Phenotypic and Molecular Characterization of Mango Cultivars in Southwest Nigeria

Abstract

Morphological and microsatellites (SSR) markers are efficient tools for determining genetic relatedness among mango cultivars. Seventeen mango cultivars were used for this study. Eight fruit quantitative traits were collected and subjected to mean separation using One-Way ANOVA and correlation using Principal Component Analysis (PCA). Also, molecular analysis was done using PCR-based SSR markers. The resulting binary matrix was analyzed using Numerical Taxonomy and Multivariate Analysis System (NTSYSpc). Significant variation (p ≤ .05) among all the 17 mango cultivars was observed for the eight quantitative traits studied. The PCA showed that the fruits length, width, thickness weights, %pulp and %stone contributed to 98.73% of the variation observed in all the mango cultivars. A total of 21 alleles were detected from the seven polymorphic primers ranging from two to five alleles per locus with an average of 3.0 alleles per locus. The polymorphic information content (PIC) ranged from 0.52 to 0.80 with an average of 0.66. Both the morphological and molecular markers showed that the mango cultivars were diverse except for ‘Saigon’ and ‘Julie’ as well as ‘Harden’ and ‘Lipen’ which though appear morphologically distinct based on the understudied traits but showed strong similarity to each other through molecular analysis. Dendrogram constructed using the Unweighted Pair Group Method with Arithmetic mean (UPGMA) based on SSR markers revealed a similarity coefficient of 48–93% indicating high level of variability and the presence of outbreeding. Results of the morphological and microsatellite (SSR) analyses showed wide diversity among the mango cultivar used in this study.

Keywords

• allele
• genetic diversity
• microsatellites
• traits
• ssr markers
• outbreeding