Abstract Detail

Biology of Isoetales, a colloquium in honor of Dr. W. Carl Taylor

Bernardino de Souza Pereira, Jovani [1], Pinangé , Diego S. B.  [1], Carvalho-Filho, Nelson [1], Guimarães, José T. F. [1], Oliveira, Guilherme [1], Giulietti-Harley, Ana M. [1].

The evolutionary history of Neotropical Isoetes, relicts from South America.

Brazil comprises the largest tropical area from South America and presents a huge diversity of environments, which reflects in its highly diverse flora. The country presents the greatest diversity of plants in the world. In the genus Isoetes, Brazil is one of the richest regions with 27 species. Besides the taxonomic diversity, our study revealed that the genus is also phylogenetically diverse in this region. The species are represented in two of the major clades of Isoetes (American and Gondwanan core). Climate changes along with aquatic environment degradation may have been causing the decline of the populations in its largest ecosystems such as Cerrado, Caatinga, Atlantic and Amazon rain forest. Given these factors, to study taxonomy and phylogenetic relationships of the Brazilian Isoetes species and to address the conservation status of the species are key to the understanding of the evolutionary history of the genus as well as to establish policies to conservation of the populations. In this talk, I will address the progress and perspectives of the studies in the genus Isoetes from Caatinga, Cerrado and Amazon ecosystems in Brazil. Our study showed that these species are relicts more closely related to species from India, Africa and Australia (Gondwanan core clade) than species from subtropical and temperate areas from southeastern Brazil and the western coastal region from South America (Andes). Although phylogenetic studies have well supported these species in the Gondwanan core clade, the relationships among them still need to be better resolved. Also, our data including chromosome countings and nuclear DNA contents indicate hybridization followed by duplication of the chromosome number as confounding factors to resolve the phylogenetic relationships among these species. Efforts to assess the diversity and conservation status of these populations in Central-Western and Northern Brazil led us to rediscover species that were known only from the type-specimens collected more than one and a half century ago. We also highlight the need not only to compare but also to statistically test the morphological differences among the species towards a better taxonomy of Isoetes from South America.

1 - Instituto Tecnológico Vale, Belém, PA, 66055090, Brazil

Keywords:
Gondwanan core clade
Brazilian Amazon
Phylogenetic Comparative Methods
Taxonomy
Polyploidy.

Presentation Type: Colloquium Presentations
Session: C05, Biology of Isoetales, a colloquium in honor of W. Carl Taylor
Location: 101/Mayo Civic Center
Date: Tuesday, July 24th, 2018
Time: 10:15 AM
Number: C05008
Abstract ID:209
Candidate for Awards:None