高温、干旱及其复合胁迫对多歧苏铁生理影响研究

Effects of High Temperature,Drought and Their Combined Stress on Physiological Characteristics of Cycas multipinnata

以多歧苏铁离体叶片为材料,研究高温、干旱及干热复合胁迫处理对多歧苏铁的生理影响。结果表明:高温、干旱及干热复合胁迫处理后,色素含量无显著变化;光系统Ⅱ最大光化学效率和实际光化学效率以及电子传递速率均比CK显著下降,且高温及干热复合胁迫处理间无显著差异,但都显著低于干旱处理;干旱处理后的光系统II处非调节性能量耗散的量子产量和光化学淬灭系数均与对照无显著变化,但高温及干热复合胁迫处理后光系统II处非调节性能量耗散的量子产量显著升高,光化学淬灭系数显著降低,且干热复合胁迫处理后光系统II处非调节性能量耗散的量子产量显著高于高温处理。高温及干热复合胁迫处理后,丙二醛含量显著降低,但干旱处理后其含量无显著变化。高温处理后过氧化物酶活性显著升高,干旱和干热复合胁迫下超氧化物歧化酶和过氧化物酶活性显著升高。各种胁迫处理后,可溶性糖含量并无显著变化,但高温和干旱胁迫处理后脯氨酸含量显著降低。因此,干旱对多歧苏铁的影响最小,干热复合胁迫对其影响最大,抗氧化酶在多歧苏铁抗高温、干旱和干热复合胁迫中起着重要作用。

The physiological effects of high temperature,drought and combined stress treatment on Cycas multipinnata were studied by using the leaves of C.multipinnata in vitro.Results show there is no significant change in pigment content after high temperature,drought and dry heat combined stress treatment.The maximum photochemical efficiency and actual photochemical efficiency and electron transfer rate of photosystem ii are significantly lower than CK.There is no significant difference between high temperature and dry heat combined stress treatment,but they are significantly lower than drought treatment.The quantum yield and photochemical quenching coefficient of non-regulated energy dissipation at the photosystem ii after drought treatment are not significantly different from the control.The quantum yield of non-regulated energy dissipation at photosystem ii increase significantly after high temperature and dry heat combined stress treatment,and the photochemical quenching coefficient decrease significantly.Quantum yield of non-regulated energy dissipation at photosystem ii after dry heat combined stress treatment is significantly higher than high temperature treatment.After high temperature and dry heat combined treatment,the content o!malondialdehyde decrease significantly,but its content do not change significantly after drought treatment.The activity ol peroxidase is significantly increased alter high temperature treatment,and the activities ol superoxide dismutase and peroxidase are significantly increased under drought and dry heat stress.Alter various stress treatments,the soluble sugar content do not change significantly,but the proline content decreases significantly alter treatment under high temperature and drought stress.Therefore,the effect of drought on polymorphic cycads is the least,and dry-heat combined stress has the greatest impact on it.Antioxidant enzyme plays an important role in the resistance ol polymorphic cycads to high temperature,drought and dry heat.