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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, 2020Co-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.
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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)
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, 2020Co-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.
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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)
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: Markus Fischer, Matthias Schleuning, Mathias Templin, Vicky Huaman, Giovana Vadillo, Thomas Becker, Walter DurkaAbstract: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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genetic rescue persists beyond first generation Outbreeding in small populations of a rare plant
Proceedings of The Royal Society B: Biological Sciences, 2007Co-Authors: Yvonne Willi, Markus Fischer, Mark Van Kleunen, Stefan DietrichAbstract:Habitat fragmentation commonly causes genetic problems and reduced fitness when populations become small. Stocking small populations with individuals from other populations may enrich genetic variation and alleviate inbreeding, but such artificial gene flow is not commonly used in conservation owing to potential Outbreeding depression. We addressed the role of long-term population size, genetic distance between populations and test environment for the performance of two generations of offspring from between-population crosses of the locally rare plant Ranunculus reptans L. Interpopulation Outbreeding positively affected an aggregate measure of fitness, and the fitness superiority of interpopulation hybrids was maintained in the second offspring (F2) generation. Small populations benefited more strongly from interpopulation Outbreeding. Genetic distance between crossed populations in neutral markers or quantitative characters was not important. These results were consistent under near-natural competition-free and competitive conditions. We conclude that the benefits of interpopulation Outbreeding are likely to outweigh potential drawbacks, especially for populations that suffer from inbreeding.
Mary V Price - One of the best experts on this subject based on the ideXlab platform.
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Outbreeding depression varies among cohorts of ipomopsis aggregata planted in nature
Evolution, 2000Co-Authors: Nickolas M Waser, Mary V Price, Ruth G ShawAbstract:Abstract Outbreeding depression in progeny fitness may arise from disruption of local adaptation, disruption of allelic coadaptation, or a combination of these “environmental” and “physiological” mechanisms. Thus the minimum spatial scale over which Outbreeding depression arises should depend on the spatial scale of gene dispersal and (with an environmental mechanism) of change in selection regimes. We previously reported substantial Outbreeding depression in lifetime fitness of progeny resulting from crosses among parents separated by 100 m in natural populations of the herbaceous plant Ipomopsis aggregata. In this paper we explore the effect of crossing distance on fitness in two additional experiments begun in 1987 and 1990. We planted seed progeny derived from partial diallel crossing designs in randomized blocks in maternal environments and scored emergence of seedlings, survival, and eventual flowering of individuals over the subsequent six to eight years. Nested within each diallel design were cros...
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crossing distance effects in delphinium nelsonii Outbreeding and inbreeding depression in progeny fitness
Evolution, 1994Co-Authors: Nickolas M Waser, Mary V PriceAbstract:-Depending on its genetic causes, Outbreeding depression in quantitative characters may occur first in the free-living F, generation produced by a wide cross. In 1981-1985, we generated F, progenies by hand-pollinating larkspurs (Delphinium nelsonii) with pollen from 1I-m, 3-m, 10m, or 30-m distances. From the spatial genetic structure indicated by previous electrophoretic and reciprocal transplantation studies, we estimate that these crosses range from being inbred (f z 0.06) to outbred. We planted 594 seeds from 66 maternal sibships under natural conditions. As of 1992, there was strong evidence for both inbreeding depression and Outbreeding depression. Progeny from intermediate crossing distances grew approximately twice as large as more inbred or outbred progeny in the first 5 yr after planting (P = 0.013, repeated measures ANOVA), and survived almost 1 yr longer on average (contrast of 3-m and 10-m treatments versus 1 m and 30 m; P = 0.028, ANOVA). Twenty maternal sibships produced flowering individuals; only four and two of these represented 1-m and 30-m crossing distances, respectively (P = 0.021, G-test). The cumulative fitness of intermediate distance sibships averaged about twice that of 1-m sibships, and five to eight times that of 30-m sibships (P = 0.0 17, ANOVA). Thus, even though progeny of 1r-m crosses were inbred to a degree only about one-eighth that of selfing, inbreeding depression approximated 50%, and Outbreeding depression equaled or exceeded 50% for all fitness components.
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CROSSING‐DISTANCE EFFECTS IN DELPHINIUM NELSONII: Outbreeding AND INBREEDING DEPRESSION IN PROGENY FITNESS
Evolution, 1994Co-Authors: Nickolas M Waser, Mary V PriceAbstract:-Depending on its genetic causes, Outbreeding depression in quantitative characters may occur first in the free-living F, generation produced by a wide cross. In 1981-1985, we generated F, progenies by hand-pollinating larkspurs (Delphinium nelsonii) with pollen from 1I-m, 3-m, 10m, or 30-m distances. From the spatial genetic structure indicated by previous electrophoretic and reciprocal transplantation studies, we estimate that these crosses range from being inbred (f z 0.06) to outbred. We planted 594 seeds from 66 maternal sibships under natural conditions. As of 1992, there was strong evidence for both inbreeding depression and Outbreeding depression. Progeny from intermediate crossing distances grew approximately twice as large as more inbred or outbred progeny in the first 5 yr after planting (P = 0.013, repeated measures ANOVA), and survived almost 1 yr longer on average (contrast of 3-m and 10-m treatments versus 1 m and 30 m; P = 0.028, ANOVA). Twenty maternal sibships produced flowering individuals; only four and two of these represented 1-m and 30-m crossing distances, respectively (P = 0.021, G-test). The cumulative fitness of intermediate distance sibships averaged about twice that of 1-m sibships, and five to eight times that of 30-m sibships (P = 0.0 17, ANOVA). Thus, even though progeny of 1r-m crosses were inbred to a degree only about one-eighth that of selfing, inbreeding depression approximated 50%, and Outbreeding depression equaled or exceeded 50% for all fitness components.
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, 2020Co-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.
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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)
