Abstract ID: 3.9863 | Accepted as Talk | Talk/Oral | TBA | TBA

The environmental conditions (including mirco-climate conditions) experienced by a mother plant during seed development can significantly influence the traits of its offspring. Maternal environmental effects are crucial for understanding how plant species cope with climate variability and how plants can adapt in rapidly changing environments such as alpine ecosystems. To date, most studies on this topic in alpine environments have focused on the effects of a warmer maternal environment, while other climatic factors, such as reduced precipitation, remain underexplored. Here we investigated the effects of a drier maternal environment on seed morphology, germination and seedling water stress tolerance in three Australian alpine species. We used rain-out shelters to impose a 60% reduction in precipitation (i.e. modify microclimatic conditions) on maternal plants over one year. Seeds were then collected from plants grown under rain-out shelters and control conditions, measured for size and mass, and subjected to germination tests under a gradient of water potential solutions (0 to -1 MPa, PEG6000). Seedlings were also grown and subjected to a gradient of watering treatments (100%, 80% and 60% pot capacity) in a climate chamber experiment. Overall, our results showed that a drier maternal environment affected seed morphological traits with contrasting species-specific responses and increased seed and seedling tolerance to water stress. Seed mass and size decreased significantly in two of the species studied, while seeds of another species were heavier than controls under drier maternal conditions. The germination capacity of seeds from drier maternal environments was higher than that of control seeds under low water availability in all three species. Seedlings from a drier maternal environment had a greater total leaf area and experienced less stress (as indicated by relative water content and chlorophyll fluorescence) under low water availability than control seedlings. Finally, we discuss the relevance of maternal environmental effects for potential conservation and management activities of alpine ecosystems in a changing climate.