NAA, IBA and IAA) were to determine the optimum conditions for in vitro rooting of microshoots. The best results were accomplished with NAA 5.41 µM (89% rooting) and with IBA at 2.85 or 5.71µM (86% and 86.5%) rooting, respectively).
