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Roupala montana var. brasiliensis is a timber tree species native to the Cerrado and Atlantic Forest areas of Brazil. The wood was exploited for international markets, but there is no information on the conservation status of its natural populations, nor on other key aspects, such as mating system, gene flow, and inbreeding depression, essential for the species' sustainable management and conservation. We report the first study of any Roupala species to apply a validated set of species-specific microsatellite markers to genotype adults, juveniles, and seedlings, and analyse genetic diversity, inbreeding, effective population size, and mating system. We studied four populations of the species in areas of mixed Ombrophilous forest with different disturbance levels (undisturbed to strongly disturbed) in southern Brazil. The species occurs at low frequency in the study forests, but the populations are genetically diverse without significant differences in genetic diversity levels related to disturbance. The study also indicated resistance to the severe fragmentation associated with low density of individuals, with a stable mating system showing preferential outcrossing, with some inbreeding (tm ≈ 0.83, F > 0.165). Despite being spatially isolated from each other, the populations are not reproductively isolated, receiving immigrant pollen from long distances, although there was no evidence of gene flow into the populations via seeds. Seedlings from self-fertilization show low levels of inbreeding depression, which may reflect earlier pre-germination selection events. There was loss of allelic wealth in the younger cohorts, which may be a warning of the fragility of the genetic diversity detected in populations. We consider the implications of the results for the development of ex and in situ conservation and tree improvement programs. [ABSTRACT FROM AUTHOR] more...

Worldwide, the significant fragmentation of tropical forests has resulted in the isolation of tree populations; this in turn has affected genetic diversity due to increases in inbreeding, leading to inbreeding depression (ID). Ex situ provenance and progeny trials are an effective strategy for population genetic conservation that can help combat the negative impacts of forest fragmentation on tree populations. Balfourodendron riedelianum is an endangered tree of the Atlantic Forest, for which conservation and environmental reforestation strategies are needed to ensure the preservation of the species. Microsatellite loci were used to genotype adult trees and descendant seedlings in an ex situ provenance and progeny trial located in São Paulo State, Brazil. The aim was to inform seed production management strategies for environmental restoration based on estimates of effective population size (Ne), pollen dispersal, mating pattern and ID for the traits root collar circumference (RCC) and plant height (H). The Ne (148.9) is adequate for sort-term ex situ conservation. Seedlings were predominantly outcrossed (93–96.2%), but selfing (3.8–7%) and mating between relatives (20–28.1%) show that the species is self-compatible. Pollen was dispersed through a pattern of isolation by distance. Selfed and biparental inbred seedlings showed lower values of RCC (2.98–3.10 mm) and observed heterozygosity (Ho = 0.25–0.34), and higher fixation index (F = 0.29–0.61) than seedlings from mating between unrelated trees (RCC = 3.30 mm, Ho = 0.51, F = 0.07). Mating among full-sibs showed the highest ID (8.1–12.4%). In the studied provenance and progeny trial, the selection of one tree per plot can minimize the production of biparental inbred seeds. Our results show that the provenance and progeny trial can serve as a seed source for environmental restoration. [ABSTRACT FROM AUTHOR] more...

Abstract: Hymenaea stigonocarpa is a neotropical tree that is economically important due to its high‐quality wood; however, because it has been exploited extensively, it is currently considered threatened. Microsatellite loci were used to investigate the pollen and seed dispersal, mating patterns, spatial genetic structure (SGS), genetic diversity, and inbreeding depression in H. stigonocarpa adults, juveniles, and open‐pollinated seeds, which were sampled from isolated trees in a pasture and trees within a forest fragment in the Brazilian savannah. We found that the species presented a mixed mating system, with population and individual variations in the outcrossing rate (0.53–1.0). The studied populations were not genetically isolated due to pollen and seed flow between the studied populations and between the populations and individuals located outside of the study area. Pollen and seed dispersal occurred over long distances (>8 km); however, the dispersal patterns were isolated by distance, with a high frequency of mating occurring between near‐neighbor trees and seeds dispersed near the parent trees. The correlated mating for individual seed trees was higher within than among fruits, indicating that fruits present a high proportion of full‐sibs. Genetic diversity and SGS were similar among the populations, but offspring showed evidence of inbreeding, mainly originating from mating among related trees, which suggests inbreeding depression between the seed and adult stages. Selfing resulted in a higher inbreeding depression than mating among relatives, as assessed through survival and height. As the populations are not genetically isolated, both are important targets for in situ conservation to maintain their genetic diversity; for ex situ conservation, seeds can be collected from at least 78 trees in both populations separated by at least 250 m. [ABSTRACT FROM AUTHOR] more...

Throughout the world, large trees are increasingly rare. Cariniana legalis is the tallest tree species of the Brazilian Atlantic Forest, reaching up to 60 m in height. Due to extensive deforestation of the Atlantic Forest, remnant C. legalis populations are small and spatially isolated, requiring the development of strategies for their conservation. For in situ and ex situ genetic conservation to be effective, it is important to understand the levels and patterns of spatial genetic structure (SGS), and gene flow. We investigated SGS and pollen flow in three small, physically isolated C. legalis stands using microsatellite loci. We measured, mapped, and sampled all C. legalis trees in the three stands: 65 trees from Ibicatu population, 22 trees from MGI, and 4 trees from MGII. We also collected and genotyped 600 seeds from Ibicatu, 250 seeds from MGI, and 200 seeds from MGII. Significant SGS was detected in Ibicatu up to 150 m, but substantial levels of external pollen flow were also detected in Ibicatu (8%), although not in MGI (0.4%) or MGII (0%). Selfing was highest in MGII (18%), the smallest group of trees, compared to MGI (6.4%) and Ibicatu (6%). In MGI and MGII, there was a strong pattern of mating among near-neighbors. Seed collection strategies for breeding, in situ and ex situ conservation and ecological restoration, must ensure collection from seed trees located at distances greater than 350 m and from several forest fragments. [ABSTRACT FROM AUTHOR] more...

This study examines the levels of gene flow, the distance and the patterns of pollen and seed dispersal, the intra-population spatial genetic structure (SGS) and the effective population size of a spatially isolated Myracrodruon urundeuva population using five microsatellite loci. The study was carried out in the Paulo de Faria Ecological Station, São Paulo State, Brazil and included the sampling and mapping of 467 adult-trees and 149 juveniles. Open-pollinated seeds (514) from 29 seed-trees were also sampled and genotyped. Significant SGS was detected in both adult ( S = 0.0269) and juveniles trees ( S = 0.0246), indicating short-distance seed dispersal. Using maternity analysis, all juveniles had the mother-tree assigned within the stand. A father-tree within the stand was also assigned for 97.3% of the juveniles and 98.4% of offspring. The average pollen dispersal distance measured in juveniles $$ \left( {\hat{\delta } = 1 3 8\pm 1 6 9 {\text{ m}},{\text{ mean}} \pm {\text{SD}}} \right) $$ and offspring $$ \left( {\hat{\delta } = 2 5 2\pm 20 4 {\text{ m}}} \right) $$ were higher than the average seed dispersal distance measured in juveniles $$ \left( {\hat{\delta } = 1 2 4\pm 1 50{\text{ m}}} \right) $$. About 70% of the pollen from juveniles and 51% from offspring traveled less than 200 m and, 72% of the seeds traveled less than 50 m. The effective population size of the studied sample indicates that the 467 adult-trees and 145 juveniles correspond respectively to 335 and 63 individuals that are neither inbred nor relatives. The results are discussed in relation to their impact on seed collection practices and genetic conservation. [ABSTRACT FROM AUTHOR] more...