Osmotic stress and germination of Yucca elata and Menodora scabra, two species of plants native to the desert of Chihuahua

Plant propagation is essential for the restoration of degraded ecosystems. Arid areas sustain some drought tolerant plant species such as Yucca elata (Engelm.) Engelm. and Menodora scabra A. Gray. It is widely accepted that drought can increase in intensity and frequency under the current scenario of climate change. Therefore, we conducted a germination study to test these two native plant species of the Chihuahuan desert under different levels of osmotic stress and to determine their response under different levels of drought. In both species, increasing levels of drought affected germination, but germination of Y. elata was not inhibited (13 % of germination) even at -1.5 MPa, while germination of M. scabra was inhibited (0 % germination) at this osmotic potential. These responses show germination of Y. elata is less affected by drought than germination of M. scabra. Therefore, this represents different potential alternatives of reproduction in restoration programs for these species. Whereas Y. elata may be successfully reproduced by seed under dry field conditions, M. scabra may require seedling production and field transplantation or the use of nursing plants in the field.