Genotyping of Pigeon Pea [Cajanus cajan (L.) Millsp.] Accessions Obtained from International Institute of Tropical Agriculture (IITA) Germplasm Using Random Amplified Polymorphic DNA

Abstract

Genotyping of crop plants, especially pigeon pea is very strategic in the global quest for crops that will be suitable for the precarious climate change as it provides genotypes for introgression. 22 pigeon pea accessions obtained from IITA germplasm were evaluated for genetic diversity. Genomic DNA was extracted using SDS protocol from young leaves of each accession and quantification was done. 12 RAPD primers were used for PCR DNA amplification and bands were visualized under UV light using ethidium bromide. Data analyses were computed using power marker version 3.25 and GenAlex 6.41 software. Results obtained revealed that the polymorphic information content ranged from 0.6458-0.9436 while percentage polymorphism ranged from 71.4-100. Average percentage polymorphism was 88.6%. UPGMA- based cluster generated two major clusters with 12 and 10 accessions, respectively. Principal coordinates (PCoA) contributed 20.75% to the total diversity. Though showing two clusters, it was not population-dependent. AMOVA result gave 0.00% to variation among the population while variation within population was 100%. Additionally, genetic diversity parameters such as heterozygosity, mean Nei unbiased genetic distance, genetic identity were 0.015, 0.006 and 0.994, respectively. However, Shannon’s information index, diversity and unbiased diversity were 1.858±0.02, 0.648±0.005 and 0.503±0.005. Pigeon pea accessions used in this present study revealed very narrow genetic diversity suggesting that they came from one population. The little variability observed may have been contributed by the accession TCc CITA 3. The implication of the results taking together is that further genotyping should be carried out using other DNA markers before explicit conclusion can be made.