Environmental v. genetically driven variation in ecophysiological traits of Nothofagus pumilio from contrasting elevations

2007 ◽  
Vol 55 (6) ◽  
pp. 585 ◽  
Author(s):  
Andrea C. Premoli ◽  
Carol A. Brewer
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Common Garden ◽  
High Elevation ◽  
Field Conditions ◽  
Summer Drought ◽  
Nothofagus Pumilio ◽  
Ecophysiological Traits ◽  
Use Efficiency ◽  
The Common

Nothofagus pumilio (Poepp. et Endl.) Krasser is a broadleaved deciduous tree that dominates high-elevation forests in the southern Andes. We evaluated the degree to which differences in stomatal density and physiological traits (net assimilation, conductance and water use efficiency) were related to environmental and genetic influences with elevation by comparing plants growing under field and common garden conditions. Low-elevation leaves under field conditions had fewer stomata, although this pattern was not maintained in the common garden. Assimilation rates were >40% higher for high-elevation plants in the field, and 18% higher in the common garden, than those for low-elevation plants. In addition, under field conditions high-elevation plants tended to have higher stomatal conductance and lower instantaneous water use efficiency than did low-elevation plants; however, these differences were not significant in the common garden. Thus, assimilation seems to be under genetic control whereas ecophysiological traits related to the use of water appear to be more responsive to environmental cues. Our results suggest that plants growing along elevational gradients may show complex ecophysiological patterns. These patterns may be acquired by genetically driven responses to conditions that are fixed throughout the life span of individuals, such as soil nutrients. Also plastic adjustments may favour opportunistic use of available water during the dry season, particularly under Mediterranean-type climate regimes with summer drought.

The effect of strobilurins on leaf gas exchange, water use efficiency and ABA content in grapevine under field conditions

2012 ◽  
Vol 169 (4) ◽  
pp. 379-386 ◽  
Author(s):  
Antonio Diaz-Espejo ◽  
María Victoria Cuevas ◽  
Miquel Ribas-Carbo ◽  
Jaume Flexas ◽  
Sebastian Martorell ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Water Use Efficiency ◽  
Water Use ◽  
Leaf Gas Exchange ◽  
Field Conditions ◽  
Use Efficiency ◽  
Aba Content

scholarly journals Variability in Water Use Efficiency of Grapevine Tempranillo Clones and Stability over Years at Field Conditions

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 701 ◽  
Author(s):  
Ignacio Tortosa ◽  
Cyril Douthe ◽  
Alicia Pou ◽  
Pedro Balda ◽  
Esther Hernandez-Montes ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Genetic Material ◽  
Clonal Diversity ◽  
Field Conditions ◽  
Northern Spain ◽  
Use Efficiency ◽  
The Stability ◽  
Near Future ◽  
Expected Increase

One way to face the consequences of climate change and the expected increase in water availability in agriculture is to find genotypes that can sustain production at a lower water cost. This theoretically can be achieved by using genetic material with an increased water use efficiency. We compared the leaf Water Use Efficiency (WUEi) under realistic field conditions in 14 vine genotypes of the Tempranillo cultivar (clones), in two sites of Northern Spain for three and five years each to evaluate (1) if a clonal diversity exists for this traits among those selected clones and (2) the stability of those differences over several years. The ranking of the different clones showed significant differences in WUEi that were maintained over years in most of the cases. Different statistical analyses gave coincident information and allowed the identification of some clones systematically that had a higher WUEi or a lower WUEi. These methods also allowed the identification of the underlying physiological process that caused those differences and showed that clones with a higher WUEi are likely to have an increased photosynthetic capacity (rather than a different stomatal control). Those differences could be useful to orientate the decision for vines selection programs in the near future.

Rapid increases in shrubland and forest intrinsic water-use efficiency during an ongoing megadrought

2021 ◽  
Vol 118 (52) ◽  
pp. e2118052118
Author(s):  
Steven A. Kannenberg ◽  
Avery W. Driscoll ◽  
Paul Szejner ◽  
William R. L. Anderegg ◽  
James R. Ehleringer
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Pinus Ponderosa ◽  
Plant Density ◽  
High Elevation ◽  
American Southwest ◽  
Past Century ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency ◽  
Negative Impacts

Globally, intrinsic water-use efficiency (iWUE) has risen dramatically over the past century in concert with increases in atmospheric CO2 concentration. This increase could be further accelerated by long-term drought events, such as the ongoing multidecadal “megadrought” in the American Southwest. However, direct measurements of iWUE in this region are rare and largely constrained to trees, which may bias estimates of iWUE trends toward more mesic, high elevation areas and neglect the responses of other key plant functional types such as shrubs that are dominant across much of the region. Here, we found evidence that iWUE is increasing in the Southwest at one of the fastest rates documented due to the recent drying trend. These increases were particularly large across three common shrub species, which had a greater iWUE sensitivity to aridity than Pinus ponderosa, a common tree species in the western United States. The sensitivity of both shrub and tree iWUE to variability in atmospheric aridity exceeded their sensitivity to increasing atmospheric [CO2]. The shift to more water-efficient vegetation would be, all else being equal, a net positive for plant health. However, ongoing trends toward lower plant density, diminished growth, and increasing vegetation mortality across the Southwest indicate that this increase in iWUE is unlikely to offset the negative impacts of aridification.

scholarly journals Deficit irrigation at different growth stages of the common bean (Phaseolus vulgaris L., cv. Imbabello)

1997 ◽  
Vol 54 (spe) ◽  
pp. 1-16 ◽  
Author(s):  
M. Calvache ◽  
K Reichardt ◽  
O.O.S. Bacchi ◽  
D. Dourado-Neto
Keyword(s):  
Water Stress ◽  
Water Use Efficiency ◽  
Water Use ◽  
Management Practice ◽  
Growth Stages ◽  
Crop Water ◽  
Traditional Management ◽  
Crop Water Use ◽  
Use Efficiency ◽  
The Common

To identify specific growth stages of the common bean crop at which the plant is less sensitive to water stress, in which irrigation could be omitted without significant decrease hi final yield, two field experiments were conducted at "La Tola" University Experimental Station, Tumbaco, Pichincha, Ecuador, on a sandy loam soil (Typic Haplustoll). The climate is tempered and dry (mean air temperature 16°C and mean relative humidity 74%, during the cropping season) 123 and 109 mm of rainfall were recorded during the experimental cropping periods (July to October), of 1992 and 1994, respectively. The treatments consisted of combinations of 7 irrigation regimes including normal watering; full stress; (traditional management practice); single stress at vegetative stage; flowering; seed formation and ripening, and of 2 levels of applied N (20 and 80 kg/ha). These 14 treatment combinations were arranged and analysed in a split-plot design with 4 replications. The plot size was 33.6 m² (8 rows, 7 m long) with a plant population of 120,000 pl/ha. Irrigation treatments were started after uniform germination and crop establishment Soil water content was monitored with a neutron probe down to 0.50 m depth, before and 24 h after each irrigation. The actual evapotranspiration of the crop was estimated by the water-balance technique. Field water efficiency and crop water use efficiency were calculated. Yield data showed that the treatments which had irrigation deficit had lower yield than those that had supplementary irrigation. The flowering stage was the most sensitive to water stress. Nitrogen fertilization significantly increased the number of pods and gram yield. Crop water use efficiency (kg/m³) was the lowest with stress at the flowering period, and the yield response factor (Ky) was higher hi treatments of full stress and stress at flowering. In relation to the traditional management practice adopted by farmers, only treatments of normal watering and stress at maturation had 13 and 10% higher crop water use efficiency, respectively.

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