Maternal effects on growth and competitive ability in a commonly used restoration species

Abstract

Maternal effects in production gardens may improve or inhibit the performance of seeds planted in large-scale restoration. In ex situ experiments, we tested seeds of the native grass Poa secunda J. Presl (Poaceae) produced by the same maternal families grown in 3 different production garden environments. We measured progeny performance for 5 variables: germination, emergence, growth, competitive tolerance, and competitive ability. Seed size was correlated with root morphology, with larger seeds producing less root volume. Larger seeds conferred better germination and higher competitive ability only in some progeny growth environments. We found that the production garden affected seed size in some maternal families more than others. Also, other effects of the production garden were uncorrelated with seed size: early plant size, final plant size, and competitive tolerance. Adaptive maternal effects were found for germination in one production environment and for early plant size in another production environment. By understanding the influence of maternal effects under field conditions, we may be able to manipulate production environments to maximize the performance and competitive ability of restoration materials.