低温胁迫对设施小青菜叶片抗衰老特性的影响

Effects of Low Temperature Stress on Anti-senility of Brassica chinensis

以小青菜品种"新场青一号"为试材,利用人工环境控制试验研究的方法,研究了低温胁迫对设施小青菜的叶绿素含量、保护酶活性、细胞膜透性及抗衰老特性的影响,以期为小青菜设施种植的低温灾害防控提供指导。结果表明:在-6~0℃范围内,小青菜叶片的叶绿素含量随着低温胁迫强度的加剧和持续时间的延长而明显下降;叶片组织的超氧化物歧化酶(SOD)活性随着胁迫温度的降低而不断升高,过氧化物酶(POD)活性和过氧化氢酶(CAT)活性随着处理时间的延长,均表现出先升高后降低的趋势;丙二醛(MDA)含量则表现出了先升高后降低再升高的特点;叶片的相对电导率随着胁迫温度的降低而升高,而温度越低,增长幅度越大。研究认为,小青菜叶片的抗衰老特性随气温降低而降低,细胞膜透性变得越差,-4℃持续9h时,细胞活性受到不可恢复的伤害,因此,该温度为小青菜低温胁迫产生结构性伤害的临界温度。

Brassica campestris L. ‘Xinchangqing 1’was used as test material,the effects of low temperature stress on the chlorophyll,protective enzyme activity,and cell membrane permeability of Brassica chinensis were studied by using artificial environment control experiment.The results showed that the chlorophyll content of Brassica chinensis leaves decreased with the increasing of low temperature stress intensity and prolonged duration in the range from -6 ℃ to 0 ℃.SOD activity of leaf tissue increased with the decrease of stress temperature,the activities CAT and POD increased first and then decreased with the prolonging of treatment time.The content of MDA increased first,then decreased and increased again.The relative electrical conductivity of leaves increased with the decrease of temperature,while the lower the temperature,the greater the growth rate.The results showed that the anti-aging properties of the leaves of Brassica chinensis decreased with the decrease of temperature and the cell membrane permeability became worse.When the temperature was -4 ℃ for 9 hours,the cell viability was irreversibly damaged.Therefore,it was the critical temperature of structural damage of Brassica chinensis under low temperature stress.