IN VITRO REGENERATION OF TRECULIA AFRICANA DECNE. FROM EMBRYO EXPLANTS ON THE MEDIA OF MURASHIGE AND SKOOG (MS) AND GAMBORG ET AL. (B5)

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ABSTRACT

The effect of three different concentrations of sucrose namely 2, 3 and 4% were investigated on the in vitro regeneration of embryo explants of Treculia africana Decne. on the media of Murashige and Skoog (MS) (1962) and Gamborg et al. (B5) (1968) respectively without any growth regulator. The experimental design was a 2 x 5 factorial in a completely randomized design with each treatment consisting of ten replicates. Results showed that while both media including control supported the in vitro regeneration of T. africana embryo explants, B5 medium was found to be significantly superior (P≤0.05) to MS medium in all the growth parameters studied. B5 medium at 4% sucrose elicited the best response in all the growth parameters determined while control gave the least response. The protocol reported here can be used for large scale propagation of true-to-type T. africana plants within a short time for the purpose of improvement through genetic transformation (mutagenesis) and the development of a viable conservation programme.

CHAPTER ONE
INTRODUCTION

There are approximately 400,000 species of higher plants, of which 250,000 have been identified or described (FAO 1996). Among them, some could be described as endangered, rare, vulnerable or endemic and all these are of plant genetic resource (PGR) conservation concern to the country considering the unprecedented rates of occurrence in comparison with normal natural history rate (Ogbu et al., 2010). . The causes of the loss of our plant bio resources in general have been identified to include overexploitation, massive deforestation, and desertification, paucity of institutional frame work to engage in deliberate conservation of PGR relevant to food and agriculture/forestry, inadvertent emphasis on more exotic crop species/ varieties to the neglect of our useful indigenous plants etc. (Ogbu et al., 2010). Given the combined effort of these deleterious factors, genetic erosion becomes inevitable where no
deliberate effort is made to forestall it (Petters, 2000).
Treculia africana Decne. (African bread fruit, Wild jack fruit, or African boxwood), is an important multipurpose indigenous tree species in Africa belonging to the taxonomic family Moraceae. The tree serves for the provision of nutritive food for the local population.
Analysis of the hexane extract of the seeds indicates that it contains a stearine solid fat fraction, resembling that of palm kernel oil and an aleine fraction with a composition similar to that of cotton seed oil; carbohydrate content 40-50% starch, 3-8% glucose and a good protein content with its lysine 50% higher than that of soya beans and methionine content 1.65% as in soya beans Nutrecul Agroforestry Company (N A C, 2013),. Lyseine is the most limiting amino acid of all vegetable protein; therefore, T. africana seems to have an important role in those regions that have a shortage of good protein sources and especially where kwashiorkor appears.

Despite the dietary and economic importance of African breadfruit, it has remained an underutilized
species till now and its potentials remain under-exploited. This problem is capable of causing serious threat of erosion of its genetic resources as well as extinction threat. T. africana is currently included in the list of endangered species of Southern Nigeria (Meregini, 2005) and this is quite worrisome. The underutilization has been caused by a number of reasons. Firstly, increase in population pressure especially in the urban places due to ruralurban migration. The increased population is resulting in the conversion of more forests to agricultural lands, industrial estates and homes in order to satisfy the basic needs (food, clothing and shelter) of the teeming population. Currently, erstwhile village fruit tree forests
which served as sanctuaries for in situ and some degree of ex situ conservation of choice plants in several communities are now being shared out to community members for the purpose of agricultural production and even being sold or leased out to companies. The thinking of the village heads is that the establishment of such companies in their domain will provide jobs for their subjects as well as bestow development on their communities. This is however to the contrary often-times as rather than assisting to actualize the development dream, most of these companies end up exploring and over-exploiting the natural resources in these areas and degrade the land through unsustainable exploitation (resulting in grave consequences) which leave the people highly vulnerable to environmental shocks (Nuga and
Ofodile, 2010). The Niger Delta region of southern Nigeria is currently having this experience. FAO (2005) reported that Nigeria has the world‘s highest deforestation rate of primary forests and a further report, FAO (2006) revealed that the country has lost a staggering 79% of its old-growth forests between 1990 and 2005.
Added to that, the fully grown trees have such a large size that minority of the people would want to leave it in their compound for food, ornamental or aesthetic purposes. The height of the tree and the fruit on the tree of the unimproved varieties such that the fruit cannot be plucked rather falls downs on its own instills fear in the mind of many. This is because falling down of the fruit head on an individual may cause death or serious injury. South easterners believe that the fruit of the species have some mystical powers which cause the death of persons the fruit falls on accidentally (Nuga and Ofodile, 2010). It is viewed as a “taboo” for the fruit to fall on a person. The resultant effect of this belief is the felling of African breadfruit trees found in home gardens in spite of the increasing demand for its products.
Also, the long gestation period of ten (10) or more years of the species has not helped matters either. This leads to the second reason which is non-improvement and limited cultivation of the species.

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