Interactive effects of temperature, carbon dioxide and watering regime on seed germinability of two genotypes ofArabidopsis thaliana

Abstract

AbstractWe examined the combined effects of temperature, carbon dioxide (CO2) and watering regime during seed maturation on subsequent germinability and total phenolics ofArabidopsis thaliana[wild-type (WT) andabi1-1mutant] seeds. Mature seeds were collected from plants that were grown under lower (22/18°C, 16 h light and 8 h dark) or higher (28/24°C, 16 h light and 8 h dark) temperatures, at ambient (400 μmol mol–1) or elevated (700 μmol mol–1) CO2concentration, and well-watered or water-stressed. Germinated and non-germinated (viable, rotten and empty) seed percentages, germination rate and total phenolics were determined for both genotypes. Higher maturation temperatures increased seed germination percentage, but decreased germination rate, percentage of rotten and non-germinated viable seeds, and total phenolics. Elevated CO2increased seed total phenolics. Water stress decreased the percentage of non-germinated viable seeds. Neither of the two latter factors affected other measured parameters. Seeds of theabi1-1mutant had higher total phenolics. The fate of seeds was mostly affected by higher temperatures and water stress. Also, seeds of theabi1-1mutant had higher germination rate, empty seed percentage and total phenolics than seeds of the WT genotype. Germination percentage was highest for the WT seeds that matured on the water-stressed plants that were grown under higher temperatures at ambient CO2. It can be concluded that higher temperatures had highest effects on seed germinability and other parameters, and elevated CO2did not alleviate the negative effects of higher temperatures on seed viability.