Combined Effects of Temperature and Carbon Dioxide on Plant Growth and Subsequent Seed Germinability of Silene noctiflora

Effects of global climate change on invasive alien species of plants and on the resulting progeny have received little attention. We examined the combined effects of temperature and carbon dioxide (CO2) on plant growth and physiological characteristics, reproductive yield components, and subsequent germination patterns of fresh- and dry-stored seeds of night-flowering catchfly (Silene noctiflora). Plants were grown under two temperature regimes (22°/18°C and 28°/24°C) at ambient (370 μmol mol−1) and elevated (740 μmol mol−1) CO2 concentrations in controlled-environment growth chambers. Higher temperature reduced plant height; average individual leaf area; capsule length, width, and mass; sound seed number; and mass per capsule but increased specific leaf mass. Elevated CO2 increased single sound seed mass. Higher temperature decreased both percentage and rate of germination, whereas elevated CO2 decreased germination percentage but increased germination rate. Seed germination increased with storage duration. Higher temperature increased transpiration. However, elevated CO2 decreased transpiration but increased net CO2 assimilation and water use efficiency. Elevated CO2 increased chlorophyll b but decreased chlorophyll a:b ratio. Ethylene production was enhanced by increased temperature. We conclude that despite the negative effects of higher temperature on some plant characteristics, S. noctiflora has the potential to thrive under conditions of climate change.