干旱与复水对喀斯特地区红背山麻杆生长及叶绿素荧光动力学参数的影响  

Growth and Chlorophyll Fluorescence Kinetics Parameters of Alchornea trewioides under Drought and Re-watering in Karst Areas

作　　者：赵英[1] 吴敏[1] 叶晓霞[1] 任琪[1] 邓平[1] 朱宇林[1,2] ZHAO Ying;WU Min;YE Xiaoxia;REN Qi;DENG Ping;ZHU Yulin(Yulin Normal University,Yulin,Guangxi 537000,China;Guangxi Agricultural Vocational University,Nanning 530000,China)

机构地区：[1]广西玉林师范学院,广西玉林537000 [2]广西农业职业技术大学,南宁530000

出　　处：《西北植物学报》2023年第9期1537-1546,共10页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金项目(31800205);广西自然科学基金项目(2019JJA130069);广西中青年教师科研基础能力提升项目(2020KY14018);广西大学生创新创业训练项目(S202310606120);广西壮族自治区林业局项目(桂林科字[2021]第34号)。

摘　　要：为了探讨红背山麻杆对喀斯特地区干旱环境的生理适应机制,以一年生红背山麻杆扦插苗为试验材料,采用自然干旱法,对轻度(干旱14 d)、中度(干旱28 d)和重度(干旱42 d)干旱胁迫及复水处理的红背山麻杆扦插苗生长、光合色素含量及荧光参数进行测定和分析。结果表明,(1)随干旱胁迫时间的延长,红背山麻杆扦插苗叶片相对含水量显著降低,株高和基径增长缓慢,复水后的叶片相对含水量显著增加,而株高和基径无明显变化;(2)随干旱胁迫时间的延长,扦插苗叶片叶绿素a(Chla)、叶绿素b(Chlb)、叶绿素[Chl(a+b)]含量及Chla/b先增加后降低,并在不同程度干旱胁迫及复水后均显著高于对照(CK),轻度和中度干旱胁迫复水后高于对照,重度干旱胁迫复水后也能恢复至对照水平。(3)随干旱胁迫加剧,扦插苗叶片荧光参数F_(o)显著增加,F_(m)、F_(v)/F_(o)、F_(v)/F_(m)逐渐减小,代表单位反应中心活性的参数A_(bs)/R_(c)、T_(ro)/R_(c)、E_(to)/R_(c)显著增加,代表受体侧电子传递活性的参数Ψ_(po)、Ψ_(o)、Ψ_(Eo)下降,表示热耗散的参数D_(io)/R_(c)急剧增加。不同干旱胁迫复水后,F_(o)、A_(bs)/R_(c)、T_(ro)/R_(c)、E_(to)/R_(c)、D_(io)/R_(c)、ΨDo比干旱胁迫处理降低,F_(m)、F_(v)/F_(o)、F_(v)/F_(m)、Ψ_(po)、Ψ_(o)、Ψ_(Eo)适度恢复,F_(m)还能恢复到CK水平,而Ψ_(o)、Ψ_(Eo)均未恢复到CK水平。可见,红背山麻杆幼苗生长受轻度和中度干旱胁迫影响较小,而受重度干旱胁迫影响较大;叶片光合色素含量及比值在干旱胁迫后显著增加;重度干旱胁迫导致PSⅡ反应中心失活,电子传递受阻,热能耗散增加;但他们在水分环境条件改善时仍可在一定程度上恢复,红背山麻杆具有强的抗旱性和较高的旱后恢复能力,可作为喀斯特地区植被恢复过程中的先锋物种。In order to explore the physiological adaptation mechanism of Alchornea trewioides to the arid environment of Karst area,we measured and analyzed the growth,photosynthetic pigments and fluorescence parameters of one-year-old cutting seedlings of A.trewioides under light drought stress(14 d),moderate drought stress(28 d),severe drought stress(42 d)and re-watering conditions.The results showed that, (1) with the prolongation of drought stress time, the relative water content in leaves decreasedsignificantly, and the plant height and basal diameter increased slowly. After re-watering, the relativewater content in leaves increased significantly, while the plant height and basal diameter did notchange significantly. (2) With the extension of drought stress time, the contents of chlorophyll a (Chla),chlorophyll b (Chlb), chlorophyll [Chl (a+b)] and Chla/b ratio in the leaves of cutting seedlings increasedfirst and then decreased, and were significantly higher than those in the control (CK) after differentdegrees of drought stress and rewatering. After rewatering under mild and moderate drought stress,the contents Chla, Chlb, Chl (a+b) and Chla/b ratio in the leaves of cutting seedlings were higher thanthose of the control, and they could be restored to the control level after rewatering under severe droughtstress. (3) With the aggravation of drought stress, the fluorescence parameter F_(o) of cutting seedlings increasedsignificantly, F_(m), F_(v)/F_(o) and F_(v)/F_(m) decreased gradually, the parameters A_(bs)/R_(c), T_(ro)/Rc andE_(to)/Rc representing the activity of unit reaction center increased significantly, the parameters Ψ_(po), Ψ_(o) andΨ_(Eo) representing the electron transport activity of receptor side decreased, and the parameter D_(io)/Rc representingheat dissipation increased sharply. Rewatering after different drought stress treatments, F_(o), A_(bs)/R_(c), T_(ro)/Rc, E_(to)/Rc, D_(io)/Rc, ΨDo were lower than those under drought stress, F_(m), F_(v)/F_(o), F_(v)/F_(m),Ψ_(po), Ψ_(o) and Ψ_(Eo) were

关 键 词：红背山麻杆 干旱和复水 生长 叶绿素荧光参数 

分 类 号：Q945[生物学—植物学]