Respiratory rates and freezing tolerance of embryos of Inga vera Willd. subsp. affinis (DC.) T.D. Penn. from different regions

ABSTRACT: Recalcitrant seeds are sensitive to desiccation and low storage temperatures, but there is a gradient of recalcitrance between different species and between populations of the same species. Therefore, tolerance to drying and low temperatures, as well as the respiratory rates of seeds, can be conditioned by the source of the material. The present study aimed to evaluate the relationship among desiccation and low temperature tolerance, and respiratory rates of Inga vera embryos from different regions. The embryos were submitted to three drying levels and incubated for up to fifteen days at -4, -2, 2 and 5 °C. Then, they were evaluated for respiration, germination and electrical conductivity. The embryos tolerated freezing at -4 °C since they were associated with certain levels of drying and a consequent change in the energy status of water. In conclusion, the conditions in which the embryos are formed define their degree of maturation at dispersal, hence their tolerance to desiccation and freezing.

摘要：顽拗性种子对脱水及低温贮藏条件敏感，但不同物种间以及同一物种的不同种群间，顽拗性程度存在梯度差异。因此，种子的脱水与低温耐受性，以及种子呼吸速率，均受材料来源的调控。本研究旨在探究不同区域来源的维拉印加豆（Inga vera）胚的脱水耐受性、低温耐受性与呼吸速率三者间的关联。实验将这些胚置于三个脱水梯度下处理，并分别在-4℃、-2℃、2℃及5℃条件下培养长达15天，随后对其呼吸速率、萌发能力以及电导率进行检测评估。经特定程度脱水处理后，这些胚可耐受-4℃的低温冷冻，这与其水分能量状态发生相应改变有关。综上，胚发育所处的环境条件决定了其脱离母株时的成熟度，进而决定了其脱水与冷冻耐受性。