Phenotypic Evaluation of Traits and Barcode Identification using Plastid-specific Ribulose Bisphosphate Carboxylase (Rbcl) Analysis on Lablab Beans [Lablab purpureus (L.) Sweet]

Abstract

Background: The importance of grain legumes in world food sustainability cannot be overemphasized. Minor legumes on the other hand, contribute to agricultural strengthening, especially in the context of sustainable crop and livestock production systems. In the context of assessing different legume species for crop improvement and identification, twenty (20) accessions of Lablab purpureus (L.) Sweet collected to determine the degree of trait variability and to identify accessions with potentials, which can contribute to grain and forage production. Methods: The present study involved the evaluation of twenty (20) accessions of Lablab purpureus (L.) Sweet from IITA, Ibadan. The accessions were grown in the experimental plot and DNA from young and healthy leaves were isolated for determination of genetic diversity using ribulose bisphosphate carboxylase (rbcL). The accessions were also categorized into groups based on the performances and the highest discriminating traits that accounted for greater variability using principal component analysis (PCA) and cluster analysis (CA) respectively. Result: Cluster analysis grouped all the twenty accessions into three clusters, where cluster I, cluster II and cluster III comprised of eight, seven and five accessions respectively. The PCA revealed hundred seed-weights, number of pod per plant and seed length as the most discriminating trait that accounted for greater variability in the Lablab accessions considered and they should be considered in the hyacinth bean improvement programs. Based on diverse level of phenotypic traits, accessions from each cluster were selected for barcode identification and comparison with other cultivars from other region. Results of the molecular analysis showed two clusters and authenticated the use of universal primers, ribulose bisphosphate carboxylase (rbcL) for DNA barcoding for successful amplification, identification and discrimination of Lablab purpureus (L). This revealed diversity of the considered accessions and provided information on relatedness to other accessions from other region of the world.