重金属铅对榉树幼树叶绿素荧光参数的影响  

Response of chlorophyll fluorescence characteristic of Zelkova schneideriana sapling to Pb pollution

作　　者：邱岚 何颀 黄鑫浩 朱凡[3] 王仁杰 梁惠子 QIU Lan;HE Qi;HUANG Xinhao;ZHU Fan;WANG Renjies;LIANG Huizi(College of Agroforestry Engineering and Planning, Tongren University, Tongren 554300, Guizhou, China;Chenzhou Institute of Forestry Science, Chenzhou 423000, Hunan, China;College of Life Science and Technology, Central South University of Forestry ＆ Technology, Changsha 410004, Hunan, China)

机构地区：[1]铜仁学院农林工程与规划学院,贵州铜仁554300 [2]郴州市林业科学研究所,湖南郴州423000 [3]中南林业科技大学生命科学与技术学院,湖南长沙410004

出　　处：《中南林业科技大学学报》2018年第6期123-129,共7页Journal of Central South University of Forestry & Technology

基　　金：湖南省重点研发计划项目(2017NK2171);国家林业局"948"项目(2014-4-62);湖南省财政厅研究经费资助项目

摘　　要：以阔叶树种榉树1年生幼树为对象,采用室内盆栽,通过4次连续掺入PbCl_2溶液于土壤中,研究连续Pb处理榉树叶片的光合和光系统Ⅱ(PSⅡ)叶绿素荧光特性,以揭示铅胁迫下榉树抗逆性的机制。结果表明,4次Pb处理下榉树的最大净光合速率(P_n)、蒸腾速率(T_r)、气孔导度(G_s)和气孔阀值(Ls)均表现为P_b处理<对照,且差异性显著(P<0.05),胞间CO_2(Ci)则表现为Pb处理>对照,出现了由非气孔限制引起的P_n下降。4次Pb处理下PSⅡ最大光化学效率(F_v/F_m)、PS_Ⅱ实际光化学效率(Y_Ⅱ)均低于对照,其中YⅡ差异显著(P<0.05);光化学猝灭(qP)显著降低,非光化学猝灭(NPQ)显著升高,说明榉树在铅胁迫下发生了明显光抑制现象,但有效地将PSⅡ的过剩光能以热的形式耗散掉。铅对榉树PSⅡ量子产量的转化和分配有影响,Y_Ⅱ(PSⅡ非环式电子传递效率)显著低于对照,Y_(NPQ)(可调节性能量耗散)和Y_(NO)(非调节性能量耗散)高于对照,说明榉树能有效地通过自身调节,将过剩光能以热的形式耗散,使PSII反应中心受伤害的程度降至最低,这进一步说明了榉树幼树对Pb具有较强的抗逆性。Pot experiment study was applied on one-year-old sapling of broad-leaf species Zelkova schneideriana. Photosynthesis and PS Ⅱ chlorophyll fluorescence characteristic of Z. schneideriana blade was tested through four times＇ continuous spraying of Pb Cl2 solution in order to reveal the mechanism of lead（Pb） resistance. The results showed that with four times＇ Pb dealing, the maximum net photosynthetic rate（Pn）, transpiration rate（Tr）, stomatal conductance（Gs）, and limited stomatal value（Ls） were significantlyless than the control（P〈0.05）. Intracelluar CO2 concentration（Ci） was greater than the control and appeared that Pndecrease was cause by nonstomatal limitation. Under four times＇ dealing, maximal PSII photochemical efficiency（Fv/Fm） and actual PS II photochemical efficiency（YⅡ） were lower than the control, amongthe YⅡ presented significant difference（P〈0.05）. The significant decrease of photochemical quenching（qP） decreased and increase of non-photochemical quenching（NPQ） indicated that Z. schneideriana occurred the photo inhibition phenomenon forced by Pb, but efficiently dissipated the excess light energy of PS II in the form of heat. Pb produced impact on the transformation and distribution of PS II＇s quantum yield. Actual photochemical efficiency was lower than the contrast, quantum yield of regulated energy dissipation（Y（NPQ）） and quantum yield of non-regulated energy dissipation（Y（NO）） were higher than the contrast, which revealed that Z. schneideriana could can effectively through its own regulation, excess light energy in the form of heat dissipation. This further shows that Z. schneideriana had strongstress resistanceunder Pb pollution stress.

关 键 词：叶绿素荧光 热耗散 抗逆性 Pb 榉树 

分 类 号：S718.55[农业科学—林学]