TITLE:
DNA Fingerprinting and Assessment of Genetic Diversity among 22 Cowpea [Vigna unguiculata (L.) Walp] Varieties Grown in Ghana
AUTHORS:
Benjamin A. Danso, Daniel K. Dzidzienyo, Ruth N. A. Prempeh, Marian D. Quain
KEYWORDS:
Cowpea, Characterization, Diversity, Simple Sequence Repeats
JOURNAL NAME:
Open Access Library Journal,
Vol.5 No.12,
December
21,
2018
ABSTRACT: Identification of varieties based on only morphological traits is limited by the influence of environment on such morphological traits. Deoxyribonucleic acid (DNA) fingerprinting offers an efficient system of identifying varieties at the DNA level without any environmental interference. This work used 20 Simple Sequence Repeat (SSR) markers to characterise twenty-two cowpea [Vigna unguiculata (L.) Walp] varieties for the purposes of varietal protection and further assessed for genetic diversity. This study was conducted at the Biotechnology laboratory of Council for Scientific and Industrial Research-Crops Research Institute, Ghana (CSIR-CRI). The varieties were made up of 15 cultivars released by CSIR-CRI, Ghana, 5 cultivars released by CSIR-Savannah Agricultural Research Institute, Ghana (SARI), 1 advanced line, 1 landrace and 1 exotic variety. Nineteen out of the 20 SSR markers used in this study were polymorphic. These polymorphic primers generated a range of 1 to 6 alleles per primer with polymorphic information content (PIC) varying from 0.107 (SSR-6608) to 0.656 (SSR-6613). Allele frequency ranged from 0.136 (SSR- 6371) to 0.841 (SSR-6608) with mean of 0.445. With the aid of Darwin software, dissimilarity matrix and a dendrogram were generated from the molecular data to evaluate and group the varieties based on genetic resemblance. Three pairs of varieties (Agyenkwa and Adom; Hewale and Ayiyi; Zamzam and Hewale) recorded the highest genetic distance of 0.652 each. The genetic information gathered for each variety has been made available to the breeding institutions. The genetic diversity detected among the varieties fingerprinted will be helpful to plant breeders in selecting parents for future cowpea improvement programmes.