EVOLUTION OF GYNODIOECY AND MAINTENANCE OF FEMALES: THE ROLE OF INBREEDING DEPRESSION, OUTCROSSING RATES, AND RESOURCE ALLOCATION IN SCHIEDEA ADAMANTIS (CARYOPHYLLACEAE)

摘要: Levels of inbreeding depression, outcrossing rates, and phenotypic patterns resource allocation were studied to examine their relative importance in the maintenance high numbers females gynodioecious Schiedea adamantis (Caryophyllaceae), an endemic Hawaiian shrub found a single population on Diamond Head Crater, Oahu. In studies depression two greenhouse environments, families hermaphrodites exhibited significant (i = 0.60), based multiplicative fitness function using seeds per capsule, germination, survival, inflorescence biomass progeny. Differences between inbred outcrossed progeny smallest at early stage capsule more pronounced later stages survival production. These results are consistent with caused by many mutations small effect. Using allozyme analyses, coefficient adult plants field was not significantly different from zero, implying that 8 nature may be equal one. The locus estimate rate for 0.50 survived flowering; corrected disproportionate loss before flowering selfing, adjusted zygote 0.32, suggesting considerable selfing occurs hermaphrodites. Females totally outcrossed. When compared reproductive output field, produced over twice as plant hermaphrodites, primarily because had far capsules than greater mass seed either provisioning or reduced depression. There no differential mortality respect sex seven year period. higher number females, combined substantial relatively rates probably responsible this population. predicted frequency data production, rate, is 42%, remarkably close observed 39%. High levels suggest quantitative genetic variation present traits affecting population, despite low variability presumed founder