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Patterns of Pollen Flow and Genetic Differentiation Among Pollen Pools in Quercus salicina in a Warm Temperate Old–growth Evergreen Broad-leaved Forest

K. F. GOODNIGHT (1989): Estimating relatedness using genetic markers. Evolution 43: 258-275. RAYMOND, M. and F. ROUSSET (1995): GENEPOP (version 1.2): population genetics software for exact tests and ecumenicism. Journal of Heredity 86: 248-249. SHARP, W. M. and H. H. CHISMAN (1961): Flowering and fruiting in the white oaks. I. Staminate flowering through pollen dispersal. Ecology 42: 365-372. SMOUSE, P. E., R. J. DYER, R. D. WESTFALL and V. L. SORK (2001): Two-generation analysis of pollen flow across a landscape. I

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Analysis of the Genetic Diversity and Population Structure of Latvian Ash (Fraxinus excelsior L.) Stands using Nuclear and Chloroplast SSR Markers

Abstract

Common ash (Fraxinus excelsior L.) has a widespread distribution throughout Europe, and Latvia is almost at the north eastern edge of the distribution range. In Europe, ash is threatened by ash dieback, a disease caused by the introduced ascomycete Hymenoscyphus fraxineus. Chloroplast and nuclear DNA markers have been used to study the genetic diversity and population structure of ash both in a broader pan-European context as well as in more restricted regions. Some of the markers analysed in these previously published reports were also utilised in this study, enabling comparisons of the genetic parameters calculated from the nuclear SSR marker data and of the haplotypes identified with the chloroplast markers. Analysis of chloroplast markers revealed one dominant haplotype in Latvian stands, which corresponds to the haplotype previously found in Eastern Europe and Scandinavia. A second haplotype, corresponding to a previously reported central European haplotype was found in all individuals from the Ķemeri stand, indicating that this stand was naturally established from introduced germplasm, which was planted in a neighbouring park. The nuclear SSR markers revealed low levels of differentiation of Latvian F. excelsior stands, probably due efficient pollen flow between stands. The analysis of both chloroplast and nuclear DNA markers has revealed different aspects of the structure and provenance of Latvian F. excelsior populations.

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Hedgerows Have a Barrier Effect and Channel Pollinator Movement in the Agricultural Landscape

Abstract

Agricultural intensification and the subsequent fragmentation of semi-natural habitats severely restrict pollinator and pollen movement threatening both pollinator and plant species. Linear landscape elements such as hedgerows are planted for agricultural and conservation purposes to increase the resource availability and habitat connectivity supporting populations of beneficial organisms such as pollinators. However, hedgerows may have unexpected effects on plant and pollinator persistence by not just channeling pollinators and pollen along, but also restricting movement across the strip of habitat. Here, we tested how hedgerows influence pollinator movement and pollen flow. We used fluorescent dye particles as pollen analogues to track pollinator movement between potted cornflowers Centaurea cyanus along and across a hedgerow separating two meadows. The deposition of fluorescent dye was significantly higher along the hedgerow than across the hedgerow and into the meadow, despite comparable pollinator abundances. The differences in pollen transfer suggest that hedgerows can affect pollinator and pollen dispersal by channeling their movement and acting as a permeable barrier. We conclude that hedgerows in agricultural landscapes can increase the connectivity between otherwise isolated plant and pollinator populations (corridor function), but can have additional, and so far unknown barrier effects on pollination services. Functioning as a barrier, linear landscape elements can impede pollinator movement and dispersal, even for highly mobile species such as bees. These results should be considered in future management plans aiming to enhance the persistence of threatened pollinator and plant populations by restoring functional connectivity and to ensure sufficient crop pollination in the agricultural landscape.

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Logging decreases the pollen dispersal distance in a low-density population of the tree Bagassa guianensis in the Brazilian Amazon

Maine, USA. Canadian. Journal of Forest Resources 35: 143-150. KLEIN, E. K., N. DESASSIS and S. ODDOU-MURATORIO (2008): Pollen flow in the wild service tree, Sorbus torminalis (L.) Crantz. IV. Whole interindividual variance of male fecundity estimated jointly with the dispersal kernel. Molecular Ecology 17: 3323-3336. LACERDA, A. E. B., E. R. NIMMO and A. M. SEBBENN (2013): Modelling the long-term impacts of logging on genetic diversity and demography of Hymenaea courbaril. Forest Science 59: 15-26. LACERDA, E. B. L., A

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Gene dispersal via seeds and pollen and their effects on genetic structure in the facultative-apomictic Neotropical tree Aspidosperma polyneuron

, Ghazoul J (2012) Forest fragmentation genetics in a formerly widespread island endemic tree: Vateriopsis seychellarum (Dipterocarpaceae). Molecular Ecology 21:2369–2382. Available at http://dx.doi.org/10.1111/j.1365-294X.2012.05543.x . Gaino APSC, Silva AM, Moraes MA, Alves PF, Moraes MLT, Freitas MLM, Sebbenn AM (2010) Understanding the effects of isolation on seed and pollen flow, spatial genetic structure and effective population size of the dioicious tropical tree species Myracrodruon urundeuva. Conservation Genetics 11:1631–1643. Available at http

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Evaluation of Selected Ornamental Asteraceae as a Pollen Source for Urban Bees

-analysis of bees’ responses to anthropogenic disturbance. Ecology, 60 (8), 2068-2076. http://doi org/10.1890/08-1245.1 Wróblewska, A., Ayers, G.S., & Hoopingarner, R.A. (1993). Nectar production dynamics and bee reward: a comparison between Chapman’s honey plant ( Echinops sphaerocephalus L.) and Blue globe thistle ( Echinops ritro L.). American Bee Journal, 133 (11), 789-796. Wróblewska, A. (1995). Flowering period and pollen flow of some ornamental species of the Asteraceae family. In Proceedings of 34 th International Apicultural Congress of

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Genetic structure and diversity of Polylepis australis (Rosaceae) tree populations from central Argentina: Implications for forest conservation

Abstract

Worldwide, large areas of forest are being transformed to other land cover types and the resulting fragmented populations may suffer from restricted gene flow leading to genetic pauperization and increased inbreeding. To assess the genetic constitution of fragmented Polylepis australis mountain forests of central Argentina, analyses of the structure and diversity of ISSR markers were carried out for 90 trees distributed throughout five river basins with differing degrees of fragmentation. Overall, average polymorphism (P) ranged between 87.2 and 94.9% (95% criterion) while marker diversity index (M) varied between 0.35 and 0.39; values which are comparable with other wind-pollinated tree species. Analysis of molecular variance (AMOVA) revealed that most genetic variation occurred within river basins (97.8%), with only a little occurring between river basins (2.2%; ΦST = 0.02). In addition, Mantel’s test indicated that P. australis does not follow the usual pattern of isolation by distance; instead the UPGMA method showed that trees from the two most degraded river basins formed a group while trees from the three better preserved basins formed another. As such, either effective pollen flow has maintained high levels of genetic diversity, or present day genetic variability is a remnant of a recently fragmented ancestral panmictic population. We conclude that, at present, genetic degradation in P. australis populations of central Argentina is not as important as ecological degradation – such as soil loss, intensive browsing by livestock or increased frequencies of wildfires, and that genetic variability is still fully available for forest restoration.

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Pollen contamination and nonrandom mating in a Eucalyptus camaldulensis Dehnh seedling seed orchard

Abstract

Eucalyptus camaldulensis has potential for timber, energy, pulp and cellulose production in Brazil due to its ability to adapt to a variety of environmental conditions. The use of improved seeds, selected for economic growth traits, is necessary to increase productivity of commercial stands. Seed seedlings orchards (SSO) are one option for improved seed production. However, pollen contamination from unimproved populations, as well as non-random mating in the SSO, can decrease the predicted genetic gains in selected populations. Thus, we investigate the mating system, pollen flow and dispersal patterns in an E. camaldulensis SSO and progeny test (PT), established with seedlings collected in the SSO, using seven microsatellite loci. All trees in the SSO were mapped, sampled, and genotyped. For the PT, we sampled, genotyped, and measured the total height of seedlings from 25 families. We detected 10 % inbreeding in the PT, resulting mainly from selfing. Furthermore, we found a correlated mating rate of 18.5 % in the SSO, indicating that within the PT there are some full-sibs. Using paternity analysis, we found 14.7 % pollen contamination and a pattern of pollen dispersal between near neighbor trees in the SSO. We found 9.5 % of inbreeding depression for seedlings height. Due to pollen contamination and nonrandom mating in the SSO, the actual genetic gains for growth traits in the PT are probably lower than the predicted genetic gains. We discuss some management strategies in the SSO that can be used to increase genetic gains in commercial reforestation established using seeds collected from the SSO

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Gene flow and mating system of the tropical tree Sextonia rubra

References AUSTERLITZ, F. and P. E. SMOUSE (2001): Two-Generation Analysis of Pollen Flow Across a Landscape. II. Relation Between {{Phi}}ft, Pollen Dispersal and Interfemale Distance. Genetics 157: 851-857. AUSTERLITZ, F. and P. E. SMOUSE (2002): Two-Generation Analysis of Pollen Flow Across a Landscape. IV. Estimating the Dispersal Parameter. Genetics 161: 355-363. BAWA, K. S., S. H. BULLOCK, D. R. PERRY, R. E. COVILLE and M. H. GRAYUM (1985): Reproductive biology of tropical lowland rain forest trees. II

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High Levels of Outcrossing in a Family Trial of Western Australian Sandalwood (Santalum spicatum)

References ADAMS, D. R., S. BHATNAGAR and R. COOKSON (1975): Sesquiterpenes of Santalum album and Santalum spicatum. Phytochemical Reports 14: 1459-1460. AUSTERLITZ, F. and P. SMOUSE (2001a): Two-Generation analysis of pollen flow across a landscape. II. Relation between Φft, pollen dispersal and interfemale distance. Genetics 157: 851-857. AUSTERLITZ, F. and P. SMOUSE (2001b): Two-generation analysis of pollen flow across a landscape. III. Impact of adult population structure. Genetical Research 78: 271

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