低温胁迫对苦瓜成苗及幼苗生理生化特性的影响

摘要

The effects of seeding germination of bitter gourd varieties DTFS and 11-13-1-3-4 by low temperature in early spring were observed. The variation of cytomembrane permeability, the activity of SOD and CAT and POD, the content of free proline and soluble sugars, the root system activity in two varieties under low temperature stress were observed. The result showed that the seedling rate would reduce in 4 °C and 8°C , and longer stress would lead to lower rate. The seedling rate won't reduce significantly at the low temperature stress of 12 °C for 7-9 days. The chilling stress would increase leaf cell plasma membrane permeability, enhance the activity of SOD and POD of the seedlings, increase proline content and soluble sugars content. Low temperature stress would significantly reduced CAT activity and the root system activity of the seedlings.%以苦瓜自交系DTFS和11-13-1-3-4为材料,研究低温胁迫对发芽种子成苗的影响以及低温胁迫下苦瓜幼苗叶片质膜相对透性、超氧化物歧化酶(Supeuoxide dismutase,SOD)活性、过氧化氢酶(Catalase,CAT)活性和过氧化物酶(Peroxidase,POD)活性、游离脯氨酸含量、可溶性糖含量以及根系活力的变化规律.结果表明,低温胁迫显著降低了苦瓜发芽种子的成苗率,低温处理时间越长,发芽种子的成苗率越低；12℃低温持续7～9 d基本不会对苦瓜成苗产生重大伤害.低温胁迫使苦瓜幼苗叶片细胞内质膜的相对透性、SOD和POD活性、游离脯氨酸和可溶性糖含量增加,使苦瓜幼苗叶片CAT活性和幼苗的根系活力降低.