Genetic Diversity of some African Yam Bean Accessions in Ebonyi State Assessed using InterSimple Sequence Repeat (ISSR) markers

Abstract

The genetic variability of 17 accessions of African yam bean [Sphenostylis stenocarpa (Hochst ex. A. Rich) Harms] collected from eight different local government areas of Ebonyi State, Nigeria, was evaluated using Inter-Simple Sequence Repeat (ISSR) markers. A total of 18 primers were used to access the degree of polymorphism in the ISSR loci out of which 14 primers produced clear amplification bands that were used for the diversity analysis. The 14 markers amplified a total of 107 alleles ranging from 3 in ISSR 825 to 11 in ISSR 811and ISSR 826 with a mean of 8.27 alleles per primer. The polymorphic information content (PIC) values ranged from 0.38 to 0.88 with a mean value of 0.74. Twelve (12) out of the 14 ISSR primers (including ISSRs 811, 901, 835, 814, 818, 889, 826, 816, 890, 858, 827 and 825) demonstrated high potentials to discriminate among the African yam bean accessions by yielding PIC values as high as 0.66 to 0.88. A dendrogram of the ISSR data by Unweighted Pair Group Mean with Arithmetic (UPGMA) procedure clustered the 17 accessions into four major groups showing the genetic relatedness of the accessions and germplasm migrations among the producing LGAs of the State. The clustering pattern indicates that accessions from Abakaliki and Afikpo North LGAs of the State are more closely related, and so also are accessions from Ikwo and Afikpo South. The study revealed wide variation among the African yam bean accessions in Ebonyi State indicating ample opportunity for genetic improvement of the species.