Hierarchical Approaches to the Analysis of Genetic Diversity in Plants: A Systematic Overview

Hierarchical analysis highlights the nature of relationship between and among type samples as outlined by standard descriptors. It produces an output called dendrogram, which depicts the hierarchical structure of genetic interaction in clusters/groups. Genetic diversity is the variation of heritable characteristics in a population. It results from one or more of the following; evolution, mutation, migration, domestication, plant breeding and selection. Knowledge about genetic diversity and relationships among plants may be an invaluable aid in plant breeding and classification. The analyses of genetic diversity rely on pedigree, morphological, biochemical and most recently molecular (DNA-based) data through PCR or non-PCR techniques. For accurate and unbiased assessment of genetic diversity, adequate attention has to be devoted to: sampling strategies, choice of genetic distance as well as judicious combination of analytical techniques and statistical tools. A critical distinction in ways of analyzing genetic diversity in plant lies in the data used for analysis. Based on the data type, the hierarchy may be expressed with; phenogram, cladogram or phylogram, which are forms of dendrogram. The resulting dendrogram is often used to predict if a population is genetically diverse or homogenous.Keywords: Genetic diversity, Hierarchical approach, Plant, Clustering, Descriptive Characters, Marker