Date of Award
12-17-2002
Document Type
Thesis
Abstract
Gynodioecy, the co-occurrence of females and hermaphrodites, is considered an intermediate step in the evolution of separate sexes in flowering plants. Highly variable female frequencies among populations suggest structuring of sex determining genes and differences in the relative fitness of females and hermaphrodites as seed parents. I investigated spatial variability in sex ratio and the effects of inbreeding on offspring quality in Silene acaulis. Female frequencies varied among populations from 0.32 to 0.69, and most were at temporal equilibrium. Females were significantly clumped within two of six populations. Females produced from 4 to 27 times as many fruits as hermaphrodites. Self-pollination of hermaphrodites reduced offspring survivorship and growth by an average of 67% compared to outcrosses. Overall, spatial variation in female frequency suggests a role of founder events and local seed dispersal. Low fruit production and reduced quality of inbred offspring suggest hermaphrodites may be functioning primarily as pollen donors.
Recommended Citation
Keller, Stephen Robert, "The ecological genetics of gynodioecy in Silene acaulis L. (Caryophyllaceae): spatial sex structure and inbreeding depression" (2002). Biological Sciences. 102.
https://ualaska.researchcommons.org/uaf_grad_bio_sciences/102
Handle
http://hdl.handle.net/11122/5233