干旱胁迫下不同中间砧对“岳冠”苹果叶片光合特性及叶绿素荧光特性的影响

Effects of different interstocks on photosynthetic and chlorophyll fluorescence characteristics in leaves of ‘Yueguan’ apple under different drought stress conditions

以2 a生盆栽岳冠/辽砧2号/山定子、岳冠/GM256/山定子、岳冠/77-34/山定子和岳冠/山定子为试验材料,研究在正常供水、轻度干旱胁迫、中度干旱胁迫和重度干旱胁迫下,不同中间砧对‘岳冠’叶片光合特性、快速叶绿素荧光诱导动力学参数及动力学曲线(OJIP)的影响。结果表明:轻度干旱胁迫可提高岳冠/山定子的叶绿素a(6.3%)、叶绿素a+b(5.9%)、Pn(9.7%)和4种砧穗组合的WUE(73.0%、116.1%、155.3%、105.7%),中度和重度干旱胁迫可降低4种砧穗组合的Pn(1219.2%、938.5%、786.7%、583.3%和8475.0%、9826.5%、1895.1%、1384.4%)、Gs(813.0%、875.4%、866.5%、508.3%和1066.7%、592.1%、852.1%、1274.4%)和Tr(783.3%、695.0%、795.2%、356.8%和527.7%、341.7%、403.6%、692.2%),增加了Ci(49.3%、48.3%、53.0%、51.5%和83.1%、108.5%、67.0%、55.2%);另外,经过OJIP曲线分析,中度和重度干旱胁迫曲线中明显出现了K相,J相值也显著升高,且随着干旱胁迫程度的增加,各砧穗组合叶绿素荧光参数中Fo、W K和V J逐渐增加,Fv/Fm、Fv/Fo、PI abs、PI total、ABS/CSm、TRo/CSm、ETo/CSm和RC/CSm逐渐降低。中度和重度干旱胁迫导致PSⅡ供体侧、受体侧和反应中心受到不同程度破坏,造成电子传递受阻,降低叶片光能吸收利用率,同时也使PSI遭到破坏,从而打破两个光系统的协调性,岳冠/山定子和岳冠/77-34/山定子组合破坏程度显著低于其他组合,说明在干旱胁迫中后期,岳冠/山定子和岳冠/77-34/山定子组合的抗旱性强于另外两种组合。

Yueguan/Liaozhen 2/Malus baccata,Yueguan/GM256/Malus baccata,Yueguan/77-34/Malus baccata and Yueguan/Malus baccata of two years old were grafted in pots as test materials to study the effects of different interstocks on photosynthetic characteristics,the fast chlorophyll fluorescence induction dynamics parameters and curves(OJIP)of leaves under the different drought stress treatments,that included normal water supply,slight water stress,medium water stress and severe water stress.The results showed that slight water stress increased chlorophyll A(6.3%),chlorophyll A+B(5.9%),Pn(9.7%)of Yueguan/Malus baccata and WUE(73.0%,116.1%,155.3%,and 105.7%)of 4 stion.Medium water stress and severe water stress decreased Pn(1219.2%,938.5%,786.7%,583.3%and 8475.0%,9826.5%,1895.1%,1384.4%),Gs(813.0%,875.4%,866.5%,508.3%and 1066.7%,592.1%,852.1%,1274.4%)and Tr(783.3%,695.0%,795.2%,356.8%and 527.7%,341.7%,403.6%,692.2%)of 4 stion,and Ci(49.3%,48.3%,53.0%,51.5%and 83.1%,108.5%,67.0%,55.2%)increased.In addition,after the analysis of OJIP curves,The K phase appeared clearly under the medium and severe water stress,and the J phase value also increased significantly.Moreover,with the increase of the degree of water stress,Fo,W K and V J in the chlorophyll fluorescence parameters of each stion increased gradually;Fv/Fm,Fv/Fo,PI abs,PI total,ABS/CSm,TRo/CSm,ETo/CSm and RC/CSm decreased gradually.This showed that medium water stress and severe water stress caused the PSII donor side,receptor side and reaction center to damage in different degree.This resulted in that the electron transfer was blocked and the efficiency of the solar energy absorption of leaves was reduced.At the same time,PSI had been destroyed,thereby broke the coordination of the two light systems.The destruction of Yueguan/Malus baccata and Yueguan/77-34/Malus baccata was significantly lower than others.This showed that the drought resistance of Yueguan/Malus baccata and Yueguan/77-34/Malus baccata were better than the other two stion in the medium and late water stress.