不同水分对三江平原湿地小叶章生长、气体交换和叶绿素荧光参数的影响

Influence of Different Water Treatment on the Growth,Leaf Gas Exchange,and Chlorophyll Fluorescence in Calamagrostis angustifolia in Sanjiang Plain Wetland

为探究不同水分对三江平原湿地优势植物小叶章光合生理特性的影响,采用盆栽试验,研究5种水分处理(模拟典型草甸,TM;模拟沼泽化草甸,WM;模拟沼泽,M;极度水淹,EF;极度干旱,ED)对小叶章生长、叶片气体交换及叶绿素荧光参数的影响。结果表明:与TM处理相比,WM处理生长指标、叶片气体交换及叶绿素荧光参数均无明显变化(P>0.05);M处理小叶章生长指标、气孔导度(G_(s))、蒸腾速率T_(r)、最大光化学效率(F_(v)/F_(m))、实际光化学量子效率(Φ_(PSⅡ))、电子传递速率(ETR)、光化学猝灭系数(qP)均显著低于TM和WM处理,水分利用效率(WUE)、非光化学猝灭系数(qN)则显著高于TM和WM处理;EF和ED处理小叶章生长指标、净光合速率(P_(n))、G_(s)、T_(r)、F_(v)/F_(m)、Φ_(PSⅡ)、ETR及qP均显著低于TM和WM处理(P<0.05),Ci、WUE、qN则显著高于TM和WM处理(P<0.05),且各指标下降或增加的幅度ED处理>EF处理。说明水淹或干旱处理下小叶章光合速率的降低均是由光合机构活性降低的非气孔因素引起的,小叶章通过调节PSII功能能来适应水淹和干旱的环境,表现出较强的适应性和可塑性。

This study investigated the effects of different water treatments on the growth and leaf photosynthetic physiological characteristics of Calamagrostis angustifolia in Sanjiang Plain wetland.A pot experiment was conducted by manipulating five different water treatments,i.e.,typical meadow(TM),wet meadow(WM),marsh(M),extreme flooding(EF)and extreme drought(ED).The growth index,leaf gas exchange,and chlorophyll fluorescence of Calamagrostis angustifolia were measured.The results showed that WM treatment did not have any significant effect(P>0.05)on growth,leaf gas exchange,and chlorophyll fluorescence of C.angustifolia compared to that under TM treatment.M treatment significantly decreased(P<0.05)the growth,stomatal conductance(G_(s)),transpiration rate(T_(r)),maximum photochemical efficiency(F_(v)/F_(m)),actual photochemical quantum efficiency(Φ_(PSⅡ)),electron transport rate(ETR),photochemical quenching coefficient(qP),and increased water use efficiency(WUE)and non-photochemical quenching coefficient(qN)compared to that under TM and WM treatment(P<0.05);EF and ED treatments significantly reduced the growth,net photosynthetic rate(P_(n))、G_(s)、T_(r)、F_(v)/F_(m)、Φ_(PSⅡ),ETR and qP(P<0.05),and enhanced intercellular CO_(2) concentration(Ci),WUE and qN compared to that under TM and WM treatment(P<0.05),and the decline effect or the increase effect were more evident under ED treatment.Under the flooding and drought treatment,the decrease in net photosynthetic rate were primarily caused by non-stomatal factors of C.angustifolia.Our results suggest that C.angustifolia were able to adapt to extreme flooding and drought by regulating photosynthetic efficiency,whereas their normal physiological metabolism was probably disrupted.