Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA.
AoB Plants. 2014 Mar 26;6(0). doi: 10.1093/aobpla/plu009. Print 2014.
Early successional species often disperse to novel environments, and if they are selfing, this dispersal will frequently be carried out by inbred individuals. If inbred immigrants are less likely to successfully establish populations than outbred immigrants, dispersal will be less effective and mating system evolution will favour outcrossing. I performed a reciprocal transplant of inbred and outbred plants grown in native and foreign planting sites to test the hypothesis that inbred immigrants had lower fitness. Inbreeding within populations was estimated with allozyme loci to confirm that the populations were inbred. While inbred and outbred plants had significantly lower fitness in foreign habitats, inbreeding depression was of similar magnitude at native sites and foreign habitats. There was no significant difference between inbred and outbred plants at foreign sites of the native habitat. Populations appear to be highly selfing, yet there is an advantage to outcrossing in both the native environment and foreign environments. The implications of this advantage with respect to mating system evolution may depend on whether novel environments are occupied or unoccupied.
早期演替种通常会扩散到新的环境中，如果它们是自交的，这种扩散通常会由近交个体进行。如果近交移民比远交移民更不可能成功建立种群，那么扩散将不那么有效，交配系统进化将有利于异交。我进行了一个将在本地和外国种植点生长的近交和远交植物进行相互移植的实验，以检验近交移民适应性较低的假设。通过等位酶基因座估算种群内的近交程度，以确认种群是近交的。尽管近交和远交植物在外国生境中的适应性显著降低，但在本地和外国生境中，近交衰退的程度相似。在本地生境的外国地点，近交和远交植物之间没有显著差异。种群似乎高度自交，但在本地环境和外国环境中，异交都有优势。这种优势对交配系统进化的影响可能取决于新环境是否被占据。
