Drought Resistance and Water Use Efficiency in Acacia saligna

1999 ◽  
Vol 47 (4) ◽  
pp. 577 ◽  
Author(s):  
Rotem Nativ ◽  
Jhonathan E. Ephrath ◽  
Pedro R. Berliner ◽  
Yehoshua Saranga

Acacia saligna (Labill.) H.Wendl, a potential crop for forage and wood production, is considered highly drought-resistant. The aim of this study was to characterise some of the physiological traits contributing to drought resistance in A. saligna. Two experiments were conducted: (i) 4-year-old A. saligna were grown in the field under dryland and irrigated treatments and (ii) 6-month-old A. saligna were grown in pots and irrigated to replenish 100% of the transpiration demand (control), or 75% 50% or 25% of the control. Soil-water deficits in the field elicited an increase in osmotic potential in phyllodes. Stomatal conductance was negatively correlated with air vapor pressure deficit under drought conditions in both experiments, whereas under irrigation in the field it was correlated with solar radiation. In the field, dry matter (DM) production under irrigation was only 14% greater (not significant) than under dryland. In the pot experiment, DM production was significantly reduced, and water use efficiency (WUE) and chlorophyll content increased with reduced availability of water. The greater WUE induced by drought could have resulted from stomatal regulation and increased chlorophyll content. Carbon isotope ratios were correlated with the WUE, and may be utilised for selection to further improve the WUE of A. saligna under drought conditions.

1999 ◽  
Vol 47 (4) ◽  
pp. iii
Author(s):  
Kingsley S. Rowan ◽  
David H. Ashton

Acacia saligna (Labill.) H.Wendl, a potential crop for forage and wood production, is considered highly drought-resistant. The aim of this study was to characterise some of the physiological traits contributing to drought resistance in A. saligna. Two experiments were conducted: (i) 4-year-old A. saligna were grown in the field under dryland and irrigated treatments and (ii) 6-month-old A. saligna were grown in pots and irrigated to replenish 100% of the transpiration demand (control), or 75% 50% or 25% of the control. Soil-water deficits in the field elicited an increase in osmotic potential in phyllodes. Stomatal conductance was negatively correlated with air vapor pressure deficit under drought conditions in both experiments, whereas under irrigation in the field it was correlated with solar radiation. In the field, dry matter (DM) production under irrigation was only 14% greater (not significant) than under dryland. In the pot experiment, DM production was significantly reduced, and water use efficiency (WUE) and chlorophyll content increased with reduced availability of water. The greater WUE induced by drought could have resulted from stomatal regulation and increased chlorophyll content. Carbon isotope ratios were correlated with the WUE, and may be utilised for selection to further improve the WUE of A. saligna under drought conditions.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xin Jia ◽  
Ke Mao ◽  
Ping Wang ◽  
Yu Wang ◽  
Xumei Jia ◽  
...  

AbstractWater deficit is one of the major limiting factors for apple (Malus domestica) production on the Loess Plateau, a major apple cultivation area in China. The identification of genes related to the regulation of water use efficiency (WUE) is a crucial aspect of crop breeding programs. As a conserved degradation and recycling mechanism in eukaryotes, autophagy has been reported to participate in various stress responses. However, the relationship between autophagy and WUE regulation has not been explored. We have shown that a crucial autophagy protein in apple, MdATG8i, plays a role in improving salt tolerance. Here, we explored its biological function in response to long-term moderate drought stress. The results showed that MdATG8i-overexpressing (MdATG8i-OE) apple plants exhibited higher WUE than wild-type (WT) plants under long-term moderate drought conditions. Plant WUE can be increased by improving photosynthetic efficiency. Osmoregulation plays a critical role in plant stress resistance and adaptation. Under long-term drought conditions, the photosynthetic capacity and accumulation of sugar and amino acids were higher in MdATG8i-OE plants than in WT plants. The increased photosynthetic capacity in the OE plants could be attributed to their ability to maintain optimal stomatal aperture, organized chloroplasts, and strong antioxidant activity. MdATG8i overexpression also promoted autophagic activity, which was likely related to the changes described above. In summary, our results demonstrate that MdATG8i-OE apple lines exhibited higher WUE than WT under long-term moderate drought conditions because they maintained robust photosynthesis, effective osmotic adjustment processes, and strong autophagic activity.


2020 ◽  
Vol 11 ◽  
Author(s):  
Saqib Saleem Akhtar ◽  
Daniel Buchvaldt Amby ◽  
Josefine Nymark Hegelund ◽  
Lorenzo Fimognari ◽  
Dominik K. Großkinsky ◽  
...  

2013 ◽  
Vol 864-867 ◽  
pp. 2236-2239
Author(s):  
Jun Ying Jin ◽  
Wei Hua Zhang ◽  
Bao Chang

The application of water retaining agent could evidently improve water use efficiency. The WUE was increased with the duration of using water retaining agent, compared with the control, it increased 5 to 11 times with the duration of 8 to16d, and the growth (eg. height, the ratio of shoot to root, and yield et al) and physiological indices (eg. root activities and chlorophyll contents) were not affected. Moreover, compared with the control, the proline content increased 3 times, which showed that the application of water retaining agent improve the drought resistance, and the maximum threshold was 16d for keeping the normal growth of Hemarthria compressa in this study.


2017 ◽  
Vol 8 ◽  
Author(s):  
Pradeep Kumar ◽  
Youssef Rouphael ◽  
Mariateresa Cardarelli ◽  
Giuseppe Colla

Plants ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 123 ◽  
Author(s):  
James Bunce

High intrinsic water-use efficiency (WUEi), the ratio of leaf photosynthesis to stomatal conductance, may be a useful trait in adapting crops to water-limited environments. In soybean, cultivar differences in stomatal response to vapor pressure deficit have not consistently translated into differences in WUEi in the field. In this study, six cultivars of soybeans previously shown to differ in WUEi in indoor experiments were grown in the field in Beltsville, Maryland, and tested for mid-day WUEi on nine clear days during the mid-seasons of two years. Measurement dates were chosen for diverse temperatures, and air temperatures ranged from 21 to 34 °C on the different dates. Air saturation deficits for water vapor ranged from 0.9 to 2.2 kPa. Corrected carbon isotope delta values for 13C (CID) were determined on mature, upper canopy leaves harvested during early pod filling each year. WUEi differed among cultivars in both years and the differences were consistent across measurement dates. Correlations between mean WUEi and CID were not significant in either year. It is concluded that consistent cultivar differences in WUEi exist in these soybean cultivars under field conditions, but that carbon isotope ratios may not be useful in identifying them because of cultivar differences in mesophyll conductance.


Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 153 ◽  
Author(s):  
Katherine Sinacore ◽  
Heidi Asbjornsen ◽  
Virginia Hernandez-Santana ◽  
Jefferson S. Hall

Drought conditions may have differential impacts on growth, transpiration, and water use efficiency (WUE) in mixed species and monospecific planted forests. Understanding the resistance (i.e., the capacity to maintain processes unchanged) of different tree species to drought, and how resistance is affected by complementary interactions within species mixtures, is particularly important in the seasonally dry tropics where projected increases in the frequency and severity of drought threaten tree planting efforts and water resources. Complementary interactions between species may lead to more resistant stands if complementarity leads to greater buffering capacity during drought. We examined growth, transpiration, and WUE of mixtures and monocultures of Terminalia amazonia (J.F. Gmel.) Exell and Dalbergia retusa Hemsl. before and during a prolonged drought using intensive measurements of tree sap flow and growth. Tree sapwood area growth was highest for T. amazonia in mixtures during normal (6.78 ± 4.08 mm2 yr−1) and drought (7.12 ± 4.85 mm2 yr−1) conditions compared to the other treatments. However, stand sapwood area growth was greatest for T. amazonia monocultures, followed by mixtures, and finally, D. retusa monocultures. There was a significant decrease in stand transpiration during drought for both mixtures and T. amazonia monocultures, while Dalbergia retusa monocultures were most water use efficient at both the tree and stand level. Treatments showed different levels of resistance to drought, with D. retusa monocultures being the most resistant, with non-significant changes of growth and transpiration before and during drought. Combining species with complementary traits and avoiding combinations where one species dominates the other, may maximize complementary interactions and reduce competitive interactions, leading to greater resistance to drought conditions.


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