Genetic variability in mango genotypes detected by RAPD markers.
Souza V. A. B. de, Lima P. S. da C.
Author Affiliation: Embrapa Meio-Norte, Cx. Postal 1, CEP 64006-220 Teresina, Piaui State, Brazil.
: 303-310
Abstract : Forty mango genotypes of the Embrapa Meio-Norte mango collection were examined for random amplified polymorphic DNA (RAPD) markers with 32 random primers. Thirteen of these 32 initially screened primers that indicated more polymorphic DNA amplification patterns were selected for the RAPD reactions. Each genotype was characterized by its banding pattern, using 1-kb DNA ladder as standard DNA. A genetic similarity matrix based on Jaccard's coefficient, and a phenogram using unweighted pair-group method with arithmetic average (UPGMA) clustering was constructed. Initially, the genotypes were grouped into two distinct groups (J=0.36): one formed by 'Mallika' and 'Amrapali' and another comprised of the other genotypes, which was subdivided into other two groups (J=0.41), one formed by 'Manzanilo', 'Van Dyke' 'Palmer' and 'Keitt', and the other including the remaining genotypes. This latter group was still splited in two other groups (J=0.54), one including 'Edward', 'Winter', 'Alfa Emprapa 142', 'Kensington' and the advanced breeding selection CPAC 98/86 ('Beta') and the other, including 'Santa Alexandrina', 'Sensation', 'Glenn', 'Irwin' and all 25 Rosa's genotypes. In Rosa's group, the similarity coefficient ranged from 0.55 to 0.98, indicating a reasonable amount of genetic variation within this cultivar. Bootstrap consistency test, however, indicated that only three groups ('Mallika' and 'Amrapali', 'Van Dyke', 'Palmer' and 'Keitt', and 'Irwin' and 'Glenn') were really diverged.