干旱和水涝胁迫对幼龄油松生长及光合作用的影响  

Effects of drought and waterlogging on growth and photosynthesis of potted young Pinus tabulaeformis Carr.

作　　者：王巧[1,2] 刘秀梅[1,2] 王华田[1,2] 孟先鹏 曹桂萍[3] 李健[3] 黄昌豹 

机构地区：[1]山东农业大学林学院山东省高校森林培育重点实验室,山东泰安271018 [2]国家林业局泰山森林生态系统定位研究站,山东泰安271018 [3]泰山风景名胜区管理委员会,山东泰安271000

出　　处：《中国水土保持科学》2015年第6期40-47,共8页Science of Soil and Water Conservation

基　　金：国家公益行业科研专项"泰山古油松监测保护与复壮集成技术的研究"(201104002-6);泰安市科技计划项目"泰山油松古树保护"(2011-40)

摘　　要：干旱和水涝是影响油松成活、生长和树势健壮的主要生态逆境。采用盆栽试验方法,研究了生长季节持续干旱、水涝逆境对4年生油松幼树的根系、叶片生长、生物量分配及光合作用的影响,以阐明水分逆境对幼龄油松生长及光合生理特性的影响,探讨油松生长对不同程度水分胁迫的适应性。结果表明:1)干旱胁迫初期,根系粗度增加,毛细根数量增多;随着胁迫时间延长,树势逐渐衰弱,毛细根逐渐减少,土壤水势及小枝水势显著降低;干旱胁迫50 d以上植株逐渐死亡;净光合速率、气孔阻力、胞间二氧化碳浓度、蒸腾速率随胁迫时间的延长呈不断下降趋势。2)水涝胁迫初期对油松生长没有明显影响;随水涝程度的加重,油松表现为叶片发黄、失绿,土壤水势和小枝水势逐渐升高;持续水涝超过20 d,油松细根腐烂,植株逐渐死亡;气孔阻力及净光合速率呈下降趋势,且净光合速率逐渐接近为0,胞间二氧化碳浓度呈上升趋势。3)干旱胁迫和水涝胁迫2种水分逆境均显著抑制油松生长,水分胁迫处理后油松根、茎、针叶生物量呈现出不同程度降低,且干旱胁迫的下降幅度大于水涝胁迫。因此,旱季要控制油松幼苗土壤水分条件,促进油松毛细根的生长,增强其水分利用率;雨季及时排水,确保排水深度至根系集中分布层以下,以优化油松苗木培育、提高苗木造林成活率。Drought and waterlogging are the main ecological adversities which affect the survival,growth and vigor of Pinus tabulaeformis Carr. In order to determine the influence of water condition on the growth and physiological adaptation to water stress of P. tabulaeformis trees,the growth of roots and needles,biomass distribution and photosynthesis of 4-year-old potted young trees under continuous drought,waterlogging and normal conditions were studied. We also measured indexes including soil water potential,branch water potential,net photosynthetic rate,transpiration rate,stomatal conductance,intercellular CO2 concentration,root mass,stem mass,leaf mass,total biomass,caliper and the length,surface area,and diameter of needles and roots. The results showed that： 1） The roughness and numberof fine roots increased at the early stage of drought stress,but when the drought stress was prolongated,the growth vigor gradually declined with reduced number of fine roots. The soil water potential and branch water potential were also significantly reduced. The plants were easier to die when the stress time was more than 50 days. During water stress,net photosynthetic rate,transpiration rate,stomatal conductance and intercellular CO2 concentration showed a continuous decline. 2） A short-period of waterlogging stress had no significant effect on growth,but chlorosis content descended and needle color turned yellow with soil water potential and branch water potential increasing under long term of drought stress. Moreover,when the waterlogging lasted for more than 20 days,the fine roots began to decompose and the plants went to die. During the waterlogging stress,stomatal conductance decreased with net photosynthetic rate approaching to zero,but intercellular CO2 concentration increased. 3） Drought and waterlogging stress inhibited the growth significantly,and the biomass of roots,stems and needles decreased with stress time increasing. The descending range of drought stress treatment was larger than waterlogging treatment. In

关 键 词：油松 干旱胁迫 水涝胁迫 光合特性 生长 生物量分配 盆栽 

分 类 号：S791.254[农业科学—林木遗传育种]