Mutational origin of genetic diversity in groundnut (Arachis hypogaea L.)

Abstract

To investigate the mutational origin and nature of genetic diversity in groundnut, mutants derived from Dharwad Early Runner and others along with natural types, and intra and interspecific derivatives belonging to all the four botanical types were assessed for their morphological, biochemical and molecular diversity. Similarity among the natural and mutant categories suggests the key role of mutations in creating enormous diversity in terms of different subspecies and botanical types of groundnut. Behaviour of the Dharwad Early Runner derived mutants and several unusual features are indicative of the non- Mendelian turnover mechanisms. Multiple gene differences between the mutants and their parents, paternal inheritance and tissue-specific expression of glutamate oxloacetate transaminase isozyme, response of mutants to 5-azacytidine (a demethylating agent) and limited molecular diversity compared to enormous morphological diversity suggests the possible involvement of epigenetic mechanisms in the differentiation of groundnut into different subspecies and botanical varieties.