Decreased Germination Percentage Research Articles

Ameliorative effects of TiO2 nanoparticles and sodium nitroprusside on seed germination and seedling growth of wheat under PEG-stimulated drought stress

Abstract: Seed germination and early seedling growth are sensitive to drought stress in wheat. A factorial experiment was arranged based on a completely randomized design with three replicates to study the impacts of TiO2 nanoparticles (TiO2 NPs: 0, 500, 1000 and 2000 mg.L) and sodium nitroprusside (SNP: 0 and 100 μM), as NO donor, on seed germination and seedling growth of wheat under polyethylene glycol (PEG)-induced drought stress (0, -0.4 and -0.8 MPa). Our results revealed that PEG-stimulated drought stress significantly decreased germination percentage (GP), germination energy (GE), germination rate (GR), root length (RL), shoot length (SL), root fresh weight (RFW), shoot fresh weight (SFW) and vigor index (VI) but increased mean germination time (MGT) in wheat seeds. However, application of TiO2 NPs and SNP alone or in combination significantly enhanced GP, GE, GR, RL, SL, RFW, SFW and VI up to 23.72%, 50%, 33.74%, 85.38%, 93.28%, 73%, 91.91% and 91.04% respectively, but significantly reduced MGT up to 28.36% under severe drought stress. Our results showed that application of TiO2 NPs and SNP alone or in combination can significantly alleviate the adverse effects of PEG-stimulated drought stress on seed germination and early seedling growth of wheat.

Respon Beberapa Genotip Kacang Tunggak (Vigna unguiculata L.) terhadap Cekaman Salinitas

Salinity stress in plants still an important problem in agriculture throughout the world. Salinity makes plants unable to grow and produce well. Cowpea is one of the legume plants that is tolerant of drought and acidity so that it is prospectively developed on land such as dry land and acid soils. The purpose of this study was to determine cowpea genotypes that showed the most tolerant response to salinity and to know the interaction of genotypes and salinity. The tools used in the study were stationery,shovels,buckets,dipper,rulers,analytical scales,camera, pots, portable EC meters,chlorophyll meters. The materials used in the study were the seeds of ten cowpea genotypes (MLG 17013, MLG 17019,MLG17027,MLG17042,MLG17051,MLG17055,MLG17057,MLG17060,KT-4,KT-5),soil,water,fertilizer,urea,TSPfertilizer,KCL fertilizer, manure, NaCl and labels. This study using slit plot design with 3 replications. The mainplot is EC soil at 4 dS/m and 8 dS/m and nonstress. The subplot is 10 genotypes of cowpea. The study was carried out in a greenhouse of the Various Peanut and Tuberculosis Research Institute,Malang Regency,East Java. The research was conducted from March to June 2018. The results of the study were that salinity affected the decrease in germination percentage,plant height, number of branches, chlorophyll index,weight of pod/plant, number of pods/plants,length of pods/plants, weight of 100 seeds,weight of planting seeds,age of flowering and age of harvesting. The conclusions from the study were that the 3 most tolerant genotypes based on stress tolerance index (ITC) and based on scoring of cowpea plants showed tolerance from somewhat tolerant to sensitive.

Dimethylthiourea antagonizes oxidative responses by up-regulating expressions of pyrroline-5-carboxylate synthetase and antioxidant genes under arsenic stress

Dimethylthiourea is an important plant growth regulator that mediates various physiological and metabolic processes of the plants. In the present study, role of dimethylthiourea in conferring arsenic stress tolerance to Cajanus cajan L. was investigated. Exposure to arsenic resulted in oxidative damage as evidenced by decreased germination percentage, radicle length, biomass accumulation, membrane stability index, protein, glyoxalase I and II, and antioxidants, together with enhanced cell death, reactive oxygen species, lipid peroxidation and activity of lipoxygenase in C. cajan L. However, exogenous application of dimethylthiourea along with arsenic decreased the reactive oxygen species and lipoxygenase activity, while increased the membrane stability index and antioxidants activities. Moreover, dimethylthiourea also up-regulated the glyoxalase (I and II) activity and the gene expression of antioxidants under arsenic stress. Also, dimethylthiourea application reduced the arsenic content than that measured in arsenic alone treated samples. Interestingly, treatment of dimethylthiourea uplifted the contents of ascorbic acid and glutathione, together with proline via up-regulating the activity and gene expression of pyrroline-5-carboxylate synthetase, one of the chief enzymes of its biosynthetic pathway. Enlisted findings suggested that dimethylthiourea can improve plant resistance to arsenic toxicity by regulating the gene expression of antioxidants and proline biosynthesizing enzymes, thereby reducing reactive oxygen species, lipid peroxidation and arsenic accumulation.

Genetic variability for seedling stage salinity tolerance in barnyard millet [Echinochloa frumentaceae (Roxb.) Link

Barnyard millet (Echinochloa frumentaceae) has a potential to withstand salinity. The existing genetic variability for salinity tolerance in 32 barnyard millet accessions was assessed based on the morpho-physiological parameters governing salt tolerance viz., germination percentage, relative germination rate, root length, shoot length, seedling length, vigour index, relative salt injury rate and relative water content. Under gradual increase in the intensity of salt stress, decrease in germination percentage, relative germination rate, root length, shoot length, seedling length, vigour index, relative water content and increase in relative salt injury rate was observed. The antioxidant assay also revealed that catalase and peroxidase activity increased with rise in salt level in tolerant genotypes (ACM161, ACM295, ACM335, GECH10, IEc167) but the enzyme activity in the salt sensitive genotypes (IEc134, IEc348, IEc607) declined with increase in salt concentration, when compared to control. The salt tolerant genotypes maintained higher relative water content and enzyme activity under salt stress. Hence, this may be the underlying mechanism for salt tolerance.

Pretreatment with NaCl Promotes the Seed Germination of White Clover by Affecting Endogenous Phytohormones, Metabolic Regulation, and Dehydrin-Encoded Genes Expression under Water Stress.

This study was designed to examine the effects of NaCl pretreatment on the seed germination of white clover (Trifolium repens cv. Ladino) under water stress induced by 19% polyethylene glycol (PEG) 6000. Lower concentrations of NaCl (0.5, 1, and 2.5 mM) pretreatment significantly alleviated stress-induced decreases in germination percentage, germination vigor, germination index, and radicle length of seedlings after seven days of germination under water stress. The soaking with 1 mM of NaCl exhibited most the pronounced effects on improving seed germination and alleviating stress damage. NaCl-induced seeds germination and growth could be associated with the increases in endogenous gibberellic acid (GA) and indole-3-acetic acid (IAA) levels through activating amylases leading to improved amylolysis under water stress. Seedlings pretreated with NaCl had a significantly lower osmotic potential than untreated seedlings during seed germination, which could be related to significantly higher soluble sugars and free proline content in NaCl-treated seedlings under water stress. For antioxidant metabolism, NaCl pretreatment mainly improved superoxide dismutase, peroxidase, ascorbate peroxidase, and glutathione reductase activities, transcript levels of FeSOD, APX, and DHAR, and the content of ascorbic acid, reduced glutathione, and oxidized glutathione during seed germination under water stress. The results indicated that seeds soaking with NaCl could remarkably enhance antioxidant metabolism, thereby decreasing the accumulation of reactive oxygen species and membrane lipid peroxidation during germination under water stress. In addition, NaCl-upregulated dehydrin-encoded genes SK2 expression could be another important mechanism of drought tolerance during seeds germination of white clover in response to water stress.

Allelopathic effect of two medicinal plants on seed germination, seedling growth and grain production of purslane (Portulaca oleraceae L.) weed

<p>A laboratory factorial (2 × 5) experiment was carried out based on completely randomized block in four replications to evaluate the effect of plant species and concentration of their allelopathic extracts on seed germination and seedling growth of purslane weed (<em>Portulaca oleraceae</em> L.). The first factor studied was plant species (<em>Artemisia sieberi </em>and <em>Salvia syriaca</em>) and the second one the concentration percentage of plant ethanol extract (0.0, 5 %, 10 %, 15 % and 20 %). The effect of <em>Artemisia </em>on<em> </em>germination reduction of purslane<em> </em>was stronger compared to <em>Salvia.</em> The results indicated that higher extract concentration led to decreased germination percentage, germination speed and seedling growth indices of purslane including leaf length, leaf number, leaf width, leaf dry mass, stem mass and stem length. The effect of <em>Artemisia </em>was higher than that of <em>Salvia</em>. In a complementary experiment, the effect plant residues of <em>Artemisia </em>and <em>Salvia </em>(0.0, 1, 2, 3 and 4 g kg<sup>-1</sup> soil) were evaluated in a factorial experiment base on completely randomized block design with three replications. The results of field experiment showed that plant residues significantly (P ≤ 0.01) reduced capsule number per plant, seed number per capsule, seed production and shoot dry mass, while its effect on 1000-seed mass was not substantial. The effect of plant species and the interaction of plant species and their allelopathic extracts concentration had no major impact on the above-mentioned properties. The increase in plant residues in soil, led to the reduction of growth and seed production of purslane induced by plant number per unit area and capsule per plant. <em>Artemisia sieberi </em>Bess<em>. </em>and<em> Salvia syriaca </em>L.<em> </em>residues can be successfully used for non-chemical control of purslane weed.</p>

Reactive Oxygen Species and Gibberellin Acid Mutual Induction to Regulate Tobacco Seed Germination.

Seed germination is a complex process controlled by various mechanisms. To examine the potential contribution of reactive oxygen species (ROS) and gibberellin acid (GA) in regulating seed germination, diphenylene iodonium chloride (DPI) and uniconazole (Uni), as hydrogen peroxide (H2O2) and GA synthesis inhibitor, respectively, were exogenously applied on tobacco seeds using the seed priming method. Seed priming with DPI or Uni decreased germination percentage as compared with priming with H2O, especially the DPI + Uni combination. H2O2 and GA completely reversed the inhibition caused by DPI or Uni. The germination percentages with H2O2 + Uni and GA + DPI combinations kept the same level as with H2O. Meanwhile, GA or H2O2 increased GA content and deceased ABA content through corresponding gene expressions involving homeostasis and signal transduction. In addition, the activation of storage reserve mobilization and the enhancement of soluble sugar content and isocitrate lyase (ICL) activity were also induced by GA or H2O2. These results strongly suggested that H2O2 and GA were essential for tobacco seed germination and by downregulating the ABA/GA ratio and inducing reserve composition mobilization mutually promoted seed germination. Meanwhile, ICL activity was jointly enhanced by a lower ABA/GA ratio and a higher ROS concentration.

Assessment of Certain Plant Species degrading Total Petroleum Hydrocarbons in Contaminated Soil

Biological techniques, especially phytoremediation, have long been recognized as cost-effective and environment friendly to eliminate pollutants from soil. This article is based on a study conducted to assess the capability of alfalfa, ryegrass and white clover to remove total petroleum hydrocarbons (TPHs) from soil. The presence of petroleum contamination significantly decreased germination percentage and rate along with biomass of alfalfa and white clover compared to uncontaminated soil. With regards to ryegrass, there was no significant difference in seed germination percentage and biomass, although the presence of petroleum decreased seed germination rate. The results indicated that these plants had effect on TPHs remediation; and removal of TPH from soil was directly related to density levels and time. Therefore, alfalfa and ryegrass in their highest density levels reduced the maximum concentration of TPHs at the end of the experiment by almost 64.41% and 60.36%, respectively, whereas only slight changes were observed in non-vegetated soil.

Increased Expression of 9-Cis-Epoxycarotenoid Dioxygenase, PtNCED1, Associated With Inhibited Seed Germination in a Terrestrial Orchid, Phaius tankervilliae.

The phytohormone abscisic acid (ABA) is involved in regulating seed dormancy and germination. A crucial step of ABA biosynthesis in higher plants is the oxidative cleavage of cis-epoxycarotenoids by 9-cis-epoxycarotenoid dioxygenase (NCED). Seed development in orchids is unusual because the embryos are minute in size, without obvious histodifferentiation, and lack endosperm. To understand the regulation of ABA biosynthesis in orchid seeds, we isolated and characterized a full-length cDNA encoding an NCED homolog, PtNCED1, from developing seeds of an ornamental orchid, Phaius tankervilliae. Germination percentage was high at 90 days after pollination (DAP), when a globular embryo proper with a degenerating suspensor was evident. After 90 DAP, seed maturation was accompanied by a decrease in water content and a concomitant increase in ABA content and PtNCED1 mRNA level along with a marked decrease in germination percentage. Mature seeds pretreated with NaOCl solution lowered ABA content and improved seed germination. Moreover, after seed germination, developing protocorms could respond to dehydration stress. Dehydration of protocorms stimulated an increase in PtNCED1 level along with ABA content. Our results provide evidence of the involvement of PtNCED1 in regulating endogenous ABA content in developing seeds and protocorms. The accumulation of endogenous ABA content in orchid seeds may have a critical role in seed dormancy and the protocorm response to water stress after seed germination.

Comparative Assessment of salt tolerance in five Indian varieties of Rice (Oryza sativa L.)

Drought and salt stress are the two major abiotic determinants of plant growth and productivity. This study deals with comparative assessment of drought and salt responses of five rice varieties namely ‘Karuna’, ‘Neeraja’, ‘Thekkancheera’, ‘Rasmi’ and ‘Aryan’ under varying concentrations of sodium chloride (50mM, 100mM, 150mM, and 200mM), respectively. Germination percentage, root length and shoot length were determined after two weeks. As expected, in all the three varieties, the seed germination percentage, shoot and root length decreased with the increase in salt stress. The highest values of the aforementioned parameters were observed in the untreated controls and lowest values were recorded in the test samples subjected to 200 mM NaCl, respectively. The response of the varieties to increasing salt tolerance was in order ‘Rasmi’ > ‘Karuna’, ‘Neeraja’ > ‘Thekkancheera’ > ‘Aryan’. During the experiment, ‘Rashmi’ showed less decrease in germination percentage, root and shoot length as compared to the other varieties. These results indicate that ‘Rashmi’ variety is more tolerant to salt stress. Thus, in future, after further physiological and molecular evidences, this variety can be strategically grown as an alternative to other cereal crops, under salt-stressed environments.

Performance assessment and optimization of maize dehusker cum sheller - A technology for Northern Transition Zone of Karnataka

Maize (Zea mays L.) is one of the major crops in Karnataka state grown for commercial and seed-production purpose. In Northern Transition Zone (Hyderabad-Karnataka region), the major farming sizes of land are limited small to medium holding and they were in the need of economical technique for maize dehusking and shelling operation suited to medium capacity. In present study, the medium sized electric motor (2.23 kW) operated maize dehusker cum sheller (MDS) was developed and evaluated for selected operational parameters, viz. cylinder peripheral speed(6.2, 6.6, 7.1 and 7.6 m/s), concave clearance (20, 25, 30 and 35 mm) and feed rate (400, 600 and 800 kg/h). The machine performance parameters revels that, the dehusking efficiency and shelling efficiency were showed increasing trend with cylinder peripheral speed (S) from 6.2 to 7.6 m/s; whereas decreasing trend against increase in Concave Clearance (C) from 20 mm to 35 mm. The total losses of grains in machine were found lowest between feasible at 25 to 30 mm of C for all feed rates (F). In seed-quality parameters, the decreased germination percentage with increase in S was observed. The increased broken grains (%) and seed-coat damage (%) were identified with increased inS and decrease in C as well as F. The highest desirability value (obtained from numerical optimization technique) was obtained for operational parameter combination of S at 7.1 m/s with C at 25 mm under 600 kg/h of F. The total cost of the MDS was ` 34500 with benefit-cost ratio of 2.24. The performance of machine was also satisfactory for producing maize seeds for seeding purpose without compromising its performance.

Lethal Dose (LD50) Fixation and Sensitivity of Fenugreek (Trigonellafoenum-graecumL.) to Gamma Radiation for Induction of Mutation

Fenugreek (Trigonella foenum-graecumL.) is an annual crop, mainly used as a spiceand leafy vegetable crop in many parts of the world. Classical breeding in fenugreek is restricted due to its low genetic variability and small flower size which hamper manual emasculation and pollination. Mutation breeding is an effective way to enrich genetic variability in crop plants. An experiment was conducted to determine the lethal dose of the physical mutagen gamma rays in fenugreek. The dry seeds of fenugreek were exposed to different doses of gamma rays i.e. 150Gy, 200Gy, 250Gy, 300Gy and 350Gy. These irradiated seeds were sown in the Petri plates with non-irradiated seeds (control). As the dose of gamma rays increased, there was a decrease in germination percentage, seedling survival, root length, shoot length and vigour index. Among five doses of gamma rays, the maximum seed germination was observed at lowest dose 150Gy (93%), followed by 200Gy (83%), 250Gy (76%), 300Gy (76%) and 350Gy (64%). The seedling survival was decreased from 90% (in control) to 56% in 350Gy dose of gamma rays. The gamma rays dose of 150Gy gave stimulatory effect on seedlings growth. The growth parameters were dose dependent, as the dose of gamma rays increased from 200Gy to 350Gy. The gamma rays dose of 350Gy showed 64% seeds germination and 56% of seedlings survival. Therefore, it is concluded that the LD50 dose for fenugreek is close to 350Gy. This information would be highly useful for initiating mutation breeding programme in fenugreek

Evaluation of inoculum potential of pathogens in seeds: relation to physiological quality and DNA quantification by qPCR

Abstract: Given what is already known in regard to seed health and the availability of molecular methods for detection of the pathogens Stenocarpella maydis and Stenocarpella macrospora in maize seeds, Colletotrichum gossypii var. cephalosporioides in cotton seeds, and Corynespora cassiicola in soybean seeds, the aim of this study was to evaluate seed vigor according to different inoculum potentials. The fungus isolates were inoculated on seeds by the technique of water restriction, through which different inoculum potentials are obtained, corresponding to times of seed exposure of 0, 24, 48, and 96 hours for maize and cotton seeds, and 0, 36, 108, and 144 hours for soybean seeds. The seeds were subjected to germination, electrical conductivity, health, and qPCR tests. Results of the blotter test showed that in most pathosystems, there was a higher incidence of the fungi with an increase in inoculum potential. A decrease in germination percentage was observed in all species as inoculum potential increased, as well as further degradation of seed membranes. The qPCR test confirmed that the most damaged seeds in the tests had higher presence of the pathogens.

Divergence in Life History Traits between Two Populations of a Seed-Dimorphic Halophyte in Response to Soil Salinity.

Production of heteromorphic seeds is common in halophytes growing in arid environments with strong spatial and temporal heterogeneity. However, evidence for geographic variation (reflecting local adaptation) is almost nonexistent. Our primary aims were to compare the life history traits of two desert populations of this halophytic summer annual Suaeda corniculata subsp. mongolica and to investigate the phenotypic response of its plant and heteromorphic seeds to different levels of salt stress. Dimorphic seeds (F1) of the halophyte S. corniculata collected from two distant populations (F0) that differ in soil salinity were grown in a common environment under different levels of salinity to minimize the carryover effects from the field environment and tested for variation in plant (F1) and seed (F2) traits. Compared to F1 plants grown in low soil salinity, those grown in high salinity (>0.2 mol⋅L-1) were smaller and produced fewer seeds but had a higher reproductive allocation and a higher non-dormant brown seed: dormant black seed ratio. High salinity during plant growth decreased germination percentage of F2 black seeds but had no effect on F2 brown seeds. Between population differences in life history traits in the common environment corresponded with those in the natural populations. Phenotypic differences between the two populations were retained in F1 plants and in F2 seeds in the common environment, which suggests that the traits are genetically based. Our results indicate that soil salinity plays an ecologically important role in population regeneration of S. corniculata by influencing heteromorphic seed production in the natural habitat.

Non-chemical Control of Root Parasitic Weeds with Biochar.

This study tested whether soil-applied biochar can impact the seed germination and attachment of root parasitic weeds. Three hypotheses were evaluated: (i) biochar adsorbs host-exuded signaling molecules; (ii) biochar activates plants’ innate system-wide defenses against invasion by the parasite; and (iii) biochar has a systemic influence on the amount of seed germination stimulant produced or released by the host plant. Three types of experiments were performed: (I) pot trials with tomato (Solanum lycopersicum) infested with Phelipanche aegyptiaca PERS. (Egyptian broomrape) and three different types of biochar at concentrations ranging from 0 to 1.5% weight, wherein tomato plant biomass, P. aegyptiaca biomass, and number of P. aegyptiaca-tomato root attachments were quantified; (II) split-root biochar/no-biochar experiments under hydroponic growing conditions performed in polyethylene bags with tomato plant rootings, wherein P. aegyptiaca seed germination percentage and radicle attachment numbers were quantified; and (III) germination trials, wherein the effect of biochar adsorption of GR-24 (artificial germination stimulant) on P. aegyptiaca seed germination was quantified. Addition of biochar to the pot soil (Experiment I) resulted in lower levels of P. aegyptiaca infection in the tomato plants, mainly through a decrease in the number of P. aegyptiaca attachments. This led to improved tomato plant growth. In Experiment II, P. aegyptiaca seed germination percentage decreased in the biochar-treated root zone as compared with the no-biochar control root zone; P. aegyptiaca radicle attachment numbers decreased accordingly. This experiment showed that biochar did not induce a systemic change in the activity of the stimulant molecules exuded by the tomato roots, toxicity to the radicles, or a change in the ability of the radicles to penetrate the tomato roots. The major cause for the decrease in germination percentage was physical adsorption of the stimulant molecule by the biochar (Experiment III). Adding biochar to soil to reduce infections by root parasitic weeds is an innovative means of control with the potential to become an important strategy both for non-chemical treatment of this family of pests, and for enhancing the economic feasibility of the pyrolysis/biochar platform. This platform is often viewed as one of a handful of credible strategies for helping to mitigate climate change.

Effect of some environmental factors on seed germination of Eryngium caeruleum M. Bieb. populations

ABSTRACT Th e eff ects of alternating and constant temperatures and light regimes, osmotic and salt stress and pH were tested on seed germination in four populations of Eryngium caeruleum . Laboratory experiments revealed that the four populations exhibited diff erent responses to alternating temperature and light conditions. Alternating temperature and photoperiod had a greater positive eff ect on seed germination compared to complete darkness. Th e optimal constant temperature within 10 oC to 15 oC for seed germination of each population was determined in a light/dark photoperiod. Seed germination severely decreased under water stress and was completely inhibited at -0.8 MPa osmotic potential. Saline stress sharply decreased germination percentage. Germination was restricted by pH lower and higher than 5 and 8, respectively. Th e information obtained from this study helps to fi ll the gap of knowledge about seed germination requirements of E. caeruleum and enhance our understanding of this species distribution and its potential to develop in stressful and/or new habitats.

ISOLATION AND IDENTIFICACTION OF FUNGIS RHIZOCTONIA SOLANI FROM ZINNIA SEEDS, TEST ITS PATHOGENICITY AND CONTROL IT BY ENVIRONMENTALLY FRIENDLY PRODUCTS

This study was conducted to isolate the fungus Rhizoctonia solani associated with Zinnia seeds, test its pathogenicity and evaluation the effect of alcohol extract of coontail and lotus, grapefruit extract, sea bloom 29 and Bioimmune on this pathogene. This fungus was presented in 3 samples from 11 samples and was recorded for the first time on this plant in Iraq. All the isolates caused a significant reduction in seeds germination. Isolate A22 gave the highest decrease in percentage of germination (4%). This isolate gave 100% disease incidence and 96.5% disease severity compared to control (2.5%). The percentage of germination capacity and seed germination of the seed primed with PEG solution and planted in soil inoculated by this isolate was 45%. The alcoholic extract of coontail 0.2% and Bioimmune 12% caused a significant superiority in the inhibition of this isolate . Also these two extracts caused a significant reduction in disease incidence 77.5% and 72.5% and diseasse severity 72.5% and 70% compared to control 100% and 99.38%.

Mutagenic effect of sodium azide (NaN3) on M2 generation of Brassica napus L. (variety Dunkled)

The present study was aimed to investigate the effect of different doses (0.2%, 0.4%, 0.6% and 0.8%) of sodium azide (SA) on M2 generationof Brassica napus (variety Dunkled) on some qualitative, quantitative and biochemical parameters. The result showed that days to germination, days to flowering and days to siliqua maturation were delayed (9.4, 98 and 153 days respectively) in higher treatment as compared to control (5.4, 96 and 147 days respectively). Higher concentration of SA (0.8%) decreased germination percentage (88.56%), plant height (97.95 cm), stem diameter (3.49 cm), number of branches/plant (3.49), number of leaves/plant (10), number of siliqua/plant (64.68), number of seed/siliqua (20.09) and 1000 seeds weight (3.91g) as compared to control. An increase was noticed for siliqua length (5.42 cm) in higher concentration of SA (0.8%) as compared to control (5.24 cm). Proximate analysis showed a significant decrease in oil, oleic acid and glucosinolates contents percentage (42.6%, 54.9%, and 58.5 μmol/g respectively) in higher concentration of SA (0.8%) as compared to control (44.7%, 58.1% and 71.3 μmol/g respectively) while a significant increase was noticed in proteins, moisture, linoleic acid and erucic acid percentage (28.4%, 5.9%, 9% and 37.3% respectively) in higher concentration of SA (0.8%) as compared to control (26.8%, 5.5%, 8.4% and 35.2% respectively. Keywords: Sodium Azide (SA); Brassica napus; morphological and biochemical parameters http://dx.doi.org/10.19045/bspab.2017.60018

Effects of salinity, drought, and priming treatments on seed germination and growth parameters of Lathyrus sativus L.

ABSTRACTGermination of plants is one of the most important stages during their growth, which is often influenced by environmental stresses, especially drought and salinity. This study was conducted to investigate the effects of salinity and drought on seed germination and growth of Lathyrus sativus. The experiment was laid out in a completely randomized design with factorial arrangement in four replications. Salinity treatments were 0, 2, and 4 dS/m and drought treatments included 0, 0.4, 0.8, and 1.2 MPa. Salinity and drought treatments were prepared by using sodium chloride and polyethylene glycol 6000, respectively. The results showed that salinity and drought stresses decreased germination percentage, and root and radicle length.

Germination and growth of Atriplex prostrata and Plantago coronopus: Two strategies to survive in saline habitats

We investigated the effects of NaCl on germination, germination rate, growth, proline content, polyamine levels (putrescine, spermidine and spermine) and total polyamines in Atriplex prostrata and Plantago coronopus. The seeds collected from Brujuelo (salt marshes, Jaén, southern Spain) were germinated under control (water) and saline conditions (50, 100, and 200mM NaCl) for 20days at 25°C. Salinity decreased germination percentage and the germination rate in A. prostrata, and P. coronopus with increasing salt concentrations. In seedlings at day 6 and 10 of the experiment, both the length and fresh mass increased in A. prostrata for all saline treatments with respect to control, whereas in P. coronopus, only fresh mass increased with 50 and 100mM NaCl, indicating its lower salinity tolerance. With respect to proline, the maximum increase occurred with 200mM NaCl in A. prostrata; however in P. coronopus the values were low and without significant differences between treatments. The polyamine levels changed, in P. coronopus spermidine and spermine increased with salt, while in A. prostrata putrescine and spermidine decreased. These results indicate that the increase of proline was accompanied by a decrease of total polyamines (putrescine+spermidine+spermine) in A. prostrata while P. coronopus had high total polyamine levels with low values of proline, demonstrating that these plants use different strategies to adapt to saline environments.