Effects of parental age and stress on stress tolerance of offspring in duckweed

Abstract

Demographic senescence is the population-level declines in rates of survival and reproduction with increasing age. Although offspring are often assumed to be of equal quality, offspring fitness can change with parental age. Many factors contribute to offspring fitness, including the ability to tolerate stress. Parental and ancestral environments also have the ability to affect offspring stress tolerance. The effects of parental age and ancestral salt stress on offspring ability to tolerate salt stress were examined in an asexual, aquatic plant. It was found that parental age affected the response, but not the overall fitness of offspring exposed to salt stress. Ancestral stress prepared offspring for stress through a reduced time to produce a first offspring, although these offspring may have been of lower quality. The studies done show the importance of stress history on future fitness.