We describe alloenzyme variation in A. angustifolia populations of three separate geographical areas in southern Brazil. The genetic structure of populations was examined in seedtrees, embryos and effective pollen. Seven out of 24 enzyme loci were polymorphic. The average number of alleles per locus (24 loci) was 1.54, with 2.44 alleles per polymorphic locus. Mean expected and observed heterozygosities at the polymorphic loci were H e = 0.128 and H o = 0.132 for seed-trees, and H e = 0.142 and H o = 0.161 for embryos. All measures of genetic variability were highest in the most northern populations. Differences among localities explained 84.14 % and 92.06 % of the total genetic diversity in embryos and seed trees, respectively. Sex ratio was 1:1 in almost all populations. Female and male gene pools differed in allele frequencies, most significantly at loci 6-Pgdh-B and Skdh-B. This explains the excess of heterozygotes detected among embryos. No inbreeding or excess of heterozygotes was detected among adult seed trees. Genetic variation in A. angustifolia revealed a latitudinal gradient.
Araucaria angustifolia (Bert.) O.Ktze. is an economically important tree in southern Brazil. Indiscriminate exploitation is threatening this species with extinction. Conservation programs are urgently needed to save the remaining forest, and such programs must be guided by biological studies that genetically characterise the remaining populations. Pollen and seed dispersion patterns determine the distance of gene flow and directly influence genetic structure and effective population size. A. angustifolia is a wind-pollinated dioecious tree. For pollen-dispersal airflow, physical characteristics of pollen grain, such as size and shape, must be considered. The aim of this work was to determine the homogeneity of effective pollen clouds as well as to infer the physical characteristics of pollen. The homogeneity of pollen clouds of A. angustifolia was assessed for 70 trees of natural population in Brazil. Analysis of genetic variability and differentiation of the effective pollen clouds detected high diversity at the MDH-B and 6-PGDH-B loci. Heterogeneity G-tests indicated pollen pool heterogeneity in four of seven examined loci (GOT-B, PGM-A, SKDH-B and 6-PGDH-B). The pollen grains measured 61.50 μm. The floating rate ranged from 12.02 to 18.98 cm s–1. The physical characteristics of the pollen suggest that pollen dispersion is likely to be limited.
Geographic distribution forecast of Araucaria angustifolia (Bertol.) O. Kuntze. was studied. This is a native species that occurs more frequently in the southern region of Brazil and, to a lesser extent, in the southeasthern region. The study was based on points of occurrence that were collected over several years by Embrapa Forests and complemented by points obtained from herbaria, banks and several educational institutions, including the biological collections database Reference Center Environmental Information (CRIA), which gathers information from various herbaria in Brazil. We used mathematical models occurrence prediction, including: Bioclim, and Niche Mosaic. The models were selected for best representing the regions of occurrence. In addition to the points of occurrence, to compose the spatial modeling environmental data, climate, soil, and topography were needed. In the study we used only climate data such as the average minimum air temperature, average maximum air temperature, accumulated rainfall, and average relative humidity. We didn't use soil data because there was not a detailed survey available throughout the area of occurrence of the species. We conclude that the naturally occurring region of Araucaria was well represented using only the climate data and two models that well represented the occurrence of regions. With climate change, there is a strong tendency to reduce the potential area of Araucaria in Brazil, especially in regions at lower latitudes and altitudes.
Resumo -A araucária (Araucaria angustifolia (Bertol.) O. Kuntze.), conhecida como pinheiro-do-paraná, é uma espécie florestal nativa do Brasil, adaptada às regiões serranas frias e úmidas do sul e do sudeste do país e torna-se vulnerável diante das mudanças climáticas globais. Apresenta grande valor econômico, social e ambiental, pois é uma das espécies nativas com maior incremento e potencial de ganho genético, apresenta excelente qualidade de madeira e ainda produz sementes que podem ser usadas na alimentação humana e animal. Com o objetivo de conhecer a distribuição natural atual e o habitat das populações, percorremos parte das bordas da região de ocorrência da araucária, marcando a posição geográfica e altitude. Com as informações de campo, juntamente com dados secundários do Centro de Informações Ambientais (CRIA), mapeamos a distribuição da araucária no presente e simulamos para as próximas décadas, considerando a projeção de cenários climáticos futuros. Estes estudos são essenciais para a melhor compreensão dos riscos de extinção e das medidas mitigadoras que poderiam ser adotadas para reduzir os impactos das mudanças climáticas globais sobre a espécie, contribuindo, dessa maneira, para a sua conservação. Distribution and habitat of brazilian-pine according to global climate changeAbstract -Araucaria angustifolia (Bertol.) O. Kuntze., also known as brazilian-pine, is a forest native species from Brazil. A. angustifolia is more vulnerable to global climate change, considering it is living in cold and humid mountain regions from southern and southeastern Brazil. Among the native Brazilian forest species, it presents one of the greatest growth and genetic gain potential. It shows excellent wood quality and can still be used in human and animal food, presenting great economic, social and environmental value. In order to determine current distribution of the species and better know its habitat, we worked in the regions representing the borders of natural occurrence, identifying populations and getting trees altitude and geographycal position. Field information along with secondary data from the Environmental Information Center (CRIA) were used to map current distribution of brazilian-pine and to project the distribution in the next decades, with the projection of future climate scenarios. Mapping studies of ecological niches in present and future climate scenarios characterizing the environments in which they are living is essential for a better understanding of the risks of species extinction and which mitigating measures could be adequate to reduce the impacts of global climate change on species, thus contributing to the conservation and knowledge of this important species.
Araucaria (Araucaria angustifolia (Bert.) O. Ktze) is a primarily dioecious species threatened with extinction that plays an important social and economic role especially in the southern region of Brazil. The aim of this work is to investigate the diversity and likely determinants of genetic lineages in this species for conservation management. For this, a collection of 30-year-old Araucaria was used. Accessions collected from 12 sites across the species range were analyzed, with ten individuals per site. The SSR genotyping was conducted with 15 loci and the data were analyzed using several complementary approaches. Descriptive statistics among sampling sites were used and diversity was partitioned non-hierarchically to estimate the size and composition of genetic clusters using a Bayesian assignment method. To explore possible biological implications of differences between Niche Models and habitat suitability, a series of statistical procedures were used, and tests were carried out using the software ENM Tools and Maxent. Populations from the southernmost zone showed higher genetic variation and a lower inbreeding coefficient compared to the northernmost zone, which may correlate with their isolation. A positive relation between genetic differentiation and geographic distance was observed. Two genetic groups (southernmost and northernmost zones) were evident. The Niche modelling showed separate ranges for each genetic lineage suggesting that differences in selection pressure may be playing a role in the apparent differentiation and may be adaptive. Finally, an evident correlation was observed between genetic data and habitat suitability. The two distinct groups observed must be considered as independent units for conservation and hybridization in breeding programs.
-We describe isoenzymes variability in six populations of Grevillea robusta from a provenances and progenies test established in a randomized block design with five plants per replication in Southern Brazil. The population genetic structure was examined by using biochemical markers in 5-year old trees, specifically at MDH-3, PGM-2, DIA-2, PO-1, PO-2, SOD-1, and SKDH-1 loci. The northern provenances (Rathdowney and Woodenbong) showed a strong divergence in relation to the average of provenances when alleles per locus (Ap), allele richness (Rs), Nei's gene diversity (H), and inbreeding coefficient (f) were considered. Inbreeding in varying degrees was detected. The commercial control showed the highest inbreeding coefficient, (f = 0.4448), whereas the provenance average was f = 0.2306, possibly due to insufficient sampling of populations in their origin (Australia). Despite its restricted natural range, a positive correlation between genetic divergence and geographic distance among original populations was detected. Genetic distance and cluster analyses based on the Bayesian model revealed three distinct provenance groups: 1) Rathdowney-QLD and Woodenbong-QLD; 2) Paddy's Flat-NSW; and 3) Mann River-NSW, Boyd River-NSW and the commercial control (material used in Brazil). The grouping of the control to both Mann River-NSW and Boyd River-NSW provenances suggests that the northern provenances have the highest potential for genetic improvement of wood productivity in Brazil, due to their high genetic diversity and low inbreeding coefficient. RESUMO -A variabilidade isoenzimática para seis populações de Grevillea robusta, oriundas de um teste de procedências/progenies, implantado no delineamento em blocos casualizados com 5 plantas por parcela, no Sul do Brasil, é descrita. A estrutura genética da população foi analisada utilizando-se marcadores bioquímicos, aos 5 anos de idade, especificamente para os locos MDH-3, PGM-2, DIA-2, PO-1, PO-2, SOD-1, e SKDH-1. As procedências do norte de ocorrência natural (Rathdowney e Woodenbong) apresentaram divergência genética superior, em relação à média das progênies, considerando o número de alelos por locus, (Ap), a riqueza alélica (Rs), a diversidade genética de Nei (H), e o coeficiente de endogamia (f). A endogamia foi detectada em diversos graus. A testemunha comercial apresentou o maior coeficiente de endogamia, (f = 0,4448), comparativamente à média das procedências (f = 0,2306), possivelmente devido à insuficiente amostragem populacional na região de origem (Austrália). Apesar de sua ocorrência natural restrita, observou-se correlação positiva entre divergência genética e distância geográfica entre as populações originais. A distância genética e análise de cluster, baseada no modelo bayesiano, mostrou três grupos de procedências distintos: 1) Rathdowney-QLD e Woodenbong-QLD; 2) Paddy's Flat-NSW; e 3) Mann River-NSW, Boyd River-NSW e a testemunha comercial (material utilizado no Brasil). O agrupamento da testemunha com as procedências Mann River-NSW e Boyd River-NSW...
Resumo -Um dos principais impedimentos para a adoção de novas espécies para as plantações comerciais é a escassez de sementes geneticamente melhoradas, em quantidade suficiente para abastecer o mercado. Portanto, o objetivo deste estudo foi estimar parâmetros genéticos que possibilitem a realização de seleção individual em um teste combinado de procedências e progênies de P. greggii como base para transformar a área num pomar de sementes por mudas. No presente trabalho, foram avaliadas cinco procedências e quarenta e sete progênies de P. greggii da região norte e central do México. O experimento foi instalado no município de Ponta Grossa, Paraná, Brasil, no delineamento de blocos casualizados com nove repetições e cinco plantas por parcela. Aos 13 anos após o plantio, avaliou-se o DAP (diâmetro do tronco a 1,3 m de altura), altura total e forma do fuste. Os parâmetros genéticos foram estimados utilizando o software SELEGEN-REML/BLUP. Constatou-se considerável variabilidade genética, fato este que indica boas possibilidades de ganho genético a partir da seleção de matrizes superiores. As procedências da região sul apresentaram alto potencial de produtividade para plantios comerciais na região de Ponta Grossa. O progresso esperado em crescimento, após um ciclo de seleção de matrizes para formação de pomar de sementes por mudas, foi de 21,6 % em volume de madeira.
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