Significant relationships among frost tolerance and net photosynthetic rate, water use efficiency and dehydrin accumulation in cold-treated winter oilseed rapes

2013 ◽  
Vol 170 (18) ◽  
pp. 1600-1608 ◽  
Author(s):  
Milan Oldřich Urban ◽  
Miroslav Klíma ◽  
Pavel Vítámvás ◽  
Jakub Vašek ◽  
Alois Albert Hilgert-Delgado ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Net Photosynthetic Rate ◽  
Water Use ◽  
Photosynthetic Rate ◽  
Frost Tolerance ◽  
Significant Relationships ◽  
Use Efficiency

Diurnal Variation of Instantaneous CO2 and H2O Gas-Exchange over Canopy and Leaf Level of Spring Maize in Arid Area

2013 ◽  
Vol 807-809 ◽  
pp. 1829-1838 ◽  
Author(s):  
Jia Xuan Guo ◽  
Xu Rong Mei ◽  
Yu Zhong Li
Keyword(s):  
Water Stress ◽  
Water Use Efficiency ◽  
Net Photosynthetic Rate ◽  
Water Use ◽  
Photosynthetic Rate ◽  
Arid Area ◽  
Theory And Practice ◽  
Filling Stage ◽  
Leaf Level ◽  
Use Efficiency

Information on the relationship between crop photosynthetic rate and water use efficiency at the leaf level and these at the canopy level is important on the study of theory and practice of high efficiency and water-saving agriculture. We simultaneous made instantaneous CO2 and H2O exchange rate, and instantaneous water use efficiency measurement at both leaf and canopy level in a rain-fed cropping system with spring corn during filling stage by Li-6400 infrared gas analysis meter and eddy correlation system. The results showed that in arid area water stress was the mainly factor influencing the net photosynthesis rate and water use efficiency. At the diurnal course, when soil relative moisture was about 40% at 0-100 cm soil layer, the maximum of net photosynthetic rate at leaf level occurred at about 10:00 under soil water stress, and at about 12:00 at canopy level on sunny days, the maximum leaf photosynthetic rate reached 1.3 mgm-2s-1 , almost close to those of irrigation corn at similar latitude area, and the maximum canopy assimilation rate were 0.9 mgm-2s-1 , reached 54.5% of those of irrigation corn at similar latitude area during filling stage, respectively;The maximum values of instantaneous water use efficiency at leaf and canopy level were 0.16 g (CO2)/ g (H2O) and 0.06 g (CO2)/ g (H2O), and ranged between 0.0055g (CO2)/ g (H2O) and 0.0123 g (CO2)/ g (H2O), 0.0113 g (CO2)/ g (H2O) and 0.0197 g (CO2)/ g (H2O) around noon, respectively. Instantaneous net photosynthetic rate and water use efficiency at leaf level were higher than those at canopy level after 10:00.

scholarly journals Characterization of coffee cultivars leaf rust-resistant subjected to framework pruning

2018 ◽  
Vol 13 (1) ◽  
pp. 63 ◽  
Author(s):  
Estevam Antonio Chagas Reis ◽  
Tainah Freitas ◽  
Milene Alves de Figueiredo Carvalho ◽  
Antônio Nazareno Guimarães Mendes ◽  
Tiago Teruel Rezende ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Net Photosynthetic Rate ◽  
Leaf Rust ◽  
Water Use ◽  
Photosynthetic Rate ◽  
Transpiration Rate ◽  
Agronomic Traits ◽  
High Yield ◽  
Area Index ◽  
Use Efficiency

The goal of our work was to evaluate physiological and agronomic traits, as well as the relationship between these traits in coffee cultivars coming from a germplasm supposedly resistant to leaf rust, and their response to framework pruning. The experiment was conducted at the Federal University of Lavras in randomized blocks with three replicates, with spacing of 3.5 x 0.7 m and plots of 12 plants. An amount of 25 coffee cultivars was evaluated, from which 23 were considered resistant and two susceptible to leaf rust. Traits analyzed were the plagiotropic branch length and number of nodes, net photosynthetic rate, transpiration rate, water use efficiency, fluorescence and chlorophyll index, leaf area index, leaf rust incidence and yield. Catucaí Amarelo 20/15 cv 479, Araponga MG1 and Tupi IAC 1669-33 cultivars show highly responsive to framework pruning. These cultivars have high yield associated to high net photosynthetic rate, water use efficiency and low transpiration rate. Moreover, the last two cultivars show a low incidence of leaf rust. The Acauã cultivar has a good response to framework pruning, showing high yield associated to lower incidence of leaf rust. Catucaí Vermelho 785/15 cultivar is not responsive to framework pruning because show lower yield, high incidence of leaf rust, low vegetative growth and low water use efficiency.

Comparison of Desert-Adapted Helianthus niveus (Benth.) Brandegee ssp. tephrodes (A. Gray) Heiser to Cultivated H. annuus L. for Putative Drought Avoidance Traits at Two Ontogenetic Stages

Helia ◽  
2016 ◽  
Vol 39 (64) ◽  
pp. 1-19 ◽  
Author(s):  
Alan W. Bowsher ◽  
Ethan F. Milton ◽  
Lisa A. Donovan
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Photosynthetic Rate ◽  
Nitrogen Concentration ◽  
Carbon Isotope Ratio ◽  
Leaf Traits ◽  
Rooting Depth ◽  
Mature Stage ◽  
Leaf Pubescence ◽  
Use Efficiency

AbstractWater availability is a major factor limiting plant productivity in both natural and agronomic systems. Identifying putative drought resistance traits in crops and their wild relatives may be useful for improving crops grown under water-limiting conditions. Here, we tested the expectation that a desert-dwelling sunflower species, Helianthus niveus ssp. tephrodes (TEPH) would exhibit root and leaf traits consistent with greater ability to avoid drought than cultivated sunflower H. annuus (ANN) in a common garden environment. We compared TEPH and ANN at both the seedling and mature stages under well-watered greenhouse conditions. For traits assessed at the seedling stage, TEPH required a longer time to reach a rooting depth of 30 cm than ANN, and the two species did not differ in root:total biomass ratio at 30 cm rooting depth, contrary to expectations. For traits assessed at the mature stage, TEPH had a higher instantaneous water use efficiency and photosynthetic rate on a leaf area basis, but a lower photosynthetic rate on a mass basis than ANN, likely due to TEPH having thicker, denser leaves. Contrary to expectations, ANN and TEPH did not differ in leaf instantaneous stomatal conductance, integrated water-use efficiency estimated from carbon isotope ratio, or nitrogen concentration. However, at both the seedling and mature stages, TEPH exhibited a lower normalized difference vegetative index than ANN, likely due to the presence of dense leaf pubescence that could reduce heat load and transpirational water loss under drought conditions. Thus, although TEPH root growth and biomass allocation traits under well-watered conditions do not appear to be promising for improvement of cultivated sunflower, TEPH leaf pubescence may be promising for breeding for drought-prone, high radiation environments.

scholarly journals High photosynthetic rate and water use efficiency ofMiscanthus lutarioripariuscharacterize an energy crop in the semiarid temperate region

GCB Bioenergy ◽  
2014 ◽  
Vol 7 (2) ◽  
pp. 207-218 ◽  
Author(s):  
Juan Yan ◽  
Caiyun Zhu ◽  
Wei Liu ◽  
Fan Luo ◽  
Jia Mi ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Photosynthetic Rate ◽  
Energy Crop ◽  
Temperate Region ◽  
Use Efficiency

Variation in mesophyll conductance among Australian wheat genotypes

2014 ◽  
Vol 41 (6) ◽  
pp. 568 ◽  
Author(s):  
Eisrat Jahan ◽  
Jeffrey S. Amthor ◽  
Graham D. Farquhar ◽  
Richard Trethowan ◽  
Margaret M. Barbour
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Photosynthetic Rate ◽  
Genotypic Variation ◽  
Leaf Age ◽  
Triticum Aestivum L ◽  
Mesophyll Conductance ◽  
Wheat Genotypes ◽  
Intrinsic Water Use Efficiency ◽  
Use Efficiency

CO2 diffusion from substomatal intercellular cavities to sites of carboxylation in chloroplasts (mesophyll conductance; gm) limits photosynthetic rate and influences leaf intrinsic water-use efficiency (A/gsw). We investigated genotypic variability of gm and effects of gm on A/gsw among eleven wheat (Triticum aestivum L.) genotypes under light-saturated conditions and at either 2 or 21% O2. Significant variation in gm and A/gsw was found between genotypes at both O2 concentrations, but there was no significant effect of O2 concentration on gm. Further, gm was correlated with photosynthetic rate among the 11 genotypes, but was unrelated to stomatal conductance. The effect of leaf age differed between genotypes, with gm being lower in older leaves for one genotype but not another. This study demonstrates a high level of variation in gm between wheat genotypes; 0.5 to 1.0 μmol m−2 s−1 bar−1. Further, leaf age effects indicate that great care must be taken to choose suitable leaves in studies of genotypic variation in gm and water-use efficiency.

scholarly journals Effect of Microsprinkler Irrigation under Plastic Film on Photosynthesis and Fruit Yield of Greenhouse Tomato

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Mingzhi Zhang ◽  
Zhenguang Lu ◽  
Qingjun Bai ◽  
Yushun Zhang ◽  
Xinqiang Qiu ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Photosynthetic Rate ◽  
Dry Matter ◽  
Photosynthetic Characteristics ◽  
Fruit Yield ◽  
Dry Matter Accumulation ◽  
Plastic Film ◽  
Greenhouse Tomato ◽  
Use Efficiency

The aim of this study is to exam the effect of microsprinkler irrigation technology under plastic film (MSPF) and to evaluate the reasonable micropore group spacing and capillary arrangement density in the greenhouse. Compared with drip irrigation under plastic film (DIPF) and microsprinkling irrigation (MSI) conditions, the effects of different micropore group spacing (L1: 30 cm micropore group spacing, L2: 50 cm micropore group spacing) and capillary arrangement density (C1: one pipe for one row, C2: one pipe for two rows, and C3: one pipe for three rows) with the MSPF on photosynthetic characteristics and fruit yield of tomatoes were studied using completely randomized trial design. The results showed that under the same irrigation amount, compared with DIPF and MSI, the photosynthetic rate of tomatoes treated with L1C2 increased by 8.24% and 13.55%, respectively. The total dry matter accumulation, yield, and water use efficiency at condition of L1C2 increased by 12.16%, 19.39%, and 10.03% compared with DIPF and 26.38%, 20.46%, and 31.02% compared with MSI, respectively. The results provide evidence that the MSPF can be applied to greenhouse tomatoes. The photosynthetic rate, total dry matter accumulation, yield, and water use efficiency of tomato leaves cultivated at a micropore group spacing of 30 cm were 1.07, 1.13, 1.14, and 1.13 times higher than those of 50 cm, respectively. With the decrease in capillary arrangement density, the photosynthetic characteristics of the tomato leaves, the total dry matter accumulation, and yield of tomatoes all experienced a decline. It is recommended to use a combination of one pipe for two rows of capillaries at a 30 cm micropore group spacing as the technical parameter of greenhouse tomato with MSPF in arid and semiarid sandy loam soils.

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