The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
John D. Thompson - One of the best experts on this subject based on the ideXlab platform.
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evidence for local Outbreeding Depression in the mediterranean island endemic anchusa crispa viv boraginaceae
Heredity, 2001Co-Authors: Angelique Quilichini, Max Debussche, John D. ThompsonAbstract:Evidence for local Outbreeding Depression in the Mediterranean island endemic Anchusa crispa Viv. (Boraginaceae)
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evidence for local Outbreeding Depression in the mediterranean island endemic anchusa crispa viv boraginaceae
Heredity, 2001Co-Authors: Angelique Quilichini, Max Debussche, John D. ThompsonAbstract:In this study we examined the relative effects of inbreeding and Outbreeding on offspring fitness over two generations in Anchusa crispa Viv., a rare species which on Corsica (France) occurs in small populations composed of patches of few individuals. Self- and outcross-pollinations were carried out in a single population and F(1) progeny grown to flowering. Plants grown from selfing and outcrossing were then selfed or outcrossed to produce F(2) individuals in four combinations of pollination treatments over two generations, i.e. self + self, self + outcross, outcross + self and outcross + outcross. In the F(1) generation, selfed progeny had a significantly greater number of cymes per plant than outcrossed progeny (P=0.006). Plants from two generations of selfing had fewer seeds per fruit (P=0.06) but a significantly greater survival rate (P < 0.001) and a greater number of cymes (P=0.06) than those from two generations of outcrossing. Selfed F(2) from outcrossed F(1) had a significantly greater number of cymes (P < 0.01) than outcrossed F(2) from outcrossed F(1). In the comparison between selfed and outcrossed F(2) from selfed F(1) the former had a significantly greater survival rate (P < 0.001), but the latter significantly more flowers per cyme (P < 0.05). Together, these results indicate that Outbreeding Depression may occur on a very local scale within populations of this rare endemic species, with important implications for the conservation of rare plants.
Angelique Quilichini - One of the best experts on this subject based on the ideXlab platform.
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evidence for local Outbreeding Depression in the mediterranean island endemic anchusa crispa viv boraginaceae
Heredity, 2001Co-Authors: Angelique Quilichini, Max Debussche, John D. ThompsonAbstract:Evidence for local Outbreeding Depression in the Mediterranean island endemic Anchusa crispa Viv. (Boraginaceae)
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evidence for local Outbreeding Depression in the mediterranean island endemic anchusa crispa viv boraginaceae
Heredity, 2001Co-Authors: Angelique Quilichini, Max Debussche, John D. ThompsonAbstract:In this study we examined the relative effects of inbreeding and Outbreeding on offspring fitness over two generations in Anchusa crispa Viv., a rare species which on Corsica (France) occurs in small populations composed of patches of few individuals. Self- and outcross-pollinations were carried out in a single population and F(1) progeny grown to flowering. Plants grown from selfing and outcrossing were then selfed or outcrossed to produce F(2) individuals in four combinations of pollination treatments over two generations, i.e. self + self, self + outcross, outcross + self and outcross + outcross. In the F(1) generation, selfed progeny had a significantly greater number of cymes per plant than outcrossed progeny (P=0.006). Plants from two generations of selfing had fewer seeds per fruit (P=0.06) but a significantly greater survival rate (P < 0.001) and a greater number of cymes (P=0.06) than those from two generations of outcrossing. Selfed F(2) from outcrossed F(1) had a significantly greater number of cymes (P < 0.01) than outcrossed F(2) from outcrossed F(1). In the comparison between selfed and outcrossed F(2) from selfed F(1) the former had a significantly greater survival rate (P < 0.001), but the latter significantly more flowers per cyme (P < 0.05). Together, these results indicate that Outbreeding Depression may occur on a very local scale within populations of this rare endemic species, with important implications for the conservation of rare plants.
Robert H Devlin - One of the best experts on this subject based on the ideXlab platform.
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growth and survival trade offs and Outbreeding Depression in rainbow trout oncorhynchus mykiss
Evolution, 2007Co-Authors: Wendy E Tymchuk, Fredrik L Sundstrom, Robert H DevlinAbstract:The purpose of this study was to examine, using a rainbow trout (Oncorhynchus mykiss) model system, the fitness consequences of three generations of introgression of genotypes adapted to two different environments (culture and nature). The experiments also isolated the influence of competitive interactions and risk of predation on the relative growth and survival of the wild and backcrossed lines. Line crosses representing fast-growing pure domestic (D), slow-growing pure wild (W), domestic x wild hybrids (F1), F1 x wild backcrosses (B1), and B1 x wild backcrosses (B2) were generated and reared under (1) culture conditions, (2) seminatural conditions with competition among genotypes, and (3) seminatural conditions under risk of predation. Survival of the fry in a seminatural environment with competition fit an additive model of gene action with the domestic fish having the highest survival and the wild fish the lowest, but under risk of predation Outbreeding Depression was suggested by low survival of the B2 lines. Evidence of a trade-off in growth and survival under risk of predation along with observations of genetically determined behavioral differences among the strains may provide some explanation for the observed differences in survival among the strains. This information is relevant to improving our evolutionary understanding of the interaction among genomes, and the influence of environment, during hybridization events. Results from this experiment indicate that alteration of phenotype likely played a prominent role in the reduced fitness experienced by progeny produced after three generations of introgression, supporting the theory that disruption of genotypes selected for adaptation to local conditions may be a primary cause of Outbreeding Depression in species such as salmon.
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growth and survival trade offs and Outbreeding Depression in rainbow trout oncorhynchus mykiss
Evolution, 2007Co-Authors: Wendy E Tymchuk, Fredrik L Sundstrom, Robert H DevlinAbstract:Abstract The purpose of this study was to examine, using a rainbow trout (Oncorhynchus mykiss) model system, the fitness consequences of three generations of introgression of genotypes adapted to two different environments (culture and nature). The experiments also isolated the influence of competitive interactions and risk of predation on the relative growth and survival of the wild and backcrossed lines. Line crosses representing fast-growing pure domestic (D), slow-growing pure wild (W), domestic × wild hybrids (F1), F1 × wild backcrosses (B1), and B1 × wild backcrosses (B2) were generated and reared under (1) culture conditions, (2) seminatural conditions with competition among genotypes, and (3) seminatural conditions under risk of predation. Survival of the fry in a seminatural environment with competition fit an additive model of gene action with the domestic fish having the highest survival and the wild fish the lowest, but under risk of predation Outbreeding Depression was suggested by low surviv...
Markus Fischer - One of the best experts on this subject based on the ideXlab platform.
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effects of inbreeding Outbreeding and supplemental pollen on the reproduction of a hummingbird pollinated clonal amazonian herb
Biotropica, 2011Co-Authors: Walter Durka, Mathias Templin, Vicky Huaman, Giovana Vadillo, Matthias Schleuning, Markus Fischer, Thomas BeckerAbstract:Understory herbs are an essential part of tropical rain forests, but little is known about factors limiting their reproduction. Many of these herbs are clonal, patchily distributed, and produce large floral displays of nectar-rich 1-d flowers to attract hummingbird pollinators that may transport pollen over long distances. The aim of this study was to investigate the effects of clonality, cross-proximity, and patchy distribution on the reproduction of the hummingbird-pollinated Amazonian herb Heliconia metallica. We experimentally pollinated flowers within populations with self-pollen and with pollen of different diversity, crossed flowers between populations, and added supplemental pollen to ramets growing solitarily or in conspecific patches. Only flowers pollinated early in the morning produced seeds. Selfed flowers produced seeds, but seed number and mass were strongly reduced, suggesting partial sterility and inbreeding Depression after selfing. Because of pollen competition, flowers produced more seeds after crosses with several than with single donor plants. Crosses between populations mostly resulted in lower seed production than those within populations, suggesting Outbreeding Depression. Ramets in patches produced fewer seeds than solitary ramets and were more pollen-limited, possibly due to geitonogamy and biparental inbreeding in patches. We conclude that high rates of geitonogamy due to clonality and pollen limitation due to the short receptivity of flowers and patchy distribution constrain the reproduction of this clonal herb. Even in unfragmented rain forests with highly mobile pollinators, Outbreeding Depression may be a widespread phenomenon in plant reproduction.
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between population Outbreeding affects plant defence
PLOS ONE, 2010Co-Authors: Roosa Leimu, Markus FischerAbstract:Between-population crosses may replenish genetic variation of populations, but may also result in Outbreeding Depression. Apart from direct effects on plant fitness, these Outbreeding effects can also alter plant-herbivore interactions by influencing plant tolerance and resistance to herbivory. We investigated effects of experimental within- and between-population Outbreeding on herbivore resistance, tolerance and plant fitness using plants from 13 to 19 Lychnis flos-cuculi populations. We found no evidence for Outbreeding Depression in resistance reflected by the amount of leaf area consumed. However, herbivore performance was greater when fed on plants from between-population compared to within-population crosses. This can reflect Outbreeding Depression in resistance and/or Outbreeding effects on plant quality for the herbivores. The effects of type of cross on the relationship between herbivore damage and plant fitness varied among populations. This demonstrates how between-population Outbreeding effects on tolerance range from Outbreeding Depression to Outbreeding benefits among plant populations. Finally, herbivore damage strengthened the observed Outbreeding effects on plant fitness in several populations. These results raise novel considerations on the impact of Outbreeding on the joint evolution of resistance and tolerance, and on the evolution of multiple defence strategies.
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Between-Population Outbreeding Affects Plant Defence
2010Co-Authors: Roosa Leimu, Markus FischerAbstract:Between-population crosses may replenish genetic variation of populations, but may also result in Outbreeding Depression. Apart from direct effects on plant fitness, these Outbreeding effects can also alter plant-herbivore interactions by influencing plant tolerance and resistance to herbivory. We investigated effects of experimental within- and betweenpopulation Outbreeding on herbivore resistance, tolerance and plant fitness using plants from 13 to 19 Lychnis flos-cuculi populations. We found no evidence for Outbreeding Depression in resistance reflected by the amount of leaf area consumed. However, herbivore performance was greater when fed on plants from between-population compared to within-population crosses. This can reflect Outbreeding Depression in resistance and/or Outbreeding effects on plant quality for the herbivores. The effects of type of cross on the relationship between herbivore damage and plant fitness varied among populations. This demonstrates how between-population Outbreeding effects on tolerance range from Outbreeding Depression to Outbreeding benefits among plant populations. Finally, herbivore damage strengthened the observed Outbreeding effects on plant fitness in several populations. These results raise novel considerations on the impact o
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mating structure and inbreeding and Outbreeding Depression in the rare plant gentianella germanica gentianaceae
American Journal of Botany, 1997Co-Authors: Markus Fischer, Diethart MatthiesAbstract:Isolation and small size of populations as a result of habitat destruction and fragmentation may negatively affect plant fitness through pollinator limitation and increased levels of inbreeding. To increase genetic variation in small populations of rare plants artificial gene flow has been suggested as a management tool. We investigated whether pollinator limitation and inbreeding Depression could reduce fitness in Gentianella germanica, an endangered biennial of increasingly fragmented calcareous grasslands in Central Europe. We experimentally excluded pollinators and generated progenies by hand-pollinating flowers with pollen from different distances. G. germanica was highly selfing. Pollinator exclusion strongly reduced seed set, indicating that pollinator limitation could potentially reduce plant fitness. Germination rate as well as number of leaves and rosette size of progeny from 10-m crosses was higher than that of progeny from open pollinations, self-, 1-m, and interpopulation crosses. After 6 mo of growth differences in the number of surviving plants persisted, whereas differences in plant size did not. The results suggest that inbreeding Depression may reduce plant performance in G. germanica. Outbreeding Depression in the performance of progeny from interpopulation crosses indicates that caution is necessary in using artificial interpopulation gene flow as a management tool.
Max Debussche - One of the best experts on this subject based on the ideXlab platform.
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evidence for local Outbreeding Depression in the mediterranean island endemic anchusa crispa viv boraginaceae
Heredity, 2001Co-Authors: Angelique Quilichini, Max Debussche, John D. ThompsonAbstract:Evidence for local Outbreeding Depression in the Mediterranean island endemic Anchusa crispa Viv. (Boraginaceae)
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evidence for local Outbreeding Depression in the mediterranean island endemic anchusa crispa viv boraginaceae
Heredity, 2001Co-Authors: Angelique Quilichini, Max Debussche, John D. ThompsonAbstract:In this study we examined the relative effects of inbreeding and Outbreeding on offspring fitness over two generations in Anchusa crispa Viv., a rare species which on Corsica (France) occurs in small populations composed of patches of few individuals. Self- and outcross-pollinations were carried out in a single population and F(1) progeny grown to flowering. Plants grown from selfing and outcrossing were then selfed or outcrossed to produce F(2) individuals in four combinations of pollination treatments over two generations, i.e. self + self, self + outcross, outcross + self and outcross + outcross. In the F(1) generation, selfed progeny had a significantly greater number of cymes per plant than outcrossed progeny (P=0.006). Plants from two generations of selfing had fewer seeds per fruit (P=0.06) but a significantly greater survival rate (P < 0.001) and a greater number of cymes (P=0.06) than those from two generations of outcrossing. Selfed F(2) from outcrossed F(1) had a significantly greater number of cymes (P < 0.01) than outcrossed F(2) from outcrossed F(1). In the comparison between selfed and outcrossed F(2) from selfed F(1) the former had a significantly greater survival rate (P < 0.001), but the latter significantly more flowers per cyme (P < 0.05). Together, these results indicate that Outbreeding Depression may occur on a very local scale within populations of this rare endemic species, with important implications for the conservation of rare plants.
