Genetic structure and diversity of Senefeldera verticillata (Euphorbiaceae) in semideciduous seasonal forest fragments
Senefeldera verticillata (Euphorbiaceae) is a species that exclusively occurs in the Atlantic Forest; it is used in the restoration and recovery of degraded areas and has therapeutic uses. Due to the scarcity of information on genetic patterns of this species, genetic diversity was characterized by the use of molecular markers, Inter Simple Sequence Repeats (ISSR). Leaf samples were collected from two populations located in the National Forest (FLONA) of Pacotuba and in the Private Reserve of Natural Patrimony (RPPN) Cafundó. Twelve ISSR primers were used, resulting in 179 amplification products, with 76% polymorphic bands. The genetic diversity values of Nei (H’) and Shannon index (I) were 0.329 and 0.503, respectively. The estimated historical gene flow among the fragments was high (Nm = 13.542). Molecular analysis of variance showed that most of the genetic diversity is within conservation units (95%), with genetic differentiation among populations considered moderate (ΦST = 0.0501). Thus we propose conservation of genetically dissimilar individuals in the two localities, so that the existing variability is preserved. Six groups were identified by the unweighted arithmetic means clustering method, in which 30 matrices of both fragments were collected in a single group. Bayesian analysis indicated that there is a small degree of genetic variation among populations, though organization of groups by locality was not confirmed by the STRUCTURE software. We were able to identify genetic divergence among the trees evaluated in these conservation units, demonstrating the usefulness of the ISSR markers. In addition, this information could help in the adoption of strategies for the selection of respresentative specimens to compose a seed bank of native forest species of the state of Espírito Santo.