Abstract
Inbreeding depression is a major selective force favoring outcrossing in flowering plants. However, some self- fertilization should weaken the harmful effects of inbreeding by exposing deleterious alleles to selection. This study examines the maintenance of inbreeding depression in the predominantly outcrossing species Pinus sylvestris L. (Scots pine). Open-pollinated and self-fertilized progeny of 23 maternal trees, originating from a natural stand in southern Finland, were grown at two sites. We observed significant inbreeding depression in two of the four life stages measured. Inbreeding depression was largest for seed maturation (delta = 0.74), where seedset in open-pollinated strobili (70.9%) was about four times higher than in selfed strobili (18.3%). Inbreeding depression in postgermination survival (upto an age of 23 years) was also high (delta = 0.62-0.75). No significant differences in height (delta = 0.05) or flowering (delta = 0.14) of the trees after 23 years were observed. Cumulative inbreeding depression was high (delta = 0.90-0.94) and differed significantly among maternal families (range 0.45-1.00). The magnitude of inbreeding depression among the 23 maternal parents was not significantly correlated between early (seed maturation) and later (postgermination survival) life stages, suggesting that its genetic basis varies across the life cycle. Size differences among the progeny types diminished in time due to nonrandom size-specific mortality, causing a decrease in the inbreeding depression estimates for height over time. Our results indicate that Scots pine exhibits high levels of inbreeding depression during both early and later stages of the Life cycle. It is argued that self-fertilization in Scots pine is inefficient in purging the genetic load caused by highly deleterious mutations because of the nearly complete loss of selfed individuals over time. This results in an effectively random mating outcrossing population. [KEYWORDS: deleterious alleles; inbreeding depression; purging recessive mutations; selective interference; self-fertilization; size-specific mortality Self-fertilization; outcrossing rates; lethal mutations; genetic-basis; evolution; plants; populations; fitness; coevolution; selection]
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 15
Claim · model-written summary
Significant inbreeding depression was observed in two of four life stages of Scots pine.
- Taxon
- Pinus sylvestris L.
Pinus sylvestrist0 - Organ / stage
- life stagese1
- Outcome
- inbreeding depressione1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e1“We observed significant inbreeding depression in two of the four life stages measured”
Claim · model-written summary
Inbreeding depression was largest for seed maturation.
- Taxon
- Pinus sylvestris L.Pinus sylvestrist0
- Organ / stage
- seed maturatione2
- Outcome
- Inbreeding depressione2
- Value
- delta = 0.74e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e2“Inbreeding depression was largest for seed maturation (delta = 0.74)”
Claim · model-written summary
Seedset in open-pollinated strobili was about four times higher than in selfed strobili.
- Taxon
- Pinus sylvestris L.Pinus sylvestrist0
- Organ / stage
- strobilie3
- Outcome
- seedsete3
- Direction
- highere3
- Value
- four timese3
- Comparator
- selfed strobilie3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e3“seedset in open-pollinated strobili (70.9%) was about four times higher than in selfed strobili (18.3%)”
Claim · model-written summary
Inbreeding depression in postgermination survival was high.
- Taxon
- Pinus sylvestris L.Pinus sylvestrist0
- Organ / stage
- postgermination survivale4
- Outcome
- Inbreeding depression in postgermination survivale4
- Value
- delta = 0.62-0.75e4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e4“Inbreeding depression in postgermination survival (upto an age of 23 years) was also high (delta = 0.62-0.75)”
Claim · model-written summary
No significant difference in tree height from inbreeding after 23 years.
- Taxon
- Pinus sylvestris L.Pinus sylvestrist0
- Outcome
- heighte5
- Value
- delta = 0.05e5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e5“No significant differences in height (delta = 0.05) or flowering (delta = 0.14) of the trees after 23 years were observed”
Claim · model-written summary
No significant difference in flowering from inbreeding after 23 years.
- Taxon
- Pinus sylvestris L.Pinus sylvestrist0
- Outcome
- floweringe5
- Value
- delta = 0.14e5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e5“No significant differences in height (delta = 0.05) or flowering (delta = 0.14) of the trees after 23 years were observed”
Claim · model-written summary
Cumulative inbreeding depression was high.
- Taxon
- Pinus sylvestris L.Pinus sylvestrist0
- Outcome
- Cumulative inbreeding depressione6
- Value
- delta = 0.90-0.94e6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e6“Cumulative inbreeding depression was high (delta = 0.90-0.94) and differed significantly among maternal families (range 0.45-1.00)”
Claim · model-written summary
Cumulative inbreeding depression differed significantly among maternal families.
- Taxon
- Pinus sylvestris L.Pinus sylvestrist0
- Outcome
- Cumulative inbreeding depressione6
- Value
- range 0.45-1.00e6
- Qualifier
- among maternal familiese6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e6“Cumulative inbreeding depression was high (delta = 0.90-0.94) and differed significantly among maternal families (range 0.45-1.00)”
Claim · model-written summary
Inbreeding depression magnitude among maternal parents was not significantly correlated between early and later life stages.
- Taxon
- Pinus sylvestris L.Pinus sylvestrist0
- Organ / stage
- seed maturatione7
- Outcome
- magnitude of inbreeding depressione7
- Comparator
- postgermination survivale7
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e7“The magnitude of inbreeding depression among the 23 maternal parents was not significantly correlated between early (seed maturation) and later (postgermination survival) life stages”
Claim · model-written summary
The genetic basis of inbreeding depression is suggested to vary across the life cycle.
- Taxon
- Pinus sylvestris L.Pinus sylvestrist0
- Outcome
- genetic basise7
- Qualifier
- varies across the life cyclee7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e7“suggesting that its genetic basis varies across the life cycle”
Claim · model-written summary
Size-specific mortality is suggested to cause the decrease in inbreeding depression estimates for height.
- Taxon
- Pinus sylvestris L.Pinus sylvestrist0
- Outcome
- inbreeding depression estimates for heighte7
- Qualifier
- nonrandom size-specific mortalitye7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e7“Size differences among the progeny types diminished in time due to nonrandom size-specific mortality, causing a decrease in the inbreeding depression estimates for height over time”
Claim · model-written summary
Inbreeding depression estimates for height decreased over time.
- Taxon
- Pinus sylvestris L.Pinus sylvestrist0
- Outcome
- inbreeding depression estimates for heighte7
- Direction
- decreasee7
- Qualifier
- over timee7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e7“Size differences among the progeny types diminished in time due to nonrandom size-specific mortality, causing a decrease in the inbreeding depression estimates for height over time”
Claim · model-written summary
Scots pine exhibits high levels of inbreeding depression during both early and later life stages.
- Taxon
- Scots pinePinus sylvestrise0
- Organ / stage
- early and later stagese0
- Outcome
- high levels of inbreeding depressione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Our results indicate that Scots pine exhibits high levels of inbreeding depression during both early and later stages of the Life cycle”
Claim · model-written summary
Self-fertilization is argued to be inefficient in purging the genetic load in Scots pine.
- Taxon
- Scots pinePinus sylvestrise1
- Outcome
- purging the genetic loade1
- Qualifier
- because of the nearly complete loss of selfed individuals over timee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e1“It is argued that self-fertilization in Scots pine is inefficient in purging the genetic load caused by highly deleterious mutations because of the nearly complete loss of selfed individuals over time”
Claim · model-written summary
The result is an effectively random mating outcrossing population.
- Taxon
- Pinus sylvestris L.Pinus sylvestrist0
- Outcome
- effectively random mating outcrossing populatione2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Scots Pine (Pinus sylvestris L.)”
e2“This results in an effectively random mating outcrossing population”