Abstract
Using surveys of natural populations, experimental crosses, and common garden trials, we tested the hypothesis that hybrid cottonwoods (Populus fremontii x P. angustifolia) from the Weber River in northern Utah would produce as many viable offspring as their parental species. We found that both F1 generations and backcross generations can be just as fit as the parent taxa. First, F1 hybrids produced as many viable seed as P. angustifolia (but less than P. fremontii), and backcross genotypes produced as many viable seeds as both parent taxa. Second, hybrids produced nearly two times as many ramets from root sprouts as P. angustifolia and four times as many ramets as P. fremontii. Third, the high mortality of germinated seedlings of all tree types (i.e., >90%) and very low mortality of asexually derived tamers provide hybrids with equal sexual reproduction and enhanced asexual reproduction, especially since backcross hybrids exhibit transgressive segregation in ramet production. Our findings suggest that the introgression of P. fremontii seed traits into the hybrid genome is responsible for their equivalent performance (at least to one parent) in sexual reproduction, while the contributions of asexual traits from P. angustifola results in hybrids having equal or greater fitness.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 981-990 |
| Number of pages | 10 |
| Journal | American Journal of Botany |
| Volume | 89 |
| Issue number | 6 |
| State | Published - 2002 |
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Keywords
- Hybrid fitness
- Introgression
- Populus
- Ramets
- Seed viability
- Sexual and asexual reproduction
- Transgressive segregation
ASJC Scopus subject areas
- Plant Science
Cite this
Cottonwood hybrids gain fitness traits of both parents : A mechanism for their long-term persistence? / Schweitzer, Jennifer A.; Martinsen, Gregory D.; Whitham, Thomas G.
In: American Journal of Botany, Vol. 89, No. 6, 2002, p. 981-990.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Cottonwood hybrids gain fitness traits of both parents
T2 - A mechanism for their long-term persistence?
AU - Schweitzer, Jennifer A.
AU - Martinsen, Gregory D.
AU - Whitham, Thomas G
PY - 2002
Y1 - 2002
N2 - Using surveys of natural populations, experimental crosses, and common garden trials, we tested the hypothesis that hybrid cottonwoods (Populus fremontii x P. angustifolia) from the Weber River in northern Utah would produce as many viable offspring as their parental species. We found that both F1 generations and backcross generations can be just as fit as the parent taxa. First, F1 hybrids produced as many viable seed as P. angustifolia (but less than P. fremontii), and backcross genotypes produced as many viable seeds as both parent taxa. Second, hybrids produced nearly two times as many ramets from root sprouts as P. angustifolia and four times as many ramets as P. fremontii. Third, the high mortality of germinated seedlings of all tree types (i.e., >90%) and very low mortality of asexually derived tamers provide hybrids with equal sexual reproduction and enhanced asexual reproduction, especially since backcross hybrids exhibit transgressive segregation in ramet production. Our findings suggest that the introgression of P. fremontii seed traits into the hybrid genome is responsible for their equivalent performance (at least to one parent) in sexual reproduction, while the contributions of asexual traits from P. angustifola results in hybrids having equal or greater fitness.
AB - Using surveys of natural populations, experimental crosses, and common garden trials, we tested the hypothesis that hybrid cottonwoods (Populus fremontii x P. angustifolia) from the Weber River in northern Utah would produce as many viable offspring as their parental species. We found that both F1 generations and backcross generations can be just as fit as the parent taxa. First, F1 hybrids produced as many viable seed as P. angustifolia (but less than P. fremontii), and backcross genotypes produced as many viable seeds as both parent taxa. Second, hybrids produced nearly two times as many ramets from root sprouts as P. angustifolia and four times as many ramets as P. fremontii. Third, the high mortality of germinated seedlings of all tree types (i.e., >90%) and very low mortality of asexually derived tamers provide hybrids with equal sexual reproduction and enhanced asexual reproduction, especially since backcross hybrids exhibit transgressive segregation in ramet production. Our findings suggest that the introgression of P. fremontii seed traits into the hybrid genome is responsible for their equivalent performance (at least to one parent) in sexual reproduction, while the contributions of asexual traits from P. angustifola results in hybrids having equal or greater fitness.
KW - Hybrid fitness
KW - Introgression
KW - Populus
KW - Ramets
KW - Seed viability
KW - Sexual and asexual reproduction
KW - Transgressive segregation
UR - http://www.scopus.com/inward/record.url?scp=0036294668&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036294668&partnerID=8YFLogxK
M3 - Article
C2 - 21665697
AN - SCOPUS:0036294668
VL - 89
SP - 981
EP - 990
JO - American Journal of Botany
JF - American Journal of Botany
SN - 0002-9122
IS - 6
ER -