Leaf gas exchange characteristics,biomass partitioning,and water use efficiencies of two C4 African grasses under simulated drought  

作　　者：Kevin Z.Mganga Jana Kuhla Andrea Carminati Johanna Pausch Mutez A.Ahmed 

机构地区：[1]Copernicus Institute of Sustainable Development,Utrecht University,Utrecht,the Netherlands [2]Department of Agricultural Sciences,South Eastern Kenya University,Kitui,Kenya [3]Bayreuth Center of Ecology and Environmental Research(BayCEER),University of Bayreuth,Bayreuth,Germany [4]Department of Environmental Systems Science,ETH Zurich,Zürich,Switzerland [5]Department of Land,Air and Water Resources,University of California Davis,Davis,California,USA

出　　处：《Grassland Research》2023年第1期37-45,共9页草地研究（英文）

基　　金：Academy of Sciences for the Developing World,Grant/Award Number:TWAS‐DFG Cooperation Visits Program for scientist。

摘　　要：Background:Few studies have evaluated the effect of drought on the morphophysiological characteristics of African C_(4) grasses.We investigated how drought affects leaf gas exchange characteristics,biomass partitioning,and water use efficiencies of Enteropogon macrostachyus and Cenchrus ciliaris.Methods:The grasses were grown in a controlled environment under optimum conditions,that is,70%of the maximum water‐holding capacity(WHC)for the first 40 days.Thereafter,half of the columns were maintained under optimum or drought conditions(30%of maximum WHC)for another 20 days.Results:Under optimum conditions,C.ciliaris showed a significantly higher photosynthetic rate,stomatal conductance,and transpiration rate than E.macrostachyus.Drought decreased the photosynthetic rate,stomatal conductance and transpiration rate only in C.ciliaris.The net photosynthetic rate,stomatal conductance,and leaf transpiration of E.macrostachyus did not differ significantly under optimum and drought conditions.E.macrostachyus showed an increase in its water use efficiencies under drought to a greater extent than C.ciliaris.Conclusions:Our results demonstrate that C.ciliaris is more sensitive to drought than E.macrostachyus.The decrease in the intercellular CO_(2) concentration and the increase in stomatal limitation with drought in C.ciliaris and E.macrostachyus suggest that stomatal limitation plays the dominant role in photosynthesis of the studied African C_(4) grasses.

关 键 词：biomass fractions C_(4)grasses DROUGHT PHOTOSYNTHESIS stomatal conductance TRANSPIRATION 

分 类 号：S812[农业科学—草业科学]