Testing for stress-dependent inbreeding depression in Impatiens capensis (Balsaminaceae)

Heschel, M.S. and Hausmann, N. and Schmitt, J. (2005) Testing for stress-dependent inbreeding depression in Impatiens capensis (Balsaminaceae). American Journal of Botany, 92 (8). pp. 1322-1329.

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The relevance of inbreeding depression to the persistence of plant populations can depend upon whether stress magnifies inbreeding depression for fitness-related traits. To examine whether drought stress exacerbates inbreeding depression in gas exchange traits and biomass, we grew selfed and outcrossed progeny of inbred lines from two populations of Impatiens capensis in a greenhouse experiment under water-limited and moist soil conditions. Drought stress did not magnify the degree of inbreeding depression for any of the traits measured. In fact, in one population there was a trend for stronger inbreeding depression under well-watered, benign conditions. Furthermore, significant inbreeding depression for carbon assimilation rate and stomatal conductance was only detected in the lines from one population. In contrast, inbreeding depression for biomass was detected within both populations and differed among lines. Drought stress exerted significant selection on physiological traits, favoring increased carbon assimilation rates and decreased stomatal conductance in drought-stressed plants. Patterns of selection did not differ between inbred and outcrossed plants but did differ marginally between populations. Thus, estimates of selection were not biased by the mixed mating system per se, but may be biased by combining individuals from populations with different histories of selection and inbreeding

Item Type: Article
Uncontrolled Keywords: carbon assimilation rate; drought stress; inbreeding depression; natural selection; stomatal conductance
Author Affiliation: Department of Ecology and Evolutionary Biology, Brown University, Box G-W, Providence, Rhode Island 02912 USA
Subjects: Crop Improvement > Plant Breeding
Divisions: Other Crops
Depositing User: Ms K Syamalamba
Date Deposited: 19 Aug 2011 05:39
Last Modified: 19 Aug 2011 05:39
Official URL: http://dx.doi.org/10.3732/ajb.92.8.1322
URI: http://eprints.icrisat.ac.in/id/eprint/2587

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