首页|土壤逐渐干旱条件下玉米和构树光合特性的变化

土壤逐渐干旱条件下玉米和构树光合特性的变化

Changes in Photosynthetic Characteristics of Zea mays L.and Broussonetia Papyrifera(Linn.)L'Hér.ex Ven.under Progressive Soil Drought

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在气候和喀斯特地形地貌的影响下,一些喀斯特地区依旧处在日益严重和频发的干旱情况中,这会对植物的光合特性和叶绿素荧光特性产生严重的影响.本文以喀斯特地区两种土壤(粉砂质壤土(Ld)和粉砂质粘壤土(Lc))和两种植物(玉米(Zea mays L.)和构树(Broussonetia Papyrifera(Linn.)L'Hér.ex Ven.))为研究对象,研究了在逐渐干旱的条件下构树和玉米叶片的光合参数和叶绿素荧光变量的变化规律.研究结果表明,干旱胁迫期间,两种植物的净光合速率(A)、蒸腾速率(E)和气孔导度(gsw)均逐渐降低,胞间C02浓度(Ci)后期显著上升,水分利用效率(WUE)均表现为先上升后下降的趋势.在相同土壤中玉米的WUE高于构树,不同土壤中同种植物的最大WUE均为Ld高于Lc.玉米在两种土壤条件下的初始荧光(Fo)随时间的变化呈现前期先降低,中期稳定,后期再快速升高的趋势,最大光化学效率(Fv/Fm)的变化趋势与Fo相反.构树的Fo则只存在先下降后升高两个阶段,其Fv/Fm的变化趋势也与Fo相反.同时根据叶片A、gsw和Ci的变化趋势判别出气孔限制和非气孔限制分别是干旱前中期和后期影响玉米和构树光合特性的主要因素,且Lc和Ld中玉米的两种限制的交替时间节点分别为第10天和第9天,构树为第10天和第7天,当超过这个时间点,植物即使复水光合作用也无法回升,也可称此节点为调亏灌溉点.本研究可为了解喀斯特地区植物对干旱环境的适应性和用水特征以及田间水分管理提供科学依据.
Under the influence of climate and karst topography,some karst areas are still experiencing increasingly severe and frequent drought conditions,seriously impacting the photosynthetic and chlorophyll fluorescence properties of plants.In this study,two soils(silty loam(Ld)and silty clay loam(Lc))and two plant species(Zea mays L.and Broussonetia papyrifera(Linn.)L'Hér.ex Ven.))in the karst area were taken to study the changes in photosynthetic parameters and chlorophyll fluorescence variables in brachy-cardia and maize leaves under progressive drought conditions.The results showed that during drought stress,the net photosynthetic rate(A),transpiration rate(E)and stomatal conductivity(gsw)of both plants decreased gradually,the intercellular CO2 concentration(Ci)increased significantly during the late stage,and the water use efficiency(WUE)first increased and then decreased.The WUE of Zea mays L.was higher than that of Broussonetia papyrifera(Linn.)L'Hér.ex Ven.in the same soil,and the maximum WUE of the same plant species in different soils was higher in Ld than in Lc.The initial fluorescence(Fo)of Zea mays L.under both soil condi-tions decreased firstly during the early stage,stabilizing during the middle stage,and then increased rapidly during the late stage.The maximum photochemical efficiency(Fv/Fm)showed an opposite trend to that of Fo.In comparison,Fo of Broussonetia papyrifera(Linn.)L'Hér.ex Ven.only decreased during the early stage and then increased,and its Fv/Fm trend was also opposite to that of Fo.According to the trend of leaf A,gsw and Ci,stomatal restriction and non-stomatal restrictions were identified as the main factors af-fecting the photosynthetic characteristics of Zea mays L.and Broussonetia papyrifera(Linn.)L'Hér.ex Ven.in the pre-middle and late drought period,respectively.Moreover,the alternating time nodes of the two types of restriction in Lc and Ld were day 10 and day 9 for Zea mays L.and day 10 and day 7 for Broussonetia papyrifera(Linn.)L'Hér.ex Ven.When these time points were exceeded,the plants could not recover from photosynthesis even after rehydration,this node can be referred as the point of deficit regulation irriga-tion.This study can deliver a scientific fundament for understanding the adaptability and water use characteristics of plants to arid envi-ronment and field water management in karst areas.

karstsoilZea mays L.Broussonetia papyrifera(Linn.)L'Hér.ex Ven.photosynthetic parameterschlorophyll fluo-rescence parametersstress of drought

周英、吴沿友、李海涛、苏跃、罗亮

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中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳 550081

中国科学院大学,北京 100049

贵州农业职业学院,贵州清镇 551400

喀斯特 土壤 玉米 构树 光合参数 叶绿素荧光参数 干旱胁迫

贵州省科技厅扶持计划项目(2021)国家自然科学基金项目贵州省科技创新人才项目(2016)

YB453U1612441-25672

2024

10.14050/j.cnki.1672-9250.2023.51.017

地球与环境
中国科学院地球化学研究所

地球与环境

CSTPCD北大核心
影响因子：0.875
ISSN：1672-9250
年,卷(期)：2024.52(3)
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