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 (R² = 0.68), germination speed index (R² = 0.69), and plumule length (R² = 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.

摘要

几项研究使用化学试剂来抑制渗透势并在体外模拟水分胁迫条件，假设对渗透胁迫的耐受性是幼苗在田间存活和建立的优势。然而，实验室中的发芽和幼苗生长如何促进幼苗的出现、存活和建立尚不清楚。我们评估了sideoats grama（Bouteloua curtipendula ）在田间条件下对体外渗透压的抵抗力与出现、建立和存活之间的关系). 在实验室模拟的渗透势 0、-0.5、-1.0 和-1.5 MPa 下评估了对渗透压的抵抗力。在田间条件下的出现、建立和存活在两个实验地点进行了两年的评估。该研究的结果表明，田间存活率与 发芽抑制 ( R ² = 0.68)、发芽速度指数 ( R ² = 0.69) 和胚芽长度 ( R ² = 0.68)呈正相关 ( p < 0.05)在实验室确定。换句话说，受体外影响最大的基因型渗透压代表了该领域最大的生存和建立。在选择在自然条件下具有高存活和建立能力的新的 sideoats grama 基因型时，应考虑此信息。