scholarly journals Physiological behavior of Campomanesia xanthocarpa O. Berg. seedlings under flooding and shading

2021 ◽  
Vol 42 (6) ◽  
pp. 3149-3166
Author(s):  
Maílson Vieira Jesus ◽  
◽  
Silvana de Paula Quintão Scalon ◽  
Daiane Mugnol Dresch ◽  
Jéssica Aline Linné ◽  
...  
Keyword(s):  
Native Species ◽  
Photochemical Efficiency ◽  
Photosynthetic Apparatus ◽  
Photochemical Process ◽  
Gas Exchanges ◽  
Photochemical Efficiency Of Psii ◽  
Short Period ◽  
Physiological Information ◽  
High Level ◽  
Main Factor

Physiological information about native species, make it possible to know their potential for use in programs to recovery degraded areas. Nowadays climate changes are severe and factors as water and light are involved with plant development and growth. We hypothesized that shading may contribute to adjusting the characteristics of photosynthetic metabolism of Campomanesia xanthocarpa seedlings under flooding. Thus, this work aimed to evaluate the flooding times and shading levels for gas exchanges and the maximal photochemical efficiency of PSII (Fv/Fm) in C. xanthocarpa seedlings. Seedlings were grown under two water regimes (control and flooding), three levels of shading (0, 30, and 70%) and 4 evaluation periods (0, 15, 30, and 45 days). We verified damages to the photosynthetic apparatus and reductions in the efficiency of the photochemical process under flooding and at a high level of shading (70%) in a short period (15 days). However, seedlings showed favourable responses to the adjustment over the 45 days of exposure to those conditions. According to the multivariate analysis, it was possible to identify the relation between photosynthetic rate and stomatal conductance as the main factor of metabolic adjustments in the tolerance of C. xanthocarpa to flooding and high shading intensity. C. xanthocarpa was more sensitive to short periods of flooding conditions and full sun and high level of shading (70%), however, it presented better adjustment responses to flooding periods when associated with 30% shade.

scholarly journals Gas exchanges and photochemical efficiency of hydroponic bell pepper under salinity and plant density

2019 ◽  
Vol 23 (1) ◽  
pp. 3-8
Author(s):  
Antônio R. Cavalcante ◽  
José A. Santos Júnior ◽  
Guilherme de F. Furtado ◽  
Lúcia H. G. Chaves
Keyword(s):  
Electrical Conductivity ◽  
Salt Stress ◽  
Plant Density ◽  
Photochemical Efficiency ◽  
Photosynthetic Apparatus ◽  
Bell Pepper ◽  
Gas Exchanges ◽  
Hydroponic System ◽  
Salinity Levels ◽  
Pepper Plants

ABSTRACT Gas exchanges and chlorophyll a fluorescence are ways to physiologically analyze the response of plants to salt stress. In this context, the present work was conducted between August and November 2016 in a greenhouse at the Federal University of Campina Grande (7°12’52” S, 35°54’24” W, mean altitude of 550 m), using bell pepper plants cv. All Big, exposed to levels of nutrient solution electrical conductivity (1.7, 3.7, 5.7, 7.7, 9.7 and 11.7 dS m-1) and cultivated in hydroponic system, spaced by 0.2 and 0.3 m, focusing on the analysis of gas exchanges and photochemical efficiency. The experimental design was completely randomized, in a 6 x 2 factorial scheme, with five replicates. Plant density influenced the sensitivity of the gas exchanges to salinity and, when reduced, mitigated its effects at higher salinity levels. Increasing plant density at high levels of electrical conductivity caused damage to the photosynthetic apparatus and even reduced the levels of efficiency of the photosystem II from 3.98 dS m-1.

scholarly journals Differences in photosynthetic capacity, chlorophyll fluorescence, and antioxidant system between invasive Alnus formosana and its native congener in response to different irradiance levels

Botany ◽  
2016 ◽  
Vol 94 (12) ◽  
pp. 1087-1101 ◽  
Author(s):  
Shi-liang Liu ◽  
Rong-jie Yang ◽  
Bo Ren ◽  
Mao-hua Wang ◽  
Ming-dong Ma
Keyword(s):  
Invasive Species ◽  
Chlorophyll Fluorescence ◽  
Antioxidant System ◽  
Photosynthetic Rate ◽  
Native Species ◽  
Antioxidant Activities ◽  
Photochemical Efficiency ◽  
High Irradiance ◽  
Invasion Success ◽  
Photochemical Efficiency Of Psii

We compared the invasive Alnus formosana (Burk.) Makino with its native congener (Alnus cremastogyne Burk.) at three irradiances in terms of photosynthesis, chlorophyll fluorescence, and antioxidant system. The increased light-saturated photosynthetic rate (Amax) and light saturation point (LSP) contributed directly to the increased performance of the invasive. The invasive species had also higher plasticity in carotenoid and total chlorophyll than the native species at 100% irradiance, potentially contributing to invasion success in high-irradiance locations via photoprotection. Moreover, the diurnal photoinhibition of photosynthesis, as judged by the maximum photochemical efficiency of PSII (Fv/Fm) of dark-adapted leaves, was more severe in the native species than in the invasive species. With increasing irradiance, the invasive exhibited increased antioxidant activities and higher antioxidant levels to support the adverse conditions of both low- and high-irradiance acclimation. In contrast, the intercellular CO2 concentration (Ci) and stomatal limitation (Ls) decreased with increases in the net photosynthetic rate (An), stomatal conductance (Gs), and transpiration rate (Tr). We speculated that Ls was the main factor inhibiting the An for both studied species. These results first indicated that the invasive may occupy new habitats successfully through tolerating shading at low irradiance and out-compete native species through higher Amax and antioxidant levels when irradiance is increased.

scholarly journals GAS EXCHANGES, QUANTUM YIELD AND PHOTOSYNTHETIC PIGMENTS OF WEST INDIAN CHERRY UNDER SALT STRESS AND POTASSIUM FERTILIZATION

2019 ◽  
Vol 32 (2) ◽  
pp. 429-439 ◽  
Author(s):  
ADAAN SUDARIO DIAS ◽  
GEOVANI SOARES DE LIMA ◽  
FRANCISCO WESLEY ALVES PINHEIRO ◽  
HANS RAJ GHEYI ◽  
LAURIANE ALMEIDA DOS ANJOS SOARES
Keyword(s):  
Electrical Conductivity ◽  
Salt Stress ◽  
Quantum Yield ◽  
Chlorophyll A ◽  
Photosynthetic Pigments ◽  
Photochemical Efficiency ◽  
Photosynthetic Apparatus ◽  
West Indian ◽  
Gas Exchanges ◽  
Potassium Fertilization

ABSTRACT Water resources in the semi-arid region of Northeast Brazil commonly contain high salt concentrations, compromising the quality of water for agriculture. Thus, adopting techniques that make the use of these resources feasible in agriculture is fundamental. The present study aimed to evaluate the gas exchanges, quantum yield and photosynthetic pigments of grafted West Indian cherry subjected to salt stress and potassium fertilization under greenhouse conditions in the municipality of Campina Grande, PB, Brazil. Treatments were distributed in randomized blocks, composed of two levels of electrical conductivity - ECw (0.8 and 3.8 dS m-1) of water and four doses of potassium (50, 75, 100 and 125% of the dose recommended for the crop), with three replicates. The dose relative to 100% corresponded to 19.8 g of K2O per plant. Gas exchanges, chlorophyll a fluorescence and photosynthetic pigments of West Indian cherry are negatively affected by irrigation using water with electrical conductivity of 3.8 dS m-1, which compromises the photosynthetic apparatus of the plant, a situation evidenced by the reduction in photosystem II quantum efficiency. Increasing potassium doses led to increments in transpiration, chlorophyll a maximum fluorescence and chlorophyll b content in West Indian cherry grown under salt stress, but do not attenuate the negative effects of irrigation with 3.8 dS m-1 water on its potential photochemical efficiency.

scholarly journals Exogenous putrescine alleviates photoinhibition caused by salt stress through increasing cyclic electron flow in cucumber

2018 ◽  
Author(s):  
Xinyi Wu ◽  
Sheng Shu ◽  
Yu Wang ◽  
Ruonan Yuan ◽  
Shirong Guo
Keyword(s):  
Salt Stress ◽  
Electron Flow ◽  
Critical Role ◽  
Photochemical Efficiency ◽  
Cyclic Electron Flow ◽  
Photochemical Quenching ◽  
Photochemical Efficiency Of Psii ◽  
High Level ◽  
Non Photochemical Quenching ◽  
Related Proteins

AbstractWhen plants suffer from abiotic stresses, cyclic electron flow (CEF) is induced for photoprotection. Putrescine (Put), a main polyamine in chloroplasts, plays a critical role in stress tolerance. To elucidate the mechanism of Put regulating CEF for salt-tolerance in cucumber leaves, we measured chlorophyll fluorescence, P700 redox state, ATP and NADPH accumulation and so on. The maximum photochemical efficiency of PSII (Fv/Fm) was not influenced by NaCl and/or Put, but the activity of PSI reaction center (P700) was seriously inhibited by NaCl. Salt stress induced high level of CEF, moreover, NaCl and Put treated plants exhibited much higher CEF activity and ATP accumulation than single salt-treated plants to provide adequate ATP/NADPH ratio for plants growth. Furthermore, Put decreased the trans-membrane proton gradient (ΔpH), accompanied by reducing the pH-dependent non-photochemical quenching (qE) and increasing efficient quantum yield of PSII (Y(II)). The ratio of NADP+/NADPH in salt stressed leaves was significantly increased by Put, indicating that Put relieved over-reduction pressure at PSI accepter side. Taken together, our results suggest that exogenous Put enhances CEF to supply extra ATP for PSI recovery and CO2 assimilation, decreases ΔpH for electron transport related proteins staying active, and enable the non-photochemical quenching transformed into photochemical quenching.

HALIMA KHUDAYBERDIEVA POETRY MASTERY TO USE SYMBOLS AND IMAGES

2020 ◽  
Vol 3 (3) ◽  
pp. 49-52
Author(s):  
Mehrinoz Abbosova ◽  
Keyword(s):  
Deep Understanding ◽  
Artistic Representations ◽  
High Level ◽  
Main Factor

The article deals with the skill of using symbols and emblems in the poetry of the poetess Halima Khudaiberdieva. Poetry is one of the highest forms of art, and its perception requires a high level,high taste, deep understanding from the reader. The article lists important aspects of the requirements for an original poem. It is emphasized that the main factor of mystery in the poem are symbols and allusions. Some examples from the poems of the poet are given and analyzed. Through this, an attempt was made to explore the artistic representations of the poet’s poetry

scholarly journals Long Term Interactions of Native and Invasive Species in a Marine Protected Area Suggest Complex Cascading Effects Challenging Conservation Outcomes

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 71
Author(s):  
Charalampos Dimitriadis ◽  
Ivoni Fournari-Konstantinidou ◽  
Laurent Sourbès ◽  
Drosos Koutsoubas ◽  
Stelios Katsanevakis
Keyword(s):  
Invasive Species ◽  
Native Species ◽  
High Performance ◽  
Marine Protected Area ◽  
Habitat Degradation ◽  
Population Increase ◽  
Rocky Reef ◽  
Cascading Effects ◽  
High Level

Understanding the interactions among invasive species, native species and marine protected areas (MPAs), and the long-term regime shifts in MPAs is receiving increased attention, since biological invasions can alter the structure and functioning of the protected ecosystems and challenge conservation efforts. Here we found evidence of marked modifications in the rocky reef associated biota in a Mediterranean MPA from 2009 to 2019 through visual census surveys, due to the presence of invasive species altering the structure of the ecosystem and triggering complex cascading effects on the long term. Low levels of the populations of native high-level predators were accompanied by the population increase and high performance of both native and invasive fish herbivores. Subsequently the overgrazing and habitat degradation resulted in cascading effects towards the diminishing of the native and invasive invertebrate grazers and omnivorous benthic species. Our study represents a good showcase of how invasive species can coexist or exclude native biota and at the same time regulate or out-compete other established invaders and native species.

Geographic Variation in Dominance of Spinosad Resistance in Colorado Potato Beetles (Coleoptera: Chrysomelidae)

2020 ◽  
Author(s):  
Coby Klein ◽  
Mitchell Baker ◽  
Andrei Alyokhin ◽  
David Mota-Sanchez
Keyword(s):  
New York ◽  
Long Island ◽  
New York State ◽  
The United States ◽  
Island Population ◽  
Potato Beetle ◽  
Rate Of Increase ◽  
Short Period ◽  
Leptinotarsa Decemlineata Say ◽  
High Level

Abstract Eastern New York State is frequently the site of Colorado potato beetle (Leptinotarsa decemlineata, Say) populations with the highest observed levels of insecticide resistance to a range of active ingredients. The dominance of a resistant phenotype will affect its rate of increase and the potential for management. On organic farms on Long Island, L. decemlineata evolved high levels of resistance to spinosad in a short period of time and that resistance has spread across the eastern part of the Island. Resistance has also emerged in other parts of the country as well. To clarify the level of dominance or recessiveness of spinosad resistance in different parts of the United States and how resistance differs in separate beetle populations, we sampled in 2010 beetle populations from Maine, Michigan, and Long Island. In addition, a highly resistant Long Island population was assessed in 2012. All populations were hybridized with a laboratory-susceptible strain to determine dominance. None of the populations sampled in 2010 were significantly different from additive resistance, but the Long Island population sampled in 2012 was not significantly different from fully recessive. Recessive inheritance of high-level resistance may help manage its increase.

scholarly journals Native Amazonian Canga Grasses Show Distinct Nitrogen Growth Responses in Iron Mining Substrates

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 849
Author(s):  
Cecilio F. Caldeira ◽  
Madson O. Lima ◽  
Silvio J. Ramos ◽  
Markus Gastauer
Keyword(s):  
Native Species ◽  
Perennial Grasses ◽  
Growth Responses ◽  
Adaptive Traits ◽  
N Application ◽  
Gas Exchanges ◽  
Stomatal Morphology ◽  
Iron Mining ◽  
Adverse Environmental Conditions ◽  
Biomass Increase

Native species may have adaptive traits that are advantageous for overcoming the adverse environmental conditions faced during the early stages of mine land rehabilitation. Here, we examined the nitrogen (N) growth responses of two native perennial grasses (Axonopus longispicus and Paspalum cinerascens) from canga in nutrient-poor iron mining substrates. We carried out vegetative propagation and recovered substantial healthy tillers from field-collected tussocks of both species. These tillers were cultivated in mining substrates at increasing N levels. The tillering rates of both species increased with the N application. Nonetheless, only in P. cinerascens did the N application result in significant biomass increase. Such growth gain was a result of changes in leaf pigment, stomatal morphology, gas exchanges, and nutrients absorption that occurred mainly under the low N additions. Reaching optimum growth at 80 mg N dm−3, these plants showed no differences from those in the field. Our study demonstrates that an input of N as fertilizer can differentially improve the growth of native grasses and that P. cinerascens plants are able to deposit high quantities of carbon and protect soil over the seasons, thus, making them promising candidates for restoring nutrient cycling, accelerating the return of other species and ecosystem services.

scholarly journals Study on Tourism Flow Network Patterns on May Day Holiday

2021 ◽  
Vol 13 (2) ◽  
pp. 947
Author(s):  
Shanshan Wu ◽  
Lucang Wang ◽  
Haiyang Liu
Keyword(s):  
Transportation Network ◽  
Edge Structure ◽  
Flow Network ◽  
Factors Affecting ◽  
Spatial Distribution Characteristics ◽  
Transportation Modes ◽  
May Day ◽  
High Level ◽  
Network Patterns ◽  
Main Factor

The development of tourism is based on tourism flow and studying a tourism flow network can help to elucidate its mechanism of operation. Transportation network is the path to realize the spatial displacement of tourism flow. This study used “Tencent migration” big data to explore the spatial distribution characteristics and rules of tourism flow in China, providing suggestions for the development of tourism. The results demonstrate that the 361 cities studied can be divided into three types: destination-oriented, tourist-origin-oriented, and destination-oriented and tourist-origin-oriented. There are significant differences in the quantity of flow, the area of concentration, and the factors affecting the flow in the three types of cities. The larger the flow of tourism between cities, the higher the network level, and the wider the network range. The high-level nodes are closely related, while the peripheral nodes are more widely distributed, with weak attractiveness and inconvenient traffic, forming a “core-edge” structure. Different network patterns are established for different modes of transportation. The degree of response of different types of transportation to distance is the main factor influencing the network patterns of diverse paths. These findings have practical implications for the choice of appropriate travel destinations and transportation modes for tourists.

scholarly journals Influence of High Temperature on Photosynthesis, Antioxidative Capacity of Chloroplast, and Carbon Assimilation among Heat-tolerant and Heat-susceptible Genotypes of Nonheading Chinese Cabbage

HortScience ◽  
2017 ◽  
Vol 52 (11) ◽  
pp. 1464-1470 ◽  
Author(s):  
Lingyun Yuan ◽  
Yujie Yuan ◽  
Shan Liu ◽  
Jie Wang ◽  
Shidong Zhu ◽  
...  
Keyword(s):  
High Temperature ◽  
Chinese Cabbage ◽  
Photosynthetic Capacity ◽  
Photochemical Efficiency ◽  
Membrane Integrity ◽  
Photosynthetic Apparatus ◽  
Carbon Assimilation ◽  
Light Reaction ◽  
Chlorophyll Contents ◽  
Heat Tolerant

High temperature (HT) is a major environmental stress limiting oversummer production of nonheading Chinese cabbage (NHCC, Brassica campestris ssp. chinensis Makino). In the present study, the effects of HT on photosynthetic capacity, including light reaction and carbon assimilation, were completely investigated in two NHCC, ‘xd’ (heat-tolerant), and ‘sym’ (heat-susceptible). The two genotypes showed significant differences in plant morphology, photosynthetic capacity, and photosynthate metabolism (carboassimilation). HT caused a decrease in photosynthesis, chlorophyll contents, and photochemical activity in NHCC. However, these main photosynthetic-related parameters, including net photosynthetic rate (PN), maximal photochemical efficiency of PSII (Fv/Fm), and total chlorophyll content in ‘xd’, were significantly higher than those of ‘sym’ plants. The antioxidant contents and antioxidative enzyme activities of ascorbic acid-reduced glutathione cycle in the chloroplast of ‘xd’ were significantly higher than those of ‘sym’. Microscopic analyses revealed that HT affected the structure of photosynthetic apparatus and membrane integrity to a different extent, whereas ‘xd’ could maintain a better integrated chloroplast shape and thylakoid. Inhibited light reaction also hampered carbon assimilation, resulting in a decline of carboxylation efficiency and imbalance of carbohydrate metabolism. However, larger declined extents in these data were presented in ‘sym’ (heat-susceptible) than ‘xd’ (heat-tolerant). The heat-tolerant genotype ‘xd’ had a better capacity for self-protection by improved light reaction and carbon assimilation responding to HT stress.

Sign in / Sign up

Export Citation Format

Share Document