Relationship between germination under osmotic stress and development in Bouteloua curtipendula genotypes: implications for restoration management

Abstract

Several studies have used chemical agents to inhibit the osmotic potentials and simulate water stress conditions in vitro, assuming that tolerance to osmotic stress is an advantage for seedling survival and establishment in the field. However, how the germination and seedling growth in the laboratory contribute to seedling emergence, survival and establishment are not well-known. We evaluate the relationship between the resistance to the in vitro osmotic stress and the emergence, establishment, and survival under field conditions in sideoats grama (Bouteloua curtipendula). The resistance to osmotic stress was evaluated in the osmotic potentials 0, −0.5, −1.0, and −1.5 MPa, simulated in the laboratory. The emergence, establishment, and survival under field conditions were evaluated in two experimental sites for two years. Results from this study revealed that the survival in the field was positively related (p < 0.05) to the inhibition of germination (R 2 = 0.68), germination speed index (R 2 = 0.69), and plumule length (R 2 = 0.68) determined in the laboratory. In other words, the genotypes most affected by the in vitro osmotic stress presented the greatest survival and establishment in the field. This information should be considered for selecting new sideoats grama genotypes of high survival and establishment capacity in natural conditions.