Photosynthetic Response to Light and Nutrients in Sun-Tolerant and Shade-Tolerant Rainforest Trees. II. Leaf Gas Exchange and Component Processes of Photosynthesis

1992 ◽  
Vol 19 (1) ◽  
pp. 19 ◽  
Author(s):  
WA Thompson ◽  
LK Huang ◽  
PE Kriedemann

Species with contrasting shade tolerance were grown under three light by two nutrient treatments. Gas exchange by intact leaves, leaf disk O2 evolution and chlorophyll fluorescence were measured. In shade-tolerant evergreen species (Argyrodendron sp., A. trifoliolatum and Flindersia brayleyana) photosynthetic activity of seedlings in air at light saturation (A) was lower under weak (30 pmol quanta m-2 day-1 ), compared with medium (130) or strong light (535). In Toona australis, a shade-intolerant and deciduous tree, A was reduced 44% from strong to weak light treatment on high nutrients (71 mg N L-1 nutrient solution). Nevertheless, nitrogen-use efficiency for leaf photosynthesis was highest in Toona under all growing conditions and, with higher specific leaf area, probably contributes towards fast occupancy of sites which underlies early succession in this species. All species made photosynthetic and respiratory adjustments from strong to medium to weak light, which resulted in a lower light compensation point (Q0). Such adjustments were accentuated by low nutrient supply (1.0 mg N L-1 nutrient solution) and were especially pronounced for shade-intolerant Toona. Reduced Q0 in Toona was accompanied by lower A and light saturation point (QA). Both species of Argyrodendron showed no decrease in QA despite reduction in Q0 under weak light.Contrary to expectation, photosynthetic responses to light × nutrient treatments did not correlate with degree of shade tolerance accorded each species by rainforest ecologists.

HortScience ◽  
2014 ◽  
Vol 49 (7) ◽  
pp. 901-904 ◽  
Author(s):  
Carolina Aparicio ◽  
Miguel Urrestarazu ◽  
María del Pilar Cordovilla

Changes caused by NaCl salinity on growth, gas exchange, chemical composition, and oxidative stress symptoms have been measured in six olive (Olea europaea L.) cultivars (Casta Cabra, Cornicabra, Frantoio, Ocal, Picual, and Picudo) grown in nutrient solution in a growth chamber pot experiment. Six-month-old plants were transplanted to a sand–perlite culture and irrigated with half-strength Hoagland nutrient solution containing 0 and 200 mm NaCl for 12 weeks. Salinity significantly depressed growth and leaf gas exchange, but to a different degree in each cultivar, Picudo was the cultivar that showed less growth inhibition. The effectiveness of Na+ exclusion mechanism in the roots differed significantly among studied cultivars, working effectively in ‘Ocal’ and ‘Picudo’ and being less efficient in ‘Picual’. Furthermore, ‘Picudo’ showed the ability to maintain the concentration of leaf K+ under the stress condition. ‘Ocal’ accumulated phenolic compounds and did not reduce carotenoid or total thiol concentration under saline stress. Between the cultivars studied, ‘Picudo’ and ‘Ocal’ were the most tolerant.


HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 622-627 ◽  
Author(s):  
Guiseppe Colla ◽  
Youssef Roupahel ◽  
Mariateresa Cardarelli ◽  
Elvira Rea

A greenhouse experiment was carried out to determine growth, yield, fruit quality, gas exchange and mineral composition of watermelon plants (Citrullus Lanatus L. `Tex'), either ungrafted or grafted onto two commercial rootstocks `Macis' [Lagenaria siceraria (Mol.) Standl.] and `Ercole' (Cucurbita maxima Duchesne × Cucurbita moschata Duchesne) and cultured in NFT. Plants were supplied with a nutrient solution having an electrical conductivity (EC) of 2.0 or 5.2 dS·m–1. The saline nutrient solution had the same basic composition, plus an additional of 29 mm of NaCl. Increased salinity in the nutrient solution decreased total yield. The reduction in total yield in saline treatments compared to control was due to a reduction in the fruit mean mass and not to the number of fruit per plant. Total fruit yield was 81% higher in grafted than in ungrafted plants. The lowest marketable yield recorded on ungrafted plants was associated with a reduction in both fruit mean mass and the number of fruits per plant in comparison to grafted plants. Salinity improved fruit quality in all grafting combinations by increasing dry matter (DM), glucose, fructose, sucrose, and total soluble solid (TSS) content. Nutritional qualities of grafted watermelons such as fruit DM, glucose, fructose, sucrose, and TSS content were similar in comparison to those of ungrafted plant. In all grafting combinations, negative correlations were recorded between Na+ and Cl– in the leaf tissue and net assimilation of CO2 Grafting reduced concentrations of sodium, but not chloride, in leaves. However, the sensitivity to salinity was similar between grafted and ungrafted plants and the higher total yield from grafting plants was mainly due to grafting per se.


1999 ◽  
Vol 124 (1) ◽  
pp. 46-51 ◽  
Author(s):  
Anthony W. Whiley ◽  
Christopher Searle ◽  
Bruce Schaffer ◽  
B. Nigel Wolstenholme

Leaf gas exchange of avocado (Persea americana Mill.) and mango (Mangifera indica L.) trees in containers and in an orchard (field-grown trees) was measured over a range of photosynthetic photon fluxes (PPF) and ambient CO2 concentrations (Ca). Net CO2 assimilation (A) and intercellular partial pressure of CO2 (Ci) were determined for all trees in early autumn (noncold-stressed leaves) when minimum daily temperatures were ≥14 °C, and for field-grown trees in winter (cold-stressed leaves) when minimum daily temperatures were ≤10 °C. Cold-stressed trees of both species had lower maximum CO2 assimilation rates (Amax), light saturation points (QA), CO2 saturation points (CaSAT) and quantum yields than leaves of noncold-stressed, field-grown trees. The ratio of variable to maximum fluorescence (Fv/Fm) was ≈50% lower for leaves of cold-stressed, field-grown trees than for leaves of nonstressed, field-grown trees, indicating chill-induced photoinhibition of leaves had occurred in winter. The data indicate that chill-induced photoinhibition of A and/or sink limitations caused by root restriction in container-grown trees can limit carbon assimilation in avocado and mango trees.


2017 ◽  
Vol 218 ◽  
pp. 230-239 ◽  
Author(s):  
Anderson Lopes Peçanha ◽  
Jefferson Rangel da Silva ◽  
Weverton Pereira Rodrigues ◽  
Tiago Massi Ferraz ◽  
Alena Torres Netto ◽  
...  

2020 ◽  
Vol 48 (2) ◽  
pp. 1027-1042
Author(s):  
Éva ÓNODY ◽  
Károly HROTKÓ ◽  
Magdolna SÜTÖRINÉ DIÓSZEGI

The pot in pot (PIP) system is a new alternative to container above ground (CAG) cultivation in nurseries. Our study estimates plant water usage of plants in CAG and PIP. Main variables as plant species, nursery container type and year effect on morphological parameters (plant size, leaf area, fresh and dry weight), on daily water use (weighed DWU), transpiration of leaves (DT) supplemented with species effect were analysed. Twenty plants grown in 5 L plastic pots of each combination were investigated. For leaf area measurement by AM350 we sampled 30 leaves from each plant. Fourty plants were weighed by a digital scale (Dyras, KSCL-300), morning and evening on each sampling day. Leaf gas exchange was measured on the same days by using leaf gas exchange analyzer (LCi, ADC Scientific Ltd.). From the two investigated deciduous (tatarian dogwood) and evergreen species (cherry laurel), only the tatarian dogwood showed improved quality in the PIP system (enhanced canopy increment, fresh and dry weight).  Significant difference showed the two species in DWU, and in DT. The tatarian dogwood used 626 g day-1 water (194 %) compared to the cherry laurel’s 341 g day-1 water use in 2015, while in 2016 this ratio was 144% in favor of tatarian dogwood. We measured higher initial morning weight (IWC) in PIP system. The transpiration measurements on single selected leaves overestimated the real transpiration compared to DWU. The DT of the deciduous tatarian dogwood responses more sensitive to environmental conditions than the evergreen cherry laurel.


Agronomy ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 76 ◽  
Author(s):  
Vu Phong Lam ◽  
Sung Jin Kim ◽  
Jong Seok Park

The objective of this study was to determine the proper electrical conductivity (EC) of a nutrient solution (NS) for accumulating bioactive compounds of Agastache rugosa without decreasing plant growth. Six-week-old seedlings were transplanted in a deep flow technique system with Hoagland NS with a 2.0 dS·m−1 EC for the initial week. From eight days after transplanting, the plants were treated with six EC treatments of 0.5, 1.0, 2.0, 4.0, 6.0, and 8.0 dS·m−1 for three weeks. Plant growth parameters, leaf gas exchange parameters, the relative chlorophyll value, and the ratio of variable to maximum fluorescence (Fv/Fm) were measured, and the rosmarinic acid (RA), tilianin, and acacetin concentrations were analyzed at 28 days after transplanting. The results showed that almost all plant growth parameters were maximized at 2.0 and 4.0 dS·m−1 and minimized at 8.0 dS·m−1 compared with the other EC treatments. The relative chlorophyll and Fv/Fm values were maximized at 2.0 and 4.0 dS·m−1. Similarly, leaf gas exchange parameters were increased at 2.0 and 4.0 dS·m−1. The RA content exhibited significantly higher values at 0.5, 1.0, 2.0, and 4.0 dS·m−1 compared with other treatments. The tilianin and acacetin contents exhibited the significantly highest values at 4.0 and 0.5 dS·m−1, respectively. These results suggest optimal EC treatment at 4.0 dS·m−1 for increasing bioactive compounds in A. rugosa plants without decreasing plant growth. Excessively high or low EC induced salinity stress or nutrient deficiency, respectively. Furthermore, among the plant organs, the roots of A. rugosa contained the highest RA concentration and the flowers contained the highest tilianin and acacetin concentrations, which revealed a higher utilization potential of the roots and flowers for bioactive compounds.


HortScience ◽  
2012 ◽  
Vol 47 (11) ◽  
pp. 1574-1579 ◽  
Author(s):  
Md. Jahedur Rahman ◽  
Haruhisa Inden ◽  
Masaaki Kirimura

There is increasing interest in reducing fertilizer cost and establishing proper irrigation management for sustainable vegetable production. Nigari, an effluent of salt industries, is cheaper than commercial fertilizers. Another important vegetable production factor is nutrient application timing to improve soilless cultivation in crops like sweet pepper. Therefore, this study evaluated the effects of nigari and nutrient solution application timing on leaf gas exchanges of sweet pepper cultivated under a soilless system. Treatments included three nigari rates [no nigari plus a standard nutrient solution as control, 2 mL·L−1 nigari + additional nitrogen–phosphorus–potassium (N–P–K) to equal the standard, and 4 mL·L−1 nigari + additional N–P–K to equal the standard]. Three daily application timings (T1 = 0700 hr + 1500 hr, T2 = 0900 hr + 1500 hr, and T3 = 0700 hr + 0900 hr + 1500 hr) were used for each nutrient solution. Leaf gas exchange parameters were studied during the vegetative and reproductive growth stages of sweet pepper cv. Papri new-E-red. Photosynthetic responses and its related parameters, namely transpiration (E), stomatal conductance (gS), and maximum photosynthesis (Amax), were significantly affected by nigari rates and nutrient solution application timing. Photosynthesis-related parameters, E, gS, Amax, and initial slope of photosynthesis in response to light curve were the highest and light compensation point (LCP) and leaf vapor pressure deficit (LVPD) were the lowest at 2 mL·L−1 nigari compared with the control at both plant vegetative and reproductive growth stages. For nutrient solution application timing, the highest E, gS, and Amax were observed at T3 treatment at both plant growth stages. Furthermore, marketable yield of sweet pepper was the highest when 2 mL·L−1 nigari was applied at 0700, 0900, and 1500 hr a day. Leaf gas exchange parameters showed that nutrient solution application timing of 0700, 0900, and 1500 hr a day was better for obtaining high yield of sweet pepper under nigari treatment in soilless culture.


2019 ◽  
Author(s):  
Maria D. Pissolato ◽  
Neidiquele M. Silveira ◽  
Paula J. Prataviera ◽  
Eduardo C. Machado ◽  
Amedea B. Seabra ◽  
...  

AbstractNitric oxide (NO) is an important signaling molecule associated with many biochemical and physiological processes in plants under stressful conditions. Nitrate reductase (NR) not only mediates the reduction of NO3− to NO2− but also reduces NO2− to NO, a relevant pathway for NO production in higher plants. Herein, we hypothesized that sugarcane plants supplied with more NO3− as a source of N would produce more NO under water deficit. Such NO would reduce oxidative damage and favor photosynthetic metabolism and growth under water limiting conditions. Sugarcane plants were grown in nutrient solution and received the same amount of nitrogen, with varying nitrate:ammonium ratios (100:0 and 70:30). Plants were then grown under well-watered or water deficit conditions, in which the osmotic potential of nutrient solution was −0.15 and −0.75 MPa, respectively. Under water deficit, plants exhibited higher root [NO3−] and [NO2−] when supplied with 100% NO3−. Accordingly, the same plants also showed higher root NR activity and root NO production. We also found higher photosynthetic rates and stomatal conductance in plants supplied with more NO3−, which improved root growth. ROS accumulation was reduced due to increases in the activity of catalase in leaves and superoxide dismutase and ascorbate peroxidase in roots of plants supplied with 100% NO3− and facing water deficit. Such positive responses to water deficit were offset when a NO scavenger was supplied to the plants, thus confirming that increases in leaf gas exchange and plant growth were induced by NO. Concluding, NO3− supply is an interesting strategy for alleviating the negative effects of water deficit on sugarcane plants, increasing drought tolerance through enhanced NO production. Our data also provide insights on how plant nutrition could improve crop tolerance against abiotic stresses, such as drought.HighlightsNitrate supply improves sugarcane growth under water deficit.Nitrate supply stimulated nitrate reductase activity and NO synthesis in sugarcane roots facing water deficit.Leaf gas exchange was increased by nitrate supply as well as root growth under water limiting conditions.Antioxidant responses were also improved in plants supplied exclusively with nitrate.Nitrogen management may be an interesting strategy for improving drought tolerance in sugarcane fields.


1998 ◽  
Vol 123 (4) ◽  
pp. 714-718 ◽  
Author(s):  
Thomas E. Marler ◽  
Michael V. Mickelbart

The influence of drought stress on leaf gas exchange and chlorophyll fluorescence characteristics of field-grown papaya (Carica papaya L.) plants was determined under a range of incident light fluxes and times of day. These data may aid in improving management systems for papaya production which minimize detrimental effects from suboptimal environmental conditions. Water was withheld from field-grown `Red Lady' plants in one study and `Tainung #2', `Red Lady', and `Sunrise' plants in a second study until soil matric potential was -60 to -70 kPa. Drought-stressed plants exhibited reduced net CO2 assimilation (ACO2) above light saturation, photosynthetic photon flux (PPF) at which light saturation for ACO2 occurred, and apparent quantum yield compared to well-watered plants. The light compensation point of drought-stressed plants was greater than that of well-watered plants. Leaf chlorophyll fluorescence characteristics were not influenced by drought stress. The daily pattern of leaf gas exchange was dependent on climatic conditions. For sunny days, ACO2, stomatal conductance of water (gs), and water use efficiency of well-watered plants were maximal at mid-morning, declined during midday, and then partially recovered during late afternoon. In drought-stressed plants, leaf gas exchange was relatively constant after a brief early morning maximum. On overcast days, the responses of gas exchange variables in relation to time of day followed smooth bell-shaped patterns regardless of the level of drought stress. Combined with previously published data, these results indicate that the influence of drought stress on gas exchange is highly dependent on time of day, ambient sky conditions, plant size, and speed with which drought stress occurs.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 780E-780
Author(s):  
Thomas E. Marler

A container study and a hydroponics study were conducted to determine gas-exchange and ion content of `Cariflora' papaya plants as influenced by a combination of salinity and flooding. Plants grown in nutrient solution were subjected to 1 or 8 dS·m–1 as salinity treatments and 6.54, 3.62, or 0.92 mg oxygen/liter as the flooding treatments. Plants in the container study were subjected to 0, 4, or 8 dS·m–1 as salinity treatments, and half of the plants in each salinity level were flooded. Leaf gas-exchange began to decline by day 1 in all plants receiving flooding, and was zero by day 5. In contrast, gas-exchange of plants experiencing salinity began a slow decline after 5 to 7 days. Stomatal conductance of salinized plants was 25% to 33% of the control plants in the container study after 39 days. No interaction occurred between flooding and salinity treatments since the stomatal response to flooding was so rapid across all levels of salinity. Roots and stems played a major role in storing Na+ and Cl– in salinized plants. For example, stems contained more than two times the dry weight concentration of both ions as did leaves. Older leaves accumulated more Na+ and Cl– than did younger leaves. Flooding decreased Na+ and Cl– accumulation in roots, stems, and leaves in all salinized plants.


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