The effect of leaf water potential on the carbon-dioxide uptake rate during different growth stages of wheat (Triticum aestivum L.)

Rising temperatures and increasing water scarcity, which are already important issues, are expected to intensify in the near future due to global warming. Optimizing irrigation in agriculture is a challenge. Understanding the response of crop development stages to water deficit stress provides an opportunity for optimizing irrigation. Here we studied the response of two barley varieties (Rihane, Martin), to water deficit stress at three development stages (tillering, stem elongation, and heading) by measuring water status and grain yield components in a field experiment in Tunisia. The three stages were selected due to their importance in crop growth and grain development. Water deficit stress was initiated by withholding water for 21 days at the three stages with subsequent re-watering. Water deficit led to a progressive decrease in leaf water potential. In both varieties, heading was the stage most sensitive to water deficit. Leaf water potential measurements indicated that water deficit stress was more severe during heading, which to some extent may have influenced the comparison between growth stages. During heading, the number of ears per plant and weight of a thousand grains were reduced by more than 70% and 50%, respectively compared with stress at tillering. Comparison of yield components showed differences between the two barley varieties only when the water deficit was produced during the tillering stage.

Download Full-text

Carbon dioxide enrichment and water stress interaction on growth of two tomato cultivars

The Journal of Agricultural Science ◽

10.1017/s0021859600042246 ◽

1984 ◽

Vol 102 (3) ◽

pp. 687-693 ◽

Cited By ~ 26

Author(s):

Alejandra Paez ◽

H. Hellmers ◽

B. R. Strain

Keyword(s):

Carbon Dioxide ◽

Water Stress ◽

Plant Growth ◽

Water Potential ◽

Leaf Water Potential ◽

Osmotic Potential ◽

Water Status ◽

Carbon Dioxide Concentration ◽

Leaf Water ◽

Total Leaf

SummaryIf atmospheric carbon dioxide concentration continues to increase, plant growth and crop yield could be affected. New Yorker and Better Boy cultivars of tomato (Lycopersicon esculentum) were used to investigate possible intraspecific variation in the response of crop species to increased CO2. Because precipitation and temperature are predicted to change with the increasing atmospheric CO2 concentration, the response of the two cultivars to the interaction between CO2 and water stress was also examined. Seeds of the two cultivars were germinated and grown under controlled environmental conditions, in either 350 or 675 μ1 CO2/1.The plant water status of the two cultivars was inherently different but was little affected by the CO2 concentration when the plants were well watered. When water was withheld for 5 days the total leaf water potential and osmotic potential decreased in both CO2 treatments but less rapidly in high CO2 than in low. Under low CO2 total leaf water potential decreased to a lower value than osmotic potential. The differences were due, at least in part, to the reduced stomatal conductance and transpiration rate under high CO2.Increased CO2 ameliorated the detrimental effects of drought stress on plant growth. The results indicate that increased CO2 could differentially affect the relative drought resistance of species cultivars.

Download Full-text

Effects of Waterlogging at Vegetative and Reproductive Growth Stages on Photosynthesis, Leaf Water Potential and Yield in Mungbean

Plant Production Science ◽

10.1626/pps.5.117 ◽

2002 ◽

Vol 5 (2) ◽

pp. 117-123 ◽

Cited By ~ 17

Author(s):

Selina Ahmed ◽

Eiji Nawata ◽

Tetsuo Sakuratani

Keyword(s):

Water Potential ◽

Leaf Water Potential ◽

Leaf Water ◽

Growth Stages ◽

Reproductive Growth ◽

Vegetative And Reproductive Growth

Download Full-text

Carbon dioxide enrichment restrains the impact of drought on three maize hybrids differing in water stress tolerance in water stressed environments

International Journal of Plant Biology ◽

10.4081/pb.2014.5535 ◽

2014 ◽

Vol 5 (1) ◽

Cited By ~ 2

Author(s):

Jinyoung Yang ◽

Richard C. Sicher ◽

Moon S. Kim ◽

Vangimalla R. Reddy

Keyword(s):

Carbon Dioxide ◽

Water Stress ◽

Amino Acid ◽

Water Potential ◽

Stress Tolerance ◽

Leaf Water Potential ◽

Leaf Water ◽

Genotypic Differences ◽

Maize Hybrid ◽

The Impact

Three maize genotypes were grown in controlled environment chambers with ambient (38 Pa) or elevated (70 Pa) carbon dioxide and water stress treatments were initiated 17 days after sowing. Shoot dry weight of the drought tolerant hybrid in both CO2 treatments was 44 to 73% less than that of the intermediate and sensitive hybrids when seedlings were well watered. Decreased shoot and root dry weights of the tolerant maize hybrid due to drought were about one-half that of the other two hybrids. Genotypic differences were observed in decreases of soil water content, leaf water potential, net photosynthesis and stomatal conductance in response to drought. Eleven of 19 amino acids measured in this study increased, methionine was unchanged and alanine and aspartate decreased in response to drought in the ambient CO2 treatment. Increased amino acid levels under elevated CO2 were observed at the end of the experiment. Significant genotypic differences were detected for amino acid responses to drought. Effects of drought on all three genotypes were mitigated by CO2 enrichment. Decreased shoot growth likely improved the stress tolerance of a highly drought resistant maize hybrid by reducing moisture loss, improving soil moisture content and increasing leaf water potential.

Download Full-text

Effect of Water Deficit on Carbon Dioxide Exchange and Leaf Elongation Rate of Panicum maximum Var. trichoglume

Functional Plant Biology ◽

10.1071/pp9760401 ◽

1976 ◽

Vol 3 (3) ◽

pp. 401 ◽

Cited By ~ 16

Author(s):

MM Ludlow ◽

TT Ng

Keyword(s):

Carbon Dioxide ◽

Water Potential ◽

Leaf Water Potential ◽

Net Photosynthesis ◽

Stomatal Resistance ◽

Leaf Water ◽

Carbon Dioxide Exchange ◽

Leaf Elongation ◽

Water Deficits ◽

Water Potentials

The responses of carbon dioxide exchange and leaf elongation of potted P. maximum var. trichoglume plants to water deficits were investigated in controlled environments and outdoors during drying cycles down to -92 bars leaf water potential, The sensitivities of net photosynthesis and leaf elongation to water deficits were similar. The leaf water potentials at which net photosynthesis and elongation ceased (c. -12 bars), and stomatal resistance increased substantially (- 6 bars), were relatively unaffected by nitrogen supply, environmental conditions during growth, and whether plants had previously experienced stress. However, these factors influenced the rate of net photosynthesis, at high leaf water potentials by affecting stomatal resistance and at moderate water potentials by affecting both stomatal and intracellular resistances. Stomata1 resistance was more sensitive than intracellular resistance to water deficits. Dark respiration rate decreased with leaf water potential, and was higher in plants receiving additional nitrogen. At moderate leaf water potentials (-7 to -9 bars), net photosynthesis of this C4 grass exhibited light saturation and rates similar to C3 plants. We suggest that the difference in behaviour of controlled-environment-grown and field-grown plants to water deficits observed with some species is unlikely to be due to differences in the aerial environment, but may result from differences in the rate at which stress develops. The ecological significance and evolution of the C4 syndrome are discussed briefly.

Download Full-text