SIMPLE SEQUENCE REPEATS (SSR) ANALYSIS OF GENETIC INTRASPECIFIC RELATIONSHIPS OF MORINGA OLEIFERA POPULATIONS FROM NIGERIA

Moringa oleifera Lam. (Moringaceae) is a multi-purpose economic plant whose commercial demand is on the increase in Africa. To meet this demand, it is significant to step up collections and diversity studies adaptable to higher productivity and utilization. The present study focuses on recently collected landraces/accessions of six populations of M. oleifera from different eco-geographical locations within Nigeria. A total of 70 accessions were evaluated for genetic intraspecific diversity using 20 SSR markers. Among the 20 SSR markers screened, 10 primer pairs (forward and reverse) were selected based on clear amplification products and reproducible scorable bands. Analysis of Molecular Variance (AMOVA), Principal Coordinates Analysis (PCoA) and cluster analysis (CA) were used to evaluate the genetic intraspecific diversity. A total number of 74 alleles with a range of 4 to 15 were detected among the 70 accessions. On the average, 7.4 alleles per locus were amplified in each accession. Allele frequency varied from 0.214 to 0.671 with a mean of 0.477; gene diversity from 0.487 to 0.885 with a mean of 0.669 while the average PIC value was 0.633. The observed and expected heterozygosity varied from 0.00 to 0.50 with a mean of 0.972 and from 0.00 to 0.250 with a mean of 0.567, respectively. AMOVA shows that 8 % of the genetic diversity was attributed to differences among the populations while 92 % of the variation (significant at p = 0.001) was due to differences within populations. Allelic patterns across the six populations aligned with the AMOVA result. The results of PCoA and CA identified high intraspecific similarities with few exceptions. Similarity coefficients (SC) of CA ranged from 0.53 to 1.00 and delineated the 70 accessions into seven groups. All accessions are distinguishable from each other at SC 1.00 except (soN066 and taN085) and (anN045 and anN047). The genetic relationships highlighted are significant for conservation, cultivation and genetic improvement of M. oleifera in view of the species socio-economic relevance to the people of Nigeria and Africa in general