Water use efficiency and shoot biomass production under water limitation is negatively correlated to the discrimination against13C in the C3grasses Dactylis glomerata, Festuca arundinacea and Phalaris arundinacea.
Climate change impacts rainfall patterns which may lead to drought stress in rain-fed agricultural systems. Crops with higher drought tolerance are required on marginal land with low precipitation or on soils with low water retention used for biomass production. It is essential to obtain plant breeding tools, which can identify genotypes with improved drought tolerance and water use efficiency (WUE). In C3plant species, the variation in discrimination against13C (Δ13C) during photosynthesis has been shown to be a potential indicator for WUE, where discrimination against13C and WUE were negatively correlated. The aim of this study was to determine the variation in the discrimination against13C between species and cultivars of three perennial C3grasses (Dactylis glomerata (cocksfoot), Festuca arundinacea (tall fescue) and Phalaris arundinacea (reed canary grass)) and test the relationships between discrimination against13C, season-long water use WUEB, shoot and root biomass production in plants grown under well-watered and water-limited conditions. The grasses were grown in the greenhouse and exposed to two irrigation regimes, which corresponded to 25% and 60% water holding capacity, respectively. We found negative relationships between discrimination against13C and WUEBand between discrimination against13C and shoot biomass production, under both the well-watered and water-limited growth conditions (p < 0.001). Discrimination against13C decreased in response to water limitation (p < 0.001). We found interspecific differences in the discrimination against13C, WUEB, and shoot biomass production, where the cocksfoot cultivars showed lowest and the reed canary grass cultivars highest values of discrimination against13C. Cocksfoot cultivars also showed highest WUEB, shoot biomass production and potential tolerance to water limitation. We conclude that discrimination against13C appears to be a useful indicator, when selecting C3grass crops for biomass production under drought conditions.
Swedish University of Agricultural Sciences, Department of Biosystems and Technology, Box 103, SE-230 53 Alnarp, Sweden. Electronic address: Linda.Maria.Martensson@slu.se.
Linda-Maria
LM
Mårtensson
Swedish University of Agricultural Sciences, Department of Biosystems and Technology, Box 103, SE-230 53 Alnarp, Sweden.
Georg
G
Carlsson
Swedish University of Agricultural Sciences, Department of Biosystems and Technology, Box 103, SE-230 53 Alnarp, Sweden.
Thomas
T
Prade
Aarhus University, Department of Agroecology, Blichers Allé 20, DK-8830 Tjele, Denmark.
Kirsten
K
Kørup
Aarhus University, Department of Agroecology, Blichers Allé 20, DK-8830 Tjele, Denmark.
Poul Erik
PE
Lærke
Swedish University of Agricultural Sciences, Department of Biosystems and Technology, Box 103, SE-230 53 Alnarp, Sweden.
Erik Steen
ES
Jensen
D018533:Biomass; D002247:Carbon Isotopes / Q000032:analysis / Q000378:metabolism*; D031745:Dactylis / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D055864:Droughts; D031751:Festuca / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D031783:Phalaris / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D010788:Photosynthesis / Q000502:physiology; D018517:Plant Roots / Q000254:growth & development; D018520:Plant Shoots / Q000254:growth & development; D006109:Poaceae / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D012621:Seasons; D012987:Soil / Q000737:chemistry; D013312:Stress, Physiological; D014867:Water / Q000378:metabolism*
D002247:Carbon Isotopes; D012987:Soil; D014867:Water
Cocksfoot; Drought tolerance; Perennial grasses; Reed canary grass; Tall fescue