Seedling Growth Parameters Research Articles

Normal ve Düşük Sıcaklıklarda Pamuğun Çimlenme ve Fide Gelişimine Tuzluluğun Etkisi

The objective of the study was to investigate the effects of salinity stresses (50, 100, 150, 200 and 250 mM of NaCl) on germination and early seedling growth of six cotton varieties (Lydia, Carisma, Flash, BA151, BA525 and ST468) under optimum (25°C) and low temperature (18°C) conditions. Germination percentage, mean germination time, germination index, germination stress tolerance index, seedling length, vigor index, seedling fresh and dry weight of cotton varieties were investigated. Results showed that low temperature led to decreasing in germination and seedling growth, and caused retardation of mean germination time. Under suboptimal temperature, germination percentage reduced from 86.3% to 77.8% and seedling length decreased from 12.02 cm to 5.36 cm. Each increase in salinity levels higher than 50 mM resulted in decreasing in germination and seedling growth parameters of cotton varieties. No seedling growth was observed at 250 mM of NaCl at 18°C. Cotton varieties showed different tolerance levels to salinity, while they could tolerate it up to 100 mM. It was concluded that Flash and ST468 varieties exhibited better performance under salinity stresses both at optimal and suboptimal temperatures.

Environment friendly degradation and detoxification of Congo red dye and textile industry wastewater by a newly isolated Bacillus cohnni (RKS9)

Textile industry wastewater (TIWW) is a major source of environmental pollution causing serious threats to all life forms and thus, it must be adequately treated before its final discharge for the safety of environment and public health. In the present study, a potential bacterial strain (RKS9) was isolated from textile (wastewater & sludge) sample for the effective treatment of TIWW resulting in a significant reduction in pollution parameters such as ADMI color (93.87%), COD (77.35%), BOD (86.02%), TDS (66.75%), TOC (67.25%), TSS (60.34%), and phenol (68.55%) within 48 h. This bacterium also decolorized 99% of Congo red dye (100 mg L −1 ) within 12 h and removed 59.76%, 40.51%, 52.71% and 26.51% cadmium, chromium, lead and nickel, respectively from the TIWW. The activities of azoreductase, laccase, lignin peroxidase (LiP) and manganese peroxidase (MnP) was monitored and metabolites produced during the treatment of dye and TIWW were also analyzed by FT-IR and GC–MS. The phytotoxicity of the untreated and treated TIWW was assessed by seed germination and seedling growth parameters of Phaseolus mungo L. and results showed a significant reduction in the toxicity of the treated TIWW, suggesting that the isolated bacterium RKS9 has a remarkable potential to effectively decolorize/detoxify TIWW. • Textile industry wastewater (TIWW) has different dyes as residual pollutants. • TIWW causes severe environmental and health threats. • Bacteria Bacillus cohnni was used to treat CR dye and TIWW. • FT-IR and GC–MS were used to characterize TIWW pollutants and metabolites. • Toxicity of untreated and treated TIWW was evaluated by seed germination test.

In vitro Effect of Caesalpinia sappan and Crateva magna Extracts in Enhancing Seed Germination and Seedling Growth of KDML105 Rice Variety

Background: Rice (Oryza sativa L.) is a major cereal crops planted in Thailand for both local consumption and export. The objective of this study was to investigate the allelopathic effect of Caesalpinia sappan L. and Crateva magna (Lour.) DC. extracts in promoting a rice cultivar, Khao Dowk Mali 105 (KDML105) seed germination and seedling growth, at 7 and 14 days after sowing (DAS). Methods: The C. sappan and C. magna plants were cleaned with tap water and air dried in room temperature then cut into small pieces and ground into fine powder. Plant crude extracts was prepared using ethanol as solvent. Result: The results showed that rice seed treatment with C. sappan and C. magna extracts was significant (all p less than 0.05), increasing root length, shoot fresh and dry weight and root fresh and dry weight of rice seedlings at 14 DAS. Seed treatment with these two plant extracts led to a significantly greater vigor index of the KDML105 rice seedling cultivar, when compared with the control. Interestingly, the seed treatment with C. magna extract at a 100 ppm concentration was found to produce the highest enhancement in the overall rice seedling growth parameters, including the vigor index of seedlings. The results showed that a low concentration of C. magna extracts can be potentially used in promoting seedling growth of rice since they improved the overall growth parameters.

Potentiality of Bat Guano as Organic Manure for Improvement of Growth and Photosynthetic Response in Crop Plants

Potentiality of guano of Black-bearded Tomb bat (Taphozous melanopogon) on the growth and physiological response in two crops, i.e., finger millet (Eleusine coracana) and black gram (Vigna mungo) was assessed in the pot experiments. Plants are grown in different treatments prepared by mixing garden soil with fresh and deposited bat guano, farmyard manure and chemical fertilizer. Addition of fresh and deposited guano in garden soil improves the soil pH, EC, OC, N, P and K. The growth parameters of finger millet and black gram seedlings were significantly (p < 0.05) higher in garden soil amended with fresh and deposited guano compared to other treatments. The leaf photosynthetic rate (PN), transpiration rate (E), stomatal conductance (gs), water use efficiency and carboxylation efficiency were significantly higher (p < 0.05) in both the crops grown on fresh and deposited guano treatments. In addition, minimum fluorescence (Fo) and maximum fluorescence (Fm) were significantly higher in both millet and black gram seedlings grown on fresh and deposited guano treatments but the maximum photochemical efficiency of PSII (Fv/Fm) was not significantly (p < 0.05) different among the treatments. Based on the results, fresh and deposited guano in soil amendments has a promoting effect on growth biomass and photosynthesis of both the crops. Taken together, the present study suggests that guano of microchiropteran bat Taphozous melanopogon can be used as a substitute of organic manure for better plant growth and crop productivity.

Characterizing reduced height wheat mutants for traits affecting abiotic stress and photosynthesis during seedling growth.

Most high-yielding, semidwarf wheat (Triticum aestivum L.) grown around the world contains either Rht1 or Rht2 genes. The success of these high-yielding cultivars is greatest in the most productive farming environments but provide marginal benefits in less favorable growing conditions such as shallow soils and low-precipitation dryland farming. Further, growing evidence suggests semidwarf genes not only affect early seedling growth but limit grain yield, especially under abiotic stress conditions. There are 23 other reduced-height mutants reported in wheat, most of which have not been functionally characterized. We evaluated these mutants along with their parents for several traits affecting seedling emergence, early seedling growth, and photosynthetic efficiency. Two- to seven-fold differences in coleoptile length, first leaf length, root length, and root angle were observed among the genotypes. Most of the mutations had a positive effect on root length, while the root angle narrowed. Coleoptile and first leaf lengths were strongly correlated with emergence. A specialized deep planting experiment identified Rht5, Rht6, Rht8, and Rht13 with significantly improved seedling emergence compared to the parent. Among the mutants, Rht4, Rht19, and Rht12 ranked highest for photosynthetic traits while Rht9, Rht16, and Rht15 performed best for early seedling growth parameters. Considering all traits collectively, Rht15 showed the most promise for utilization in marginal environments followed by Rht19 and Rht16. These wheat mutants may be useful for deciphering the underlying molecular mechanisms of understudied traits and breeding programs in arid and semiarid regions where deep planting is practiced.

Effect of Spacing and Nitrogen Fertilizer on Survival and Growth of &lt;i&gt;Betula utilis&lt;/i&gt;

The present study reports the effect of spacing and nitrogen fertilizer on the growth and survival of Betula utilis seedlings under field conditions in temperate region of Kashmir Himalaya. The study was conducted at the field of Faculty of Forestry, Benhama, Ganderbal, SKUAST, Kashmir. The different levels of nitrogen fertilizer (25 kg N ha -1 , 50 kg N ha -1 , 75 kg N ha -1 and 100 kg N ha -1 ) were applied to the Betula utilis seedlings that were transplanted in the field at two spacing viz., 60 × 60 cm and 100 × 100 cm to observe the effect of nitrogen fertilization and spacing on growth and survival of one year old seedlings in the field. The effect of spacing, fertilizer and their interaction (S x T) exert significant effect on survival and seedling growth parameters like height increment, collar diameter, number of leaves, leaf area, root biomass, shoot biomass and total plant biomass under open field conditions. Among these fertilizer doses, it was observed that application of 75 kg N ha -1 in two equal splits (first dose one month after transplanting and the second dose one month after the first application) to the seedlings of Betula utilis with 100 x 100 cm spacing was recorded to be the best treatment combination for producing more biomass per plant, healthy planting stock and for better plant survival. The present study exhibits that optimum levels of nitrogen and optimum

Norway Spruce Seedlings from an Eastern Baltic Provenance Show Tolerance to Simulated Drought

In Northern Europe, an increase in heterogeneity of summer precipitation regime will subject forests to water deficit and drought. This is particularly topical for Norway spruce (Picea abies Karst.), which is a drought sensitive, yet economically important species. Nevertheless, local populations still might be highly plastic and tolerant, supporting their commercial application. Accordingly, the tolerance of Norway spruce seedlings from an Eastern Baltic provenance (western part of Latvia) to artificial drought according to soil type was assessed in a shelter experiment. To simulate drought, seedlings were subjected to reduced amounts (0%, 25%, 50%, 75%, and 100%) of naturally occurring precipitation (irrigation intensity). Three soil types (oligotrophic mineral, mesotrophic mineral, and peat) were tested. Seedling height, chlorophyll a concentration, and fluorescence parameters were measured. Both growth and photochemical reactions were affected by the irrigation intensity, the effect of which experienced an interacted with soil type, implying complex controls of drought sensitivity. Seedlings were more sensitive to irrigation intensity on mesotrophic mineral soil, as suggested by growth and photosynthetic activity. However, the responses were nonlinear, as the highest performance (growth and fluorescence parameters) of seedlings occurred in response to intermediate drought. On peat soil, which had the highest water-bearing capacity, an inverse response to irrigation intensity was observed. In general, fluorescence parameters were more sensitive and showed more immediate reaction to soil water deficit than concentration of chlorophyll on mesotrophic mineral and peat soils, while the latter was a better indicator of seedling performance on oligotrophic soil. This indicated considerable plastic acclimation and hence tolerance of seedlings from the local Norway spruce population to drought, though drought sensitivity is age-dependent.

Improved salt tolerance of Chenopodium quinoa Willd. contributed by Pseudomonas sp. strain M30-35.

BackgroundPlant-growth-promoting rhizobacteria (PGPR) can promote plant growth and enhance plant tolerance to salt stress. Pseudomonas sp. strain M30-35 might confer abiotic stress tolerance to its host plants. We evaluated the effects of M30-35 inoculation on the growth and metabolite accumulation of Chenopodium quinoa Willd. during salt stress growth conditions.MethodsThe effects of M30-35 on the growth of C. quinoa seedlings were tested under salt stress. Seedling growth parameters measured included chlorophyll content, root activity, levels of plant- phosphorus (P), and saponin content.ResultsM30-35 increased biomass production and root activity compared to non-inoculated plants fertilized with rhizobia and plants grown under severe salt stress conditions. The photosynthetic pigment content of chlorophyll a and b were higher in M30-35-inoculated C. quinoa seedlings under high salt stress conditions compared to non-inoculated seedlings. The stability of P content was also maintained. The content of saponin, an important secondary metabolite in C. quinoa, was increased by the inoculation of M30-35 under 300 mM NaCl conditions.ConclusionInoculation of M30-35 rescues the growth diminution of C. quinoa seedlings under salt stress.

Optimization of EMS mutagen dose for short day onion

The present experiment was conducted to investigate the effect of chemical mutagen on biological parameters such as seed germination, shoot and root length and to fix the lethal dose (LD50) of EMS in short day Indian onion cultivar Bhima Dark Red. Presoaked seeds of onion were treated with different doses (0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2 % v/v) of Ethyl Methane Sulfonate. The optimal mutagenic doses were calculated using Probit Analysis based on germination percentage which were considered useful in developing onion mutagenized population to create genetic variability for various qualitative and quantitative traits. Seed germination was recorded after 7 and 12 days of sowing, while seedling parameters such as seedling height, dry and fresh weight of seedlings were taken after 12 days. Data revealed that the mutagenic agent significantly reduced seed germination and seedling growth parameters in terms of shoot and root length as compared to control. Significant reduction in the seed germination percent with the enhancement of concentration of EMS dose was exhibited.

Running title: Endophyte Co-treatment on Persian Oak Tree Evaluation of Endophyte Co-treatment on Persian Oak Tree (Quercus brant ii)Issue Type: Regular Issue

The Zagros forests are one of the typical crucial ecosystems placed in western Iran. A remarkable area of these forests situated in Kermanshah province. Due to human manipulation, ecological and climate change are deteriorating. In this investigation, microbial isolation and treatments were offered to evaluate their effects on oak growth. Samples collected from Quercus brant ii of Kermanshah regions, Iran, and were cultivated on ISP2 and NA medium, kept at 28°C for one month. The Microscopic identification and phosphate solubilization assay for primary and nitrogen fixation, hydrogen cyanide, protease, and phytohormone production performed. Lastly, Seedlings with selected isolate treated and growth and survival parameters measured. All strains were able to produce auxin and gibberellin in different values. All of the isolates able to solubilize phosphate. The outcomes of nitrogen fixation ability, protease, and siderophore production diverged among strains. Picked isolates exhibited hormone production properties as well as biocontrol influences according to tests. Co-treatment of Streptomyces sp. Qb2-Pseudomonas sp. Qb, Streptomyces sp. Qb2-Bacillus sp. Qb and Streptomyces sp. Qb2- Pseudomonas sp. Qb had a notable effect on seedling growth parameters (P <0 •001), oak species survival (P <0 •001), and improved significantly the longitudinal growth, diameter, and dry weight percent of seedlings (P <0 •005) Respectively. Streptomyces sp. Qb2 and Bacillus sp. Qb strains had the highest and lowest inhibition effects on bacterial plant pathogen, Pseudomonas syringae. Streptomyces sp. Qb2 strains significantly promote root formation. To our understanding, this is the first record of Streptomyces endophyte isolation from Iranian oak trees with biocontrol and growthinducing impacts. It is also proposed to apply the co-treatment plan to increase biocontrol effects and growth induction.

Seed Fatty Acid Composition and Germination Studies in Garcinia dhanikhariensis S.K. Srivastava (Clusiaceae): A Novel Tropical Fruit Species from Bay Islands, India

ABSTRACT Garcinia dhanikhariensis is an endemic tropical species distributed in the Bay Islands, India. The species has been found to be of horticultural significance owing to its edible fruits and potential as natural colorant. Being an endemic species, identifying the potential uses and standardization of nursery techniques of G. dhanikhariensis could be helpful in conserving and popularizing it. The present investigation aimed at determining fatty acid composition of seed fat using GC-MS and standardization of seed germination technique for mass multiplication. Results revealed that seeds had higher saturated fatty acids, dominant being stearic acid (43.62%) and oleic acid (42.40%). Among the pretreatments studied, soaking of seeds in potassium nitrate (0.1%) or gibberellic acid (500 mg/L) was recommended based on superior germination percentage and seedling growth parameters. The effect of seed source on germination characteristics was also studied, which revealed considerable variability among the collections. Regenerated seedlings were successfully transplanted without any mortality. Thus, seeds of G. dhanikhariensis were found to be novel sources of industrially important stearic acid and oleic acid. Nursery protocol discussed here would be useful for mass multiplication of this novel fruit species.

Effects of foliar spraying with low concentration NaCl on the growth and physiological responses of cucumber seedlings under temperature regulation in solar greenhouse

In order to clarify the effects of foliar spraying the solution with low concentration NaCl on the growth and matter accumulation of vegetables under the temperature-regulated solar greenhouse, we carried out an experiment on cucumber seedlings with two cotyledons, under two tempera-ture regimes and four concentrations of NaCl. Low-medium temperature zone (L) and medium-high temperature zone (H) were set by low tunnel with plastic film in the greenhouse. The solutions with different concentrations of NaCl, 0 mmol·L-1 (L0 and H0), 5 mmol·L-1 (L5 and H5), 10 mmol·L-1 (L10 and H10) and 15 mmol·L-1 (L15 and H15), were sprayed every day to the cucumber seedlings. The seedling growth, plant biomass, nutrient accumulation and photosynthetic gas exchange parameters of cucumber seedlings were measured at the 21th day of spraying treatment. Compared with the control groups (L0 and H0), NaCl spraying significantly increased dry matter and plant water content by 38.6% (L5)-50.2% (L10) and 20.8% (L5)-52.2% (L10) in L zone, 8.9% (H5)-23.3% (H10) and 8.7% (H5)-10.1% (H10) in H zone, respectively. The treatment of 10 mmol·L-1 NaCl (L10 and H10) under both temperature regimes increased dry matter accumulation and plant water content than other treatments. Nevertheless, the highest normalized strong seedling index (SI) with the highest stomatal conductance (gs) and photosynthetic rate (Pn) was only found in L5 treatment. L10 treatment promoted foliar expansion much more than H10 treatment. In addition, foliar spraying NaCl with concentrations from 5 mmol·L-1 to 10 mmol·L-1 under both temperature regimes significantly increased the accumulation of soluble sugar, free amino acids and soluble protein, which were preferentially allocated to the stem or root of cucumber seedlings. Results of two-way ANOVA showed significant effects of both temperature and NaCl concentration on dry biomass, leaf area, Pn, plant water content, SI, gs and free amino acid content. On the contrary, there were significant interactions between temperature and NaCl concentration in affecting plant water content, SI, gs and free amino acid content (except leaf). In conclusion, foliar spraying with 5-10 mmol L-1 NaCl could promote growth and physiological indices of cucumber seedlings, with the effect being higher under low temperature regime. More importantly, foliar spraying of proper concentration (L5 and H10) of NaCl could stimulate biomass accumulation more than water retention in cucumber seedlings, which would provide a relevant breeding target for high water-use efficiency in cucumber.

Effect of selenite-ion on the integrity of winter rye seedlings (Secale cereale L.) membranes in drought conditions

The effect of selenite-ion on the reactions of lipid peroxidation, the electrolyte release, the membrane damage coefficient and the growth parameters of winter rye seedlings of the Tatiana variety under optimal water supply conditions and during a seven-day drought was studied. Seeds treatment with 5.8·10-3 M sodium selenite solution reduced the accumulation of lipid peroxidation products in the leaves - lipid fatty acid hydroperoxides and malondialdehyde under optimal and stressful conditions. To a greater extent, selenite-ion reduced the content of malondialdehyde compared to hydroperoxides (by 25%). The effect of selenium on lipid peroxidation reaction was more effective in drought conditions. The inhibition of electrolyte release from seedlings leaves enriched with selenium was revealed. The coefficient of membrane damage in drought conditions was lower in the variant with selenite-ion (by 37%). The large mass of aboveground seedling organs, length and weight of the root system when treating seeds with sodium selenite were noted. The obtained data are discussed in connection with the effect of selenium on the content of auxins, expressing genes responsible for the antioxidant enzymes synthesis.

Determination of phytochemical components of Origanum majorana leaf extract by GC-MS spectroscopy and their effect on flax seedling growth

This study was conducted to examine the phytochemical components of Origanum majorana leaf extract by chemical methods and by GC-MS spectroscopy and to test the impact of these components on flax seedling growth. Biochemical analysis of Origanum majorana leaf extracts in both acetone and methanol showed the presence of the four tested components: coumarins, steroids, flavonoids and tannins. In addition, methanol extract exhibited about 92% inhibition of DPPH reaction indicating a high level of antioxidant activity. The bioactive constituents were detected by GC-MS spectroscopy for their retention time, molecular formula and peak area %. The data of GC-MS revealed the presence of 30 components. The major components detected in ethanol leaf extract of Origanum majorana were: c-sitosterol (12.93%), octadeca-9,12,15-trienoic acid (8.65%), hexadecanoic acid (6.64%), neophytadiene (6.47%), ursolic acid (5.48%), phthalic acid, di (2-propylpentyl) ester (5.06%), 1-phenanthrenemethanol, 1,2,3,4,4a,9,10,10a-octahydro-1,4a-dimethyl-7-(1-methylethyl)-, [1S-(1a,4aa,10aa)]- (4.69%), tetracosane, 11-decyl- (3.85%), 3,7,11,15-tetramethyl-2-hexadecen-1-ol (3.75%), dl-a-tocopherol (3.46%) and squalene (2.95%). The presoaking of flax seeds in aqueous leaf extract of Origanum majorana for 12 hours before sowing induced significant increases in all the measured growth parameters of 17-day old seedlings compared to control (water presoaking). Germination percentage was increased by 33%, shoot length by 16%, root length by 27%, shoot fresh weight by 7%, root fresh weight by 3%, shoot dry weight by 40% and root dry weight by 100%. Thus, leaf extract of Origanum majorana could be recommended as a phyto-promotor of flax seedling growth.

Efficiency of cow dung based vermi-compost on seed germination and plant growth parameters of Tagetes erectus (Marigold)

Vermi-composting is an environmental friendly and economic process to decompose organic waste. The objective of this study was to produce vermi-compost using Eiseniafetida and to investigate the impact of vermi-compost (VC) and organic manure (cow dung) on seed germination, seedlings, and growth parameters of Tagetes erecta. Physio-chemical parameters of vermi-compost and organic manure were recorded. A potting experiment was designed, germination medium containing soil, sand, and various concentrations of vermi-composts. The composition of germinating media was: TO (Sand + Soil), TCC (Sand + Soil + Cow dung), 10% VC (Sand + Soil + 0.1 kg VC), 15% VC (Sand + Soil + 0.15 kg VC), 20% VC (Sand + Soil + 0.2 kg VC), 25% VC (Sand + Soil + 0.25 kg VC), 30% VC (Sand + Soil + 0.3 kg VC), and 35% VC (Sand + Soil + 0.35 kg VC). Seed germination, seedling, vegetative plant growth, and flowering parameters were evaluated in different germinating media. Pre and post-physio-chemical parameters of germination media were also recorded to check their stability and quality. Results showed that 20% VC was effective for the early initiation of seed germination (2.0 ± 0.0 days) and all growth parameters of marigold seedlings. The germination percentage at 20% VC was recorded as 87.5 ± 1.40 %. The best vegetative plant growth and flowering parameters of marigold plants were observed with 35% VC after transplantation. Findings showed that vermi-compost is the best-suited germination and growing media, which not only improved the soil health but also promoted seed germination and plant growth. Our study undoubtedly indicates that vermi-compost is a more encouraging and advantageous bio-fertilizer and can be used as a powerful and effective for immediate marigold production.

Effect of the suspension of Ag-incorporated TiO2 nanoparticles (Ag-TiO2 NPs) on certain growth, physiology and phytotoxicity parameters in spinach seedlings.

In this work, the effect of the inoculation of silver-incorporated titanium dioxide nanoparticles (Ag-TiO2 NPs) in spinach seeds was evaluated on certain growth, physiology and phytotoxicity parameters of the plants. This is an important crop for human consumption with high nutritional value due to their low calorie and fat content, providing various vitamins and minerals, especially iron. These NPs were obtained by means of the sol-gel method and heat treatment; the resulting powder material was characterized using X-ray diffraction and scanning electron microscopy and the influence of these NPs on plants was measured by estimating the germination rate, monitoring morphological parameters and evaluating phytotoxicity. The photosynthetic activity of the spinach plants was estimated through the quantification of the Ratio of Oxygen Evolution (ROE) by the photoacoustic technique. Samples of TiO2 powder with particle size between 9 and 43 nm were used to quantify the germination rate, which served to determine a narrower size range between 7 and 26 nm in the experiments with Ag-TiO2 NPs; the presence of Ag in TiO2 powder samples was confirmed by energy-dispersive X-ray spectroscopy. The analysis of variance showed that the dependent variable (plant growth) could be affected by the evaluated factors (concentration and size) with significant differences. The statistical trend indicated that the application of the Ag-TiO2 NPs suspension of lowest concentration and smallest particle size could be a promoting agent of the growth and development of these plants. The inoculation with NPs of 8.3 nm size and lowest concentration was related to the highest average ROE value, 24.6 ± 0.2%, while the control group was 20.2 ± 0.2%. The positive effect of the Ag-TiO2 NPs treatment could be associated to the generation of reactive oxygen species, antimicrobial activity, increased biochemical attributes, enzymatic activity or improvements in water absorption.

Effects of Different Salt and Putrescine Applications on Germination and Seedling Growth in Bean (Phaseolus vulgaris L.)

Bu çalışma, dünyada ve ülkemizde yaygın olarak yetiştiriciliği yapılan ve tuzluluğa hassas sebze türleri içerisinde yer alan fasulyede farklı tuz ve putresin uygulamalarının çimlenme ve fide gelişimi üzerine etkilerini belirlemek amacıyla yapılmıştır. Bitkisel materyal olarak Öz Ayşe sırık taze fasulye çeşidi kullanılmıştır. Çalışmada, 3 farklı tuz (NaCl) seviyesi (50, 100 ve 200 mM) ve 3 farklı putresin dozunun (0.1, 1 ve 2 mM) kullanıldığı toplam 16 farklı uygulama ele alınmış olup, tuz ve putresinin ayrı ayrı ve birlikte etkileri incelenmiştir. Çimlendirme ve fide denemesi şeklinde yürütülen çalışmada; çimlenme oranı, radikula ve plumula uzunluğu, radikula yaş ve kuru ağırlığı, plumula yaş ve kuru ağırlığı, fide boyu, gövde çapı, kök uzunluğu, fide yaş ve kuru ağırlığı, kök yaş ve kuru ağırlığı, yaprak sayısı, klorofil, renk (L*, a*, b*, C* ve h°), pH, elektriksel iletkenlik ve kuru madde miktarı belirlenmiştir. Araştırma sonucunda uygulamalar arasında incelenen özellikler bakımından önemli farklılıklar bulunmuştur. Tuzluluğun fasulye tohumlarında çimlenmeyi büyük ölçüde engellediği tespit edilmiştir. Tuzluluk şiddetinin artması ile çimlenme oranında ve fide büyümesinde önemli derecede azalma görülmüştür. Tuz stresi altında putresin uygulamaları çimlenme özellikleri ve fide gelişim parametrelerinde artış sağlamıştır. Genel olarak putresin uygulamalarının tuz stresinin çimlenme ve fide gelişimi üzerinde meydana getirdiği olumsuz etkileri azalttığı belirlenmiştir. Sonuç olarak, putresinin 0.1 ve 1 mM’lık dozlarının 2 mM’lık doza göre hem tuzlu şartlarda hem de normal şartlarda çimlenme ve fide büyümesi üzerinde daha etkili olduğu tespit edilmiştir.

Effect of chromium (VI) toxicity on morpho-physiological characteristics, yield, and yield components of two chickpea (Cicer arietinum L.) varieties.

The ever-increasing industrial activities over the decades have generated high toxic metal such as chromium (Cr) that hampers the crop productivity. This study evaluated the effect of Cr on two chickpea (Cicer arietinum L.) varieties, Pusa 2085 and Pusa Green 112, in hydroponic and pot-grown conditions. First, growth parameters (seed germination, seedling growth, and biomass production) and physio-biochemical parameters (oxidative stress and the content of antioxidants and proline) were measured to evaluate the performance of both varieties grown hydroponically for 21 days at concentrations of 0, 30, 60, 90 and 120 μM Cr in the form of potassium dichromate (K2Cr2O7). In both varieties, significantly deleterious effects on germination and seedling growth parameters were observed at 90 and 120 μM, while growth was stimulated at 30 μM Cr. Significant increases in malondialdehyde and hydrogen peroxide content and electrolyte leakage demonstrated enhanced oxidative injury to seedlings caused by higher concentrations of Cr. Further, increasing concentrations of Cr positively correlated with increased proline content, superoxide dismutase activity, and peroxide content in leaves. There was also an increase in peroxisomal ascorbate peroxidase and catalase in the leaves of both varieties at lower Cr concentrations, whereas a steep decline was recorded at higher Cr concentrations. In the pot experiments conducted over two consecutive years, growth, yield, yield attributes, grain protein, and Cr uptake and accumulation were measured at different Cr concentrations. Pusa Green 112 showed a significant reduction in plant growth, chlorophyll content, grain protein, pod number, and grain yield per plant when compared with Pusa 2085. Overall, our results indicate that Pusa 2085 has a higher Cr tolerance than Pusa Green 112. Therefore, Pusa 2085 could be used to further elucidate the mechanisms of Cr tolerance in plants and in breeding programmes to produce Cr-resistant varieties.

Cross-tolerance Physiology of Chickpea (Cicer arietinum L.) Genotypes under Combined Salinity and High Temperature Stress Condition

Background: Chickpea at seedling stage is highly sensitive to salinity and high temperature stress. Many studies explained plant responses under independent salinity and high temperature stress, but very little findings had revealed the combined effects of these two stresses on plants. So, the present experiment was aimed to study the response of chickpea genotypes for growth parameters and stress tolerance indices at seedling stage under individual and combined salinity and high temperature stress.Methods: A laboratory experiment during rabi season of 2018-2019 was conducted with thirty chickpea genotypes by comparing their responses under different salinity stresses i.e. EC 4.0 dSm-1 and 8.0 dSm-1 and high temperature (37°C). Seedling growth parameters i.e. germination percentage, vigour index and seedling dry weight along with stress tolerance indices like yield stability index and tolerance index were measured for 10-day-old seedlings.Result: The results revealed genotypic variations for all the parameters, based on which the genotypes KPG-59, IPC 2013-74 and NDG 15-6 were identified as tolerant, whereas KWR-108, BG-3075 and BG-3076 as susceptible. Interestingly, the results also showed that the tolerant genotypes exhibited maximum cross-tolerance at highest level of stress (T5) for germination percentage and vigour index, over control (T0), which might be attributed to their acclimatization while facing different stresses during early growth. So, the genotypic variations in chickpea for these parameters at germination stage might be good criteria for selection of tolerant genotypes under salinity and high temperature individually and also when combined.

Identification of rice genotypes for seedling stage multiple abiotic stress tolerance

Under changing climatic conditions, crops are expected to experience combination of abiotic stresses rather than challenged by a single abiotic stress and hence, breeding for specific abiotic stress tolerance is unavailing. Exposure of crops to abiotic stress during seedling stage leads to poor crop establishment due to early death of seedlings. Hence, tolerance to multiple abiotic stress at seedling stage is imperative for breeding crops. Therefore, there is a need to identify donors for multiple abiotic stress tolerance in rice. Our study aimed at identifying rice genotypes which has multiple abiotic stress tolerance particularly for salinity, drought and heat stress, the most common abiotic stresses under tropical condition. We hypothesis that since abiotic stress tolerance mechanism involves multi-layered regulatory networks, identifying genotypes conferring tolerance through overlapping mechanisms across different abiotic stress might be a multiple abiotic stress tolerant genotype. An important adaptive mechanism for stress tolerance is high root to shoot ratio and this physiological trait has been used as a criterion for tolerance. Twelve rice genotypes were grown under induced water deficit, salinity and high temperature conditions and seedling growth parameters were recorded. Root shoot ratio on length basis was derived from the recorded parameters and the data was normalized by Z distribution and plotted using scatter plot across stresses. KR15058 and KR15007 were identified as the seedling stage multiple abiotic stress tolerant lines by scatter plot analysis. These lines are promising source for the crop improvement programme for developing a multiple stress tolerant genotype with superior agronomical background.