摘要
为揭示樟子松(Pinus sylvestris var.mongolica)幼苗生理指标对干旱胁迫及复水的响应特征,以2 a生樟子松幼苗为研究对象,采用盆栽试验,设置对照(80%)、轻度(40%)、中度(20%)、重度(10%)和极重度(5%)干旱5种水分处理,测定分析其干旱时和复水后水分、光合、叶绿素荧光、渗透调节物质和抗氧化酶活性指标变化。结果表明:(1)轻度干旱胁迫对樟子松幼苗生理状态影响较小,中度和重度干旱胁迫下幼苗超氧化物歧化酶、过氧化物酶活性达到最高值,与对照相比分别增加了25.26%和38.8%,极重度干旱胁迫下幼苗叶片净光合速率、蒸腾速率和稳态光适应淬灭系数相比对照下降了94.76%、87.19%和72.35%,同时叶片丙二醛含量达到最高。(2)复水后樟子松幼苗叶绿素荧光、叶片脯氨酸含量基本恢复至对照水平,但极重度干旱胁迫后复水叶片光合指标平均仅恢复至对照的28.51%。叶片水分利用效率、可溶性糖含量和抗氧化酶活性复水后均显著高于对照(P<0.05)。综上所述,极重度干旱胁迫主要降低樟子松幼苗光合作用能力、破坏细胞膜稳定性,而适度干旱后复水可以提高植株水分利用和活性氧清除能力,进而提高植株抗旱性。研究结果可为樟子松人工林高效栽培、抚育管理和抗旱评价提供理论参考。
In this study,we investigated the physiological responses of Pinus sylvestris var.mongolica seedlings to drought stress and subsequent rehydration.A pot experiment was conducted using 2-year-old seedlings subject-ed to five water treatments,including control(80%),light drought(40%),moderate drought(20%),severe drought(10%),and extremely severe drought(5%).We measured leaf water content,photosynthesis,chlorophyll fluorescence,leaf osmoregulatory substances,and antioxidant enzyme activity during drought and after rehydra-tion.The results showed the following:(1)The physiological state of the seedlings was minimally affected by the light drought.The activities of superoxide dismutase and peroxidase peaked under moderate and severe drought stress,increasing by 25.26%and 38.8%,respectively.Conversely,the net photosynthetic rate,transpiration rate,and photochemical quenching coefficient under extremely severe drought stress decreased by 94.76%,87.19%,and 72.35%,respectively,while the leaf malondialdehyde content was the highest in this condition.(2)The chlo-rophyll fluorescence and leaf proline content of the seedlings were restored to control levels after rehydration.However,the average photosynthetic indices of rehydrated leaves only returned to 28.51%after extremely severe drought stress.Additionally,leaf water use efficiency,soluble sugar content,and antioxidant enzyme activity were significantly higher than the control after rehydration(P<0.05).In conclusion,extremely severe drought stress primarily reduces photosynthetic ability and disrupts the cell membrane stability of Pinus sylvestris var.mongolica seedlings.Conversely,rehydration after moderate drought improves water utilization and the scaveng-ing ability of reactive oxygen species,thereby improving drought resistance.This improved information provides theoretical insights for the efficient cultivation,management,and evaluation of drought resistance in the Pinus syl-vestris var.mongolica plantation.
作者
王梓翔
任悦
鲁莹
高广磊
丁国栋
张英
WANG Zixiang;REN Yue;LU Ying;GAO Guanglei;DING Guodong;ZHANG Ying(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;College of Desert Control Science and Engineering,Inner Mongolia Agricultural University,Hohhot 010018,Inner Mongolia,China;State Key Laboratory for Efficient Production of Forest Resources,Beijing 100083,China;Yanchi Ecology Research Station of the Mu Us Desert,Yanchi 751500,Ningxia,China;Engineering Research Center of Forestry Ecological Engineering,Ministry of Education,Beijing 100083,China;Key Laboratory of State Forestry and Grassland Administration on Soil and Water Conservation,Beijing 100083,China)
出处
《干旱区研究》
CSCD
北大核心
2024年第12期2120-2131,共12页
Arid Zone Research
基金
国家自然科学基金项目(32371962)。
关键词
樟子松
干旱胁迫
复水
生理特征
Pinus sylvestris var.mongolica
drought stress
rehydration
physiological characteristics
