Antarctic pearlwort (Colobanthus quitensis) populations respond differently to pre-germination treatments

Abstract

Seed germination depends on various biotic and abiotic interactions associated with maternal habitat. The formation of soil seed banks is a key strategy and has ecological implications, especially with regard to species that develop in extreme habitats. When establishing germplasm banks of these species from seeds, seed dormancy becomes one of the main difficulties. In this research, we study Colobanthus quitensis, a species with wide latitudinal and altitudinal distribution, inhabiting extreme environments from southern Mexico to maritime Antarctica. Furthermore, this species has been described to have a secondary dormancy that is dependent on the environment. In order to perform research without needing to have regular access to this species’ habitats, it is therefore vital to possess plant material from different populations representing the species distribution. Thus, we evaluated the effects of various pre-germination treatments on germination percentage and time in four populations of the species. A differential and significant effect was evidenced, both among treatments and populations. Acid scarification increased germination percentage and decreased germination time. The best treatments were determined by population, and direct seeding after a brief period of cold stratification (4 °C) allowed us to achieve good germination percentages in at least three of the studied populations. This new evidence allows optimization in the introduction, development, characterization, and availability of plant material of the different C. quitensis populations in the Antarctic Vascular Plant Germplasm Bank.