Determination of genetic diversity of Nigerien sesame (Sesamum Indicum l.) using amplified fragment length polymorphisms markers

Sesame (Sesamum indicum L.) is one of the most important oilseed crops cultivated by man. The improvement of this crop requires a large exploitation of the available genetic variability on which its success depends. The present study aims to analyze the genetic diversity within 127 accessions of the sesame collection carried out in 6 regions of Niger (Tillabéri, Dosso, Maradi, Zinder, Diffa, and Tahoua). The Amplified Fragment Length Polymorphism (AFLP) marker was used to assess the level and structure of genetic diversity among sesame accessions collected in Niger. DNA was extracted using the CTAB extraction method. A total of 179 bands were amplified with the EcoRI-ACT/MseI-CTA primer of which 83.80% were polymorphic. The population structure indicated that the material was divided into three populations. Sesame genetic diversity is not geographically structured in Niger. Principal Component Analysis (PCA) in Sesamum indicum accessions with AFLP markers showed that the variation explained by the first two axes was 10.46%. Analysis of Molecular Variance Analysis (AMOVA), based on the three populations, showed very high intra-population diversity. The hypothesis that selecting genotypes of different geographical origin will maximize the diversity available for a breeding project is not relevant for sesame in Niger.