Understanding seed moisture desorption and adsorption isotherms is important for seed quality maintenance and better predicting seed storage lifespan. Freshly harvested oilseed rape and barley seeds were dried and then rehydrated twice. Seed equilibrium relative humidity (eRH) and moisture content (MC) were determined at different humidity levels so that two cycles of desorption and adsorption could be constructed. In addition, seeds were dried to 30% RH and then rehydrated to 50% RH for five cycles to determine whether they shift to the adsorption isotherm. Monolayer MC was determined using the Gugenheim-Anderson-de Boer model. Storage experiments were conducted for seeds equilibrated at 30, 40, 50, 60 and 70% RH for two cycles of desorption and adsorption at 45°C. Isotherm curves’ shapes were similar for oilseed rape and barley, although spanning a greater MC range in barley. The hysteresis effect was observed for oilseed rape and barley seeds when dried over silica gel at <10% RH. However, this effect was only observed for barley seeds when dried to 30% RH, but not for oilseed rape seeds. Longevity was greater for adsorbing seeds than desorbing seeds at a given eRH, however, there was no significant difference in σ (the standard deviation of the normal distribution of seed deaths over time)–MC log–log relationship. The relationship shifted for seeds on the second cycle. In conclusion, if seed lots are stored at a specific RH, reaching equilibrium by desorption or adsorption can strongly influence their longevity. Also, when seeds of different species are dried to low RH, they will respond differently to a subsequent increase in RH, which could profoundly affect their longevity.

了解种子水分解吸和吸附等温线对于维持种子质量和更好地预测种子储存寿命非常重要。将新鲜收获的油菜和大麦种子干燥，然后再水化两次。在不同湿度水平下测定种子平衡相对湿度（eRH）和水分含量（MC），从而可以构建解吸和吸附的两个循环。此外，将种子干燥至 30% RH，然后再水化至 50% RH，进行五个循环，以确定它们是否移动到吸附等温线。单层 MC 使用 Gugenheim-Anderson-de Boer 模型测定。对平衡在 30%、40%、50%、60% 和 70% RH 的种子进行储存实验，在 45℃ 下进行两个解吸和吸附循环。油菜和大麦的等温线形状相似，尽管大麦中的 MC 范围更大。当在 <10% RH 的条件下通过硅胶干燥时，观察到油菜和大麦种子的滞后效应。然而，这种效应仅在干燥至 30% RH 的大麦种子中观察到，而在油菜种子中则没有。在给定的 eRH 下，吸附种子的寿命比解吸种子的寿命更长，但是，σ（种子死亡随时间的正态分布的标准差）-MC 双对数关系没有显着差异。在第二个周期中，种子的关系发生了变化。总之，如果种子批次储存在特定的相对湿度下，通过解吸或吸附达到平衡会强烈影响其寿命。此外，当不同物种的种子干燥至低相对湿度时，它们对随后相对湿度增加的反应也不同，