GENETIC DIVERSITY OF NATURAL POPULATIONS OF Annona crassiflora (MART.) BY cpDNA SEQUENCE ANALYSIS

Abstract

The severe degradation of Cerrado and the predatory extractivism that threatens many species calls for research to support future conservation programs. The ";araticunzeiro"; Annona crassiflora Mart.) is a tropical fruit tree species from Cerrado (Brazilian savannah) with high economic potential. Eighty-two individuals from eleven natural populations were submitted to genetic analysis to search for the genetic status of the species and to guide future conservation strategies. The analysis of the polymorphism present in sequences of the trnL of the chloroplastidial genome and further application of the models associated to the coalescent theory lead to the detection of high levels of genetic diversity in the species. The results showed that, in spite of the high level of genetic similarity among different populations, there is an incipient, but statistically significant, increasing differentiation process taking place due to current status of geographical isolation and genetic drift. The genetic differentiation coefficient among populations was 7.3%. The spatial genetic divergence analyses showed that genetic distances are not associated to geographical distances between populations, suggesting the absence of current gene flow among them. Populations from well conserved status and down to dangerous very low levels of genetic diversity were detected.

KEY-WORDS: Genetic diversity; cpDNA; chloroplast DNA.