Relationships between carbon isotope discrimination, water use efficiency and transpiration efficiency for dryland wheat

1993 ◽  
Vol 44 (8) ◽  
pp. 1693 ◽  
Author(s):  
AG Condon ◽  
RA Richards ◽  
GD Farquhar
Keyword(s):  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Negative Correlation ◽  
Seasonal Changes ◽  
Dry Matter ◽  
Carbon Isotope Discrimination ◽  
Transpiration Efficiency ◽  
Use Efficiency ◽  
The Relationship

Carbon isotope discrimination (-) has been shown to be negatively correlated with water use efficiency for wheat cultivars grown in the glasshouse. In the field this negative correlation has been confirmed for peanut but it has yet to be confirmed for wheat. Indeed, several field studies on wheat have shown positive (rather than negative) relationships between dry matter production and -. The aim of this study was to determine the relationship between - and water use efficiency for wheat grown in a dryland environment characterized by winterlspring-dominant rainfall and terminal drought. Eight genotypes chosen to give a range in - of c. 2.0x10-3 were grown on a red earth at Moombooldool in the Riverina region of New South Wales. Water use and above-ground dry matter (DM) were measured over the course of the season. Water use was partitioned into transpiration and soil evaporation and values of crop water use efficiency (WET) and transpiration efficiency ( WT) calculated. To account for the effect on WT of seasonal changes in the vapour pressure deficit of the air (D), crop coefficients (k) were derived by multiplying WT by the transpiration-weighted average daytime value of D for each genotype. During the preanthesis period, when there was little limitation of soil water supply on growth, there was a positive relationship between DM and -, as observed previously. The relationship between WET and - also had a positive (though non-significant) trend, but the relationship between k and - was negative, i.e. once the effects of variation in the ratio T/ET and seasonal changes in D were accounted for, the negative correlation between water use efficiency and - re-emerged. This apparent conflict between WET and k arose because genotypes with high - values developed their leaf area faster, with two important consequences. First, high - genotypes transpired more of their water supply during the winter when D was low and the exchange of water for CO2 more efficient. Second, transpiration made up a greater proportion of total water use by high - genotypes. The relationship between water use efficiency and - was further complicated as the crops depleted the soil water store after anthesis. During this period DM production tended to be greater in low - genotypes that had conserved soil water in the preanthesis period. However, DM production also remained high for two high - genotypes. The cause of this variation in post-anthesis growth among high - genotypes was not established.

Discrimination in Carbon Isotopes of Leaves Correlates With Water-Use Efficiency of Field-Grown Peanut Cultivars

1988 ◽  
Vol 15 (6) ◽  
pp. 815 ◽  
Author(s):  
GC Wright ◽  
KT Hubick ◽  
GD Farquhar
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Dry Matter Yield ◽  
Strong Negative Correlation ◽  
Matter Production ◽  
Whole Plant ◽  
Use Efficiency ◽  
The Relationship

Variation in water-use efficiency (W, g of total dry matter produced/kg water used), and its correlation with cultivar isotope discrimination in leaves (Δ) was assessed in peanut plants grown in small canopies in the field. Plants were grown in separate minilysimeters that were both embedded in the ground and positioned above the crop. Differences among cultivars were found in W and � and the relationship between W and Δ was compared for plants grown in open and closed canopies. Genetic variability in W in plants grown in the field under non-limiting water conditions was demonstrated, with Tifton-8, of Virginia habit, having the highest W (3.71 g/kg) and Rangkasbitung, an Indonesian cultivar of Spanish habit, the lowest (2.46 g/ kg). Variability in W was due to variation in total dry matter production more than that of water use. A strong negative correlation was found between Δ and W, and also between Δ and total dry matter. The relationship between whole plant W, including roots, and Δ was stronger than that between shoot W, without roots and Δ. The improvement occurred because of variation among cultivars in the root to shoot ratio. This highlights the importance of taking account of root dry matter in studies concerning W. There were significant differences in W and Δ between plants in pots above-ground compared to pots in the ground, with above-ground plants having significantly lower values of both W and Δ. The ranking of W and Δ among cultivars was not affected by the contrast in environment, which suggests these parameters are under strong genetic control. Total above-ground dry matter yield at maturity was negatively correlated with Δ, while pod yield was not. It appears a negative association between harvest index and Δ may exist; however not all cultivars used in this and other studies follow this response. Both water-use efficiency, Wand total dry matter production are negatively correlated with Δ in leaves of peanut plants grown in small canopies in the field. Measurement of Δ may prove a useful trait for selecting cultivars with improved W and total dry matter yield under field conditions.

High crop productivity with high water use in winter and summer on the Liverpool Plains, eastern Australia

2008 ◽  
Vol 59 (4) ◽  
pp. 303 ◽  
Author(s):  
R. R. Young ◽  
P.-J. Derham ◽  
F. X. Dunin ◽  
A. L. Bernardi ◽  
S. Harden
Keyword(s):  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
High Water ◽  
Crop Productivity ◽  
Transpiration Efficiency ◽  
Eastern Australia ◽  
Use Efficiency ◽  
Water Outflow ◽  
Almost All

We report exceptional productivity and associated water-use efficiency across seasons for commercial crops of rainfed spring wheat and grain sorghum growing on stored soil water in Vertosols on the Liverpool Plains, central-eastern Australia. Agreement between the independently measured terms of evapotranspiration (ET) and the soil water balance (in-crop rainfall + δsoil water) was achieved within acceptable uncertainty across almost all measurement intervals, to provide a reliable dataset for the analysis of growth and water-use relationships without the confounding influence of water outflow either overland or within the soil. Post-anthesis intrinsic transpiration efficiency (kc ) values of 4.7 and 7.2 Pa for wheat and sorghum, respectively, and grain yields of 8 and 7 t/ha from ET of 450 and 442 mm (1.8 and 1.6 g/m2.mm), clearly demonstrate the levels of productivity and water-use efficiency possible for well-managed crops within an intensive and productive response cropping sequence. The Vertosols in which the crops were grown enabled rapid and apparently unconstrained delivery of significant quantities of subsoil water (34% and 51% of total available) after anthesis, which enabled a doubling of pre-anthesis standing biomass and harvest indices of almost 50%. Durum wheat planted into only 0.30 m of moist soil and enduring lower than average seasonal rainfall, yielded less biomass and grain (2.3 t/ha) with lower water-use efficiency (0.95 g/m2.mm) but larger transpiration efficiency, probably due to reduced stomatal conductance. We argue that crop planting in response to stored soil water and management for high water-use efficiency to achieve high levels of average productivity of crop sequences over time can have a significant effect on both increased productivity and enhanced hydrological stability across alluvial landscapes.

Divergent selection for carbon isotope discrimination in crested wheatgrass

1993 ◽  
Vol 73 (4) ◽  
pp. 1027-1035 ◽  
Author(s):  
J. J. Read ◽  
K. H. Asay ◽  
D. A. Johnson
Keyword(s):  
Water Use Efficiency ◽  
Carbon Isotope ◽  
Water Use ◽  
Dry Matter ◽  
Carbon Isotope Discrimination ◽  
Forage Yield ◽  
Crested Wheatgrass ◽  
Agropyron Desertorum ◽  
Use Efficiency ◽  
Selection For

Because plant growth on semiarid rangelands is frequently water-limited, breeding for enhanced water-use efficiency (WUE, kg dry matter gained per kg water transpired) should improve forage production on these areas. In crested wheatgrass [Agropyron desertorum (Fischer ex Link) Schultes], variation for carbon isotope discrimination (Δ) has been negatively associated with WUE, suggesting that selection for lowered Δ would increase WUE. To determine the potential of altering Δ through breeding, we selected nine clones from a crested wheatgrass breeding population based on their Δ values, equally subdivided them into three groups (low, medium, and high Δ), and made a series of diallel crosses within each group. The parental clones and single-cross progenies were established in the field as replicated spaced plants on 1-m centers in spring 1989. Forage dry matter yield and Δ were determined in 1990 and 1991; leaf gas exchange traits were determined for low and high Δ classes in 1990, and for low, medium, and high Δ classes in 1991. The previous ranking of Δ classes was confirmed in the present studies. Combined across years, values for Δ, leaf CO2 exchange rate (CER), and stomatal conductance (gs) were significantly (P < 0.05) lower in the low than high Δ class. When data were combined across clones and progenies, Δ was negatively correlated with leaf intrinsic water-use efficiency (WUEi, expressed as the CER/gs ratio) in 1990 (r = −0.87**, df = 14) and in 1991 (r = −0.83**, df = 23). Forage yield and Δ were not correlated, suggesting that the two traits may be under separate genetic control. Progenies from crosses among the low-Δ clones had significantly lower Δ values than progenies from either the medium-Δ or high-Δ clones during each year and when the data were combined across years. Divergent selection for low Δ also was reflected by improved WUEi in the subsequent generation. Moreover, narrow-sense heritability values for Δ were in excess of 0.75 and correlations between progeny means for Δ and means of the corresponding midparents were significant in each of the three analyses (r = 0.87** in 1990, 0.91** in 1991, and 0.92** in the combined analysis). These results complement earlier findings and confirm that genetic improvement for WUE can be effectively achieved in crested wheatgrass through indirect selection for Δ. Key words: Agropyron desertorum, water-use efficiency, parent-progeny correlations, drought, carbon isotope ratio, grass breeding, forage yield

Dwarfing genes, water-use efficiency and agronomic performance of spring wheat

1996 ◽  
Vol 76 (4) ◽  
pp. 707-714 ◽  
Author(s):  
B. Ehdaie ◽  
J. G. Waines
Keyword(s):  
Grain Yield ◽  
Water Use Efficiency ◽  
Plant Height ◽  
Water Use ◽  
Dry Matter ◽  
Carbon Isotope Discrimination ◽  
Dwarfing Genes ◽  
Near Isogenic Lines ◽  
Isogenic Lines ◽  
Use Efficiency

The Rht1 and Rht2 dwarfing genes have been used extensively to reduce height in wheat (Triticum aestivum L.). The Rht3 gene is also a potent dwarfing gene. Information in the literature is limited or conflicting as to the comparative effects of these genes on water-use efficiency (WUE) and agronomic performance under different environments. Four near-isogenic lines, rhtrht, Rht1Rht1, Rht2Rht2, and Rht3Rht3 in Maringa and three, rhtrht, Rht2Rht2, and Rht3Rht3 in Nainan 60 bread wheat backgrounds were used to determine the effects of dwarfing genes on plant height, total dry matter (TDM) and its components, evapotranspiration efficiency (ETE, TDM/water evapotranspired), WUE (grain yield/water evapotranspired), and carbon isotope discrimination (Δ) in well-watered and droughted pot experiments in the glasshouse. The near-isogenic lines were also grown in well-watered and droughted field experiments. The dwarfing genes consistently reduced plant height and kernel weight in Maringa and Nainari 60 backgrounds under all environmental conditions. The dwarfing genes significantly increased number of spikes per plant in Nainari 60 background in the glasshouse and number of grains per plant in Maringa background under field conditions. In most cases, TDM or shoot dry matter (SDM) in short isogenic lines was significantly reduced. The reduction in grain yield was less than that of TDM or SDM. Therefore, harvest index was greater in short isogenic lines than their respective tall standard counterparts. The effects of the dwarfing genes on root dry matter were relatively small. The dwarfing genes, on average, depressed ETE by 21% and WUE by 15% only in Maringa background. Plant height was positively correlated with TDM and ETE but negatively so with Δ in glasshouse experiments. Grain yield and TDM were positively correlated with ETE. Δ was negatively associated with ETE, TDM, SDM, and grain yield under glasshouse conditions. Key words: Spring wheat, dwarfing genes, near-isogenic lines, water-use efficiency, carbon isotope discrimination

scholarly journals The relationship between the soil water storage and water-use efficiency of seven energy crops

2017 ◽  
Vol 55 (2) ◽  
pp. 210-218 ◽  
Author(s):  
S. Podlaski ◽  
S. Pietkiewicz ◽  
D. Choluj ◽  
T. Horaczek ◽  
G. Wisniewski ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Water Storage ◽  
Energy Crops ◽  
Soil Water Storage ◽  
Use Efficiency ◽  
The Relationship

scholarly journals Evaluation of the Use of Carbon Isotope Discrimination as a Selection Tool of Perennial Fodder Species for Temporary Pastures

2011 ◽  
Vol 39 (2) ◽  
pp. 34
Author(s):  
Nicusor Flavius SIMA ◽  
Rodica Maria SIMA ◽  
Stela CUNA ◽  
Gabriela CRISTEA ◽  
Valentin MIHAI
Keyword(s):  
Water Use Efficiency ◽  
Carbon Isotope ◽  
Water Use ◽  
Carbon Isotope Discrimination ◽  
Theoretical Models ◽  
Isotope Discrimination ◽  
Fodder Plants ◽  
Partial Pressures ◽  
Use Efficiency ◽  
The Relationship

Estimation of the relationship between carbon isotope discrimination (Δ13C) in perennial fodder plants and various factors such as climate, fertilization and soil could contribute to a better selection and/or improvement of genotype of fodder species. Theoretical models of carbon isotope discrimination in plants indicate a linear relationship between Δ13C and CO2 partial pressures ratio (pi/pa) from the intercellular spaces (pi) of CO2 in leaves and from the atmosphere (pa). It is also known that between pi parameter and water-use efficiency (WUE) there is a negative correlation. Eight perennial fodder legume and grass mixtures were cultivated on three levels of fertilization in order to assess mixtures for pastures that can provide sustainable quantitative and qualitative yields. The species, which composed the mixtures, were also cultivated as pure crops on the same fertilization conditions. The results of this study indicated that in five of the six species, which composed the mixture with the highest yield, pi/pa values decreased while fertilization doses increased, most likely as a result of variation in water-use efficiency.

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