SAMAMBAIAS DO PARQUE ESTADUAL CÂNION DO RIO POTI, BURITI DOS MONTES, PIAUÍ

Essa pesquisa objetivou identificar as espécies de samambaias ocorrentes em afloramentos rochosos, no Parque Estadual Cânion do Rio Poti, Buriti dos Montes, Piauí, bem como o seu padrão de distribuição geográfica, os domínios fitogeográficos, o tipo de colonização nos substratos e as formas de vida das espécies. O material botânico foi coletado, herborizado e identificado seguindo a literatura usual especializada. A flora de samambaias do Parque Estadual Cânion do Rio Poti é composta por seis espécies, Adiantum deflectens Mart., Adiantum petiolatum Desv., Ceratopteris pteridoides (Hook.) Hieron., Ceratopteris thalictroides (L.) Brongn., Cheilanthes eriophora (Fée) Mett., distribuídas em duas famílias e quatro gêneros. A família Pteridaceae é a mais representativa (5 spp.), seguida de Salviniaceae (1 sp.). Dessas espécies, três (50%) têm distribuição nas américas, duas (33,3%) são Circum-Antártica e uma (16,7%) é da América do Sul. Além disso, duas espécies (33,4%) apresentam-se distribuídas de três a cinco domínios fitogeográfico e quatro (66,6%) em dois domínios. Cinco espécies (83.3%) são amplamente distribuídas nos Estados brasileiros (18-24) e uma (16,7%) apresenta moderada distribuição (4). Este estudo é a primeira listagem florística de samambaias para o parque, sendo uma importante contribuição do grupo para o domínio fitogeográfico da Caatinga, o Estado e o parque, que amplia sobre a ocorrência e a distribuição geográfica das espécies para o estado. Esses resultados não se dão por finalizado, sendo necessários novos estudos e levantamentos florísticos do grupo em outras fitofisionomias nas áreas de delimitação dentro e fora do parque para amostrar a real diversidade.

DISTRIBUIÇÃO, MORFOLOGIA E ANATOMIA DE MONILÓFITAS (SAMAMBAIAS) AQUÁTICAS DE PEQUENAS LAGOAS NA ÁREA ITAQUI-BACANGA, ILHA DE SÃO LUÍS - MA

Foi verificada a distribuição, feita a identificação taxonômica e a caracterização morfológica das espécies de monilófitas (samambaias) aquáticas de quatro lagoas pequenas temporárias e duas perenes localizadas ao longo da estrada que corta o setor industrial da área Itaqui-Bacanga, na ilha de SãoLuís - MA, durante o período de junho a setembro de 2011. As espécies encontradas nos ambientes amostrados foram Salvinia auriculata, Salvinia molesta (Salviniaceae) e Ceratopteris thalictroides (Pteridaceae). As três espécies apresentaram caráter de ocorrência anual e as Salviniaceaeestiveram amplamente distribuídas nos ambientes aquáticos observados. Dentre as monilófitas amostradas, apenas o gênero Salvinia apresenta heterosporia, com a presença de megasporângios e microsporângios. O gênero Ceratopteris, por sua vez, é homosporado, apresentando apenas esporos masculinos, que possuem um potencial para desenvolver gametófitos que futuramente poderão ser masculinos ou hermafroditas. A superfície foliar (tricomas), no caso de Salvinia, e o caule, no caso de Ceratopteris, são importantes estruturas na flutuabilidade das plantas. As três espécies apresentam adaptações morfológicas fundamentais para o seu estabelecimento e desenvolvimento nesses locais.Distribution, morphology and anatomy of aquatic Monilophyta (ferns) in small ponds at the area Itaqui-Bacanga, São Luís Island-MAABSTRACTDistribution, taxonomic identification and morphological analysis of aquatic species of Monilophyta (ferns) were carried out in four perennial and two temporary ponds located along the road through the industrial area Itaqui-Bacanga, at the São Luís Island – MA, from June to September 2011. The species found in the study sites were Salvinia auriculata, Salvinia molesta (Salviniaceae) and Ceratopteris thalictroides (Pteridaceae), all presenting an annual occurrence in nature and Salviniaceae were widely distributed in the ponds observed. Among the monilophytes sampled, only the Salviniagenus shows heterosporia, with the presence of megasporangia and microsporangia. The genus Ceratopteris in turn is homosporate, presenting only male spores, which have a potential to develop gametophytes that in the future may be male or hermaphrodite. The leaf surface (trichomes), in the case of Salvinia, and the stem, in the case of Ceratopteris, are important structures in the buoyancy of plants. The three species show important morphological adaptations for their establishment and development in these places.Keywords: Aquatic euphillophyta; Occurrence; Morphological adaptations; Ponds.

The diversity of pteridophytes in Siberut National Park, Mentawai Islands, West Sumatra, Indonesia

Mildawati, Sobir, Sulistijorini, Chikmawati T. 2020. The diversity of pteridophytes in Siberut National Park, Mentawai Islands, West Sumatra, Indonesia. Biodiversitas 21: 3200-3208. The diversity of Pteridophytes in the Siberut National Park (Siberut NP) Mentawai Islands, West Sumatra, is still very well preserved, but the information is limited. This research aimed to study the divesrity of Pteridophyte species in the Siberut NP in order to provide its taxonomic information using morphological data. The study consisted of exploration to collect plant specimens directly in the field, observation and identification of herbarium specimens in Herbarium Bogoriense and verification using online websites from various sources. A total of 69 species of Pteridophytes classified into 36 genera, and 20 families were recorded in the Siberut NP with Polypodiaceae has the most species diversity with 12 species of 6 genera. As many as 14 species are new records for Siberut Island, i.e. Selaginella involvens (Sw.) Spring (Selaginellaceae), Asplenium simile Blume (Aspleniaceae), Diplazium montanum V.A.V.R (Athyriaceae), Stenochlaena palustris (Burm) Bedd. (Gleichnaceae), Davallia solida (Forst.) Sw. (Davalliaceae), Callistopteris apiifolia (C.Presl) Copel., Crepidomanes humile Bosch (Hymenophyllaceae), Lindsaea carvifolia Kramer, Lindsaea doryphora Kramer, Lindsaea napaea Aldrew. (Lindsaeaceae), Nephrolepis biserrata (Sw.) Schott (Nephrolepidaceae), Ceratopteris thalictroides (L.) Brongn., Haplopteris ensiformis (Sw.) E.H.Crane and Syngramma alismifolia (Pr.) J.Sm. (Pteridaceae). The habitats of Pteridophytes found were mostly terrestrial and epiphytic (34 species each), while aquatic habitat was only found to one species. The results of this study will serve as baseline information of the plant diversity in the Siberut NP that can be used as the reference for future studies on Pteridophytes and to develop their conservation strategy in the region.

Dating Whole Genome Duplication in Ceratopteris thalictroides and Potential Adaptive Values of Retained Gene Duplicates

Whole-genome duplications (WGDs) are widespread in plants and frequently coincide with global climatic change events, such as the Cretaceous–Tertiary (KT) extinction event approximately 65 million years ago (mya). Ferns have larger genomes and higher chromosome numbers than seed plants, which likely resulted from multiple rounds of polyploidy. Here, we use diploid and triploid material from a model fern species, Ceratopteris thalictroides, for the detection of WGDs. High-quality RNA-seq data was used to infer the number of synonymous substitutions per synonymous site (Ks) between paralogs; Ks age distribution and absolute dating approach were used to determine the age of WGD events. Evidence of an ancient WGD event with a Ks peak value of approximately 1.2 was obtained for both samples; however, the Ks frequency distributions varied significantly. Importantly, we dated the WGD event at 51–53 mya, which coincides with the Paleocene-Eocene Thermal Maximum (PETM), when the Earth became warmer and wetter than any other period during the Cenozoic. Duplicate genes were preferentially retained for specific functions, such as environment response, further support that the duplicates may have promoted quick adaption to environmental changes and potentially resulted in evolutionary success, especially for pantropical species, such as C. thalictroides, which exhibits higher temperature tolerance.

Spore morphology of the representatives of the subfamily Ceratopteridoideae (J. Sm.) R.M. Tryon from the family Pteridaceae E.D.M. Kirchn. (Pteridophyta)

<p>Scanning electron microscopy (SEM) was used to perform a comparative study for four representatives of the subfamily <em>Ceratopteridoideae</em> (J. Sm.) R.M. Tryon from East Asia: <em>Ceratopteris thalictroides</em> Brongn., <em>C. pteridoides</em> (Hook.) Hieron., <em>Acrostichum aureum</em> Linn., and <em>A.</em> <em>speciosum </em>Willd. The analysis of the external morphology of the representatives of <em>Ceratopteridoideae</em> revealed a strong difference between <em>Ceratopteris</em> and <em>Acrostichum</em>.</p><p>The external morphology of spores of <em>Ceratopteris</em> and <em>Acrostichum</em> exhibited the features characterizing the family Pteridaceae as a whole: tetrahedral spores with a three-ray laesure, from triangular-roundish to roundish, distinct exosporium with a pronounced surface ornamentation and absence of perisporium, the exosporium surface varying from smooth and rough to that covered with large tubercles and roller-like bulges.</p><p>The external morphology of spores of <em>Acrostichum</em> is quite simple, although among other representatives of the family Pteridaceae,<em> </em>the<em> </em>spores of <em>Ceratopteris</em> have distinctive features: very large equatorial diameter (106–124 µm); spores are almost roundish; distinct cylindrical folds running parallel to the corners of the spore across its extensive distal surface.</p><p> </p>