TY - JOUR
T1 - Inbreeding depression in an autotetraploid herb
T2 - A three cohort field study
AU - Galloway, Laura F.
AU - Etterson, Julie R.
PY - 2007/1
Y1 - 2007/1
N2 - • Autotetraploids are predicted to have reduced inbreeding depression relative to diploids. However, recent theory and information on genomic changes following autopolyploidy suggest that inbreeding depression may be closer to diploids. • In three consecutive years, self and outcross pollinations were conducted on autotetraploid Campanulastrum americanum, seeds were planted into native sites, and biennial offspring were followed through seed production. • Inbred individuals had lower germination rates, reduced survival, were smaller, and flowered later, producing fewer fruits with fewer seeds. Inbred offspring had 6% of the cumulative fitness of outcross offspring. Although performance varied substantially among cohorts, inbreeding depression for cumulative fitness was relatively constant, with δ ranging only from 0.92 to 0.95. • C. americanum, like many outcrossing species, expressed very high amounts of inbreeding depression. This supports the hypothesis that inbreeding depression of some autotetraploids may be similar to that of diploids. Furthermore, few studies have measured temporal variation in inbreeding depression. Constant inbreeding depression given a sixfold range in cohort performance suggests that inbreeding depression may be relatively robust to environmental variation experienced by natural populations.
AB - • Autotetraploids are predicted to have reduced inbreeding depression relative to diploids. However, recent theory and information on genomic changes following autopolyploidy suggest that inbreeding depression may be closer to diploids. • In three consecutive years, self and outcross pollinations were conducted on autotetraploid Campanulastrum americanum, seeds were planted into native sites, and biennial offspring were followed through seed production. • Inbred individuals had lower germination rates, reduced survival, were smaller, and flowered later, producing fewer fruits with fewer seeds. Inbred offspring had 6% of the cumulative fitness of outcross offspring. Although performance varied substantially among cohorts, inbreeding depression for cumulative fitness was relatively constant, with δ ranging only from 0.92 to 0.95. • C. americanum, like many outcrossing species, expressed very high amounts of inbreeding depression. This supports the hypothesis that inbreeding depression of some autotetraploids may be similar to that of diploids. Furthermore, few studies have measured temporal variation in inbreeding depression. Constant inbreeding depression given a sixfold range in cohort performance suggests that inbreeding depression may be relatively robust to environmental variation experienced by natural populations.
KW - Autotetraploid
KW - Cumulative fitness
KW - Environmental variation
KW - Field study
KW - Inbreeding depression
KW - Polyploidy
KW - Temporal variation
UR - http://www.scopus.com/inward/record.url?scp=33845602213&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33845602213&partnerID=8YFLogxK
U2 - 10.1111/j.1469-8137.2006.01909.x
DO - 10.1111/j.1469-8137.2006.01909.x
M3 - Article
C2 - 17204084
AN - SCOPUS:33845602213
SN - 0028-646X
VL - 173
SP - 383
EP - 392
JO - New Phytologist
JF - New Phytologist
IS - 2
ER -