Genetic assessment of Mangifera indica Linn. (Mango) from selected locations in Oyo State, Nigeria

Abstract

This study characterized five (5) varieties of mango comprising 15 accessions collected from Ogbomosho, Saki, Ibadan and other locations in Oyo State. The field experiment was laid out in a Complete Randomized Design (CRD) with three replicates. Morphological characters were assessed on the stem, leaf and fruit. Also, Molecular studies (DNA amplification and sequencing) were carried out on 15 accessions of mango. The edited sequences were blasted in the National Center of Biotechnology Information (NCBI) data website. The Results showed variability in morphological characters of Mango. Ogbomosho Acc-2 performed best for leaf width (4.53cm) and lamina length (16.25cm) while Isehin Acc-1 had the highest number of leaves per seedling (7.76cm), leaf length (17.06cm), leaf area (38.84cm), petiole length (2.27cm), plant height (24.07cm) respectively. The Number of leaves had positive correlation with Leaf length (r=0.53), Leaf Area (r=0.59), Internodal Length (r= 0.55) and strong positive correlation with plant height (r=0.73) at p≤0.05.  The success rate of amplified DNA products and sequencing was 77.78%. The query coverage of 99% and 100% confirmed positive amplification and sequencing of rbcL gene in the mango varieties.  The sequences blasted in the NCBI data website were identified to be similar to accession KX871231.1. Sequences of rbcL marker showed genetic differences among samples; Grafe and OGBM Acc -1. Genetic distance between varieties from the same location was most often lower with Grafe mango being the most distant variety with genetic distance of 0.114-0.117. There were morphological and molecular variations in mango varieties and accessions. Isehin Acc-1, Saki Acc-1 and OGBM Acc-6 accessions had better growth performance