酸胁迫对马尾松幼苗生长及根际铝形态的影响  

Effects of acid stress on growth and aluminum speciation in the rhizosphere of Masson pine(Pinus massoniana L.) seedlings

作　　者：周思婕 王平 张敏 陈舒展 许雯 朱丽婷 何销勤 龚书锐 ZHOU Sijie;WANG Ping;ZHANG Min;CHEN Shuzhan;XU Wen;ZHU Liting;HE Xiaoqin;GONG Shurui(College of Biology and the Environment,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]南京林业大学生物与环境学院

出　　处：《应用与环境生物学报》2019年第6期1292-1300,共9页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目（30771696,31270680）资助~~

摘　　要：在不同pH值(2.5、3.5、4.5和5.6)模拟酸雨处理下,研究根箱栽培马尾松(Pinus massoniana L.)幼苗生物量(根茎长、根与茎叶干重、一级侧根数)、叶绿素含量以及根系质膜相对透性的变化,在酸雨pH 3.5-5.6范围内对松树幼苗根际与非根际土壤的pH值和铝形态以及植株铝积累量进行测定,以探明酸胁迫对马尾松幼苗生长及根际铝形态的影响.结果显示:当酸雨pH从5.6降至2.5,马尾松幼苗生物量和叶绿素含量均降低,而根系质膜透性从13.2%升至36.4%,膜伤害度由轻度的4.1%提高到重度的23.2%,且重度酸胁迫下两者变化均极显著(P<0.01);此外随酸胁迫强度的增强,马尾松根际与非根际土壤pH值分别由5.95和5.91降至4.02和3.87,而根际土壤中交换态、有机结合态铝含量则分别上升至7.27和18.1 mg/kg,且马尾松植株铝积累量增加至49.46μg/株,其在植株根系中的积累量明显高于地上部分.上述结果表明,酸胁迫使得马尾松根系质膜受损程度增加,叶绿素含量减少,引起光合作用减弱,幼苗生长受到抑制;另外,酸雨能改变土壤中铝化合物的形态,增加活性铝离子溶出量,其中一部分转化成有机结合态铝,另一部分则通过根系吸收累积在幼苗植株内,阻碍马尾松生长发育.(图5表3参45)In order to understand the effects of acid stress on the growth and aluminum speciation in the rhizosphere of Masson pine(Pinus massoniana L.)seedlings,we studied the changes in seedling biomass(including root length,stem length,root dry weight,stem and leaf dry weight,and number of primary lateral roots),chlorophyll content,and relative permeability of root plasma membrane of P.massoniana cultivated using the root box method under simulated acid rain treatments with different pH values(2.5,3.5,4.5,and 5.6).The pH value and aluminum speciation in the rhizosphere and non-rhizosphere soil of P.massoniana seedlings,as well as whole-plant aluminum accumulation,were determined under acid stress with 3.5≤pH≤5.6.The results showed that with the decrease of the pH value of simulated acid rain from 5.6 to 2.5,the biomass and chlorophyll content of P.massoniana seedlings decreased,while the permeability and injury degree of root plasma membrane increased from 13.2%to 36.4%and from 4.1%to 23.2%,respectively.The changes under severe acid stress were significantly different(P<0.01).In addition,with the increase of acid stress intensity,the pH values of rhizosphere and non-rhizosphere soil of P.massoniana decreased from 5.95 to 4.02 and from 5.91 to 3.87,respectively,while the content of exchangeable and organically bound aluminum in the rhizosphere soil increased to 7.27 and 18.1 mg/kg,respectively.Aluminum accumulation in P.massoniana increased to 49.46μg/strain,and the accumulation of aluminum ions in the plant roots was significantly higher than that in the aerial parts of the plants.These results indicated that acid stress increases the damage degree of root plasma membrane and reduces the chlorophyll content,resulting in the decrease of photosynthesis rate,and consequently inhibiting the growth of P.massoniana seedlings.Moreover,these results demonstrated that acid rain can influence aluminum speciation in soil and increase the rate of dissolution of active aluminum ions,converting some into organically bound alumin

关 键 词：酸胁迫 马尾松 根际 铝形态 根系质膜 叶绿素 

分 类 号：Q945.78[生物学—植物学]