scholarly journals Comparison of fine-scale spatial genetic structure of two sympatric Rhododendron shrub species in forest habitat having different seed weights: A case study

2016 ◽  
Vol 65 (2) ◽  
pp. 39-45 ◽  
Author(s):  
Mineaki Aizawa ◽  
Chisa Nakayama ◽  
Tatsuhiro Ohkubo
Keyword(s):  
Genetic Structure ◽  
Seed Dispersal ◽  
Spatial Genetic Structure ◽  
Safe Sites ◽  
Shortest Distance ◽  
Nuclear Microsatellite ◽  
Kanto District ◽  
The Difference ◽  
Selection Of

Abstract Restricted seed dispersal is one of the most prevalent determinants of spatial genetic structure (SGS) at a fine spatial scale within a plant population. Rhododendron kaempferi and R. semibarbatum are common and coexistent Ericaceous species in the shrub layer of secondary deciduous broad-leaved forests in the northern Kanto District, central Japan. The two species have entomophilous flowers and are thought to have similar pollination styles. However, R. kaempferi produces threefold heavier seeds than R. semibarbatum. Therefore, we tested the hypothesis that the intensity of SGS was stronger in R. kaempferi than in R. semibarbatum in a forest stand. We comparatively examined the SGS for 73 individuals of R. kaempferi and 36 individuals of R. semibarbatum by using highly variable nuclear microsatellite loci. The analysis revealed significant SGS in both species at the shortest distance (<3 m); a measure to quantify SGS showed a counterintuitive result: R. semibarbatum exhibited stronger SGS than R. kaempferi. This result might be explained by the ecological consequences of R. semibarbatum producing lighter seeds, which might have greater dispersal efficacy, but its safe sites could be more restricted than those of R. kaempferi; in contrast, R. kaempferi producing heavier seeds might have more limited seed dispersal, but its safe sites for seedling establishment could be more prevalent than those for R. semibarbatum. The different strategies for the trade-off between seed weight and site selection of the two Rhododendron species might be reflected in the difference in the intensity of SGS in this study plot.

Effects of seed dispersal, adult tree and seedling density on the spatial genetic structure of regeneration at fine temporal and spatial scales

2010 ◽  
Vol 7 (1) ◽  
pp. 37-48 ◽  
Author(s):  
Fabrice Sagnard ◽  
Sylvie Oddou-Muratorio ◽  
Christian Pichot ◽  
Giovanni G. Vendramin ◽  
Bruno Fady
Keyword(s):  
Genetic Structure ◽  
Seed Dispersal ◽  
Spatial Genetic Structure ◽  
Spatial Scales ◽  
Seedling Density ◽  
Adult Tree ◽  
Temporal And Spatial

Genetic differences within natural and planted stands of Quercus petraea

2011 ◽  
Vol 6 (4) ◽  
pp. 597-605 ◽  
Author(s):  
Jiří Dostálek ◽  
Tomáš Frantík ◽  
Miroslava Lukášová
Keyword(s):  
Genetic Structure ◽  
Genetic Differentiation ◽  
Spatial Genetic Structure ◽  
Quercus Petraea ◽  
Genetic Differences ◽  
Sessile Oak ◽  
Population Structures ◽  
Nuclear Microsatellite ◽  
The Impact ◽  
Two Populations

AbstractFive sessile oak [Quercus petraea (Matt.) Liebl.] stands from the Czech Republic were studied to learn about the impact of different types of forest management regimes on the genetic differences among tree populations and on population structures. One population had not been markedly affected by human activity, two populations represented unplanted stands that were extensively managed for a long period of time using the coppice system, and two populations were planted stands. Approximately 100 trees from each stand were mapped and subsequently genotyped using 10 nuclear microsatellite loci. We determined the spatial genetic structure of each population and the genetic differentiation among the populations. We found that: (i) the populations were genetically differentiated, but the differences between the unplanted and planted stands were not markedly significant; (ii) the genetic differentiation among the populations depended on the geographical distribution of the populations; (iii) within unplanted stands, a strong spatial genetic structure was seen; and (iv) within planted stands, no spatial genetic structure was observed. Our findings implies that the analysis of spatial genetic structure of the sessile oak forest stand can help reveal and determine its origin.

scholarly journals Contrasting impacts of pollen and seed dispersal on spatial genetic structure in the bird-pollinated Banksia hookeriana

Heredity ◽  
2008 ◽  
Vol 102 (3) ◽  
pp. 274-285 ◽  
Author(s):  
S L Krauss ◽  
T He ◽  
L G Barrett ◽  
B B Lamont ◽  
N J Enright ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Seed Dispersal ◽  
Spatial Genetic Structure ◽  
Pollen And Seed Dispersal

scholarly journals Effects of seed dispersal on spatial genetic structure in populations of Rutidosis leptorrhychoides with different levels of correlated paternity

2002 ◽  
Vol 79 (3) ◽  
pp. 219-226 ◽  
Author(s):  
GUDRUN P. WELLS ◽  
ANDREW G. YOUNG
Keyword(s):  
Genetic Structure ◽  
Seed Dispersal ◽  
Genetic Relatedness ◽  
Spatial Genetic Structure ◽  
Dispersal Distance ◽  
Self Incompatibility ◽  
Southeastern Australia ◽  
Incompatibility System ◽  
Significant Patterns ◽  
Different Levels

Rutidosis leptorrynchoides is a perennial forb endemic to grasslands and grassy woodlands in southeastern Australia. Studies of seed dispersal, spatial genetic structure and clonality were carried out in four populations around the Canberra region that varied in levels of correlated paternity to examine: (1) whether R. leptorrhynchoides populations exhibit fine-scale spatial genetic structure and whether this varies between populations as a function of correlated paternity; (2) whether there is a correlation between seed dispersal distance and genetic relatedness within populations; and (3) whether clonal reproduction occurs in this species and to what degree this could account for the observed spatial genetic structure. The results show that there is variation in the magnitude and extent of spatial genetic structure between R. leptorrhynchoides populations. The three larger populations, with low to moderate full-sib proportions, showed significant patterns of coancestry between plants over scales of up to one metre, whereas the smallest population, with a high full-sib proportion, had erratically high but non-significant coancestry values. The observed patterns of genetic clumping could be explained by a combination of limited seed dispersal and correlated mating owing to limited mate availability resulting from the species' sporophytic self-incompatibility system. Clonality does not appear to be an important factor contributing to genetic structure in this species.

scholarly journals Dioecy, more than monoecy, affects plant spatial genetic structure: the case study ofFicus

2013 ◽  
pp. n/a-n/a ◽  
Author(s):  
Alison G. Nazareno ◽  
Ana L. Alzate-Marin ◽  
Rodrigo Augusto S. Pereira
Keyword(s):  
Genetic Structure ◽  
Spatial Genetic Structure

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

2016 ◽  
Vol 65 (2) ◽  
pp. 46-57 ◽  
Author(s):  
C. L. Chaves ◽  
A. M. Sebbenn ◽  
A. Baranoski ◽  
B. D. Goez ◽  
A. P.S.C. Gaino ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Seed Dispersal ◽  
Sexual Reproduction ◽  
Isolation By Distance ◽  
Spatial Genetic Structure ◽  
Dispersal Distance ◽  
Pollen Flow ◽  
Gene Dispersal ◽  
Asexual Propagation ◽  
Neotropical Tree

Abstract Facultative apomictic trees can produce offspring with a genotype identical to the mother due to asexual propagation through the embryo derived from cells in the maternal ovule tissues. These trees can also produce offspring with a genotype different from the mother due to genetic recombination. For many trees, these reproductive processes remain largely unexplored. Herein, we use microsatellite markers to identify apomictic and sexual reproduction in samples of adult and juvenile trees of the tropical, insect pollinated and wind seed dispersed Aspidosperma polyneuron, within a conservation area in Brazil. We also investigate seed and pollen flow and dispersal patterns and compare the genetic diversity, inbreeding, and intrapopulation spatial genetic structure (SGS) between adults and juveniles in two plots. Our results show that the species present both apomictic and sexual reproduction. Sexual reproduction occurred mainly by outcrossing, but we did detect instances of self-fertilization and mating among relatives, which explains the inbreeding observed in juveniles. Seed dispersal distance was shorter than pollen dispersal distance in one of the plots, suggesting that insect vectors are more efficient in gene dispersal than wind for seed dispersal in a high density tropical forest. The patterns of pollen and seed dispersal showed isolation by distance, explaining the SGS detected for adults and juveniles. Our results show that both seed and pollen flow increase the allelic diversity in the population. The regeneration of apomictic individuals may guarantee the continuation of genotypes adapted specifically to the study site, while sexual reproduction results in new genotypes.

Population structure and parentage analysis of black poplar along the Morava River

2006 ◽  
Vol 36 (5) ◽  
pp. 1067-1076 ◽  
Author(s):  
Markéta Pospíšková ◽  
Ivana Šálková
Keyword(s):  
Genetic Structure ◽  
Populus Deltoides ◽  
Spatial Genetic Structure ◽  
Glacial Refugia ◽  
Parentage Analysis ◽  
Hybrid Poplars ◽  
Adult Trees ◽  
Nuclear Microsatellite ◽  
Dispersal Distances ◽  
Morava River

Twelve nuclear microsatellite markers were used to assess the population genetic structure of the riparian pioneer tree species Populus nigra L. along the Morava River in the Czech Republic. Parentage analysis of 30 seedlings was performed to examine the extent of hybridization between P. nigra and introduced hybrid poplars and to determine the distances of pollen and seed movement. Additionally, spatial genetic structure was analysed and gene dispersal was estimated indirectly. In spite of the limited size of our studied population (65 adult trees), the apparent overall genetic diversity was high (expected heterozygosity He = 0.82) and comparable to the known diversity of P. nigra in southern Europe, where its glacial refugia were located. Introgression of Populus deltoides Bartr. ex Marsh. genes to P. nigra was confirmed, since 13% of tested seedlings descended from a Populus ×canadensis Moench female. The results of parentage analysis showed that a low percentage (20%) of offspring originated from parents located outside the study site. Dispersal distances for pollen and seeds movement ranged from 10 to 230 m and from 163 to 370 m, respectively. The study revealed significant spatial genetic structure (regression slope –0.0158), which was probably caused by limited gene flow.

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