Do plant populations on distinct inselbergs talk to each other? A case study of genetic connectivity of a bromeliad species in an Ocbil landscape

Here, we explore the historical and contemporaneous patterns of connectivity among Encholirium horridum populations located on granitic inselbergs in an Ocbil landscape within the Brazilian Atlantic Forest, using both nuclear and chloroplast microsatellite markers. Beyond to assess the E. horridum population genetic structure, we built species distribution models across four periods (current conditions, mid-Holocene, Last Glacial Maximum [LGM], and Last Interglacial) and inferred putative dispersal corridors using a least-cost path analysis to elucidate biogeographic patterns. Overall, high and significant genetic divergence was estimated among populations for both nuclear and plastid DNA (ΦST(n) = 0.463 and ΦST(plastid) = 0.961, respectively, p < .001). For nuclear genome, almost total absence of genetic admixture among populations and very low migration rates were evident, corroborating with the very low estimates of immigration and emigration rates observed among E. horridum populations. Based on the cpDNA results, putative dispersal routes in Sugar Loaf Land across cycles of climatic fluctuations in the Quaternary period revealed that the populations' connectivity changed little during those events. Genetic analyses highlighted the low genetic connectivity and long-term persistence of populations, and the founder effect and genetic drift seemed to have been very important processes that shaped the current diversity and genetic structure observed in both genomes. The genetic singularity of each population clearly shows the need for in situ conservation of all of them.

Patterns of gene flow in Encholirium horridum L.B.Sm., a monocarpic species of Bromeliaceae from Brazil

Encholirium horridum is a bromeliad that occurs exclusively on inselbergs in the Atlantic Forest biome of Brazil. These rock outcrops form natural islands that isolate populations from each other. We investigated gene flow by pollen through paternity analyses of a bromeliad population in an area of approximately 2 ha in Espírito Santo State, Brazil. To that end, seed rosettes and seedlings were genotyped using nuclear microsatellite loci. A plot was also established from the same population and specimens were genotyped to evaluate their fine-scale spatial genetic structure (SGS) through analyses of spatial autocorrelation and clonal growth. Paternity analysis indicated that 80% of the attributed progenitors of the genotyped seedlings were from inside the study area. The pollen dispersal distances within the area were restricted (mean distance of 45.5 m, varying from 3 to 156 m) and fine-scale SGS was weak (F(ij) = 0.0122, P < 0.001; Sp = 0.009). Clonal growth was found to be a rare event, supporting the monocarpy of this species.

Use of the palm Euterpe edulis martius in landscape units managed by migrants of German origin in Southern Brazil

BACKGROUND

People influence their environments through the manipulation of landscapes and species. Human influence on the landscape may lead to the development of differentiated landscape units that originate from past use and may be related to the presence of certain species. This study investigated the presence of the palm Euterpe edulis and its current and past importance in landscape units established by a community of German descendants located in southern Brazil. The objectives of this study were to characterize the use of the species, to identify the importance of E.edulis for the German immigrant community, to identify past and current uses of E.edulis, to describe the historical use of the landscape, and lastly, to identify landscape units in which E.edulis is found.

METHODS

The researched community is composed of people of German descent residing in southern Brazil. A variety of research tools were used to achieve the objectives of the research. Semi-structured interviews and free-listings were conducted in all family units. The interviews focused on groups of people in the community who had current or historical connection with the species. Group workshops and guided tours were conducted to identify different landscape units. The data were analyzed using descriptive statistics, use-value index, citation frequency, salience index, and informant perception analysis.

RESULTS

Over the historical period studied, the community demonstrated changes with respect to economic activities. These changes are reflected in the transformation of the landscape. The species E.edulis was and still is very important for people in the community; its importance is reflected in its high use value, citation frequency and salience. The species is found within various landscape units in the community as well as in homegardens and in secondary forests.

CONCLUSIONS

The landscape heterogeneity of this community is influenced by changes in economic activities and by the relationship with the conservation unit. Landscape units resulting from this relationship may be identified. The species E.edulis is found within these landscape units and is integrated into the livelihood of the community.

Relação entre bromélias epifíticas e forófitos em diferentes estádios sucessionais

O presente estudo teve como objetivo analisar a relação entre as bromélias epifíticas e a vegetação arbustiva e arbórea registrada em diferentes estádios sucessionais da Floresta Ombrófila Densa, com o intuito de detectar forófitos potenciais à colonização por bromélias. Os forófitos foram selecionados por meio do método de quadrantes centrados, e verificada a relação entre as suas características morfológicas com a ocorrência de bromélias, por meio da análise de Correlação de Spearman e teste de qui-quadrado. Foram registradas 27 espécies bromélias epifíticas pertencentes a oito gêneros, e 85 espécies forofíticas. O diâmetro foi a variável que apresentou maior influência na riqueza das bromélias. Forófitos com cascas persistentes e com textura rugosa apresentaram maior frequência de bromélias.

Development of SSR markers for Encholirium horridum (Bromeliaceae) and transferability to other Pitcairnioideae

PREMISE OF THE STUDY

We developed a set of primers for Encholirium horridum, a species closely associated with inselbergs of the Atlantic Forest, to assess genetic diversity, genetic structure, and gene flow between populations of this species. •

METHODS AND RESULTS

From an enriched genomic library, 10 primer pairs for polymorphic microsatellite regions were developed. The average number of alleles ranged from eight to 20, and the observed and expected heterozygosities ranged from 0.000 to 1.000, and from 0.000 to 0.929, respectively, across the populations. •

CONCLUSIONS

These markers will be useful in evaluating genetic diversity, spatial genetic structure, analysis of gene flow by paternity, and characterization of mating system of E. horridum.