模拟酸雨对大叶黄杨叶片叶绿素荧光参数的影响

摘要

To identify the effect of acid rain on chlorophyll fluorescence parameters in leaves of Euonymus japonicus, two-year old Euonymus japonicus trees were used as materials to study the effect of different pH simulated acid rain on chlorophyll contents and chlorophyll fluorescence parameters under plastic shed conditions. The results showed that chlorophyll contents decreased with the increasing of simulated acid rain concentration. With the increase of the simulated acid rain concentration, the non-photochemical quenching coefficient (qN) increased firstly, and then decreased, whereas the photochemical quenching coefficient (qP), maximal photochemical efficiency of photosystem Ⅱ (FV/FM) , quantum yield of photosystem II electron transport(ΦPS II )and apparent photosynthetic electron transport rate (ETR) decreased. When acid rain concentration pH was under 2. 0, leaves and chloroplast structure of Euonymus japonicus were injured, and electron transfer in photosynthesis was influenced directly, so as to damage and inhibit the photosynthetic electronic transfer process.%为了明确酸雨对大叶黄杨叶片荧光参数的影响,在拱棚条件下,以2年生大叶黄杨(Euonymus japonicus)为试材,采用人工喷洒的方法,以pH为7.0的模拟雨水为对照,研究了不同pH值(1.0、2.0、3.0、4.0、5.0)的模拟酸雨对大叶黄杨叶片的叶绿素相对含量和叶绿素荧光特性的影响.结果表明:随着酸雨浓度pH值降低,大叶黄杨叶片的叶绿素含量呈现下降的趋势；叶绿素荧光参数非光化学猝灭系数(qN)呈先上升后下降趋势；光化学猝灭系数(qP)、PSⅡ最大光化学效率(Fv/Fm)、PSⅡ电子传递量子效率(φPSⅡ)、表观光合电子传递速率(ETR)呈现下降趋势.当模拟酸雨pH≤2.0时,会对大叶黄杨的叶片造成严重的损伤,破坏叶绿体结构,直接影响了光合作用中的电子传递,导致光合电子传递过程中受到损害和抑制.