【摘要】 从未经抗寒锻炼的黑麦叶片中分离并悬浮于山梨醇溶液中的原生质体可忍受的表面积增加值(TSAI₅₀)为1020μm²,不因收缩程度而改变。原生质体的膨胀势达不到它们原来的大小就发生溶胞作用。锻炼过的原生质体TSAI₅₀值明显增加,收缩后的原生质体的膨胀势可恢复或接近于它们原来的最大表面积。 抗寒锻炼也使原生质体对高渗协迫的忍受大大增加。在0℃的高渗山梨醇或NaCl+CaCl₂溶液中,未经锻炼的原生质体的半致死浓度为3Osm,经锻炼的原生质体分别为10和7Osm。 冻融过程中,未经锻炼的原生质体在半致死温度范围内,伤害的主要形式是膨胀引起的溶胞作用,在致死温度以下,主要是脱水引起渗透失活。经锻炼的原生质体在致死温度时的伤害,主要是渗透失活。更多还原

【Abstract】 For protoplasts isolated from nonacclimated rye （Secale cereale L.cv.Puma）leaves and suspended in sorbitol solutions, the tolerable surface area increment(TSAI₅₀)was 1020μm² .This value did not vary with the extent of contraction. The lysis during expansion occurred before the original size was regained. For acclimated protoplasts suspended in sorbitol, the TSAI₅₀ increased considerably. The expansion potential of contracted acclimated protoplasts might recover or approximate their original maximum surface area.The tolerance of protoplasts to hypertonic stress during the acclimation also increased significantly. For nonacclimated protoplasts suspended in hypertonic sorbitol or NaCl+CaCl₂ solutions, the osmotic concentration at which 50% of the protoplasts lost their osmotic responsiveness(LD₅₀)was 3.0 Osm.at 0℃.However, for acclimated protoplasts suspended in sorbitol or NaCl+ CaCl₂ solutions at 0℃ the LD₅₀′s were 10 and 7 Osm.respectively.A prodominant form of injury in nonacclimated protoplasts subjucted to a freeze-thaw process in the range of the LT₅₀ was expansion-induced lysis,below the LT₅₀ was dehydration-induced loss of osmotic responsiveness.For acclimated protoplasts,the prodominant form of injury at the LD₅₀ was loss of osmotic responsiveness.更多还原