Priming effect on seed germination: Is it always positive for cacti species?

Abstract In drylands, cacti seeds experience high variability amounts of precipitation throughout a year. Seeds undergo hydration and dehydration cycles (or priming) which can increase the proportion or the speed of germination. However, these advantages differ among cacti. In this study, we test the effect of priming on the germination percentage and the mean germination time of two cacti species. We show that priming does not increase the germination percentage for these cacti species, but does reduce the time to germination. We suggest that the response of cacti seeds could be an adaptation to their habitat and microhabitat conditions.