Evolution on Islands: a colloquium to honor the careers of Daniel Crawford and Tod Stuessy
Weller, Stephen , Sakai, Ann , Culley, Theresa , Duong, Loan , Danielson, Rachel .
Transfer of male sterility genes across a species boundary.
Diversification of the endemic Hawaiian genus Schiedea (Caryophyllaceae) has resulted in a monophyletic lineage of 34 endemic species with diverse breeding systems ranging from obligate self-fertilization to sexual dimorphism. Experimental crosses between gynodioecious Schiedea salicaria and hermaphroditic S. menziesii, two West Maui species, and between the parental species and individuals from a natural hybrid zone between them, indicate that the same nuclear male sterility gene occurs in the parental species and their natural hybrids. Within the hybrid zone, selection has occurred for traits of S. salicaria, the wind-pollinated parent. Presumably, plants in the hybrid zone will eventually most closely resemble S. salicaria, with the chloroplast genome of S. menziesii as the only evidence of past hybridization. In contrast, in the absence of traits promoting wind pollination, the few female plants in a population of S. menziesii otherwise showing no evidence of hybridization with S. salicaria appear to be at a selective disadvantage. With limited gene flow from S. salicaria, selection for wind pollination in S. menziesii, independent of hybridization with S. salicaria, is expected to result in a constellation of inflorescence traits different from those of S. salicaria, but which also promote wind-pollination. Features of the inflorescence of S. menziesii indicate that independent selection for wind pollination may be underway in this species. The outcome of hybridization between Schiedea species with different breeding systems apparently depends on the opportunity for hybridization and the magnitude of selection for wind pollination.
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1 - University Of California Irvine, Department Of Ecology And Evolutionary Biology, 321 Steinhaus Hall, Irvine, CA, 92697, USA
2 - University Of California-Irvine, Department Of Ecology & Evolutionary Biology, 321 STEINHAUS HALL, IRVINE, CA, 92697-2525, USA
3 - University Of Cincinnati, Department Of Biological Sciences, 614 Rieveschl Hall, Cincinnati, OH, 45221-0006, USA
4 - University of California, Irvine, Department of Ecology and Evolutionary Biology, Irvine, CA, 92697, USA
breeding system evolution
Presentation Type: Symposium or Colloquium Presentation
Location: Franklin A/Hyatt
Date: Wednesday, July 11th, 2012
Time: 11:15 AM