干旱胁迫下小麦叶片光合-蒸腾耦合变化特征及调控机制
Characteristics of Photosynthesis-transpiration Coupling of Wheat Leaves under Different Water Treatments and Their Regulation Mechanism
刘江 1赵福年 2杨红燕 3蔡立群 4王婧 1周引弟 5孛永明6
作者信息
- 1. 甘肃农业大学 资源与环境学院,甘肃 兰州 730070
- 2. 中国气象局兰州干旱气象研究所,甘肃 兰州 730020
- 3. 聊城市土壤肥料工作站,山东 聊城 252000
- 4. 甘肃农业大学 资源与环境学院,甘肃 兰州 730070;甘肃农业大学 林学院,甘肃 兰州 730070
- 5. 甘肃农业大学 林学院,甘肃 兰州 730070
- 6. 定西市水土保持科学研究所,甘肃 定西 743000
- 折叠
摘要
叶片通过控制气孔将植物碳同化和水分消耗这2个过程紧密耦合,但在不同水分条件下这种碳水耦合关系是否会发生变化目前尚不清楚.选择西北半干旱区大田作物春小麦为研究对象,对其进行不同水分处理(充足供水CK、轻度干旱T1、中度干旱T2、重度干旱T3),在小麦拔节期选择典型晴天观测叶片光合-蒸腾日变化过程(08:00-18:00).结果表明:空气温度(t)、光合有效辐射(PAR)的日变化均为单峰型,峰值出现在12:00、16:00;叶片气孔导度(Gs)的日变化在CK、T1、T2下呈双峰型分布,在T3下无明显变化;蒸腾速率(Tr)呈现双峰型变化的是T1和T2,CK与T3则呈单峰型变化;光合速率(Pn)的日变化幅度从充足供水到严重干旱处理依次减小,且各处理在12:00前波动较大,而后呈现平缓降低的趋势.各水分处理下小麦叶片光合-蒸腾的日变化呈现显著的正相关关系,Pn在CK下的主要调控因子是PAR,在T1、T3下的主要调控因子为Gs;Tr在CK、T1下的主要调控因子是PAR,在T2、T3下的主要正调控因子为Gs,负调控因子为t.同时,当以Pn与Tr关系斜率表示小麦叶片碳水耦合关系时,发现不同水分处理下小麦叶片碳水耦合特征存在差异,尤其是重度干旱,导致小麦叶片碳水耦合关系显著降低.
Abstract
Leaves regulate stomata to closely couple the processes of plant carbon assimilation and water consumption,but it is unclear whether this carbon-water coupling relationship changes under different water conditions.This study selected spring wheat,a field crop in the semi-arid region of northwest China,as the research object.Four water treatments were applied:sufficient water supply(CK),mild drought(T1),moderate drought(T2),and severe drought(T3).Leaf photosynthesis and transpiration were observed on typical sunny days during the wheat jointing period(8:00-18:00).Results showed that air temperature(t)and photosynthetic active radiation(PAR)exhibited unimodal patterns with peaks at 12:00 and 16:00.Leaf stomatal conductance(Gs)showed bimodal distributions under CK,T1,and T2,while no obvious daily change was observed under T3.The transpiration rate(Tr)exhibited bimodal changes under T1 and T2,but unimodal changes under CK and T3.The daily variation of photosynthetic rate(Pn)decreased from sufficient water to severe drought treatments,with greater fluctuations before 12:00 and a gradual decrease thereafter.Significant positive correlations were observed between photosynthesis and transpiration under all water treatments.The main regulatory factor for Pn under CK was PAR,while under T1 and T3,it was Gs.The main regulatory factor for Tr under CK and T1 was PAR,while under T2 and T3,the primary positive regulator was Gs and the negative regulator was t.The slope of the Pn-Tr relationship indicated differences in carbon-water coupling characteristics under different water treatments,with severe drought significantly reducing the coupling.These findings provide a reference for carbon-water coupling simulations under drought conditions.
关键词
干旱胁迫/小麦叶片/光合作用/蒸腾作用Key words
drought stress/wheat leaves/photosynthesis/transpiration引用本文复制引用
基金项目
国家自然科学基金项目(42005097)
国家自然科学基金项目(31571594)
国家自然科学基金项目(41661049)
甘肃省自然科学基金项目(20JR10RA543)
定西市科技计划项目"科技人才支持专项"(DX2023BR22)
出版年
2024
国家科技期刊平台
NSTL
万方数据