RESUMO
Abstract This work is a floristic study of Selaginella in Maranhão. The species survey is based on collections from fieldwork conducted between April 2006 and February 2023 and specimens from Maranhão deposited at the CCAA, HBRA, MG, and SLUI herbaria. Ten species were identified: Selaginella conduplicata, S. convoluta, S. erythropus, S. flagellata, S. gynostachya S. marginata, S. minima, S. radiata, S. simplex, and S. sulcata. We report the first record of S. gynostachya for Maranhão and the Cerrado domain in Brazil. Until now, this species was only known from areas of Amazonia. We provide a map with records, an identification key, and comments about the identification and geographic distribution of Selaginella species in Maranhão state. For the new record, we also provide photos.
Resumo O presente trabalho trata do estudo florístico de Selaginella no Maranhão. O levantamento de espécies foi realizado com base em coletas de campo realizadas entre abril de 2006 e fevereiro de 2023 e em análise de espécimes coletados no Maranhão e depositadas nos herbários CCAA, HBRA, MG e SLUI. Foram identificadas 10 espécies: Selaginella conduplicata, S. convoluta, S. erythropus, S. flagellata, S. gynostachya S. marginata, S. minima, S. radiata, S. simplex e S. sulcata. Relatamos a primeira ocorrência de S. gynostachya para o Maranhão e também para o domínio do Cerrado Brasileiro. Até então essa espécie era registrada somente em áreas amazônicas. Neste artigo apresentamos um mapa com pontos de coleta, uma chave de identificação e comentários sobre a identificação, ecologia e distribuição geográfica para as espécies de Selaginella do Maranhão. Para o novo registro apresentamos também fotos.
RESUMO
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.