Molecular Characterization of Seedlings Derived from Two Polyemberyonic Egyptian Mango Cultivars Using SSR Markers

Abstract

The molecular characterization and genetic variability between two of commercial and polyemberyonic Egyptian mango cultivars, namely: Zebda and Ewais, with thirty seedlings of their offspring were analyzed using 8 Simple Sequences Repeat (SSR) markers. LMMA _15 marker was discarded in data analysis because of producing only one band (monomorphic locus). Other seven markers produced total of 22 alleles with a high level of Polymorphism (~100 percent). The effective number of alleles ranged from 1.7, to 3.4 with average value of 1.47. Heterozygosity per locus varied from 0.00 to 0.75 with an average of 0.36. Polymorphic Information content (PIC) value scored from 0.41 to 0.70 with average of 0.57. The discrimination power (Dp) ranged between 0.11 and 0.72 with an average of 0.50 per locus. Generally, the genetic similarity values varied between 0.12 and 100% over 32 genotypes. A cluster analysis was used to determine genetic similarities. The dendrogram can be grouped into two major clusters (I and II). Cluster I consists of Ewais seedlings exhibiting 94-100% genetic similarity among them. Cluster II consists of all seedlings of Zebda cultivar exhibiting 52-100% genetic similarity and divided to two sub clusters. Seedling (Z_C_S2) was the most divergent in first sub cluster and second sub cluster exhibited less distance and consists of all other Zebda seedlings. This study additionally indicates that SSR markers are useful for distinguishing and characterizing mango genotypes. The genetic relatedness among these genotypes could provide useful information for conservation and selection of cross parents in breeding.