scholarly journals The effect of salinity stress on ions and soluble sugars distribution in leaves, leaf sheaths and roots of rice (Oryza sativa L.) seedlings

2011 ◽  
Vol 57 (No. 1) ◽  
pp. 26-33 ◽  
Author(s):  
I. Nemati ◽  
F. Moradi ◽  
S. Gholizadeh ◽  
M.A. Esmaeili ◽  
M.R. Bihamta

In order to investigate the solutes accumulation associated with salt tolerance of rice (Oryza sativa L.), two rice genotypes including IR651 (salt-tolerant) and IR29 (salt-sensitive) were grown hydroponically in the Youshida nutrient solution. Salinity treatment was imposed 3 weeks after sowing using NaCl in two levels 0 and 100 mmol. Samples were separately collected from the youngest (sixth) leaves, leaf sheaths and roots at 72 and 240 h after salinization; then Na<sup>+</sup>, K<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>, P, Mn<sup>2+</sup>, Cl<sup>&ndash;</sup> and total soluble sugars concentration and Na+/K<sup>+</sup> ratio were determined. Total dry weight of both genotypes decreased with the application of NaCl. Salinity caused higher accumulation of Na<sup>+</sup> and Cl<sup>&ndash;</sup> in the sixth leaf and leaf sheath of IR29 than in IR651 while their concentration in root of IR651 was higher. K<sup>+</sup> concentration was decreased in the sixth leaf and leaf sheath of IR29 under NaCl stress. Reduction in Ca<sup>2+</sup> and Mg2+ concentrations were observed in sixth leaves of both genotypes. P concentration was increased in leaf sheath and root of IR29 under saline conditions while it showed no changes in IR651. Our results indicated that the tolerant genotype had mechanisms to prevent high Na<sup>+</sup> and Cl<sup>&ndash;</sup> accumulation in the sixth leaf. High total soluble sugars concentration in shoot of IR651 is probably for adjusting osmotic potential and better water uptake under salinity. These mechanisms help plant to avoid tissue death and enable to continue its growth and development under saline conditions. &nbsp;

Author(s):  
Omid Sadeghipour

A pot experiment was conducted to investigate the role of methyl jasmonate (MeJA) in alleviation of the adverse effects of salinity on cowpea. Seeds were soaked in 0, 25 and 50 µM MeJA for 20 h and then the seedlings were irrigated with different concentrations of NaCl (0, 50 and 100 mM). Salt stress markedly decreased growth attributes namely shoot length, shoot and root dry weight and leaf area. NaCl stress also significantly reduced chlorophyll value, stomatal conductance, net photosynthetic rate, total soluble proteins and relative water content (RWC). Furthermore, salinity noticeably increased proline and total soluble sugars content. Nonetheless, seeds treatment with MeJA especially 50 µM, improved the growth of cowpea plants by increasing chlorophyll value, stomatal conductance, net photosynthetic rate, total soluble proteins, proline accumulation, total soluble sugars and RWC under salt stress conditions. Thus results indicate that pretreatment of seeds with MeJA could be used as an effective technique for improving cowpea plants tolerance to salt stress.


1968 ◽  
Vol 71 (1) ◽  
pp. 15-17
Author(s):  
B. A. C. Enyi

SummaryUpland rice (Agbede) and swamp rice (BG 79) varieties grown on flooded soil, and on soil maintained at 80 and 100% moisture saturation were sprayed with solutions containing 0 ppm (MO), 10 ppm (Ml), and 20 ppm (M2) of manganese.The M 2 treatment depressed total dry weight and dry weights of leaf laminae, stems, leaf sheaths and root of both varieties grown on soil maintained at either 80 or 100% moisture saturation. The M 1 treatment increased the ear weight of Agbede grown on soil maintained at either 80 or 100% moisture saturation, while the M 2 treatment increased the ear weight of plant grown on saturated soil. In flooded soil both the M 1 and M 2 treatments significantly increased dry weight of Agbede plants, but only the M 2 treatment increased ear dry weight of BG 79. The ear weight of Agbede plants receiving M 0 and M 1 treatment decreased with increasing soil moisture while that of BG 79 increased.It is considered that manganese supply limits yield of Agbede grain grown on flooded soil.


FLORESTA ◽  
2012 ◽  
Vol 42 (2) ◽  
pp. 347
Author(s):  
Ângela Simone Freitag ◽  
Felipe Uassurê Nery ◽  
Fabiana Ribeiro Rossi ◽  
Antônio Natal Gonçalves

 O presente trabalho teve por objetivo comparar o crescimento e desenvolvimento de explantes caulinares de C. citriodora nos meios de cultura JADS e MS, mensurando-se a produção de biomassa total, proteínas totais e açúcares totais solúveis. O delineamento experimental utilizado foi de blocos ao acaso, organizados em esquema bifatorial, com parcela subdividida no tempo com três repetições por tratamento. Tratamentos: T1 (testemunha, 40 ml de meio por frasco); T2 (40 ml de meio por frasco e adição de 10 ml no dia 6); T3 (40 ml de meio por frasco e adição de 10 ml nos dias 6 e 9). Como subparcelas, sete épocas de avaliação (0, 3, 6, 9, 12, 15, 18). Concluiu-se que para o meio JADS é mais recomendado que se efetuem duas adições de meio durante a fase desenvolvimento dos explantes. Já para o MS, aconselha-se não adicionar meio de cultura durante o desenvolvimento do C. citriodora.Palavras-chave: JADS; MS; micropropagação; desenvolvimento. AbstractComparative study between two environments for cultivation of Corymbia citriodora in vitro. This research aimed to compare growth and development of C. citriodora shoots in JADS and MS environments measuring the total dry weight, total proteins, and total soluble sugars. The experimental design employed was randomized blocks, arranged in bifactorial model, with timing split plots with three replications per treatment. Treatments: T1 (control, 40 ml of medium per bottle, without addition during the assessment), T2 (40 ml of medium per bottle adding 10 ml just on third day of assessment), T3 (40 ml of medium per bottle adding 10 ml on third and fourth days of assessment) as subplots, seven assessment periods (0, 3, 6, 9, 12, 15, 18). As result, for the medium JADS it is recommended two additions of culture medium during the explants development. For MS it is not indicated add cultivating environment during C. citriodora development.Keywords: JADS; MS; micropropagation; development.  


Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 945
Author(s):  
Pedro García-Caparrós ◽  
Francisco Sabio ◽  
Francisco Javier Barbero ◽  
Rosa María Chica ◽  
María Teresa Lao

Tomato and cucumber seedlings were grown in a growth chamber to evaluate the effects of different cycles of light–dark exposure conditions (T0 (control treatment) (1 cycle of 24 h distributed in 18 h of light exposure and six hours of dark), T1 (two cycles of 12 h distributed in nine hours of light exposure and three hours of dark) and T2 (three cycles of eight hours distributed in six hours of light exposure and two hours of dark) on growth, nutrient status, pigment concentration and physiological changes. Total dry weight showed different behaviors in both species, since in tomato the total dry weight remained unchanged under varying light–dark cycles, whereas in cucumber seedlings there was a clear decrease compared to the control treatment. In both species, plants grown under T2 showed the best water content. Nitrogen, P and K content—as well as partitioning in the different organs of the plants—displayed different patterns under varying cycles of light–dark conditions in both species. Chlorophyll (b and a + b) concentration decreased significantly in both species in T1 and T2 compared to the control treatment (T0). At physiological level, the concentration of total soluble sugars and proline in leaf showed the highest value in the control treatment with 18 h of light and six hours of dark.


2015 ◽  
Vol 12 (2) ◽  
pp. 74-82 ◽  
Author(s):  
Md. Habibur Rahman ◽  
Md. Mohashin Farazi ◽  
Kohinoor Begum ◽  
Md. Serazul Islam

Rice (Oryza sativa L.) is one of the major food crops in many countries. As the cultivation of rice requires huge volume of water, long term use of Arsenic contaminated groundwater for irrigation may result in the increase of arsenic concentration in the agricultural soil and eventually accumulation in rice grains. A micro level study was conducted to investigate the transfer of arsenic from irrigation water and soil to rice plants in the arsenic affected 8 unions of Chandina upazilla, Comilla district. The level of arsenic in irrigation water (0.12±0.08 and 0.67±0.07 mg l-1) was much above the WHO permissible limit of 0.01 mg l-1 for drinking water and FAO permissible limit of 0.10 mg l-1 for irrigation water. The total soil arsenic concentrations ranged from 3.21±0.80 to 8.74±2.83 mg kg-1 dry weight of soil, which was below the maximum acceptable limit for agricultural soil of 20.0 mg kg-1 as recommended by the European Community. The accumulation of arsenic in the grain ranged from 0.12±0.04 to 0.58±0.06 mg kg-1 in Boro and 0.16±0.04 to 1.06±0.20 mg kg-1 in T. Aman. Except grain sample (T. Aman) of one union, the grains in both Boro and T. Aman of all unions did not exceed 1.0 mg kg-1 dry weight of arsenic (the permissible limit of arsenic in rice according to WHO recommendation). Thus, till now rice has remained harmless for consumption in the study area. The results clearly showed that the arsenic content in the grains of Boro rice is correlated to the intensity of arsenic contamination of irrigation water and soil. The Agriculturists 2014; 12(2) 74-82


Author(s):  
P Jasmin ◽  
WZ Prian ◽  
MN Mondol ◽  
SM Ullah ◽  
AS Chamon

A pot experiment was conducted to evaluate the effect of lead (50, 100, 150 and 200 mg kg-1) on rice (Oryza sativa) and remediation of metal contamination by applying cow dung, poultry litter and lime to alleviate lead toxicity. The lengths, fresh and dry weights of shoot, root and macronutrients decreased with increasing level of lead compared to the control. The maximum reduction was observed in the pots treated with 200 mg kg-1 lead (19.50 and 20.03% for grain, 17.15 and 19.75% for shoot and 17.96 and 30.02% for root on the fresh and dry weight, respectively). The highest reduction in macronutrient content was observed in 200 mg kg-1 lead treated pot where N, P, K, Ca and Mg concentrations were reduced by 31.14, 47.44, 22.49, 21.84 and 31.58% for shoot and 28.95, 55.64, 37.5, 49.33 and 23% for root, respectively. On the other hand lead concentration in roots and shoots were increased with increasing lead treatment compared to the control. Treatments of the amendments (cow dung, poultry litter and lime) had positive effects though cow dung outshining the rest of them. This particular organic matter had considerable decreasing impacts in lead uptake by rice. Cow dung treated pots increased fresh and dry weight by 31.48 and 32.07% for grain, 14.08 and 35.30% for shoot and 57.09 and 34.48% for root compared to pot treated with 100 mg kg-1 lead. Cow dung remediated lead concentration by 48.85, 65.00 and 62.00% for grain, shoot and root, respectively. J. Biodivers. Conserv. Bioresour. Manag. 2019, 5(2): 83-92


2018 ◽  
Vol 16 (1) ◽  
pp. 44-54 ◽  
Author(s):  
M M Islam ◽  
E Kayesh ◽  
E Zaman ◽  
T A Urmi ◽  
M M Haque

Drought stress is a major constraint to the production and yield stability of crops. Rice (Oryza sativa L.) is considered as a drought-sensitive crop species. Within this species, there are considerable varietal differences in sensitivity to this environmental stress. An experiment was conducted at the laboratory of the Department of Agronomy, Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Bangladesh during April to September 2016 to evaluate 100 rice genotypes for drought tolerance during germination and early seedling growth stage. The genotypes were tested against five levels of drought stress imposed by Polyethylene glycol 6000 (PEG-6000) @ 0, 5, 10, 15 and 20%. The experiment was laid out in a complete randomized design with four replications. The results showed that with increasing water stress, germination in all the genotypes decreased from 95.8% in control to 6.6 % in highest stress (20% PEG) level. Seedling height and dry weight also decreased in all rice genotypes with the increase in water stress level. Based on Standard Evaluation System (SES),18 genotypes were selected primarily. Among the 18 genotypes, Ratoil and Chinisakkar showed higher germination index, relative seedling height and relative seedling dry weight than the check drought tolerant BRRI dhan43 at 20% PEG. Beside these, performance of Kumridhan, Pusur and Somondori was also well at this level compared to BRRI dhan43. The genotypes Ratoil, Chinisakkar, Kumridhan, Pusur and Somondori showed the best performance under drought condition. The Agriculturists 2018; 16(1) 44-54


1988 ◽  
Vol 15 (6) ◽  
pp. 777 ◽  
Author(s):  
R Basu ◽  
N Maitra ◽  
B Ghosh

Saline (NaCl) stress in germinated seedlings of rice cv. Rupsail causes an increase in polyamine content and concomitantly an enhancement of arginine decarboxylase (ADC) activity; in the case of putrescine, the increase is 100%. The responsiveness of coleoptiles and roots is different; ADC activity is maximum in roots and coleoptiles at 50 mM and 100 mM respectively. Difluoromethyl arginine, a potent inhibitor of ADC, reduces both polyamine accumulation and ADC activity. NaCl can enhance the activity of ADC by 1.6-fold in vitro. [14C]leucine incorporation into protein at 400 mM NaCl is decreased 4- and 10-fold in coleoptiles and roots, respectively. Efflux of sugar, amino acid, polyamines and total electrolytes increased gradually with the increase in concentration of salt. Influx of Na+ and Cl- and efflux of K+ in coleoptiles and roots are directly proportional to the concentration of NaCl applied.


2001 ◽  
Vol 81 (4) ◽  
pp. 815-819 ◽  
Author(s):  
I. M. Chung ◽  
J. K. Ahn ◽  
S. J. Yun

Experiments were conducted to identify allelochemicals from rice (Oryza sativa L.) straw extracts of four rice cultivars (Gin shun, Kasawala mundara, Philippine 2 and Juma 10), and to test their biological activity on barnyard grass (Echinochloa crus-galli P. Beauv. var. oryzicola Ohwi). High performance liquid chromatography (HPLC) analysis showed that the concentration and composition of allelopathic compounds depended on the cultivar. Among the compounds identified were p-hydroxybenzoic acid at 6.87 mg g–1 in Gin shun, p-coumaric acid at 0.34 mg g–1 in Kasawala mundara, ferulic acid at 0.05 mg g–1 in Philippine 2, and p-hydroxybenzoic acid at 6.34 mg g–1 in Juma 10. Preliminary identification by HPLC analysis resulted in peaks with retention times near those of standards, including p-hydroxybenzoic acid m/z = 138). This was confirmed with electron impact/mass spectra. In a bioassay with nine known allelochemicals and their mixtures, p-hydroxybenzoic acid (10–3 M) showed the greatest inhibitory effect on barnyard grass seed germination, seedling length, and dry weight. This suggests that this compound may be a key factor in rice allelopathy on barnyard grass. Key words: Allelopathic compound, rice, barnyard grass, bioassay


2015 ◽  
Vol 42 (11) ◽  
pp. 1026 ◽  
Author(s):  
Ping Deng ◽  
Dan Jiang ◽  
Yanmin Dong ◽  
Xingyu Shi ◽  
Wen Jing ◽  
...  

Salt-tolerant mutants are valuable resources for basic and applied research on plant salt tolerance. Here, we report the isolation and characterisation of a salt-tolerant rice (Oryza sativa L.) mutant. This mutant was identified from an ethyl methanesulfonate-induced Nipponbare mutant library, designated as rice salt tolerant 1 (rst1). The rst1 mutant was tolerant to salt stress and showed significantly higher shoot biomass and chlorophyll content, but lower lipid peroxidation and electrolyte leakage under NaCl stress. The improved salt tolerance of this mutant may be due mainly to its enhanced ability to restrict Na+ accumulation in shoots under salt stress conditions. Genetic analysis indicated that the salt tolerance of the rst1 mutant was controlled by a single recessive gene. Quantitative trait locus (QTL) mapping for salt tolerance was performed using an F2 population of rst1 × Peiai 64. Two QTLs were detected, in which the locus on chromosome 6 was determined to be the candidate locus of the rst1 gene. The rst1 locus was subsequently shown to reside within a 270.4-kb region defined by the markers IM29432 and IM29702. This result will be useful for map-based cloning of the rst1 gene and for marker-assisted breeding for salt tolerance in rice.


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