scholarly journals Effects of Planting Density on Morphological and Photosynthetic Characteristics of Leaves in Different Positions on Cunninghamialanceolata Saplings

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 853
Author(s):  
Zhijun Huang ◽  
Qingqing Liu ◽  
Bo An ◽  
Xiaojian Wu ◽  
Linjun Sun ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Leaf Morphology ◽  
Leaf Gas Exchange ◽  
Photosynthetic Pigment ◽  
Net Photosynthesis ◽  
Economic Benefits ◽  
Planting Density ◽  
Gas Exchange Parameters ◽  
Pigment Contents ◽  
Exchange Parameters

The improvement of the stand yield and economic benefits of Cunninghamialanceolata (Lamb.) Hook, one of the most important plantation trees in China, has always been a concern. An appropriate planting density plays an important role in increasing productivity. To determine the optimum planting density of C. lanceolata, we measured leaf morphology, gas exchange parameters, and photosynthetic pigments in replicate leaves on 4-year-old saplings grown in four canopy positions under a low (D1), medium (D2), and high (D3) planting density (approximately 900, 2505, and 6660 trees·ha−1, respectively). We then ranked trait variations using the coefficient of variation to explore the influence of planting density. Planting density significantly influenced the leaf morphology, gas exchange parameters, and the photosynthetic pigment contents of C. lanceolata. Medium planting density (D2) resulted in a larger leaf area and specific leaf areas, a higher net photosynthesis rate, and higher photosynthetic pigment contents. The responses of leaf gas exchange parameters had the most plastic traits that responded to planting density. An appropriate planting density and leaf position might improve C. lanceolata leaf morphology and physiological attributes, which in turn would facilitate growth.

scholarly journals Synergism of Pratylenchus penetrans and Verticillium dahliae Manifested by Reduced Gas Exchange in Potato

1997 ◽  
Vol 87 (4) ◽  
pp. 435-439 ◽  
Author(s):  
Ibrahim A. M. Saeed ◽  
Ann E. MacGuidwin ◽  
Douglas I. Rouse
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Verticillium Dahliae ◽  
Leaf Gas Exchange ◽  
Joint Infection ◽  
Initial Density ◽  
Net Photosynthesis ◽  
Gas Exchange Parameters ◽  
The Relationship ◽  
Exchange Parameters

The effects of solitary and concurrent infection by Pratylenchus pene-trans and Verticillium dahliae on gas exchange of Russet Burbank potato (Solanum tuberosum) were studied in growth chamber experiments. Treatments were P. penetrans at low, medium, and high density; V. dahliae alone at one initial density; the combination of the nematode at these three densities and V. dahliae; and a noninfested control. Gas exchange parameters of leaf cohorts of different ages in the different treatments were repeatedly measured with a Li-Cor LI-6200 portable photosynthesis system. At 45 days after planting, joint infection significantly reduced net photosynthesis, stomatal conductance, and transpiration of 1- to 25-day-old leaf cohorts. Intercellular CO2 levels were significantly increased by co-infection, especially in older leaves. The synergistic effect of co-infection on gas exchange parameters was greater in the oldest cohort than in the youngest cohort. No consistent effects on leaf gas exchange parameters were observed in plants infected by the nematode or the fungus alone. The relationship between the assimilation rate and stomatal conductance remained linear regardless of solitary or concomitant infection, indicating that stomatal factors are primarily responsible for regulating photosynthesis. The significant reduction of gas exchange in leaves of co-infected plants without reduction in intercellular CO2 concentrations suggests that nonstomatal factors also play a role when both organisms are present.

scholarly journals Growth and Photosynthetic Response of Two Persimmon Rootstocks (Diospyros kaki and D. virginiana) under Different Salinity Levels

2014 ◽  
Vol 42 (2) ◽  
pp. 386-391 ◽  
Author(s):  
Meral INCESU ◽  
Berken CIMEN ◽  
Turgut YESILOGLU ◽  
Bilge YILMAZ
Keyword(s):  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Chlorophyll Concentration ◽  
Dry Mass ◽  
Diospyros Kaki ◽  
Gas Exchange Parameters ◽  
Leaf Chlorophyll ◽  
Salinity Levels ◽  
Leaf Chlorophyll Concentration ◽  
Exchange Parameters

Salinity continues to be a major factor in reduced crop productivity and profit in many arid and semiarid regions. Seedlings of Diospyros kaki Thunb. and D. virginiana L. are commonly used as rootstock in persimmon cultivation. In this study we have evaluated the effects of different salinity levels on photosynthetic capacity and plant development of D. kaki and D. virginiana. Salinity was provided by adding 50 mM, 75 mM and 100 mM NaCl to nutrient solution. In order to determine the effects of different salinity levels on plant growth, leaf number, plant height, shoot and root dry mass were recorded. Besides leaf Na, Cl, K and Ca concentrations were determined. Also leaf chlorophyll concentration, chlorophyll fluorescence (Fv’/Fm’) and leaf gas exchange parameters including leaf net photosynthetic rate (PN), stomatal conductance (gS), leaf transpiration rate (E), and CO2 substomatal concentration (Ci) were investigated. Significant decrease of leaf number, shoot length and plant dry mass by increasing salinity levels was observed in both rootstocks. D. virginiana was less affected in terms of plant growth under salinity stress. Leaf chlorophyll concentration reduction was higher in the leaves of D. kaki in comparison to D. virginiana in 100 mM NaCl treatment. By increasing salinity levels PN, gS and E markedly decreased in both rootstocks and D. kaki was more affected from salinity in terms of leaf gas exchange parameters. In addition there was no significant difference but slight decreases were recorded in leaf chlorophyll fluorescences of both rootstocks.

The impact of kaolin clay sprays on leaf gas exchange of Ginger Gold apple trees in New Brunswick

2006 ◽  
Vol 86 (Special Issue) ◽  
pp. 1377-1381 ◽  
Author(s):  
J. P. Privé ◽  
L. Russell ◽  
A. LeBlanc
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
New Brunswick ◽  
Leaf Gas Exchange ◽  
Net Photosynthesis ◽  
Apple Orchard ◽  
Kaolin Clay ◽  
Gas Exchange Parameters ◽  
Leaf Physiology ◽  
The Impact

A field trial was conducted over two growing seasons in a Ginger Gold apple orchard in Bouctouche, New Brunswick, Canada to examine the impact of Surround (95% kaolin clay) on leaf gas exchange [net photosynthesis (Pn), stomatal conductance (gs), intercellular CO2 (Ci) and transpiration (E)]. In 2004, a greater rate of Pn and gs was achieved at the higher than at the lower frequency of Surround applications. This was particularly notable at leaf temperatures exceeding 35°C. In 2005, no significant (P ≤ 0.05) differences among leaf residue groupings [Trace (< 0.5 g m-2), Low (0.5 to 2 g m-2), and High (≥ 2 g m-2)] were found for the four leaf gas exchange parameters at leaf temperatures ranging from 25 to 40°C. It would appear that under New Brunswick commercial orchard conditions, the application of Surround favours or has no effect on leaf gas exchange. Key words: Surround, particle film, leaf physiology, photosynthesis, stomatal conductance, intercellular CO2, transpiration

Effects of substrate acidity and UV-B radiation on photosynthesis of radishes

2011 ◽  
Vol 6 (4) ◽  
pp. 624-631
Author(s):  
Irena Januskaitiene
Keyword(s):  
Gas Exchange ◽  
Water Use ◽  
Raphanus Sativus ◽  
Net Photosynthesis ◽  
Enzymatic Reactions ◽  
Growth Substrate ◽  
Gas Exchange Parameters ◽  
Raphanus Sativus L ◽  
Use Efficiency ◽  
Exchange Parameters

AbstractThe aim of this study was to assess the combined effect of substrate acidity (pH 4.8; pH 3.8) and 1 kJm−2d−1 UV-B radiation on photosynthesis and growth of radishes (Raphanus sativus L.). Radishes were sown in a neutral pH 6.5 peat substrate. When the second true leaf unfolded, the growth substrate was acidified using different concentration of H2SO4 and exposed to UV-B radiation for a period of ten days. Gas exchange parameters were measured with the LI-6400 portable photosynthesis system. Content of chlorophyll was evaluated spectrophotometrically. The results showed that the greatest inhibition of net photosynthesis was observed when radishes were grown in an acidified pH 3.8 substrate. The decrease of the photosynthesis of radish plants treated with both investigated factors (substrate acidity and UV-B) were lower compared to the effect of substrate acidity alone. UV-B radiation stimulated both enzymatic reactions of photosynthesis and water use efficiency of radish plants grown in acidified peat substrates. Also, investigated factors had higher impact on biomass of tuber than biomass of foliage.

scholarly journals The effect of the application of the biological control agent EM1 on gas exchange parameters and productivity of Pisum sativum L. infected with Fusarium oxysporum Schlecht.

2012 ◽  
Vol 63 (2) ◽  
pp. 105-115 ◽  
Author(s):  
Adam Okorski ◽  
Jacek Olszewski ◽  
Katarzyna Głowacka ◽  
Sylwia Okorska ◽  
Agnieszka Pszczółkowska
Keyword(s):  
Gas Exchange ◽  
Exchange Rates ◽  
Fusarium Wilt ◽  
Chemical Control ◽  
Foliar Application ◽  
Biological Control Agent ◽  
Leaf Gas Exchange ◽  
Growth Conditions ◽  
Gas Exchange Parameters ◽  
Exchange Parameters

A pot experiment on different methods of EM 1 application was conducted in the period 2002-2004. The study was carried out under controlled growth conditions. The experimental factor was the method of EM1 application. Before application, the biological preparation EM1 was propagated as recommended by the manufacturer (Greenland). The health status of the aboveground parts of 'Ramrod' pea plants was estimated at the flowering stage. The assessment of pea leaf gas exchange parameters (An, E, Gs, and Ci) was made using a LI-Cor 6400 Portable Photosynthesis System. Soil application of EM1 combined with chemical control contributed to inhibiting Fusarium wilt of pea. Foliar application of EM1 combined with chemical control increased all gas exchange rates of pea leaves. Fusarium wilt of pea insignificantly decreased all gas exchange rates of pea leaves and the number of seeds per pod. The best method of EM1 application was soil treatment combined with chemical control, which increased all yield-related morphometric parameters of pea.

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