This paper investigates the effects of parental environment and genoty
pe on offspring provisioning, structure, and growth traits in the annu
al plant Polygonum persicaria. Replicate offspring were studied from c
loned individuals of five parental genotypes grown in high vs. low lig
ht, soil moisture, and soil nutrients. Genotypic norms of reaction wer
e determined for ecologically important offspring traits. The effects
on those traits of parental genotype, parental environment, and their
interaction were tested by analysis of variance. The results showed th
at parental genotypes altered offspring traits in response to particul
ar resource limits, such that offspring quality was maintained or enha
nced despite parental resource deprivation. By maximizing the probabil
ity of offspring success, resource-deprived parental plants may partly
offset the reduction in their fitness due to lower offspring number.
Although overall patterns of plasticity were common to all parents, ev
en this small sample revealed differences among parental genotypes in
their response to environment. This may reflect the degree to which va
riation in fitness-related offspring traits occurs within parents and
hence is unavailable to selection.