中文摘要：

为了解光合菌（PSB）对欧李幼苗抗旱性的影响,以欧李为材料,研究了叶面喷施光合菌（PSB）对干旱胁迫下幼苗叶绿素含量、叶绿素荧光特性和细胞膜伤害程度的影响。结果表明：干旱胁迫下欧李幼苗叶片的膜系统受到了伤害,光合作用的原初反应和光能在2个光系统之间的分配发生了改变。叶面喷施0.5×109 CFU/mL和2.0×109 CFU/mL PSB有效缓解了干旱引起的细胞膜丙二醛的增加,进而保护了幼苗的膜系统。同时,0.5×109CFU/mL和2.0×109 CFU/mL PSB减轻了干旱胁迫下叶绿素的分解,有效缓解了干旱对类囊体膜和PSⅡ反应中心的伤害,增强了欧李幼苗对干旱胁迫的适应能力,其最适宜的浓度为0.5×109～2.0×109 CFU/mL。但叶面喷施8.0×109 CFU/mL PSB对欧李幼苗有一定的毒害作用。

英文摘要：

In order to investigate the effects of photosynthetic bacteria（PSB） on drought resistance of Chinese dwarf cherry（Cerasus humilis Bunge） seedlings under drought stress,effects of photosynthetic bacteria on chlorophyll content,chlorophyll fluorescence characteristic and cell membrane injury in leaves of Chinese dwarf cherry were studied under drought stress by foliage spraying method.The results showed that the membrane system was damaged and the primary reaction of photosynthesis and the distribution of absorbed light energy were changed under drought stress.Spraying 0.5×109 CFU/mL and 2.0×109 CFU/mL PSB on leaves of Chinese dwarf cherry relieved the content of MDA in leaves of Chinese dwarf cherry to protect effectively the membrane system under drought stress.Meanwhile,0.5×109 CFU/mL and 2.0×109 CFU/mL PSB decreased the decomposition of chlorophyll to alleviate the damage of thylakoid membranes and PSⅡ reaction center under drought stress,and improved greatly the drought resistance.0.5×109-2.0×109 CFU/mL PSB were the optimal concentrations to spray on leaves of Chinese dwarf cherry under drought stress,but 8.0×109 CFU/mL PSB would be toxic to Chinese dwarf cherry seedlings.