摘要
研究胡杨3种典型异形叶光合生理、叶形态特征及二者的相互关系,探讨异形叶光合生理性状与叶形态性状的耦合关系及适应策略。结果表明:(1)胡杨异形叶叶长(LL)、叶宽(LW)、叶长/宽比(LL/LW)、叶面积(LA)、叶干物质含量(LDMC)与光合生理性状相关性较高,反映出叶构建模式的改变直接影响异形叶光合生理功能。(2)胡杨3种异形叶的形态性状、光合生理性状之间差异显著(P<0.05),卵形叶属净光合速率(Pn)、蒸腾速率(Tr)、光能利用率(LUE)、水分利用率(WUE)、光能吸收转化效率均高的叶形;锯齿阔卵形叶叶厚(LD)、耐强光指标(Fv/Fm)、PSⅡ光合电子传递速率(ETR)和类胡萝卜素(Car)含量高,以热耗散(NPQ)形式清除过剩激发能保护光合机构的正常运转,维持较高的Pn和干物质生产量;条形叶叶薄、比叶面积(SLA)高而叶绿素a/b(Chla/b)值低,吸收的光能主要用于非辐射能量耗散(D+E),光抑制程度重,光合效率低。(3)异形叶光合能力受控因素明显不同,条形叶主要受SLA、气孔导度(Gs)和光合氮利用率(PNUE)的影响,锯齿阔卵形叶主要受光化学猝灭系数(qP)、LD和叶磷含量(LP)的影响,而卵形叶则主要受PSⅡ有效光化学量子效率(Fv′/Fm′)和SLA的影响。(4)胡杨3种异形叶在形态性状与光合生理性状之间的权衡策略不同,通过改变叶形态性状(LW、LD、LA、SLA)差异化地调整异形叶的光合生理功能,形成不同的生理生态适应策略。此外,吸收光能分配比例(P:D+E)反映异形叶吸收光能更多分配用于热能与荧光辐射耗散,降低了光化学反应能量和光合效率,致使胡杨生长速率慢。胡杨异形叶形态性状的改变影响其光合生理功能,二者相耦合来适应荒漠环境和满足生长发育需求。
The characteristics of photosynthetic gas exchange, chlorophyll fluorescence and leaf morphological traits of three typical heteromorphic leaves of Populus euphratica and their relationships were studied. The results showed that(1) The photosynthetic physiology traits had significant correlation with morphological traits of heteromorphic leaves, such as leaf length(LL), leaf width(LW),length/width ratio(LL/LW), leaf area(LA), leaf dry matter content(LDMC), which indicated that variation of leaf construction pattern directly affected the photosynthetically physiological function of heteromorphic leaves.(2)The parameters of gas exchange, chlorophyll fluorescence and leaf morphological traits of three heteromorphic leaves had significant differences(P<0.05). Oval leaves had the characteristics with high P_n, T_r, LUE, WUE and light absorption-conversion efficiency. The serrated broad-oval leaves had thick leaves, maximum quantum efficiency of PSⅡ photochemistry(F_v/F_m), high electron transport rate(ETR)and Car content, the excess excitation energy was removed by heat dissipation(NPQ)to protect the photosynthetic apparatus and maintain high P_n. The lanceolate leaf had thin leaves, high SLA, low chlorophyll a/b(Chla/b)and absorbed light energy mainly used to nonradiative energy dissipation(D+E), so it had heavy light inhibition and low photosynthetic efficiency.(3)Photosynthetic capacity of three heteromorphic leaves were regulated by different factors. Photosynthetic capacity of lanceolate leaf was regulated mainly by SLA, stomatal conductance(Gs)and photosynthetic nitrogen use efficiency(PNUE), and photosynthetic capacity of serrated broad-oval leaf regulated by PSII photochemical quenching coefficient(qP), leaf thickness(LD)and leaf phosphorus content(LP), and photosynthetic capacity of oval leaf regulated by actual photochemical quantum efficiency(F_v′/F_m′), SLA.(4)The trade-off strategies of morphological traits and photosynthetically physiological traits of three heteromorphic leaves were obvious difference. It indicated P.euphratica changed the LW, LD,LA, SLA to differentially regulate the photosynthetically physiology function, further to develop different eco-physiological adaptation strategies with growth and environmental changes. Moreover, the ratio of absorbed light allocation(P:D+E)indicated heteromorphic leaves allocated more absorbed light energy to heat dissipation and excess excitation energy, resulting in decreasing the proportion of energy utilized in photochemistry and photosynthetic efficiency, so P.euphratica had low growth rate in arid desert region. The morphological traits variation of heteromorphic leaves directly affected their photosynthetic physiological functions, their coordination to adapt the desert environment and meet the growth needs.
作者
王海珍
徐雅丽
代雅琦
韩路
Wang Haizhen;Xu Yali;Dai Yaqi;Han Lu(College of Plant Science,Tarim University,Alar,Xinjiang 843300;College of Life Sciences,Tarim University,Alar,Xinjiang 843300)
出处
《塔里木大学学报》
2020年第3期35-43,共9页
Journal of Tarim University
基金
国家自然科学基金项目“胡杨异形叶光抑制发生的PSⅡ行为与光保护机制研究”(31660117)
“荒漠河岸林水盐梯度上植物功能性状格局与群落构建机制研究”(31860165)
新疆生产建设兵团区域创新项目“塔里木盆地北缘退化生态系统恢复技术集成与示范”(2018BB047)
新疆生产建设兵团重点领域创新团队建设计划“胡杨种质资源保护与挖掘利用创新团队”(2018CB003)。
关键词
胡杨
异形叶
功能性状
权衡
适应策略
Populus euphratica Oliv
heteromorphic leaves
function traits
trade-off
adaptation strategy
