XVI International Botanical Congess

To study the relationship between genetic variation and reproduction in the rare annual plant Melampyrum arvense (Scrophulariaceae), we created replicate experimental populations (plots) of different genetic diversity. Low diversity plots consisted of offspring from the same mother plant, medium diversity plots of offspring from different mothers in the same population, and high diversity plots consisted of offspring from plants in different populations. Both seed production and mean seed weight increased with the genetic diversity of the experimental populations. This suggests that inbreeding in small natural populations may reduce seed production and increase the risk of extinction, and that M. arvense could benefit from management measures that increase the gene-flow among isolated populations.