scholarly journals Comparative impact of different iso-osmotic solutions on osmotic adjustment in Gossypium barbadense

2020 ◽  

<p>To discriminate the specific response of ion toxicity versus osmotic stress on altering leaf solute contents, contributing of organic and/or inorganic components in osmotic adjustment and its reflection on plant performances under ionic and osmotic stresses, two cotton (Gossypium barbadense L.) cultivars, Giza 90 and Giza 83, were subjected to iso-osmotic concentration (–0.57 and –1.05 MPa) created by; NaCl, KCl and polyethylene glycol-6000. The three used osmotica altered seedling length, chlorophyll, leaf dry weight, relative water content, organic and inorganic solutes and proline. Contribution of organic solutes to osmotic adjustment tittered among the two cultivars, it was higher in PEG˃ KCl˃ NaCl in Giza 83, suggesting that the character of osmotic adjustment via salt attuned to high yield with moderate ion toxicity is effectively achieved by KCl than NaCl. At high-stress intensities, regardless to cultivar, the salt stress-induced nutritional imbalance, leaf chlorosis than osmotic stress that could be attributed to specific ion toxicity, not to osmotic stress of salt. In salt sensible cultivar only NaCl, among different osmotica, reduced leaf K+ content implying that avoidance of Na-induced K+ deficiency in leaf might stimulate salt tolerance in cotton. In our study, the capacity of plants to regulate their metabolic and physiological functions had superiority in water stress tolerance rather than osmotic adjustment.</p>

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1615
Author(s):  
Zikria Zafar ◽  
Fahad Rasheed ◽  
Ahsan Ul Haq ◽  
Faridah Hanum Ibrahim ◽  
Shazia Afzal ◽  
...  

Mitigating climate change requires the identification of tree species that can tolerate water stress with fewer negative impacts on plant productivity. Therefore, the study aimed to evaluate the water stress tolerance of young saplings of C. erectus and M. alba under three soil water deficit treatments (control, CK, 90% field capacity, FC, medium stress MS, 60% FC and high stress, HS, 30% FC) under controlled conditions. Results showed that leaf and stem dry weight decreased significantly in both species under MS and HS. However, root dry weight and root/shoot ratio increased, and total dry weight remained similar to CK under MS in C. erectus saplings. Stomatal conductance, CO2 assimilation rate decreased, and intrinsic water use efficiency increased significantly in both species under MS and HS treatments. The concentration of hydrogen peroxide, superoxide radical, malondialdehyde and electrolyte leakage increased in both the species under soil water deficit but was highest in M. alba. The concentration of antioxidative enzymes like superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase also increased in both species under MS and HS but was highest in C. erectus. Therefore, results suggest that C. erectus saplings depicted a better tolerance to MS due to an effective antioxidative enzyme system.


Author(s):  
N. I. Kasatkina ◽  
Zh. S. Nelyubina

The biological properties of plants, their mutual relations under different growth conditions and at different periods of their life, must be known for obtaining highly productive agrophytocenoses with participation of a meadow clover (Trifolium pratense L.). Botanical composition and fodder productivity of perennial grasses in agrocenoses with participation of meadow tetraploid clover Kudesnik were studied in 2014-2017. It was revealed that in the first and second years of use the agrophytocenosis, the yield of green mass was formed due to meadow tetraploid clover, the share of its participation in the first mowing was at level of 71-87% and 64-97% respectively. Specific weight of clover in multispecies agrocenoses considerably decreased by the third year of use: in the first mowing up to 32-68%, in the second - up to 8-52%. At the same time, the percentage of long-term herbaceous grasses increased: meadow timothy (Phleum pratense L.) - up to 34-54%, eastern galega (Galéga orientális Lam.) - up to 33%, changeable alfalfa (Medicago x varia Martyn) - up to 22-54%, lotus corniculatus (Lotus corniculatus L.) - up to 14-19%. The proportion of weed admixture in single-species clover planting was 12%, in agrocenoses - 2-14%. The grass mixtures clover + timothy and clover + alfalfa + timothy were less infested by weeds. High yield of dry weight of single-species sowing of meadow tetraploid clover was obtained in the first two years of use - 7.8 and 6.5 tons / ha, respectively. By the third year of use, the productivity of clover has decreased to 2.9 t / ha. On average, for three years of use, the highest yield (6.2-6.3 t / ha) was formed by agrocenoses meadow tetraploid clover + meadow timothy and meadow tetraploid clover + changeable alfalfa + meadow timothy.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 889
Author(s):  
Aviad Perry ◽  
Noemi Tel-Zur ◽  
Arnon Dag

Jojoba (Simmondsia chinensis) is a wax crop cultivated mainly in arid and semi-arid regions. This crop has been described as an alternate-bearing plant, meaning that it has a high-yield year (“on-year”) followed by a low-yield year (“off-year”). We investigated the effect of fruit load on jojoba’s vegetative and reproductive development. For two consecutive years, we experimented with two high-yielding cultivars—Benzioni and Hazerim—which had opposite fruit loads, i.e., one was under an on-year load, while the other was under an off-year load simultaneously. We found that removing the developing fruit from the shoot during an off-year promotes further vegetative growth in the same year, whereas in an on-year, this action has no effect. Moreover, after fruit removal in an on-year, there was a delay in vegetative growth renewal in the consecutive year, suggesting that the beginning of the growing period is dependent on the previous year’s yield load. We found that seed development in the 2018 season started a month earlier than in the 2017 season in both cultivars, regardless of fruit load. This early development was associated with higher wax content in the seeds. Hence, the wax accumulation rate, as a percentage of dry weight, was affected by year and not by fruit load. However, on-year seeds stopped growing earlier than off-year seeds, resulting in smaller seeds and an overall lower amount of wax per seed.


2018 ◽  
Vol 15 (2) ◽  
pp. 177-192
Author(s):  
RR Saha ◽  
A Hannan ◽  
A Nessa ◽  
MA Malek ◽  
MR Islam

An experiment on hundred wheat genotypes under different levels of osmotic stress was carried out during 2014 to select the genotype(s) tolerant to drought at germination and early seedling stage. Different levels of osmotic stress were imposed by using polyethylene glycol (PEG). Three osmotic stress levels viz. control (distilled water), 15% PEG solution and 25% PEG solution were used. Among the 100 genotypes the rate of germination percentage, final germination (%), root and shoot dry weight, amount of respiration and vigour index under PEG treatment was found significantly lower than that of control condition. Compared to control condition relative decrease in rate of germination, final germination, amount of respiration and vigour index among the wheat genotypes were found more at 25% PEG than that of 15% PEG treatment. However, the seed metabolic efficiency was significantly higher in wheat genotypes under both 15% PEG and 25% PEG treatment compared to the control condition. A significant positive correlation exists between the important growth parameters like rate of germination (%), final germination (%), shoot dry weight, root dry weight and vigour index. On the basis of these physiological traits against osmotic stress, nine genotypes of wheat such as BD-480, BD-498, BD- 501, BD-513, BD-514, BD-519, BD-592, BD-618 and BD- 633 were selected as drought tolerant.SAARC J. Agri., 15(2): 177-192 (2017)


2016 ◽  
Vol 4 (2) ◽  
pp. 206-214 ◽  
Author(s):  
Zaid Chachar ◽  
N. A. Chachar ◽  
Q.I. Chachar ◽  
S.M Mujtaba ◽  
G.A Chachar ◽  
...  

Climate change is emerging phenomena and causing frequent drought which lead to scaricity of water, which ultimately nagetively affecting wheat (Triticumaestivum L.) yield all around the world. The aim of this study was to explore the potential deought tolerant wheat genotypes for candidate genes exploration. This study was conducted during the year 2014-2015 at Plant Physiology Division, Nuclear Institute of Agriculture (NIA) Tandojam. The six wheat genotypes (cv. MT-1/13, MT-2/13, MT-3/13, MT-4/13 Chakwal-86 and Khirman) were investigated for their response at germination and seedling stage under different water stress treatments (0, -0.5, -0.75 and -1.0 MPa) in controlled conditions. The results of experiments with reference to genotypes revealed that genotype Chakwal-86 shows maximum seed germination (82.58 %), while the genotype Khirman shows maximum shoot length  (7.23 cm), root length  (15.1 cm), shoot fresh wt. (5.85 g 10-1shoots), root fresh wt.  (3.45 g 10-1roots), shoot dry wt. (1.33 g 10-1shoots), root dry wt. (0.69 g 10-1roots). Among the genotypes tested Khirman and MT-4/13 are the tolerant genotypes had the potential to perform better under drought conditions, whereas  MT-4/13 and Chakwal-86 were moderate tolerant under water stress conditions. Moreover, the genotypes i.e. MT-1/13 and MT-2/13 are the sensitive genotypes under drought environment. It is concluded from present in-vitro studies that osmotic stress significantly reduced the seed germination shoot/root length fresh and dry weight in all six wheat genotypes. The maximum reduction was found at higher osmotic stress induced by PEG-6000 (-1.0 MPa) significantly.


Agriculture ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 198 ◽  
Author(s):  
Suzanne Goh ◽  
Thohirah Lee Abdullah ◽  
Siti Hassan ◽  
Johnson Stanslas

Zingiber zerumbet (L.) Smith, known as Lempoyang in Malaysia, belongs to the family Zingiberaceae. Previous studies on Lempoyang mainly focused on the chemical properties and biological activities of the rhizome extracts of this plant. Despite the tremendous demand for the rhizomes of Z. zerumbet, there is a lack of information on cultivation practices and a scarcity of planting materials. By using the pre-soaked technique, the challenges posed by Z. zerumbet dormancy can be overcome, obtaining good quality and uniform planting material throughout the year. Besides that, it is also crucial to determine the optimum shade level and NPK fertilizer rates to obtain a high yield and good quality rhizomes of Lempoyang. Six concentrations of 6-benzylaminopurine (BAP, 0, 50, 100, 150, 200, and 250 mg/L) and ethephon (0, 150, 300, 450, 600, and 750 mg/L) were tested to evaluate their effects on breaking rhizome dormancy. Three different shade levels (full sun, 30%, and 50% shade levels) and four combinations of Nitrogen (N), phosphorus (P), and potassium (K) (NPK) fertilizer at different rates were evaluated to study their effects on plant growth and yield performance. The results showed that BAP at 100 mg/L and ethephon at 300 mg/L performed better than the other compound concentrations tested in promoting the breaking of bud dormancy. A significant interaction effect was observed between shade levels and NPK fertilizer rates in all the growth parameters examined, except for the number of tillers per plant. Plants grown under 30% shade with NPK 4 produced the highest rhizome fresh weight, dry weight, and yield, but plants grown under 50% shade with NPK 4 showed the highest plant height and number of tillers per plant.


2018 ◽  
Vol 47 (1) ◽  
pp. 183-193 ◽  
Author(s):  
Tuncay TURSUN ◽  
Sener AKINCI ◽  
Esin BOZKURT

Boron is an important micronutrient, required for all plant growth, and critical for high yield and quality of crops. The aim of the present research was to determine the effects of boron on pot-grown parsley (Petroselinum sativum Hoffm.). The experimental design consisted of four treatments using Hoagland-Arnon (1950) nutrient solutions with two different boron concentrations (B1 - 15 ppm and B2 - 150 ppm), each with and without 10 ml humic acid addition (HB1 and HB2), and controls with full strength Hoagland-Arnon solutions. Growth analyses of the parsley revealed that 15 ppm boron application caused an increase in root length leaf fresh and dry weight root fresh and dry weight and leaf area compared to control values. 150 ppm B (B2) concentration decreased all growth parameters compared to controls. The two humic acid treatments (HB1 and HB2) did not increase any of those growth parameters either in controls (C) or in the two boron (B1 and B2) concentrations. Analysis by (ICP-MS) revealed that B content in the leaves increased gradually in B1 and B2, as well as in both humic treatments where in HB2 it increased to 99.38% compared to B1. In the leaves, Mn, Zn and Fe contents behaved the same as B, increasing in all treatments, with the amounts in HB2 being significantly greater than in C, B1 and B2 leaves.


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