Reaction norm analysis of native, non-native and agricultural ecotypes of seven Brassica species to elevated soil salinity

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Daily, Nicholas
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Phenotypic plasticity is a characteristic of a genotype that enables the production of different phenotypes in response to a range of environmental conditions. In this study I investigated the differences in phenotypic response to elevated soil salinity of seven Brassica species which all have native, non-native and agricultural ecotypes. These Brassica species are a well studied group with know phylogenetic relationships. The objectives of my study were (1) to investigate the differences between the native, nonnative and agricultural ecotypes in physiological and morphological responses to elevated soil salinity, (2) to compare these physiological and morphological responses to salt between ecotypes within a species, as well as between the polyploid species and their diploid parents and (3) determine what, if any, differences in physiological and/or morphological responses to salt allow for the potential for increased fitness. Two experiments were performed to investigate these differences; one utilizing lab developed rapid cycling lines and a second utilizing native, non-native and agricultural ecotypes. I found statistically significant variation for plasticity among species, ecotypes and ploidy level for several physiological and morphological traits. Although ecotypes responded uniquely, no one particular ecotype or species was superior overall. My study provides evidence of the ability of certain ecotypes to respond to changing/novel environmental conditions which potentially contribute to invasion success.
Brassica -- Research