Distribution of Hymenachne acutigluma (Steudel) Guilliland in ponded pasture is limited by photosynthetic response to temperature

1999 ◽  
Vol 39 (4) ◽  
pp. 437 ◽  
Author(s):  
H. Kibbler ◽  
L. M. Bahnisch
Keyword(s):  
Leaf Area ◽  
Photosynthetic Rate ◽  
Photosynthetic Activity ◽  
Photosynthetic Response ◽  
Native Grass ◽  
Distribution Of Resources ◽  
Series Of Experiments ◽  
Exotic Grass ◽  
Response To Temperature ◽  
Structural Adaptations

Hymenachne amplexicaulis, an exotic grass established in ponded pasture in Central Queensland has the potential to become a weed. A suggested alternative, the native grass H. acutigluma produced little biomass when flooded. This investigation attempted to identify limitations to the growth of H. acutigluma under flooded conditions. A series of experiments compared the characteristics conferring adaptation to flooding of H. acutigluma with those of H. amplexicaulis. Photosynthetic activity of the 2 Hymenachne spp. was compared in response to light and temperature. The distribution of resources in response to reduced photosynthesis and flooding was also determined. When flooded, H. acutigluma had similar structural adaptations to H. amplexicaulis. However, H. acutigluma had a lower photosynthetic rate at reduced temperatures and the photosynthetic leaf area decreased when flooded. The implications of these findings are discussed in terms of limitations to the distribution and productivity of H. acutigluma in ponded pasture.

scholarly journals Acclimation of Photosynthetic Activity of Zantedeschia `Best Gold' in Response to Temperature and Photosynthetic Photon Flux

2002 ◽  
Vol 127 (2) ◽  
pp. 290-296 ◽  
Author(s):  
Keith A. Funnell ◽  
Errol W. Hewett ◽  
Julie A. Plummer ◽  
Ian J. Warrington
Keyword(s):  
Quantum Yield ◽  
Leaf Area ◽  
Photosynthetic Rate ◽  
Photosynthetic Activity ◽  
Natural Habitat ◽  
Photon Flux ◽  
Photosynthetic Photon Flux ◽  
Leaf Area Expansion ◽  
Response To Temperature ◽  
Area Expansion

Photosynthetic activity of individual leaves of Zantedeschia Spreng. `Best Gold' aff. Z. pentlandii (Wats.) Wittm. [syn. Richardia pentlandii Wats.] (`Best Gold'), were quantified with leaf expansion and diurnally, under a range of temperature and photosynthetic photon flux (PPF) regimes. Predictive models incorporating PPF, day temperature, and percentage leaf area expansion accounted for 78% and 81% of variation in net photosynthetic rate (Pn) before, and postattainment of, 75% maximum leaf area, respectively. Minimal changes in Pn occurred during the photoperiod when environmental conditions were stable. Maximum Pn (10.9μmol·m-2·s-1 or 13.3 μmol·g-1·s-1) occurred for plants grown under high PPF (694 μmol·m-2·s-1) and day temperature (28 °C). Acclimation of Pn was less than complete, with any gain through a greater light-saturated photosynthetic rate (Pmax) at high PPF also resulting in a reduction in quantum yield. Similarly, any gain in acclimation through increased quantum yield under low PPF occurred concurrently with reduced Pmax. It was concluded that Zantedeschia `Best Gold' is a shade tolerant selection, adapted to optimize photosynthetic rate under the climate of its natural habitat, by not having obligate adaptation to sun or shade habitats.

scholarly journals Anatomical structure of moss leaves and their photosynthetic activity

2014 ◽  
Vol 53 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Jan Krupa
Keyword(s):  
Leaf Area ◽  
Photosynthetic Rate ◽  
Vascular Plants ◽  
Photosynthetic Activity ◽  
Anatomical Structure ◽  
Moss Species ◽  
Area Unit ◽  
The One ◽  
Leaf Area Unit ◽  
Degree Of Differentiation

The photosynthetic activity of the leaf area unit increases depending on the degree of differentiation of the anatomical structure of the leaves of six chosen moss species. There is a correlation between the leaf area and the degree of differentiation of the anatomical structure resulting in enlargement of the area of contact of the assimilating cells with air. The leaves of <em>Catharinea undulata</em> having a one-layer blade and provided with several lamellae show a higher photosynthesis per 1 cm<sup>2</sup> of their surface than the one-layer leaves of <em>Mniurnm</em> or <em>Funaria. Aloina</em> leaves are the smallest in area among those of the moss species discussed, however, their photosynthetic rate is almost 4.5 times higher than in <em>Funaria</em> leaves. By analogy to the structure of leaves and their function in vascular, plants, these changes and correlations may be considered as attempts of primeval adaptation of mosses to terrestrial conditions of living.

scholarly journals Changes in peanut canopy structure and photosynthetic characteristics induced by an arbuscular mycorrhizal fungus in a nutrient-poor environment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yinli Bi ◽  
Huili Zhou
Keyword(s):  
Net Photosynthetic Rate ◽  
Leaf Area ◽  
Photosynthetic Rate ◽  
Mycorrhizal Fungus ◽  
Canopy Structure ◽  
Arbuscular Mycorrhizal ◽  
Photosynthetic Characteristics ◽  
Total Leaf Area ◽  
Tiller Angle ◽  
Amf Inoculation

AbstractA well-developed canopy structure can increase the biomass accumulation and yield of crops. Peanut seeds were sown in a soil inoculated with an arbuscular mycorrhizal fungus (AMF) and uninoculated controls were also sown. Canopy structure was monitored using a 3-D laser scanner and photosynthetic characteristics with an LI-6400 XT photosynthesis system after 30, 45 and 70 days of growth to explore the effects of the AMF on growth, canopy structure and photosynthetic characteristics and yield. The AMF colonized the roots and AMF inoculation significantly increased the height, canopy width and total leaf area of the host plants and improved canopy structure. AMF reduced the tiller angle of the upper and middle canopy layers, increased that of the lower layer, reduced the leaf inclination of the upper, middle and lower layers, and increased the average leaf area and leaf area index after 45 days of growth, producing a well-developed and hierarchical canopy. Moreover, AMF inoculation increased the net photosynthetic rate in the upper, middle and lower layers. Plant height, canopy width, and total leaf area were positively correlated with net photosynthetic rate, and the inclination angle and tiller angle of the upper leaves were negatively correlated with net photosynthetic rate. Overall, the results demonstrate the effects of AMF inoculation on plant canopy structure and net photosynthetic rate.

scholarly journals Photosynthetic activity and productivity of potato plants when using foliar dressings with complex micronutrients and humate

2021 ◽  
Vol 285 ◽  
pp. 02028
Author(s):  
Olga Savina ◽  
Svetlana Afinogenova ◽  
Valentina Krishtafovich ◽  
Bakhytkul Baikhozhaeva
Keyword(s):  
Leaf Area ◽  
Photosynthetic Activity ◽  
Growing Season ◽  
Treatment Control ◽  
Potato Plants ◽  
Photosynthetic Potential

The article presents the results of many years of research on the effect of foliar dressing with complex fertilizers and humate on photosynthetic activity and productivity of potato plants of Gala and Latona varieties. The following options have been studied: 1) without treatment (control); 2) dressing with Ekorost humate at a dose of 0.2-0.4 l/ha; 3) dressing with micronutrient Strada N at a dose of 3-5 l/ha; 4) dressing with micronutrient Strada R at a dose of 3-5 l/ha. The treatment was carried out twice during the growing season: when full shoots appeared and 14 days after the first one. Determination of the leaf area and calculation of the photosynthetic potential were carried out according to the VNIIKH method (1967) three times during the growing season in the following phases: budding, flowering, and the beginning of withering away of lower leaves. The crop was harvested by the method of continuous harvesting of the accounting area of the plots with weighing. The effectiveness of the studied agrotechnical methods has been proved. The best variant of the investigated ones is the use of Strada R. The plants of this variant formed a more powerful assimilation apparatus and had the highest photosynthetic potential, which ultimately affected the yield of tubers. The increase in the yield of two varieties of potatoes was 21.8-23.1 % in relation to the control. Gala variety turned out to be more responsive to the action of vegetative treatments in comparison with Latona variety.

scholarly journals Herbicide and Native Grass Seeding Effects on Sulfur Cinquefoil (Potentilla Recta)-Infested Grasslands

2008 ◽  
Vol 1 (1) ◽  
pp. 50-58 ◽  
Author(s):  
Bryan A. Endress ◽  
Catherine G. Parks ◽  
Bridgett J. Naylor ◽  
Steven R. Radosevich
Keyword(s):  
Ecological Restoration ◽  
Early Summer ◽  
Grass Species ◽  
Management Approach ◽  
Native Plant ◽  
Herbicide Application ◽  
Native Grass ◽  
Native Plant Species ◽  
Wide Range ◽  
Exotic Grass

AbstractSulfur cinquefoil is an exotic, perennial forb that invades a wide range of ecosystems in western North America. It forms dense populations and often threatens native plant species and communities. In this study, we address the following questions: (1) what herbicides, rates, and application times are most effective at reducing sulfur cinquefoil abundance while having the least impact on native plants; and (2) does postherbicide seeding with native grass species increase native plant abundance? In 2002, we experimentally examined the effects of five herbicides (dicamba + 2,4-D; metsulfuron-methyl; triclopyr; glyphosate; and picloram) at two rates of application (low and high), three application times (early summer, fall, and a combined early summer–fall treatment), and two postherbicide seed addition treatments (seeded or not seeded) on sulfur cinquefoil abundance, plant community composition, and species richness. Experimental plots were monitored through 2005. Picloram was the most effective herbicide at reducing sulfur cinquefoil density, the proportion of remaining adult plants, and seed production. The effects of picloram continued to be evident after 3 yr, with 80% reduction of sulfur cinquefoil in 2005. In addition, seeding of native grass seeds alone (no herbicide application) reduced the proportion of sulfur cinquefoil plants that were reproductively active. Despite reductions in sulfur cinquefoil abundance, all treatments remained dominated by exotic species because treated areas transitioned from exotic forb- to exotic grass-dominated communities. However, a one-time herbicide application controlled sulfur cinquefoil for at least 3 yr, and therefore might provide a foundation to begin ecological restoration. Herbicide applications alone likely are to be insufficient for long-term sulfur cinquefoil control without further modification of sites through native grass or forb seeding. Integrating herbicides with native plant seeding to promote the development of plant communities that are resistant to sulfur cinquefoil invasion is a promising management approach to ecological restoration.

Photosynthetic Rate, Stomatal Conductance and Leaf Area in Two Cotton Species (Gossypium barbadense and Gossypium hirsutum) and their Relation with Heat Resistance and Yield

1997 ◽  
Vol 24 (5) ◽  
pp. 693 ◽  
Author(s):  
Zhenmin Lu ◽  
Jiwei Chen ◽  
Richard G. Percy ◽  
Eduardo Zeiger
Keyword(s):  
Stomatal Conductance ◽  
Gossypium Hirsutum ◽  
Heat Resistance ◽  
Leaf Area ◽  
Photosynthetic Rate ◽  
Upland Cotton ◽  
Gossypium Barbadense ◽  
Lint Yield ◽  
Historical Series ◽  
Field And Laboratory Conditions

Gossypium barbadense L. (Pima) and Gossypium hirsutum L. (upland) cottons are the two major fibre producing species grown in the south-western United States, where lint yields are adversely affected by high temperatures. In these environments, heat-adapted upland cultivars show higher yields and heat resistance than advanced Pima cultivars. Recent studies with an historical series of commercial Pima cultivars have shown that increases in lint yield and heat resistance are tightly coupled to increases in stomatal conductance and photosynthetic rate, and to decreases in leaf area. In the present study, Pima S-6 and Pima S-7 (advanced Pima cultivars) and Deltapine 90 (advanced upland cultivar) were compared under field and laboratory conditions to determine whether the physiological and morphological gradients found in the Pima historical series extrapolate to upland cotton. In the field, Deltapine 90 showed 25–35% higher stomatal conductance, 35–50% higher photosynthetic rate and 45% smaller leaf area than Pima S-6. The higher photosynthetic rate and stomatal conductance of Deltapine 90 leaves were partially related to their sun-tracking ability. In gas exchange experiments that prevented sun-tracking, the two cultivars had comparable photosynthetic rate as a function of incident radiation, while stomatal conductance was higher in upland cotton. In the 25–35°C range, photosynthetic rate as a function of temperature remained nearly constant in both cultivars, and was higher in upland cotton at all temperatures. Stomatal conductance showed a strong temperature-dependence, and conductance value and the slope of the stomatal response to temperature were higher in Deltapine 90. In progeny from a cross between Deltapine 90 and Pima S-7, the segregation of stomatal conductance in F1 and F2 populations showed a clear genetic component. These results indicate that the differences in photosynthetic rate, stomatal conductance and leaf area associated with increases in lint yield and heat resistance in the Pima historical series are also evident in a comparison between advanced cultivars of upland and Pima cotton. Upland cotton could be used as a source of genetic variation for high stomatal conductance in Pima breeding programs.

scholarly journals MORPHOLOGICAL AND PHYSIOLOGICAL PLASTICITY OF SAPLINGS OF Cabralea canjerana (Vell.) MART. IN DIFFERENT LIGHT CONDITIONS

2019 ◽  
Vol 43 (1) ◽  
Author(s):  
Anna Paula Lora Zimmermann ◽  
Frederico Dimas Fleig ◽  
Luciane Almeri Tabaldi ◽  
Suelen Carpenedo Aimi
Keyword(s):  
Leaf Area ◽  
Photosynthetic Activity ◽  
Dry Mass ◽  
Chlorophyll B ◽  
Light Conditions ◽  
Forest Fragment ◽  
Lower Content ◽  
Physiological Plasticity ◽  
Chlorophyll A And B ◽  
Number Of Leaves

ABSTRACT This work was carried out to verify the plasticity of saplings of Cabralea canjerana plants and their capacity to adapt to different light environments by means of morphological and physiological characteristics. For this, 12 plants of a secondary Deciduous Seasonal Forest fragment were selected, six growing under canopy and six in full sun. Trees were classified according to their sociological position as emergent and dominated. The leaves were classified as apical, intermediate and basal according to their position in the canopy. The variables measured were: total number of leaves, width, length, thickness, leaf area and dry mass of leaflets; content of chlorophyll a and b and carotenoids. Emergent leaflets of the upper position of the canopy in full sun, which are considered the most exposed to luminosity, presented xeromorphic characteristics such as leaflet size reduction, greater limbus thickness, smaller leaf area and lower content of chlorophyll b. The similarity in the dry mass and pigment content demonstrates that the photosynthetic activity of the C. canjerana plants analyzed is not being affected by the different conditions of the environment, which demonstrates the plasticity of the species and its capacity of development in several light conditions.

scholarly journals Growth, physiology and yield responses of cabbage to deficit irrigation

2014 ◽  
Vol 41 (No. 3) ◽  
pp. 138-146 ◽  
Author(s):  
C. Xu ◽  
D.I. Leskovar
Keyword(s):  
Plant Growth ◽  
Water Content ◽  
Leaf Area ◽  
Photosynthetic Rate ◽  
Deficit Irrigation ◽  
Total Yield ◽  
Rio Grande ◽  
Fresh Weight ◽  
Growth Physiology ◽  
Yield Responses

Field experiments were conducted in two seasons to investigate growth, physiology and yield responses of cabbage (Brassica oleracea L. cvs Pennant and Rio Grande) to deficit irrigation. In 2012 season, 50% of crop evapotranspiration (ETc) irrigation temporarily decreased plant size, reduced leaf area, fresh weight, relative water content, specific leaf area and gas exchange during late development, and decreased head fresh weight, size, marketable and total yield. Deficit irrigation at 75% ETc had little influence on plant growth and physiology, but it still reduced both marketable and total yield. In 2013 season, 75%&nbsp;ETc irrigation had little influence on plant growth, leaf characteristics, photosynthetic rate, head fresh weight and size, but it temporarily increased chlorophyll and carotenoid content, and decreased stomata conductance, transpiration, and marketable yield. Pennant, the green-head cultivar, had higher photosynthetic rate, head fresh weight, marketable and total yield than the red-head cultivar Rio Grande. In both seasons, deficit irrigations did not influence cabbage head dry weight, indicating that most yield reduction under deficit irrigations is related to water content. &nbsp;

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