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Tests of sib diversification theories of outcrossing in Impatiens capensis : Effects of inbreeding and neighbour relatedness on production and infestation
Author(s) -
Burt Austin,
Bell Graham
Publication year - 1992
Publication title -
journal of evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.289
H-Index - 128
eISSN - 1420-9101
pISSN - 1010-061X
DOI - 10.1046/j.1420-9101.1992.5040575.x
Subject(s) - biology , outcrossing , inbreeding , genetic diversity , intraspecific competition , mating system , evolutionary biology , population , ecology , mating , pollen , demography , sociology
Several models of the evolution of genetic systems posit very strong frequency‐dependent selection acting on small spatial scales; in such circumstances a genetically diverse sibship outperforms a genetically uniform sibship, and genes for mixis may spread in a population. Such selection regimes may derive from resource limitation and/or parasite transmission. We describe a greenhouse experiment designed to test these ideas, using the annual herb Impatiens capensis . Plants were potted in pairs; the genetic variance within pots was manipulated by using progeny from either inbred or outcrossed parents and by using either full sibs or unrelated individuals. Treatment combinations designed to increase genetic diversity resulted in greater phenotypic variance in both morphology and production, though not in the density of spider mites or whiteflies. Despite evidence of resource limitation, there was no effect of genetic diversity on productivity, nor was there an effect on infestation. These results fail to support either the sib competition or the sib contagion theory of outcrossing.