scholarly journals Visible Foliar Injury and Physiological Responses to Ozone in Italian Provenances ofFraxinus excelsiorandF. ornus

2007 ◽  
Vol 7 ◽  
pp. 90-97 ◽  
Author(s):  
Nicla Contran ◽  
Elena Paoletti

We compared leaf visible injury and physiological responses (gas exchange and chlorophyll a fluorescence) to high O3exposure (150 nmol mol–1h, 8 h day–1, 35–40 days) of two woody species of the same genus with different ecological features: the mesophilic green ash (Fraxinus excelsior) and the xerotolerant manna ash (F. ornus). We also studied how provenances from northern (Piedmont) and central (Tuscany) Italy, within the two species, responded to O3exposure. Onset and extent of visible foliar injury suggested thatF. excelsiorwas more O3sensitive thanF. ornus. The higher stomatal conductance inF. ornusthan inF. excelsiorsuggested a larger potential O3uptake, in disagreement to lower visible foliar injury. The higher carbon assimilation inF. ornussuggested a higher potential of O3detoxification and/or repair. Contrasting geographical variations of ash sensitivity to O3were recorded, as Piedmont provenances reduced gas exchange less than Tuscan provenances inF. excelsiorand more inF. ornus. Visible injury was earlier and more severe inF. excelsiorfrom Piedmont than from Tuscany, while the provenance did not affect visible injury onset and extent inF. ornus.

Weed Science ◽  
1990 ◽  
Vol 38 (6) ◽  
pp. 459-462 ◽  
Author(s):  
Derrick M. Oosterhuis ◽  
Stan D. Wullschleger ◽  
Ron E. Hampton ◽  
Rosalind A. Ball

Growth chamber experiments were conducted to elucidate the morphological and physiological responses of rice to postemergence application of fenoxaprop. Two rice cultivars, ‘Newbonnet’ and ‘Mars’, and barnyardgrass were treated with 0.17 kg ai ha−1fenoxaprop at the five-leaf stage. Within 2 days of fenoxaprop application, rice cultivars developed a white chlorotic band across leaves that were in direct contact with spray droplets. Leaf elongation rates for the two rice cultivars were inhibited by 40% after 4 days and by over 50% after 14 days. Inhibition of leaf elongation by fenoxaprop contributed to an overall decrease in leaf area and shoot dry weight. Net photosynthesis was reduced by 35% in fenoxaprop-treated plants 11 days after application, although stomatal conductance was not affected. Nitrogen fertilization prior to fenoxaprop application increased foliar injury of both rice cultivars. Visible injury symptoms showed the following order of susceptibility to foliar-applied fenoxaprop: barnyardgrass > Mars rice > Newbonnet rice.


1986 ◽  
Vol 16 (6) ◽  
pp. 1289-1292 ◽  
Author(s):  
Andrea M. Eastham ◽  
Douglas P. Ormrod

Carolina poplar (Populuscanadensis Moensch 'Eugenei') and Lombardy poplar (Populusnigra L. 'Italica') were exposed to NO2 and SO2, separately or in combination, for 1 h using concentrations of 0.50 and 1.0 μL•L−1 in separate experiments to determine if foliar injury symptoms can be used as a surrogate for growth effects and if single pollutants have noninteractive effects when mixed. Lombardy poplar was more sensitive than Carolina poplar to exposures to combined SO2 and NO2 at 1.0 μL•L−1 based on visible foliar injury symptoms. In contrast, leaf growth in both species was significantly stimulated by NO2 at 0.50 μL•L−1 and stem growth significantly decreased by NO2 at 1.0 μL•L−1. There was little effect of SO2; there were significant interactions of NO2 and SO2 only in Lombardy poplar exposed to 0.50 μL•L−1. These results suggest that growth effects can not be predicted by foliar injury symptoms and that few significant growth effects are identifiable in short-term studies.


2014 ◽  
Vol 70 (4) ◽  
pp. 213-222 ◽  
Author(s):  
Prathomrak NA-NGERN ◽  
Cattleya CHUTTEANG ◽  
Masatoshi AOKI ◽  
Fumiaki TAKEMASA ◽  
Ge ZHENRUI ◽  
...  

2021 ◽  
Author(s):  
Tiago DG Nunes ◽  
Magdalena W Slawinska ◽  
Heike Lindner ◽  
Michael T Raissig

Stomata are cellular pores on the leaf epidermis that allow plants to regulate carbon assimilation and water loss. Stomata integrate environmental signals to regulate pore apertures and optimize gas exchange to fluctuating conditions. Here, we quantified intraspecific plasticity of stomatal gas exchange and anatomy in response to seasonal variation in Brachypodium distachyon. Over the course of two years we (i) used infrared gas analysis to assess light response kinetics of 120 Bd21-3 wild-type individuals in an environmentally fluctuating greenhouse and (ii) microscopically determined the seasonal variability of stomatal anatomy in a subset of these plants. We observed systemic environmental effects on gas exchange measurements and remarkable intraspecific plasticity of stomatal anatomical traits. To reliably link anatomical variation to gas exchange, we adjusted anatomical gsmax calculations for grass stomatal morphology. We propose that systemic effects and variability in stomatal anatomy should be accounted for in long-term gas exchange studies.


2020 ◽  
Vol 50 (2) ◽  
Author(s):  
Murthazar Naim Raai ◽  
Nurul Amalina Mohd Zain ◽  
Normaniza Osman ◽  
Nur Ardiyana Rejab ◽  
Nurul Amylia Sahruzaini ◽  
...  

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.


2019 ◽  
Vol 2 (3) ◽  
pp. 10-28
Author(s):  
Martina Shotaroska ◽  
Bojan Simovski ◽  
Tomcho Nikolovski ◽  
Katerina Chonevska ◽  
Ivan Minčev ◽  
...  

Subject of research in this article is the urban dendroflora of the Macedonia Park, situated on about 50,000 m2 in the Macedonian capital city of Skopje, i.e., identification and presence of the recent woody plants. Thus, observed are morphological and ecological features of the woody plants and their current state in this urban environment. The investigation relates to a seven-year period (since the establishment of the Park in 2012 up to late 2019). After the field research and the inventorisation of the woody plants in the Park, 82 taxa were identified, represented in 1,318 individuals. Most represented tree species is the hybrid Platanus × hispanica Mill. ex Münchh. with 103 individuals (7.81% of the overall urban dendroflora). Most frequent tree including infraspecific taxa is Fraxinus excelsior L. (including F. e. ‘Globosa’, F. e. ‘Jaspidea’, and F. e. ‘Pendula’) with a total number of 146 individuals (11.08%). Concerning other growth form, the mini and small tree roses of hybrid Rosa Floribunda Group outnumber all ornamental woody species with 225 bushes (17.07%). Climbers are represented with 3 taxa (3.66% of identified taxa) in pergolas (Wisteria sinensis /Sims/ Sweet, Parthenocissus quinquefolia /L./ Planch.), and wire cage topiary (Hedera helix L.). Likewise, 87 individuals (6.60%) of 10 species (12.19%) occur as remnants of the greening in the past of which 3 species are used as a green core of a small sacral architecture: Cupressus sempervirens var. horizontalis (Mill.) Loudon (with 10 trees), Platycladus orientalis (L.) Franco (3), and Pinus nigra J.F.Arnold (1). In general, the urban dendroflora is properly selected and used for greening, although certain species and individuals are withering (e.g. Betula pendula ‘Youngii’, Juniperus scopulorum ‘Skyrocket’, F. e. ‘Jaspidea’) or unsuitably used for avenue and in small alpine-like garden.


2005 ◽  
Vol 53 (8) ◽  
pp. 789 ◽  
Author(s):  
Luzimar Campos da Silva ◽  
Aristéa Alves Azevedo ◽  
Eldo Antônio Monteiro da Silva ◽  
Marco Antonio Oliva

Seedlings and young saplings of some woody species were exposed to simulated low-pH acid rain, in order to develop a response screening for tropical tree species by determination of the symptoms of foliar injury and growth responses, as well as to identify anatomical alterations in the leaf blade of the most sensitive species. Gallesia integrifolia (Spreng.) Harms, Genipa americana L., Joannesia princeps Vell., Mimosa artemisiana Heringer & Paula and Spondias dulcis Forst.f. were exposed daily to 20 min of acid rain, pH 3.0, for 10 consecutive days. The degree of leaf damage and the anatomical alterations observed were efficient parameters to determine the sensitivity to acid rain. At the end of the experiment J. princeps was the most sensitive species as determined by foliar injury and seedling growth. The degree of leaf damage was similar among the seedlings, except in S. dulcis, which showed reduced percentage of foliar injury. Necrotic and chlorotic spots on the leaf blade occurred. In the most sensitive species, J. princeps, necrotic blade tissues showed accumulation of phenolic compounds, hypertrophy and collapsed cells. Most of the structural alterations were observed in the adaxial epidermis, the palisade parenchyma and spongy parenchyma and the abaxial epidermis. Long-term experiments with seedlings of S. dulcis and saplings of G. integrifolia are suggested, to characterise the response of these species that presented fewer symptoms but whose growth was affected under acid rain.


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