scholarly journals Effects of TiO2 nanoparticles and water-deficit stress on morpho-physiological characteristics of dragonhead (Dracocephalum moldavica L.) plants

2016 ◽  
Vol 107 (2) ◽  
pp. 385 ◽  
Author(s):  
Hamid Mohammadi ◽  
Mohammad Esmailpour ◽  
Ali GHERANPAYE

<p>Water-deficit stress is the most important environmental factors limiting plant growth, and production. Nano-titanium dioxide (nano anataseTiO<sub>2</sub>) can have various profound effects on the crop physiological, biochemical and morphological characteristics. In the present research, the influences of different concentrations ofTiO<sub>2</sub> nanoparticles (NPs) (0, 10 and 40 ppm) and water-deficit stress on Dragonhead (<em>Dracocephalum moldavica</em> L.) were investigated in a factorial experiment based on randomized complete block design with three replications. Results showed that under normal irrigation, foliar application of 10 ppm TiO<sub>2</sub> NPs increased plant shoot dry mass and essential oils content. Under water-deficit stress condition, plants treated with 10 ppm TiO<sub>2</sub> NPs had more proline and much less H<sub>2</sub>O<sub>2</sub> and malondialdehyde content as compared to untreated plants. Therefore, it can be concluded that proper concentration of TiO<sub>2</sub> NPs probably can be used as an exogenous stimuli for improvement of shoot growth and essential oil content in plants. Furthermore, water-deficit stress-induced damages such as oxidative stress and membrane damage can be ameliorated by foliar application of TiO<sub>2</sub> NPs at appropriate concentrations.</p>

2011 ◽  
Vol 39 (2) ◽  
pp. 153 ◽  
Author(s):  
Nourali SAJEDI ◽  
Hamid MADANI ◽  
Ahmad NADERI

This study was carried out to investigate effects of microelements under water deficit stress at different growth stages on antioxidant enzyme alteration, chemical biomarker and grain yield of maize in the years 2007 and 2008. The experiment was conducted in a split plot factorial based on a randomized complete block design with four replications. There were three factors, water deficit stress at different stages of growth as main plot and combinations of selenium (with and without using) and microelements (with and without using) as sub plots. The result indicated that the activity of superoxide dismutase and malondialdehyde content under water deficit stress increased, but grain yield was reduced. The highest grain yield was obtained from optimum irrigation, while in the case of with water deficit stress at V8 stage it was non significant. Selenium spray increased activity of superoxide dismutase enzyme, malondialdehyde content of leaves in V8, R2 and R4 stages and also grain yield. Application of microelements increased the leaves superoxide dismutase enzyme activity and malondialdehyde content. Selenium and microelements spray under water deficit stress conditions during vegetative growth and dough stage increased grain yield in comparison to not spraying elements under water stress conditions. The present results also showed that by using selenium and microelements under water stress can obtain acceptable yield compared to not using these elements.


Author(s):  
Reynaldo Teodoro de Fatima ◽  
Jackson Silva Nobrega ◽  
Daniel De Almeida Carreiro ◽  
Amaralina Celoto Guerrero ◽  
Adriana Silva Lima ◽  
...  

Aims: The study was conducted to evaluate the fluorescence and growth of eggplant under influence of water deficit and silicon doses. Study Design: The design was a randomized complete block design, in a 5 x 2 factorial arrangement, with four replications and one plant per plot, totaling 40 experimental units. Length and Place of Study: The research was implemented between September and November 2016, in a greenhouse of the Center of Science and Technology Agrifood, at the Federal University of Campina Grande (UFCG / CCTA), Campus of Pombal-PB, Brazil. Methods: Doses of 0, 75, 150, 225 and 300 mg L-1 of silicon and the irrigation slides of 50 and 100% of real evapotranspiration - ETr were used, which were obtained by weighing the pots daily in order to keep the weight close to the field capacity. Results: The use of 50% level of the ETr provides reductions of 5.58; 7.92 and 6.84% of fluorescence in the initial, maximum and quantum yield of the photosystem. The fresh and dry mass of the stem presented the maximum productivity (140.8 and 48.1 g) in the plants irrigated with 100% Etr and treated with doses of 106 and 110 mg L-1 of Si. Conclusion: The fluorescence and biomass of the eggplant plants is reduced with the decrease in irrigation level; while the application of silicon does not result in increment in the fluorescence and dry mass of the leaf. The 100% irrigation level of the ETr associated with the application of 108 mg L-1 of silicon resulted in the best results in stem mass accumulation.


2019 ◽  
Vol 39 (04) ◽  
Author(s):  
Aliakbar Saneienejad ◽  
Mahmood Tohidi ◽  
Behnam Habibi Khaniani ◽  
Mehdi Sadeghi

The aim of this study was to investigate the effect of foliar application of methanol on the activity of antioxidant enzymes of Vigna unguiculata L. in water-deficit stress conditions. The trials were performed in a split plot design arranged in completely randomized block design with three replications in two years cultivation (2017 and 2018). Water-deficit stress treatments were considered in the main plots in four levels (25, 50, 75 and 100% of plant water requirement) and combined foliar application of methanol treatment in three levels (control, 10 and 20% vol.), and genotype treatment in two cultivars of Omidbakhsh 1057 and Mashhad in sub plots. The results showed that the effect of water-deficit stress and foliar application of methanol on the activity of antioxidant enzymes were significant (P £ 0.01). The effect of genotype on the activity of ascorbate peroxidase was just significant (P £ 0.01).


2017 ◽  
Vol 63 (4) ◽  
pp. 128-141
Author(s):  
Mohsen Janmohammadi ◽  
Farzaneh Asadi ◽  
Naser Sabaghnia ◽  
Amin Abbasi ◽  
Mojtaba Nouraein ◽  
...  

Abstract Safflower is originated from Iran and is tolerant against water deficit stress. However, in semi-arid Mediterranean climate terminal drought and heat stress adversely affect the safflower production. In order to investigate the influence of foliar application of proline (Pr) (10 and 20 mM) and glycinebetaine (GB) (2 and 4 mM) under well and deficit irrigation (37.23° N,46.16° E). Foliar spray of compatible organic solutes started from middle vegetative growth and continued till seed filling stage. Comparison of well irrigated and stress conditions revealed that severity of water deficit stress (SI) was 0.25. Evaluation of growth-related morphological characteristics such as plant height, leaf area, canopy spread and percent ground cover showed that they considerably reduced by water deficit stress. However, foliar application of compatible solutes could somewhat increase growth related parameters. Results showed that water deficit stress noticeably reduced the chlorophyll content, while foliar spray could alleviate the water deficit stress effects when compared with intact plant (non-sprayed plants). The beneficial effect of GB was more prominent than Pr, especially under deficit irrigation condition. Principal component analysis (PCA) indicated that the best performance under well irrigated condition was obtained by application of 4 mM GB while under deficit irrigation condition the best performance was recorded for plants treated with 2 and 4 mM GB and 20 mM Pr. Overall, results of current experiments showed that foliar spray with high concentration of GB may can significantly alleviate the adverse effects of water deficit stress.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. A. Gomaa ◽  
Essam E. Kandil ◽  
Atef A. M. Zen El-Dein ◽  
Mamdouh E. M. Abou-Donia ◽  
Hayssam M. Ali ◽  
...  

AbstractIn Egypt, water shortage has become a key limiting factor for agriculture. Water-deficit stress causes different morphological, physiological, and biochemical impacts on plants. Two field experiments were carried out at Etay El-Baroud Station, El-Beheira Governorate, Agriculture Research Center (ARC), Egypt, to evaluate the effect of potassium silicate (K-silicate) of maize productivity and water use efficiency (WUE). A split-plot system in the four replications was used under three irrigation intervals during the 2017 and 2018 seasons. Whereas 10, 15, and 20 days irrigation intervals were allocated in main plots, while the three foliar application treatments of K-silicate (one spray at 40 days after sowing; two sprays at 40 and 60 days; and three sprays at 40, 60, and 80 days, and a control (water spray) were distributed in the subplots. All the treatments were distributed in 4 replicates. The results indicated that irrigation every 15 days gave the highest yield in both components and quality. The highly significant of (WUE) under irrigation every 20 days. Foliar spraying of K-silicate three times resulted in the highest yield. Even under water-deficit stress, irrigation every fifteen days combined with foliar application of K-silicate three times achieved the highest values of grain yield and its components. These results show that K-silicate treatment can increase WUE and produce high grain yield requiring less irrigation.


2015 ◽  
Vol 28 (3) ◽  
pp. 230-238 ◽  
Author(s):  
PHILIPE LIMA DE AMORIM ◽  
JANAINA AZEVEDO MARTUSCELLO ◽  
JOSÉ TEODORICO DE ARAÚJO FILHO ◽  
DANIEL DE NORONHA FIGUEIREDO VIEIRA DA CUNHA ◽  
LIANA JANK

ABSTRACT: Cultivars of the genus Nopalea are known in Brazil for being tolerant to cochineal carmine attacks, thus making the cultivation of this genus a promising alternative for mitigating the negative effects of this insect on the production of biomass. With the objectives of characterizing morphologically spineless forage cactus varieties and identify morphological characteristics that may be the focus in spineless forage cactus breeding programs, an experiment was conducted in a completely randomized block design with 11 treatments and four replications. The variety Alagoas showed the highest values of weight, area and volume of cladodes. The varieties Negro Michoacan F7 and V7, Tamazunchale V12 showed the highest values of the cladode area index, the total volume of cladodes and total fresh mass production. The varieties Negro Michoacan V7 and F7 presented the highest water use efficiency and dry mass yield. Cladode volume showed the highest correlation coefficients with the fresh weight of cladodes. Aiming the release of varieties for biomass production, varieties Negro Michoacan F7, V7 and Tamazunchale V12 may substitute the Miúda variety. The number and cladode area index may be used as criteria for selection of superior varieties in breeding programs.


2013 ◽  
Vol 31 (3) ◽  
pp. 695-703 ◽  
Author(s):  
S.R. Marchi ◽  
D. Martins ◽  
N.V. Costa ◽  
J.R.V. Silva

This trial aimed to evaluate the effect of sequential applications of different plant regulators over growth and flower rachis emission of 'Meyer' zoysiagrass (Zoysia japonica). The study was conducted on 15-month old green turfgrass under a randomized complete block design with four replications. The following plant regulator and doses were tested: trinexapac-ethyl (113+113, 226+113, 226+226, 452+113, 452+226, 452+452, 678+339 e 904+452 g a.i./ha-1), prohexadione-calcium (100+100 e 200+200 g a.i. ha-1) and bispyribac-sodium (40+40 e 60+60 g a.i. ha-1), as well as an untreated control. The turfgrass was mowed again at 3.0 cm aboveground and the second plant regulator was applied when 'Meyer' zoysiagrass was between 5.0 and 6.0 cm high. The effect of the treatments was visually rated for visual injury, plant height, height and number of flower rachis, and total dry mass production of clippings. Only bispyribac-sodium had visual symptoms of injury on 'Meyer' zoysiagrass, and no intoxication was observed at 28 days after the second application (DAAB). The sequential applications of trinexapac-ethyl, prohexadione-calcium and bispyribac-sodium reduced by more than 80% the total clipping dry mass produced by 'Meyer' zoysiagrass. All the plant regulators tested also showed promising results in reducing the height and emission of rachis, especially when trinexapac-ethyl was applied at the doses 452+452, 678+339 and 904+452 g a.i. ha-1. 'Meyer' zoysiagrass turfgrass can be handled with the sequential application of a plant regulator, which reduces the need for mowing over a period up to 110 days after the application of the second plant regulator, and it also avoids deleterious visual effects over turfgrass.


Nativa ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 50
Author(s):  
Kassio Ewerton Santos Sombra ◽  
Andreza Cristina Chagas de Oliveira ◽  
Ronyce Do Nascimento Ferreira ◽  
Alexandre Caique Costa e Silva ◽  
Cleilson Do Nascimento Uchôa ◽  
...  

O trabalho objetivou avaliar os efeitos do excesso de ferro sobre a emergência e desenvolvimento inicial de genótipos de porta-enxertos cítricos. Adotou-se delineamento em blocos casualizados (DBC), em fatorial 5x2, com cinco porta-enxertos e dois substratos, repetidos quatro vezes, com parcela útil de 15 recipientes. Os genótipos consistiram do limoeiro ‘Cravo Santa Cruz’; citrandarins ‘Riverside’, ‘San Diego’ e ‘Índio’, além de, tangerineira ‘Sunki Tropical’, cultivados com ou sem óxido de ferro no substrato. Analisaram-se as porcentagens de emergência (PE) e calculou-se o índice de velocidade de emergência (IVE). Realizaram-se biometrias aos 30, 60 e 90 dias após a semeadura (DAS), mensurando-se a altura (H) e diâmetro de caule (D) das plântulas, determinando-se massa fresca (MV) e seca (MS). O excesso de ferro induziu subdesenvolvimento, e até mortalidade de plântulas já emergidas, o que refletiu diretamente nos resultados, porém, todos os genótipos apresentaram emergência superior a 75%, destacando-se o citrandarin ‘San Diego’, com maior altura e caule mais espesso, e o citrandarin ‘Riverside’ com maior sensibilidade ao estresse, registrando os menores valores. O citrandarin ’San Diego’ demonstrou tolerância o estresse e desenvolveu-se satisfatoriamente, necessitando estudos que avaliem a manutenção das características inferidas em combinação com a cultivar copa.Palavras-chave: ambiente protegido, citricultura, enxertia, estresse, mudas. EXCESS OF IRON ON THE DEVELOPMENT OF CITRUS ROOTSTOCKS ABSTRACT: The objective of this work was evaluated the effects of iron excess on the emergence and initial development of citrus rootstock genotypes. A randomized complete block design (DBC), factorial 5x2, with five rootstocks and two substrates, repeated four times, with useful plot of 15 containers was adopted. Genotypes consisted of the 'Santa Cruz' Rangpur lemon; 'Riverside', 'San Diego' and 'Indio' citrandarins, as well as 'Sunki Tropical' tangerine, grown with or without iron excess in substrate. The percentages of emergency (PE) were analyzed and the rate of emergency (IVE) was calculated. Biometry was performed at 30, 60 and 90 days after sowing (DAS), by measuring the height (H) and stem diameter (D) of the seedlings, determining fresh (MV) and dry mass (DM). The excess of iron induced underdevelopment, and even mortality of already emerged seedlings, which reflected directly in the results, however, all genotypes presented an emergency higher to 75%, standing out ’San Diego’ citrandarin, with greater height and more stem thick, and the ‘Riverside’ citrandarin with greater sensitivity to stress, registering the lowest values. 'San Diego’ citrandarin demonstrated stress tolerance and developed satisfactorily, requiring studies that evaluate maintenance of inferred characteristics in combination with cultivar canopy.Keywords: protected environment, citriculture, grafting, stress, seedlings.


Bragantia ◽  
2011 ◽  
Vol 70 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Leonardo Bianco de Carvalho ◽  
Pedro Luis da Costa Aguiar Alves ◽  
José Valcir Fidelis Martins

Determination of competitive relationships among plant species requires appropriate experimental designs and method of analysis. The hypothesis of this research was that two species growing in coexistence show different growth and development due to their relative competitiveness. This research aims to measure the relative competitiveness of wheat crop compared to Alexandergrass by the interpretation of plant density and proportional effects using replacement series experiments. Monocultures were cultivated in densities of 1, 3, 5, 10 and 15 plants per pot and analyzed by regression of dry mass data. Mixture experiment was cultivated in wheat:Alexandergrass proportions of 0:6, 1:5, 2:4, 3:3, 4:2, 5:1 and 6:0 plants per pot and analyzed by graphical interpretation of growth and production characteristics. Both experiments were carried out in randomized complete block design with four replicates. Alexandergrass was more sensitive to intraspecific competition than wheat. Alexandergrass was lightly more competitive than wheat. Number and weight of spikes and number of tillers were the wheat characteristics more affected by Alexandergrass interference.


Agronomy ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 138 ◽  
Author(s):  
Rujira Tisarum ◽  
Cattarin Theerawitaya ◽  
Thapanee Samphumphung ◽  
Teruhiro Takabe ◽  
Suriyan Cha-um

The aim of this investigation was to enhance overall growth, yield attributes as well as physio-biochemical adaptive strategies by exogenous foliar application of glycine betaine (GlyBet) in two rice varieties against water deficit stress under greenhouse conditions. Rice crop cvs. RD43 (low amylose content) and SPR1 (high amylose content) grown in clay pots containing garden soil until booting stage were chosen as the test plant material, sprayed by 0 (control) or 100 mM GlyBet and subsequently subjected to: MWD (mild water deficit by 8 d water withholding; 24.80% SWC; Soil water content) or SWD (severe water deficit by 14 d water withholding; 13.63% SWC) or WW (well-watered conditions or control). Free proline content in cv. RD43 was rapidly increased in relation to the degree of water deficit and suppressed by exogenous GlyBet, while free proline in cv. SPR1 was lower than cv. RD43. Overall growth performances and yield traits in both cultivars under MWD were maintained by exogenous application of GlyBet; however, these parameters declined under SWD even after the GlyBet application. Degradation of photosynthetic pigments and chlorophyll fluorescence in pretreated GlyBet plants under SWD were prevented, resulting in elevated net photosynthetic rate (Pn). Interestingly, Pn was very sensitive parameter that sharply declined under SWD in both RD43 and SPR1 genotypes. Positive relationships between physio-morphological and biochemical changes in rice genotypes were demonstrated with high correlation co-efficiency. Based on the key results, it is concluded that foliar GlyBet application may play an important role in drought-tolerant enhancement in rice crops.


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