MOLECULAR ANALYSIS OF GENETIC DIVERSITY IN SOURSOP (Annona muricata L.) USING SRAP MARKERS

Abstract

Knowledge of genetic diversity of cultivated plants is important under the climate change scenario and the presence of pests and diseases. Mexico is considered one of the countries with the largest diversity of species and agricultural production; therefore, crops with low genetic diversity are in a vulnerable situation. The study of genetic diversity in plants can be addressed through two methodologies: morphological and molecular characterization. The first methodology depends on environmental interactions, generating ambiguous data, while the second one, being able to detect specific DNA sequences, is considered stable and more reliable. The objective of this research was to evaluate, for the first time, the ability of SRAP (Sequencerelated amplified polymorphisms) molecular markers to determine the levels of genetic diversity of 88 soursop (Annona muricata L.) genotypes from five commercial orchards of the municipality of Compostela, Nayarit, Mexico (the world’s leading producer). Three polymorphic and reproducible combinations of SRAP markers were selected that revealed 126 alleles and 76.67 % polymorphism, the average number of bands observed with these combinations was 42. The expected heterozygosity (He) values varied among populations from of 0.144 to 0.176. Cluster analyses showed four main groups. Results of the analysis of molecular variance indicated that the largest variation (88 %) is found within populations. The information generated from this research can be useful to devise strategies for conservation and crop management.