Abstract
We examined the reproductive biology of Tolmeia menziesii and Tellima grandiflora (Saxifragaceae) and barriers to hybridization between these species. Crossing experiments and pollinator observations suggest that Tolmeia is completely self-incompatible, obligately outcrossing, and bumble bee pollinated, whereas Tellima is self-compatible, with a mixed mating system possibly facilitated by rove beetles. Hybrid crosses set seed only when Tellima was the pollen recipient. Observations of pollen style interactions indicate that self-incompatibility in Tolmeia is late-acting and that pollen tube growth is comparable between reciprocal hybrid pollinations. Seven of 40 progeny from Tolmeia x Tellima crosses were isozymically and morphologically intermediate between Tolmeia and Tellima, and were identical to a naturally occurring hybrid. The remainder were identical to Tellima, the maternal parent in successful hybrid crosses, which we attribute to either intraspecific pollen contamination, or agamospermy. Barriers to hybridization between sympatric Tellima and Tolmeia consist of divergence in floral morphology, pollinator relationships, compatibility, and a series of postzygotic isolating mechanisms including hybrid sterility.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 910-918 |
| Number of pages | 9 |
| Journal | American journal of botany |
| Volume | 83 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 1996 |
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Keywords
- Saxifragaceae
- Tellima
- Tolmeia
- insect pollination
- intergeneric hybridization
- late-acting self- incompatibility
- plant mating systems
- reproductive isolating mechanisms
Cite this
Reproductive strategies and barriers to hybridization between Tellima grandiflora and Tolmeia menziesii (Saxifragaceae). / Weiblen, George D.; Brehm, Bert G.
In: American journal of botany, Vol. 83, No. 7, 07.1996, p. 910-918.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Reproductive strategies and barriers to hybridization between Tellima grandiflora and Tolmeia menziesii (Saxifragaceae)
AU - Weiblen, George D.
AU - Brehm, Bert G.
PY - 1996/7
Y1 - 1996/7
N2 - We examined the reproductive biology of Tolmeia menziesii and Tellima grandiflora (Saxifragaceae) and barriers to hybridization between these species. Crossing experiments and pollinator observations suggest that Tolmeia is completely self-incompatible, obligately outcrossing, and bumble bee pollinated, whereas Tellima is self-compatible, with a mixed mating system possibly facilitated by rove beetles. Hybrid crosses set seed only when Tellima was the pollen recipient. Observations of pollen style interactions indicate that self-incompatibility in Tolmeia is late-acting and that pollen tube growth is comparable between reciprocal hybrid pollinations. Seven of 40 progeny from Tolmeia x Tellima crosses were isozymically and morphologically intermediate between Tolmeia and Tellima, and were identical to a naturally occurring hybrid. The remainder were identical to Tellima, the maternal parent in successful hybrid crosses, which we attribute to either intraspecific pollen contamination, or agamospermy. Barriers to hybridization between sympatric Tellima and Tolmeia consist of divergence in floral morphology, pollinator relationships, compatibility, and a series of postzygotic isolating mechanisms including hybrid sterility.
AB - We examined the reproductive biology of Tolmeia menziesii and Tellima grandiflora (Saxifragaceae) and barriers to hybridization between these species. Crossing experiments and pollinator observations suggest that Tolmeia is completely self-incompatible, obligately outcrossing, and bumble bee pollinated, whereas Tellima is self-compatible, with a mixed mating system possibly facilitated by rove beetles. Hybrid crosses set seed only when Tellima was the pollen recipient. Observations of pollen style interactions indicate that self-incompatibility in Tolmeia is late-acting and that pollen tube growth is comparable between reciprocal hybrid pollinations. Seven of 40 progeny from Tolmeia x Tellima crosses were isozymically and morphologically intermediate between Tolmeia and Tellima, and were identical to a naturally occurring hybrid. The remainder were identical to Tellima, the maternal parent in successful hybrid crosses, which we attribute to either intraspecific pollen contamination, or agamospermy. Barriers to hybridization between sympatric Tellima and Tolmeia consist of divergence in floral morphology, pollinator relationships, compatibility, and a series of postzygotic isolating mechanisms including hybrid sterility.
KW - Saxifragaceae
KW - Tellima
KW - Tolmeia
KW - insect pollination
KW - intergeneric hybridization
KW - late-acting self- incompatibility
KW - plant mating systems
KW - reproductive isolating mechanisms
UR - http://www.scopus.com/inward/record.url?scp=0029659441&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029659441&partnerID=8YFLogxK
U2 - 10.2307/2446269
DO - 10.2307/2446269
M3 - Article
AN - SCOPUS:0029659441
VL - 83
SP - 910
EP - 918
JO - American Journal of Botany
JF - American Journal of Botany
SN - 0002-9122
IS - 7
ER -