scholarly journals Elevated CO2 Increases Growth and Photosynthetic Efficiency of Citrus Rootstock Seedlings

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 531B-531
Author(s):  
J.P. Syvertsen
Keyword(s):  
Water Use ◽  
Plant Size ◽  
Single Leaf ◽  
Plant Water Use ◽  
Whole Plant ◽  
Volkamer Lemon ◽  
Citrus Rootstock ◽  
Use Efficiency ◽  
Cleopatra Mandarin ◽  
Swingle Citrumelo

The objectives of these greenhouse experiments were to determine the effects of elevated CO2 on growth, mineral nutrition, and gas exchange physiology of seedlings of four commercial Citrus rootstocks. We grew well-watered and fertilized seedlings of `Volkamer' lemon (VL), `Cleopatra' mandarin (CL), `Swingle' citrumelo (SW), and `Troyer' citrange (TC) cultivars (in decreasing order of vigor) in unshaded, air-conditioned greenhouses at ambient CO2 (350 μmol/mol) or 2x ambient CO2 for 5 months. CL was the smallest cultivar, had the lowest root/shoot (r/s) ratio,and lowest rates of CO2 assimilation (A) of leaves, transpiration (E), and water-use efficiency, (A/E). Overall, daily whole-plant water use was correlated with single-leaf E. Elevated CO2 increased both shoot and root growth similarly; therefore, r/s was not affected. Elevated CO2 increased A, leaf dry wt/area, and leaf C, but decreased transpiration and leaf N so that leaf C/N, A/N, and A/E all increased. Although plant size of the four cultivars ranked similarly at both ambient and high CO2, the more-vigorous cultivars grew proportionately more at high CO2 than the less-vigorous cultivars. Growing cultivars at elevated CO2 can yield insights into mechanisms determining vigor and relationships between A and plant growth.

scholarly journals From leaf to whole-plant water use efficiency (WUE) in complex canopies: Limitations of leaf WUE as a selection target

2015 ◽  
Vol 3 (3) ◽  
pp. 220-228 ◽  
Author(s):  
Hipólito Medrano ◽  
Magdalena Tomás ◽  
Sebastià Martorell ◽  
Jaume Flexas ◽  
Esther Hernández ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Plant Water ◽  
Plant Water Use ◽  
Whole Plant ◽  
Use Efficiency

The isohydric cv. Montepulciano (Vitis vinifera L.) does not improve its whole-plant water use efficiency when subjected to pre-veraison water stress

2014 ◽  
Vol 179 ◽  
pp. 103-111 ◽  
Author(s):  
Stefano Poni ◽  
Marco Galbignani ◽  
Eugenio Magnanini ◽  
Fabio Bernizzoni ◽  
Alberto Vercesi ◽  
...  
Keyword(s):  
Water Stress ◽  
Vitis Vinifera ◽  
Water Use Efficiency ◽  
Water Use ◽  
Vitis Vinifera L ◽  
Plant Water ◽  
Plant Water Use ◽  
Whole Plant ◽  
Use Efficiency

scholarly journals Large variation in whole-plant water-use efficiency among tropical tree species

2006 ◽  
Vol 173 (2) ◽  
pp. 294-305 ◽  
Author(s):  
Lucas A. Cernusak ◽  
Jorge Aranda ◽  
John D. Marshall ◽  
Klaus Winter
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Tree Species ◽  
Tropical Tree ◽  
Plant Water ◽  
Tropical Tree Species ◽  
Plant Water Use ◽  
Whole Plant ◽  
Use Efficiency

scholarly journals A genetic link between whole-plant water use efficiency and leaf carbon isotope composition in the C4 grass Setaria

2018 ◽  
Author(s):  
Patrick Z. Ellsworth ◽  
Max J. Feldman ◽  
Ivan Baxter ◽  
Asaph B. Cousins
Keyword(s):  
Plant Breeding ◽  
Water Use Efficiency ◽  
Water Use ◽  
Genetic Architecture ◽  
Isotope Composition ◽  
Plant Water ◽  
Breeding Programs ◽  
Plant Water Use ◽  
Whole Plant ◽  
Use Efficiency

AbstractIncreasing whole plant water use efficiency (yield per transpiration; WUEplant) through plant breeding can benefit the sustainability of agriculture and improve crop yield under drought. To select for WUEplant, an efficient phenotyping method that reports on the genetic contribution of component traits such as transpiration efficiency (TEi; rate of CO2 assimilation per stomatal conductance) must be developed. Leaf carbon stable isotope composition (δ13Cleaf) has been proposed as a high-throughput proxy for TEi, and a negative correlation between δ13Cleaf and both WUEplant and TEi has previously been demonstrated in several C4 grass species. Therefore, the aim of the research presented here was to determine if the same loci control δ13Cleaf, WUEplant, and TEi under well-watered and water-limited conditions in a recombinant inbred line (RIL) population of closely related C4 grasses Setaria viridis and S. italica. Three quantitative trait loci (QTL) for δ13Cleaf were co-localized with transpiration, biomass, and a linear model of WUE. When WUEplant was calculated for allele classes based on the three QTL for δ13Cleaf, δ13Cleaf was negatively correlated with WUEplant as theory predicts when WUEplant is in part driven by differences in TEi. In any population, multiple traits can influence WUEplant; however, the analysis of δ13Cleaf in this RIL population demonstrates that there is genetic control of TEi that significantly contributes to WUEplant. Furthermore, this research suggests that δ13Cleaf can be used in marker-assisted breeding to select for TEi and as a tool to better understand the physiology and genetic architecture of TEi and WUEplant in C4 species.Significance StatementOverextended water resources and drought are major agricultural problems worldwide. Therefore, selection for increased plant water use efficiency (WUEplant) in food and biofuel crop species is an important trait in plant breeding programs. Leaf carbon isotopic composition (δ13Cleaf) has potential as a rapid and effective high throughput phenotyping method for intrinsic transpiration efficiency (TEi), an important leaf-level component trait of WUEplant. Our research shows that δ13Cleaf and WUEplant share a common genetic architecture through their shared relationship with TEi. This suggests that δ13Cleaf can be used as a screen for TEi in marker-assisted plant breeding programs to improve crop drought resistance and decrease agricultural water consumption.

scholarly journals (330) Growth and Nutritional Response of Six Citrus Rootstocks to Increasing Levels of Copper

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1066A-1066
Author(s):  
Joseph Albano ◽  
Kim Bowman
Keyword(s):  
Nutrient Solution ◽  
Poncirus Trifoliata ◽  
Citrus Groves ◽  
Whole Plant ◽  
Volkamer Lemon ◽  
Florida Citrus ◽  
Cleopatra Mandarin ◽  
Swingle Citrumelo

Nutrient disorders related to excessive levels of copper in soils are common in Florida citrus groves that have been under production for many years, mainly due to the continual use of copper-containing pesticides. The objectives of the study were to investigate the growth and nutritional response of six citrus rootstocks (nonbudded) grown in 4-L containers in sand to increasing concentrations of copper. The rootstocks included: Swingle citrumelo (Citrusparadisi Macf. × Poncirus trifoliata [L.] Raf.), Volkamer lemon (C. volkameriana Ten. and Pasq.), Cleopatra mandarin (Citrusreticulata Blanco), Flying Dragon (P. trifoliata); and two new USDA series rootstocks, US-812 (Sunki mandarin × P. trifoliata released in 2001), and US-897 (a hybrid of Cleopatra × Flying Dragon not yet released). Copper was supplied at 0.05, 0.25, 1.00, and 2.00 mg·L-1 CuEDTA incorporated into a modified Hoagland's nutrient solution. As a mean of all Cu treatments, whole plant Cu levels (μg·g-1) were: Flying Dragon, 17.33; US-897, 21.68; Cleopatra, 27.33; US-812, 28.84; Swingle, 29.74; and Volkamer, 34.05. As a mean of all Cu treatments, foliar Cu levels (μg·g-1) were greatest and least in US-812 (7.74) and Cleopatra (4.05), respectively; and root Cu levels (μg·g-1) were greatest and least in Volkamer (61.08) and Flying Dragon (30.08), respectively.

scholarly journals Non-functional and weak alleles of FRIGIDA and FLOWERING LOCUS C reduce lifetime water-use independent of leaf-level water-use-efficiency traits in Arabidopsis thaliana

2018 ◽  
Author(s):  
J.N. Ferguson ◽  
R.C. Meyer ◽  
K.D. Edwards ◽  
M. Humphry ◽  
O. Brendel ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Water Use Efficiency ◽  
Water Use ◽  
Plant Water ◽  
Flowering Locus C ◽  
Plant Water Use ◽  
Whole Plant ◽  
Leaf Level ◽  
Use Efficiency ◽  
Flowering Locus

AbstractNatural selection driven by water availability has resulted in considerable variation for traits associated with drought tolerance and leaf level water-use efficiency (WUE). In Arabidopsis, little is known about the variation of whole-plant water use (PWU) and whole-plant WUE (TE). To investigate the genetic basis of PWU, we developed a novel proxy trait by combining flowering time and rosette water use to estimate lifetime PWU. We validated its usefulness for large scale screening of mapping populations in a subset of ecotypes. This parameter subsequently facilitated the screening of water-use but also drought tolerance traits in a recombinant inbred line population derived from two Arabidopsis accessions with distinct water use strategies, namely C24 (low PWU) and Col-0 (high PWU). Subsequent quantitative trait loci (QTL) mapping and validation through near-isogenic lines identified two causal QTLs, which showed that a combination of weak and non-functional alleles of the FRIGIDA (FRI) and FLOWERING LOCUS C (FLC) genes substantially reduced plant water-use without penalising reproductive performance. Drought tolerance traits, stomatal conductance, intrinsic water use efficiency (δ13C) and rosette water-use were independent of allelic variation at FRI and FLC, suggesting that flowering is critical in determining life-time plant water use, but not leaf-level traits.

scholarly journals Fertigation Frequency Affects Growth and Water and Nitrogen Use Efficiencies of Swingle Citrumelo Citrus Rootstock Seedlings

HortScience ◽  
2010 ◽  
Vol 45 (8) ◽  
pp. 1255-1259 ◽  
Author(s):  
Juan Carlos Melgar ◽  
Arnold W. Schumann ◽  
James P. Syvertsen
Keyword(s):  
Water Use ◽  
N Uptake ◽  
Dry Weight ◽  
Irrigation Frequency ◽  
N Uptake Efficiency ◽  
Citrus Rootstock ◽  
Use Efficiency ◽  
Swingle Citrumelo ◽  
Fertilizer Solution ◽  
Leaf N

We determined if frequency of application of irrigation water plus fertilizer in solution (fertigation) could modify root and shoot growth along with growth per unit nitrogen (N) and water uptake of seedlings of the citrus rootstock Swingle citrumelo growing in a greenhouse. In the first experiment, all plants received the same amount of water with sufficient fertilizer N but in three irrigation frequencies applied in 10 1.5-mL pulses per day, one 15-mL application per day, or 45 mL applied every 3 days. Plants irrigated at the highest frequency grew the least total dry weight and had the highest specific root length. Plants with lowest irrigation frequency grew the most and used the least water so had the highest water use efficiency. There were no irrigation frequency effects on relative growth allocation between shoot and roots, net gas exchange of leaves, or on leaf N. A second experiment used identical biweekly irrigation volumes and fertilizer rates, but water and fertilizer were applied using four frequency combinations: 1) daily fertigation; 2) daily irrigation with fertilizer solution applied every 15 days; 3) fertigation every 3 days; or 4) irrigation every 3 days and fertilizer solution applied every 14 days. Total plant growth was unaffected by treatments, but the highest frequency using the lowest fertilizer concentration grew the greatest root dry weight in the uppermost soil depths. Roots grew less and leaf N was highest when N was applied every 15 days, implying that root N uptake efficiency was increased when fertigated with the highest fertilizer concentration. All plants had similar water use efficiencies. A third experiment was conducted with irrigation every 3 days and with four different N application frequencies: every 3, 6, 12, or 24 days using four fertilizer concentrations but resulting in similar total N amounts every 24 days. There were no differences in growth, gas exchange, or water use efficiency. Given the fact that all treatments received adequate and equal amounts of water and fertilizer, fertigation frequency had only small effects on plant growth, although very high frequency fertigation decreased N uptake efficiency.

Dark-adapted leaf conductance, but not minimum leaf conductance, predicts water use efficiency of soybean (Glycine max L. Merr.)

2013 ◽  
Vol 93 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Alison E. Walden-Coleman ◽  
Istvan Rajcan ◽  
Hugh J. Earl
Keyword(s):  
Glycine Max ◽  
Water Use Efficiency ◽  
Water Use ◽  
Leaf Conductance ◽  
Physiological Basis ◽  
Plant Water Use ◽  
Whole Plant ◽  
Glycine Max L ◽  
Use Efficiency ◽  
Soybean Leaves

Walden-Coleman, A. E., Rajcan, I. and Earl, H. J. 2013. Dark-adapted leaf conductance, but not minimum leaf conductance, predicts water use efficiency of soybean (Glycine max L. Merr.). Can. J. Plant Sci. 93: 13–22. The conductance to water vapor of dark-adapted leaves (gdark) has been shown to be negatively correlated with whole-plant water use efficiency (WUE) in soybean, but the physiological basis of this relationship is unknown. It is also not clear how gdark compares with the minimum leaf conductance of wilted leaves (gmin), a trait that has been studied extensively across a broad range of species. We compared gdark to gmin of soybean leaves and found that gdark values were consistently much higher than gmin values measured on the same leaves. Also, across seven soybean varieties known to differ for WUE, gdark but not gmin was correlated with WUE. Thus, gdark and gmin should be considered distinct traits. We measured gdark at two different leaf positions, and found that gdark measured at the lower leaf position (two main stem nodes below the youngest fully expanded leaf) was best correlated with WUE. We then used this method to screen a selection of current commercial soybean varieties adapted to Ontario, Canada, for variation in gdark. The range in gdark among the commercial varieties was as broad as that measured previously among more diverse genotypes, suggesting that Ontario soybean varieties might also vary widely for WUE.

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