Differences in phenotypic plasticity between plants from dimorphic seeds of Cakile edentula.

Cakile edentula produces upper and lower dimorphic seeds which disperse long and short distances, respectively, from the parent. Canonical discriminant analysis was used to determine the differences between plants from the two seed morphs in both the amount and direction of their overall plastic responses to major environmental factors. In general, plants from the long-distance dispersal seeds were less plastic than those from the short-distance dispersal seeds in response to soil moisture and sand burial. This is probably a result of broader ecological amplitude of the plants from the long-distance dispersal seeds due to their larger seed masses. Differences in the direction of overall plasticity between plants from the two seed morphs are not likely to be adaptive. However, phenotypic selection may affect the relative contribution of plants from the two seed morphs to the next generation.