The genetic diversity and population structure of two endemic Amazonian quillwort ( L.) species.

BACKGROUND

Two endemic lycophyte species and have been recently described in the State of Pará in the Amazon forest located in northern Brazil. L. has survived through three mass extinctions. Plants are considered small-sized, heterosporous, and can display a great diversity of physiological adaptations to different environments. Thus, the current study aimed to estimate the genetic variation of the populations of and to generate information about their different mechanisms for survival at the same geographical location that could point to different reproductive, adaptative and dispersal strategies and should be considered for effective conservation strategies.

METHODS

The genetic diversity and population structure of and were investigated using Inter Simple Sequence Repeat (ISSR) molecular markers. Total genomic DNA was isolated, and the genetic diversity parameters were calculated.

RESULTS

The sixteen primers produced 115 reproducible bands, 87% of which were polymorphic. A high level of polymorphic loci (81.74% and 68.48%) and a high Shannon index (Sh = 0.376 and 0.289) were observed for and , respectively. The coefficient of genetic differentiation between population areas (G) showed a higher value in (0.5440). Gene flow was higher in (1.715) and lower in populations (0.419). Overall, the results further show that and are two species with considerable genetic variation and that these differences may reflect their habitats and modes of reproduction. These results should be considered in the development of effective conservation strategies for both species.