ORIGINAL ARTICLE Genetic Resources (2021), 2 (3), 36–50 DOI: 10.46265/genresj.OBVW6791 https://www.genresj.org ISSN: 2708-3764 Biodiversity assessment of African locust bean (Parkia biglobosa) accessions from Savanna and Forest zones of Nigeria as revealed by seed storage proteins and RAPD markers Pamela E Akin-Idowu * , a , Ayodeji O Aduloju a , Omolara I Akinyoola a , Dorcas O Ibitoye b , Uterdzua Orkpeh b , Usifo G Adebo a, c and Yemisi O Olagunju a a Biotechnology Unit, National Horticultural Research Institute, P.M.B. 5432, Jericho Reservation Area, Idi-Ishin, Ibadan, Nigeria b Genetic Resources Unit, National Horticultural Research Institute, P.M.B. 5432, Jericho Reservation Area, Idi-Ishin, Ibadan, Nigeria c School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, Australia Abstract: Understanding the level and distribution of genetic diversity in African locust bean (Parkia biglobosa) would strengthen breeding and conservation programmes towards domestication and sustainable use of this species. Sixteen accessions of P. biglobosa were assessed for variability based on seed morphology, seed protein and DNA profiling. Significant variation in seed characteristics were observed across locations. Seed protein profiling by SDS-PAGE revealed homogeneity as most bands were found common in all accessions, indicating that the protein profiles are highly conserved. Protein profiling separated the 16 accessions into four major clusters at 0.93 similarity coefficient. Most accessions grouping into Cluster 1 had a similarity coefficient of close to 100% and were from the Derived Savanna suggesting the presence of duplicates. Accessions NH/2016/P14, NH/2016/P03 and NH/2016/P04 grouped into clusters II, III and IV; respectively. Sixteen RAPD markers generated a total of 256 bands of which 63.67% were polymorphic. Gene diversity ranged from 0.41 to 0.93 and Polymorphic Information Content (PIC) from 0.39 to 0.93. The RAPD-based dendrogram separated accessions into six groups at 0.68 similarity coefficient. Based on a polymorphic seed storage protein marker a genetically distinct accession NH/2016/P04 could be exploited for breeding purposes. The homogeneity of alleles and narrow genetic base as revealed by RAPD and SDS- PAGE analyses suggests possible loss of intraspecific genetic diversity. Thus, intensification of germplasm collections across the different agroecological zones and characterization using specific markers will give a better understanding of diversity of P. biglobosa in order to enhance selection towards conservation, breeding and sustainable utilization. Keywords: African locust bean, genetic diversity, agroecological zone, RAPD, SDS-PAGE, Parkia biglobosa Citation: Akin-Idowu, P. E., Aduloju, A. O., Akinyoola, O. I., Ibitoye, D. O., Orkpeh, U., Adebo, U. G., Olagunju, Y. O. (2021). Biodiversity assessment of African locust bean (Parkia biglobosa) accessions from Savanna and Forest zones of Nigeria as revealed by seed storage proteins and RAPD markers. Genetic Resources 2 (3), 36–50. doi: 10.46265/genresj.OBVW6791. © Copyright 2021 the Authors. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. ∗ Corresponding author: Pamela E Akin-Idowu (elohoidowu@hotmail.com) Introduction In Sub-Saharan Africa several indigenous agroforestry systems exist containing woody species known as multipurpose trees. Africa locust bean [Parkia biglobosa (Jacq.) R. Br. ex G. Don] is a well-known indigenous Received: 04.05.2020 Accepted: 11.06.2021 Published online: 29.06.2021