Estimate of genetic diversity in cassutinga (Croton heliotropiifolius) based on molecular markers
The Croton heliotropiifolius (Euphorbiaceae family) is a shrubby plant that has attracted attention both by the need for conservation as for their pharmacological potential. The present study aimed to characterize the diversity and structure genetic of a population of C. heliotropiifolius present in a forest fragment in the city of Itapetinga, Bahia. Young leaves were collected from 41 individuals after DNA extraction were genotyped with 18 RAPD primers and 15 ISSR primers. Frequentist and Bayesian statistical methods were used to estimate the diversity and genetic structure, being observed a total of 164 polymorphic markers (mean 4 and 4.3 bands obtained with the use of RAPD and ISSR primers, respectively). Genetic diversity ranging between 0.12 and 0.48 and Bayesian method indicated by the existence of three probable gene pools (K = 3). Indications of association between spatial distribution of plants and the genetic structure were also observed, being likely that the dynamics of the seed carriage performed by the ants and the pollination by insects are related with the results observed. These results allow the beginning of a discussion about the diversity and genetics patterns of the species, since there are no studies of this nature for C. heliotropiifolius.
Key words: Caatinga, conservation genetics, genetic variability, inter simple sequence repeat (ISSR), random amplified polymorphic DNA (RAPD).