Background: Cotton (Gossypium hirsutum L.) is often grown in locations characterized by high atmospheric evapo-rative demand. It has been hypothesized that plants which resist hydraulic flow under this condition will limit water use and conserve soil water. Therefore, in a series of controlled environment experiments ten cotton cultivars were exposed to two different temperature and vapor pressure deficit (VPD) conditions (i.e., 38 ℃, > 3 kPa and 32 ℃, 1～1.5 kPa) as well as a progressive soil drying. Then, individual differences in shoot hydraulic conductance (Kshoot) was measured using a hydraulic conductance flow meter (HCFM). Physiological parameters were reported included leaf area, dry leaf weight, stomatal conductance (gs), and water use efficiency coefficient (WUEk). Results: Differences were observed in Kshoot among cultivars under the 38 ℃, > 3 kPa but not the 32 ℃, 1～1.5 kPa environment. Under the 38 ℃, > 3 kPa environment, correlations were found between Kshoot, stomatal conductance (gs), VPD breakpoint, WUEk, total leaf area, dry leaf weight, fraction transpirable soil water (FTSW) threshold, and slope of TR decline after FTSW threshold. Conclusion: Results show that the ability of some cotton cultivars to restrict water loss under high evaporative demand through early stomatal closure is associated with the cultivars' Kshoot. The Kshoot is influential in the limitation of TR trait under high temperature and VPD.

WEDEGAERTNER Kurt;SHEKOOFA Avat;PURDOM Sam;WALTERS Kellie;DUNCAN Lori;RAPER Tyson B.

Department of Plant Sciences, University of Tennessee, 2505 E.J. Chapman Dr., Knoxville, TN 37996, USA;Department of Biosystems Engineering and Soil Science, University of Tennessee, 2506 EJ Chapman Drive, Knoxville, TN 37996

棉花研究（英文）

[1]WEDEGAERTNER Kurt;SHEKOOFA Avat;PURDOM Sam;WALTERS Kellie;DUNCAN Lori;RAPER Tyson B.-.Cotton stomatal closure under varying temperature and vapor pressure deficit, correlation with the hydraulic conductance trait)[J].棉花研究（英文）,2022(03):217-227

Kshoot,HCFM,WUEk,transpirable,FTSW

Cotton,stomatal,closure,under,varying,temperature,pressure,deficit,hydraulic,conductance,trait,Background,Gossypium,hirsutum,often,grown,locations,characterized,by,high,atmospheric,demand,It,has,been,hypothesized,that,plants,which,resist,flow,this,will,water,use,conserve,soil,Therefore,series,controlled,environment,experiments,cotton,cultivars,were,exposed,two,different,VPD,conditions,kPa,well,progressive,drying,Then,individual,differences,was,measured,using,Physiological,parameters,reported,included,leaf,area,weight,gs,efficiency,coefficient,Results,Differences,observed,among,but,not,Under,correlations,found,between,breakpoint,total,fraction,threshold,slope,TR,decline,after,Conclusion,show,ability,some,restrict,loss,evaporative,through,early,associated,influential,limitation

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