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

• Main Authors: Mirella Pupo Santos, João V.S. Rabelo Araujo, Arthur V. Sant’anna Lopes, Julio Cesar Fiorio Vettorazzi, Marcela Santana Bastos Boechat, Fernanda AbreuSantana Arêdes, Naiara Viana Campos, Emiliano Nicolas Calderon, Fernando M. Gomes Santos, Tais Nogueira Fernandes, Rodrigo Nunes da Fonseca, Messias Gonzaga Pereira, Guilherme Oliveira, Daniel Basilio Zandonadi, RodrigoLemes Martins, Francisco de Assis Esteves
• Format: Article
• Language: English
• Published: PeerJ Inc. 2020-11-01
• Series: PeerJ
• Subjects: Isoetes cangae; Isoetes serracarajensis; ISSR; Lycophyte; Gene flow; Mating system
• Online Access: https://peerj.com/articles/10274.pdf

Background Two endemic lycophyte species Isoetes cangae and Isoetes serracarajensis have been recently described in the State of Pará in the Amazon forest located in northern Brazil. Isoetes 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 I. cangae and I. serracarajensis 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 I. cangae and I. serracarajensis 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 I. cangae and I. serracarajensis, respectively. The coefficient of genetic differentiation between population areas (GST) showed a higher value in I. serracarajensis (0.5440). Gene flow was higher in I. cangae (1.715) and lower in I. serracarajensis populations (0.419). Overall, the results further show that I. serracarajensis and I. cangae 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.