Remember its origin: maternal effects during seed production influence the germination responses, seed traits, and initial root growth of Piper umbellatum

Abstract

Premise of research. Maternal environment can influence the seed ecophysiology, for example, of species that produce fruits in different seasons. Due to seasonal variations in environmental factors, differences in germination responses, seed traits, and seedling size may occur. Using seeds of Piper umbellatum produced in the same population in both the rainy and dry seasons, we evaluated the effects of temperature variations and water availability on germination parameters, root growth, and seed traits. Methodology. Eight temperature treatments (15°C, 20°C, 23°C, 25°C, 28°C, 30°C, 35°C, and alternation between 30°C and 20°C) and four water potentials (0, −0.3, −0.6, and −1.2 MPa) were performed. The following parameters were analyzed: germination onset, germination percentage (G%), mean germination time (MGT), root elongation, seed longevity during ex situ storage, and dry mass of seeds. Pivotal results. All parameters analyzed differed according to the seed production period. The rainy-season seeds had greater germinability and longevity, as they started to germinate first with higher G% and lower MGT values than the dry-season seeds, which were more sensitive to the effects of water deficit in relation to germination parameters. Dry-season seeds had higher dry mass, and their seedlings had greater root growth than those from rainy-season seeds. This balance between germination parameters and traits of seeds and seedlings reflects the existence of an intergenerational memory of stress. Conclusions. The maternal environment during the seed production period influenced germination responses, seed traits, and root growth. The first stages of plant development can be strongly impacted by climate change, and the responses to these changes can vary according to the period of seed production in the same species.