Abstract
The comparison of natural and synthetic polyploids helps understand the consequences of polyploidization and separate the effects of genome duplication from subsequent evolution. The method has, however, been used only in a limited number of ecological studies, and we know little about its possible limits.
We optimized methodology to produce synthetic polyploids in Vicia cracca and explored the differences in stomata size, time to germination and plant size between synthetic and natural polyploids and diploids. We also explored variation in relative genome size and chromosome number of synthetic polyploids and attempted to understand consequences of this variation on plant performance.
The creation of synthetic polyploids was possible even though it was met with relatively low success. Stomata length was affected directly by polyploidization.
In contrast, plant size was neither a function of polyploidization nor of subsequent evolution. Time to germination increased in synthetic polyploids, suggesting that only subsequent evolution will return the germination rate to the original levels.
While the relative genome size of synthetic polyploids fell within the range of natural polyploids, 25% of the synthetic polyploids turned out to be aneuploids. The differences in chromosome number were reflected in performance of the synthetic polyploids.
Exclusion of aneuploids from the data, however, did not affect the between-cytotype comparison. A more detailed comparison of the frequency of aneuploids among natural and synthetic polyploids is needed to understand possible differences between synthetic and natural polyploids and the effects of aneuploidy on the conclusions of ecological studies comparing natural and synthetic polyploids.