Genetic And Morphological Diversity In Monodora Myristica(gaertn.) Dunal In Eastern Nigeria

Most organisms are diploid, having two sets of chromosomes, and therefore two copies (called alleles) of each gene. However, some organisms can be haploid, triploid, tetraploid or more (having one, three, four or more sets of chromosomes respectively) (Harrison, et al, 2004). Within any single organism, there may be variation between the two (or more) alleles for each gene. This variation or polymorphism is introduced either through mutation of one of the alleles, or as a result of reproduction processes,especially if there has been migration or hybridization of organisms, so that the parents may come from different populations and gene pools. Harmless mutations and sexual recombination may allow the evolution of new characteristics which increases diversity(Andayani,et al.,2001).
Each allele codes for the production of amino acids that string together to form proteins. Thus differences in the nucleotide sequences of alleles result in the production of slightly different strings of amino acids or variant forms of the proteins.These proteins code for the development of the anatomical and physiological characteristics of the organism, which are also responsible for determining aspects of the behavior of the organism (Harrison, et al, 2004).
Plant diversity is part of the biological diversity and contributes towards achieving food security, poverty alleviation, environmental protection and sustainable development(Frankel 1984). It is being eroded rapidly in important spice plants and other crops mainly because of replacement of traditional landraces by modern, high yielding cultivars, natural catastrophes (droughts, floods, fire hazards, etc.), as well as large scale destruction and modification of natural habitats harboring wild species(Frankel 1984, Bramel-cox and Chritnick, 1998).M. myristica population is threatened by urbanization which damages its natural habitat, and leads to the cutting of most of the trees without replanting. Additionally, the plant is listed under Kew’s difficult seeds due to its inability to easily grow outside its natural habitat(Burkill, 1985). Genetic variation in traditional landraces and wild species is essential to combat pests and diseases and to produce cultivars better adapted to constantly changing environments(FAO, 1994).
Molecular tools such as have been found to be more useful and accurate in the study of inter-species and intra-species genetic diversity in several plants. Randomly amplified polymorphic DNA (RAPD) markers have been successfully employed for determination of intraspecies genetic diversity in several plants. These include Phaseolus vulgaris (Razviet al., 2013),Ocimumspp (Sairkaret al., 2012), Chrysanthemum (Martin et al., 2002), Annonacrassiflora( Cotaet al.,2011), Prosopis ( Goswami and Ranade, 1999), date palm (Corniquel and Mercier, 1994), papaya (Stiles et al., 1993), poplars (Bradshaw, et al., 1994) and amaranths (Ranade, et al. 1997). No such attempt has so far been reported for Monodoramyristica