Measurements of lethal and nonlethal inbreeding depression inform the de novo domestication of <i>Silphium integrifolium</i>

PREMISE Inbreeding depression, or the reduction in fitness of progeny with related parents, has potential to adversely affect long-term viability both wild and captive plant populations. Silphium integrifolium, a prairie native central United States, been identified as candidate for domestication perennial oilseed crop. Little is known about inbreeding depression this species, but it expected be nonnegligible because S. integrifolium self-incompatible. Here, we measure lethal expressed through embryo deaths, nonlethal changes vigor phenotypes progeny. METHODS First, made controlled crosses among unrelated individuals determine effect two different levels on seed production. Then, grew inbred outbred from population reproductive maturity measured 11 key traits. RESULTS We found that within an improved population, carried average slightly less than one allele per gamete. In progeny, significant was observed at least family eight CONCLUSIONS likely important challenge domestication, reducing overall fecundity values phenotypes. These effects may grow worse selection reduces effective size. recommend several strategies breeding help mitigate these problems.