摘要
【目的】探讨干旱胁迫下胡枝子幼苗的抗旱性。【方法】以2年生胡枝子幼苗为试验材料,设置对照(CK,田间持水量75%~80%),轻度干旱(T1,田间持水量60%~65%),中度干旱(T2,田间持水量45%~50%),重度干旱(T3,田间持水量30%~35%)4个处理,分析胡枝子幼苗在干旱胁迫条件下的生长特性、光合特性和生理变化。【结果】随着干旱胁迫的加重,胡枝子幼苗的新梢长、新梢粗、叶片数及脯氨酸含量均表现出先升高后下降的趋势,在中度干旱下达到峰值;叶绿素、丙二醛、可溶性蛋白含量及过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性变化幅度较大,且在轻度干旱下达到峰值,过氧化物酶(POD)活性呈下降趋势,且T2与T3处理差异不显著(P>0.05)。同时,胡枝子幼苗的净光合速率(P_(n))、蒸腾速率(T_(r))和气孔导度(G_(s))均随着干旱胁迫的加剧直线下降。轻度干旱时,胞间CO_(2)浓度(C_(i))变化趋势与Pn相反;重度干旱时,C_(i)变化趋势与P_(n)相同。【结论】胡枝子幼苗能够抵御中度干旱胁迫,轻度干旱是胡枝子幼苗生长的最佳条件。
【Objective】To explore the drought resistance of Lespedeza bicolor seedlings under drought stress.【Methods】The growth characteristics,photosynthetic characteristics,and physiological changes of Lespedeza bicolor seedlings under drought stress were studied using 2-year-old seedlings as experimental materials.Four treatments were set up:control(CK,field water capacity 75%-80%),mild drought(T1,field water capacity 60%-65%),moderate drought(T2,field water capacity 45%-50%),and severe drought(T3,field water capacity 30%-35%).【Results】Lespedeza bicolor newly emerged shoot length,shoot diameter,leaf number,and proline content increased first,then reduced as drought stress increased,peaking in moderate drought.Chlorophyll,malondialdehyde,soluble protein,and catalase(CAT)and superoxide dismutase(SOD)activity all varied dramatically,peaking in mild drought.Peroxidase(POD)activity had decreasing trend.Between T2 and T3,there was no significant difference(P>0.05).The net photosynthetic rate(P_(n)),transpiration rate(T_(r)),and stomatal conductance(G_(s))of Lespedeza bicolor all reduced linearly as drought stress increased.Intercellular CO_(2) concentration(C_(i))changed in the opposite direction as P_(n) under mild drought and followed the same changing pattern as P_(n) during severe drought.【Conclusion】Lespedeza bicolor seedlings could withstand moderate drought stress.Mild drought is the ideal environment for seedling growth.
作者
曾继娟
朱强
岑晓斐
李双喜
ZENG Jijuan;ZHU Qiang;CEN Xiaofei;LI Shuangxi(Ningxia Forestry Research Institute Co.,Ltd.,Yinchuan 750004,China;State Key Laboratory ofSeedling Bioengineering,Yinchuan 750004,China;Ningxia University,Yinchuan 750004,China;Ningxia Xihu Ecological Technology Co.,Ltd.,Jingyuan 756400,China)
出处
《北方农业学报》
2022年第2期53-60,共8页
Journal of Northern Agriculture
基金
宁夏回族自治区固原市科技计划项目(2018ZWYQ0056)。
关键词
胡枝子幼苗
干旱胁迫
光合特性
生理响应
Lespedeza bicolor seedlings
Drought stress
Photosynthetic characteristics
Physiological response
