scholarly journals Effects of shading on the growth, development and yield of winged bean (Psophocarpus tetragonolobus)

2020 ◽  
Vol 50 (2) ◽  
Author(s):  
Murthazar Naim Raai ◽  
Nurul Amalina Mohd Zain ◽  
Normaniza Osman ◽  
Nur Ardiyana Rejab ◽  
Nurul Amylia Sahruzaini ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Physiological Responses ◽  
Canopy Cover ◽  
Winged Bean ◽  
Psophocarpus Tetragonolobus ◽  
Photosynthetic Gas Exchange ◽  
Growth Development ◽  
The Tropics ◽  
Protein Rich

ABSTRACT: An experiment was conducted to investigate the effects of different shading regimes [i.e., 60% (heavy), 30% (moderate), and 0% (control)] on 25 traits associated with the morphological features, photosynthetic gas exchange and agronomic characteristics of winged bean (Psophocarpus tetragonolobus), an underutilized protein-rich legume from the tropics. Collectively, 80% of the studied variables displayed significant differences (P<0.05) between at least two shade treatments. Shading generally showed most pronounced effect on the physiological traits of the legume, whereby the stomatal conductance, photosynthetic and transpiration rate differed significantly among plants for all treatments. The non-shaded plants were observed to have superior growth and physiological responses than the shaded plants. Interestingly, the moderately shaded plants exhibited the highest yield per plant, which significantly differed from the non-shaded and heavily shaded plants. This indicated that winged bean can adapt to partial canopy cover, making it a potential nitrogen-fixing cash crop which can be planted together with fruit or oil trees in commercial plantations.

scholarly journals Where in the leaf is intercellular CO2 (Ci)? Considerations and recommendations for assessing gaseous diffusion in leaves

2020 ◽  
Author(s):  
Joseph R. Stinziano ◽  
Jun Tominaga ◽  
David T. Hanson
Keyword(s):  
Water Vapor ◽  
High Temperature ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Water Loss ◽  
Leaf Water ◽  
Marginal Effect ◽  
Photosynthetic Gas Exchange ◽  
Gaseous Diffusion ◽  
Intercellular Co2

AbstractThe assumptions that water vapor exchange occurs exclusively through stomata, that the intercellular airspace is fully saturated with water vapor, and that CO2 gradients are negligible between stomata and the intercellular airspace have enabled significant advancements in photosynthetic gas exchange research for nearly 60 years via calculation of intercellular CO2 (Ci). However, available evidence suggests that these assumptions may be overused. Here we review the literature surrounding evidence for and against the assumptions made by Moss & Rawlins (1963). We reinterpret data from the literature by propagating different rates of cuticular water loss, CO2 gradients, and unsaturation through the data. We find that in general, when cuticle conductance is less than 1% of stomatal conductance, the assumption that water vapor exchange occurs exclusively through stomata has a marginal effect on gas exchange calculations, but this is not true when cuticle conductance exceeds 5% of stomatal conductance. Our analyses further suggest that CO2 and water vapor gradients have stronger impacts at higher stomatal conductance, while cuticle conductance has a greater impact at lower stomatal conductance. Therefore, we recommend directly measuring Ci whenever possible, measuring apoplastic water potentials to estimate humidity inside the leaf, and exercising caution when interpreting data under conditions of high temperature and/or low stomatal conductance, and when a species is known to have high cuticular conductance.HighlightLeaf water vapor and CO2 exchange have been successfully used to model photosynthetic biochemistry. We review critical assumptions in these models and make recommendations about which need to be re-assessed.

Giant cacti: isotopic recorders of climate variation in warm deserts of the Americas

2019 ◽  
Vol 70 (22) ◽  
pp. 6509-6519 ◽  
Author(s):  
Kevin R Hultine ◽  
David L Dettman ◽  
Nathan B English ◽  
David G Williams
Keyword(s):  
Stomatal Conductance ◽  
Stable Isotope ◽  
Gas Exchange ◽  
Spatial Patterns ◽  
Atmospheric Co2 ◽  
Stable Isotope Ratios ◽  
Photosynthetic Gas Exchange ◽  
Temporal And Spatial Patterns ◽  
Partial Pressures ◽  
Temporal And Spatial

Stable isotope ratios captured in spine tissues potentially reflect temporal and spatial patterns of stomatal conductance, internal to atmospheric CO2 partial pressures, and subsequent patterns of photosynthetic gas exchange.

Effect of EMS and SA on seed germination percentage in M1 generation of Psophocarpus tetragonolobus (L.) Dc.

2016 ◽  
Vol 5 (11) ◽  
pp. 5056
Author(s):  
A. S. Sonavane
Keyword(s):  
Seed Germination ◽  
Oil Content ◽  
Germination Percentage ◽  
Mutation Breeding ◽  
Antinutritional Factors ◽  
Winged Bean ◽  
Present Level ◽  
Psophocarpus Tetragonolobus ◽  
Legume Crop ◽  
The Tropics

In the present investigation, the two chemical mutagens namely Ethyl methanesulfonate (EMS) and Sodium azide (SA) were used to induce mutations in winged bean (Psophocarpus tetragonolobus (L.) DC.). Winged bean is a potential legume crop of the tropics with high protein and oil content in the seeds. For larger scale cultivation however, the major drawbacks possessed by winged bean should be minimized. The drawbacks such as presence of undesirable antinutritional factors, absence of market demands and labour intensive nature of crop.Hence its production and productivity need to be improved from the present level. A mutation breeding programme was undertaken with the objective of developing improved varieties of winged bean so that it can be popularized among the farmers for its cultivation over large areas. Thus in the present studies, attempts have been made to induce mutations in winged bean and to find out the effect of EMS and SA on seed germination percentage in M1 generation.

scholarly journals Ecophysiology ofpotentilla gracilisdouglas ex hook (rosaceae): effects of night temperature and water stress on photosynthetic gas exchange

2019 ◽  
Author(s):  
Madhav P. Nepal ◽  
Virginia S. Berg
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Light Intensity ◽  
Light Response ◽  
Growing Season ◽  
Night Temperature ◽  
Response Curves ◽  
Photosynthetic Gas Exchange ◽  
Light Response Curves

ABSTRACTPlants in stressful environments have evolved strategies to cope with fluctuating environmental conditions.Potentilla gracilis, also known as Alpine Cinquefoil, grows in alpine meadows of the Rocky Mountains (USA), and is subjected to wide ranges of temperature, light intensity and water availability on a time scale of minutes to days during the growing season. Leaves often freeze to a brittle state at night, are exposed to high radiation while still frosty, dehydrate to wilting during the following light period, and then repeat the cycle the following day. The main objective of this research was to determine the effect of night temperature on subsequent photosynthetic gas exchange inP. gracilis. We used a photosynthetic gas exchange system to compare assimilation and stomatal conductance from light response curves of cold-acclimatedP. gracilisfollowing warm and chilling nights, and for plants at different water potentials. From the light response curves, dark respiration, light compensation point, maximum assimilation, light saturation point, and inhibition of photosynthesis were determined and were compared among the same plants under varying conditions. Assimilation and stomatal conductance decreased with the fall in measurement temperature, following chilling nights, and with the severity of water stress. Low night temperature and high photon flux density during the daytime, which are very common during the growing season in the field, cause a reduction in photosynthesis of the plant. The probable underlying damage during inhibition is likely repairable indicating protection rather than damage. The cold nocturnal temperature, with its less efficient biochemical repair capabilities, may partly be responsible for the reduction in assimilation of the following day.P. gracilisspecies exhibited persistent acquired freezing tolerance; substantial photosynthetic productivity over a wide range of light intensity and temperature; and significant tolerance of, and rapid recovery from, severe drought; making a maximum use of often challenging resources.

Yield Stability Analysis in An Underutilized Legume ‘Winged Bean’ (Psophocarpus tetragonolobus L.)

2020 ◽  
Author(s):  
Jitendra Kumar Tiwari ◽  
Raja Ram Kanwar ◽  
Rajendra Kumar Yadav ◽  
Anil Kumar Singh
Keyword(s):  
Graphical Analysis ◽  
Yield Stability ◽  
Winged Bean ◽  
Environment Interaction ◽  
Gge Biplot ◽  
Psophocarpus Tetragonolobus ◽  
Test Environment ◽  
Commercial Cultivation ◽  
Improvement Programs ◽  
The Tropics

Background: Winged bean [Psophocarpus tetragonolobus (L.) DC] is a protein rich, underexploited leguminous vegetable of the tropics. It grows abundantly in hot and humid environments. The present investigation applied AMMI and GGE biplot techniques to study the patterns of GEI in 05 winged bean genotypes, to find high yielding and most stable genotype(s) suited to Chhattisgarh state of India. Methods: An experiment was carried out to ascertain the Gene × Environment interaction (GEI), yield stability and adaptability of 05 winged bean (Psophocarpus tetragonolobus L.) genotypes in Chhattisgarh India by using AMMI and GGE biplot models. Result: First and second component of AMMI model explained more than 84.10% of GEI variation. Genotype ‘AKWB-1’ exhibited maximum trait value with specific adaptation while genotypes ‘RMDWB-1’ and ‘Ambika 11-3’ showed general adoptability. GGE biplot model explained that genotypes ‘RMDWB-1’ and ‘AKWB-1’ were the best performers in all the environments excluding E4, while ‘Ambika 11-3’ was the best performer at location E4 regarding the graphical analysis models of AMMI and GGE biplot. Winged bean genotype ‘AKWB-1’ was the most stable genotype in all the test environment in terms of mean yield and it would be recommended for commercial cultivation in Chhattisgarh state. Other high yielding and stable genotypes i.e., RMDWB-1 and Ambika 11-3 can also be used as parents in winged bean improvement programs.

Leaf-scale quantification of the effect of photosynthetic gas exchange on Δ17O of atmospheric CO2

2020 ◽  
Author(s):  
Getachew Adnew ◽  
Thijs Pons ◽  
Gerbrand Koren ◽  
Wouter Peters ◽  
Thomas Röckmann
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Photosynthetic Capacity ◽  
Isotope Composition ◽  
Diffusion Flux ◽  
Relative Difference ◽  
Leaf Water ◽  
Back Diffusion ◽  
Photosynthetic Gas Exchange ◽  
High Photosynthetic Capacity

&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Understanding the processes affecting the triple oxygen isotope composition of atmospheric CO&lt;sub&gt;2&lt;/sub&gt; during photosynthesis can help to constrain the interaction and fluxes between the atmosphere and the biosphere. We conducted leaf cuvette experiments under controlled conditions, using sunflower (&lt;em&gt;Helianthus annuus&lt;/em&gt;), an annual C&lt;sub&gt;3&lt;/sub&gt; species with high photosynthetic capacity and stomatal conductance for CO&lt;sub&gt;2&lt;/sub&gt;, an evergreen C&lt;sub&gt;3&lt;/sub&gt; species, ivy (&lt;em&gt;Hedera hybernica&lt;/em&gt;) with lower values for these traits, and a C&lt;sub&gt;4&lt;/sub&gt; species maize (&lt;em&gt;Zea mays)&lt;/em&gt; that has a high photosynthetic capacity and low stomatal conductance. The experiments were conducted at different light intensities and using CO&lt;sub&gt;2&lt;/sub&gt; with different &lt;sup&gt;17&lt;/sup&gt;O- excess. Our results demonstrate that two key factors determine the effect of photosynthetic gas exchange on &amp;#916;&lt;sup&gt;17&lt;/sup&gt;O of atmospheric CO&lt;sub&gt;2&lt;/sub&gt;: The relative difference in &amp;#916;&lt;sup&gt;17&lt;/sup&gt;O of the CO&lt;sub&gt;2&lt;/sub&gt; entering the leaf and &amp;#916;&lt;sup&gt;17&lt;/sup&gt;O of leaf water, and the back-diffusion flux from the leaf to the atmosphere, which can be quantified by the c&lt;sub&gt;m&lt;/sub&gt;/c&lt;sub&gt;a&lt;/sub&gt; ratio.&amp;#160; At low c&lt;sub&gt;m&lt;/sub&gt;/c&lt;sub&gt;a&lt;/sub&gt; the discrimination is governed by diffusion into the leaf, and at high c&lt;sub&gt;m&lt;/sub&gt;/c&lt;sub&gt;a&lt;/sub&gt; by back-diffusion of CO&lt;sub&gt;2&lt;/sub&gt; that has equilibrated with the leaf water. Plants with a higher c&lt;sub&gt;m&lt;/sub&gt;/c&lt;sub&gt;a&lt;/sub&gt; ratio modify the &amp;#916;&lt;sup&gt;17&lt;/sup&gt;O of atmospheric CO&lt;sub&gt;2&lt;/sub&gt; more strongly than plants with lower c&lt;sub&gt;m&lt;/sub&gt;/c&lt;sub&gt;a&lt;/sub&gt;.&amp;#160;&lt;/p&gt;&lt;p&gt;Based on the leaf cuvette experiments using both C&lt;sub&gt;4&lt;/sub&gt; and C&lt;sub&gt;3&lt;/sub&gt; plants, the global discrimination in &lt;sup&gt;17&lt;/sup&gt;O-excess of atmospheric CO&lt;sub&gt;2&lt;/sub&gt; due to assimilation is estimated to be -0.6&amp;#177;0.2&amp;#8240;. The main uncertainty in the global estimation is due to the uncertainty in the c&lt;sub&gt;m&lt;/sub&gt;/c&lt;sub&gt;a&lt;/sub&gt; ratio.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

Effect of Mycorrhizal Fungi on Gas Exchange of Micropropagated Guava Plantlets (Psidium guajava L.) during Acclimatization and Plant Establishment

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 501c-501
Author(s):  
Andrés A. Estrada-Luna ◽  
Jonathan N. Egilla ◽  
Fred T. Davies
Keyword(s):  
Tissue Culture ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Vapor Pressure ◽  
Mycorrhizal Fungi ◽  
Vapor Pressure Deficit ◽  
Psidium Guajava ◽  
Glomus Etunicatum ◽  
Plant Establishment ◽  
Use Efficiency

The effect of mycorrhizal fungi on gas exchange of micropropagated guava plantlets (Psidium guajava L.) during acclimatization and plant establishment was determined. Guava plantlets (Psidium guajava L. cv. `Media China') were asexually propagated through tissue culture and acclimatized in a glasshouse for eighteen weeks. Half of the plantlets were inoculated with ZAC-19, which is a mixed isolate containing Glomus etunicatum and an unknown Glomus spp. Plantlets were fertilized with modified Long Ashton nutrient solution containing 11 (g P/ml. Gas exchange measurements included photosynthetic rate (A), stomatal conductance (gs), internal CO2 concentration (Ci), transpiration rate (E), water use efficiency (WUE), and vapor pressure deficit (VPD). Measurements were taken at 2, 4, 8 and 18 weeks after inoculation using a LI-6200 portable photosynthesis system (LI-COR Inc. Lincoln, Neb., USA). Two weeks after inoculation, noninoculated plantlets had greater A compared to mycorrhizal plantlets. However, 4 and 8 weeks after inoculation, mycorrhizal plantlets had greater A, gs, Ci and WUE. At the end of the experiment gas exchange was comparable between noninoculated and mycorrhizal plantlets.

The Effects of Drought on Leaf Gas Exchange and Growth of Three Species of Herbaceous Perennials

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 540a-540
Author(s):  
K.J. Prevete ◽  
R.T. Fernandez
Keyword(s):  
Drought Stress ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Drought Tolerance ◽  
Transpiration Rate ◽  
Leaf Gas Exchange ◽  
Gas Analysis ◽  
Herbaceous Perennials ◽  
Effects Of Drought ◽  
Analysis System

Three species of herbaceous perennials were tested on their ability to withstand and recover from drought stress periods of 2, 4, and 6 days. Eupatorium rugosum and Boltonia asteroides `Snowbank' were chosen because of their reported drought intolerance, while Rudbeckia triloba was chosen based on its reported drought tolerance. Drought stress began on 19 Sept. 1997. Plants were transplanted into the field the day following the end of each stress period. The effects of drought on transpiration rate, stomatal conductance, and net photosynthetic rate were measured during the stress and throughout recovery using an infrared gas analysis system. Leaf gas exchange measurements were taken through recovery until there were no differences between the stressed plants and the control plants. Transpiration, stomatal conductance, and photosynthesis of Rudbeckia and Boltonia were not affected until 4 days after the start of stress. Transpiration of Eupatorium decreased after 3 days of stress. After rewatering, leaf gas exchange of Boltonia and Rudbeckia returned to non-stressed levels quicker than Eupatorium. Growth measurements were taken every other day during stress, and then weekly following transplanting. Measurements were taken until a killing frost that occurred on 3 Nov. There were no differences in the growth between the stressed and non-stressed plants in any of the species. Plants will be monitored throughout the winter, spring, and summer to determine the effects of drought on overwintering capability and regrowth.

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