Different Concentrations Of Sodium Azide Research Articles

Identification of Induced Chemical Mutants for Improving Yield and its Attributing Traits in Wheat (Triticum aestivum L.) against Changing Climate

Background: The enhancement of genetic traits in any crop relies on the existing variability within that particular crop. Through hybridization and traditional breeding methods, the variability within wheat crops has been nearly exhausted. Consequently, mutation breeding emerges as the sole viable and promising approach to introduce new variability for further improvements. Methods: An experiment was conducted during the Rabi seasons of 2020-21 (M1 generation) and 2021-22 (M2 generation) at the Crop Research Centre, Department of Genetics and Plant Breeding, ITM University Gwalior. The experiment assessed the impact of five different concentrations of Sodium Azide (0.02%, 0.03%, 0.04%, 0.05%, and 0.1%) and Hydroxyl Amine (0.2%, 0.3%, 0.4%, 0.5% and 0.6%), in addition to a control, on the wheat varieties MP-3382 and RVW-4106. It employed a randomized block design with three replications. Result: The findings revealed that Sodium Azide and Hydroxyl Amine, the most effective dosages were observed to be 0.1per cent and 0.4 per cent, respectively, in inducing genetic and phenotypic changes in seed quality parameters. Specifically, for the flag leaf area characteristic, the most effective concentrations were 0.03 per cent Sodium Azide and 0.4 percent Hydroxyl Amine. Plant height exhibited the greatest variability at 0.03 per cent Sodium Azide, 0.5 per cent Hydroxyl Amine and 0.1 percent Sodium Azide. A dosage of 0.5 per cent Hydroxyl Amine was found to be most effective in altering spike length. In terms of days to 50 per cent flowering, 0.05 per cent Sodium Azide was identified as the most effective dosage. From the study of traits in both the M1 and M2 generations, 12 mutants were confirmed, with seven validated for variety MP-3382 and five for variety RVW-4106.

Determination of lethal dose (LD50) and sensitivity of fenugreek (Trigonella foenum-graecum) to sodium azide for induction of mutation

The present experiment was conducted in the year 2021 at Sri Karan Narendra Agriculture University, Jobner, Rajasthan, to determine the optimum dose (LD50) and duration of the chemical mutagen treatment for the induction of desirable mutation. A set of 100 pre-soaked fenugreek seeds were treated with 12 different concentrations of sodium azide, viz. 0.3 mM, 0.6 mM, 1 mM, 2 mM, 3 mM, 4 mM, 5 mM, 6 mM, 7 mM, 8 mM, 9 mM and 10 mM for three different durations, viz. 3 h, 6 h and 9 h. Results showed that a dose-dependent decreasing tendency was observed in germination percentage, survival percentage, root length and shoot length with increasing concentration and duration of sodium azide treatment. Almost all the mutagenic treatments resulted in decrease in germination percentage, survival percentage and seedling height (root and shoot length) with increasing concentrations and duration of mutagen in laboratory conditions. Also, the LD50 value was observed as an 8 mM sodium azide concentration for 6 h in fenugreek. The mutagen treatments given at 9 h duration were detrimental for fenugreek. They cannot be used for mutation induction as they are utterly lethal after a 3 mM sodium azide concentration. So, lower treatments of mutagens have influenced less biological damage and would be suitable for inducing desirable mutations.

Mutagenic effect of hydroxyl amine and sodium azide on the performance of tomato (Solanum lycopersicum L.)

Tomato, an important vegetable crop due to its utility as raw, cooked and processed form of food, requires improved cultivar with high nutrition and yield to meet out global demand in changing agro-climatic conditions. The mutagenesis is one of the most important techniques to create genetic variability and identification of economically important traits towards the crop improvement. Therefore, the mutagenic effect of various concentrations of hydroxyl amine and sodium azide were studied on tomato var. PKM 1 for the qualitative and quantitative traits of economic importance. The seeds of tomato were obtained from Ryoth’s Depot Kurnool, Andhra Pradesh, India and treated with the different concentrations of sodium azide (SA) and hydroxyl amine (HA) 2 mM, 3 mM, 4 mM, 5 mM and 0.1, 0.15%, 0.2, 0.25%, respectively) for four hours. Study on germination per cent, seedling height, root length and pollen viability was carried out in lab and for growth parameters. M1 generation was grown in the field. The mutagens hydroxyl amine (0.1%) and sodium azide (2 Mm), showed least reduction in parameters and with increase the concentration of both chemicals, decline was noted. Highly significant differences were observed in the treatments with respect to the studied traits (seed germination, seedling survival, seedling height, root length, pollen viability, leaves per seedling and height at maturity, branches per plant and fruits per plant. The present study concluded that mutagens had detrimental effects along with creating variability. Hence, hydroxyl amine (0.1%) and sodium azide (2 Mm) could be utilized to induce variability for the improvement of tomato.

Effect of Sodium Azide on Yield and its Components in Bread Wheat (Triticum aestivum L.).

<b>Background and Objective:</b> The wheat crop is considered one of the most important crops globally, especially in Egypt. It has great nutritional importance, so it was necessary to increase productivity and any genetic improvement depends on the presence of many genetic differences so that breeders can achieve this. This study aimed to use chemical mutagenic (sodium azide) to obtain the desired genetic differences in two wheat cultivars. <b>Materials and Methods:</b> Two types of bread Sids 12 and Giza 164 were treated with different concentrations of sodium azide (NaN<sub>3</sub>) (1000, 2000, 3000, 4000, 5000 and 6000 ppm). <b>Results:</b> The highest grain/plant 78.91 g was obtained from Sis12 and 62.96 g from Giza 164 compared to the control 42.57 and 40.24 g for Sids 12 and Giza 164, respectively. Also from the results obtained, the relationship of yield was positive and significant with both grain/spike, spikelet's no./spike spikes no./plant and height/plant. On the contrary, it was negative and significant with a 1000-grain weight (-0.433). <b>Conclusion:</b> The two treatments (1000 and 2000 ppm) were the best in the Sids 12, while (1000 and 5000 ppm) were the best treatments in the Giza 164.

Characterization of Mutant Aspergillus niger and the Impact on Certain Plants

Aspergillus niger is a dangerous pathogen for many plants. It is a major cause of the destruction, rotting and decomposition of plant tissues. Toxicity caused by A. niger can be inhibited by mutation decreasing the destructive effect on plants. An 18S rDNA molecular tool was used to identify A. niger strains. Sodium azide (NaN3) is a chemical mutagen that disturbs fungal enzymatic activity and causes microbial production of cellulose-degrading enzymes, decreasing mycotoxin production. Different concentrations of sodium azide were used to treat A. niger (30, 40 and 50 µM). The study was designed on two levels: the first level concerned the mutant A. niger’s mode of action: the higher the mutagen concentration, the lower the growth diameter and spore counts. The mutant A. niger’s total proteins and flavonoids were reduced when compared to control. RAPD-PCR showed genetic variation in the genetic content of mutant fungi compared to control resulting in a polymorphism percentage of 78.56%. The second level included the effect of these mutants on two plants (onion and maize). The greater the increase in mutant concentration, the greater the increase in the plants’ morphological and physiological behavior. In conclusion, mutation reduced fungal activity and strengthened plant resistance.

Comparison of Growth and Yield Performance of (UC-82B & Local) Varieties of Tomatoes (Lycopersicum esculentum Mill.) by Grafting, Mutation and Seasonal Variations

The Comparison of Growth and Yield Performance of (UC-82B & Local) Varieties of Tomatoes (Lycopersicum esculentum Mill.) by Grafting, Mutation and Seasonal Variations was investigated with the aim of inducing variability that could be exploited in the improvement of some quality traits in Tomato plants. The seeds of two varieties of tomato: UC-82B and Local varieties were treated at three different concentrations of sodium azide (1.0mM, 1.5 mM, 2.0 mM and 0.0 mM as control). The results obtained revealed highly significant difference (P≤0.01) in the effects of sodium azide on survival rates, number of fruits, and fruit weight. Similarly, highly significant differences (P≤0.01) was found between the treatments in Survival rate, except on the number of fruits and fruit weight, where no significant differences exist. More so, significant differences were found in the traits between the seasons except in fruit number. The result shows that 1.0 mM concentration of Sodium Azide and grafting improves some important quality traits of tomato that could be utilized for further improvement of tomato crop. However, the response of variety UC to grafting was higher. Highly significant difference (P≤0.01) was found among the seasons in terms of fruit weight, and significant difference (P≤0.05) was found among the seasons on survival rate, while no significant difference was found among the seasons in terms of fruits number. More so, highly significant difference (P≤0.01) was found in the interaction of varieties with seasons on Survival rate and number of fruit tomato varieties except on fruit weight, where no significant difference was found.

Induced-Growth and Yield Responses to Three Varieties of Tomato (Lycopersicon esculentum Mill.) by Sodium Azide (NaN3) and Grafting in Wet Season

The Effect of Sodium Azize and Grafting on Vegetative Growth PreliminaYield Parameters on Tomato in Wet Season, was investigated with the aim of inducing variability that could be exploited in the improvement of some quality traits in Tomato. The seeds of three varieties of tomato: (Roma, UC-82B and Local varieties) were treated with three different concentrations of sodium azide (0.2mM, 0.4 mM, 0.6 mM and 0.0 mM as control). The result showed highly significant difference (P≤0.01) in the effects of different concentrations of sodium azide on almost all the selected traits except on the fruit diameter where no significant difference was found. More so, the result also indicated highly significant difference (P≤0.01) among the varieties on the selected traits except in germination percent (1 WAP); where significant difference (P≤0.05) was found, and in number of leaves, and fruits diameters, no significant difference exists among the varieties. Furthermore, highly significant difference (P≤0.01) was found on the effects of grafting and sodium azide singly and in combine dosage as treatments on germination percent (1 and 2 WAP), and on number of leaves/plant. Significant difference (P≤0.05) was found on the effects of these treatments on the survival rate, while, no significant difference was found on the effects of the treatments on the number of fruits, fruit diameter, and pH. More so, no significant differences was found in the interactions except in the interaction in the interactions of variety and treatments on the number of leaves where highly significant difference (P≤0.01) was found.

Genetic improvement of a neglected and underutilised oilseed crop: sesame (Sesamum indicum L.) through mutation breeding

Sesame (Sesamum indicum L.) also known as Queen of oilseeds is being cultivated worldwide for its oil content for nutritional and medicinal value. Low productivity is one of the major constraints of sesame cultivation. Systematic efforts are made using induced mutagenesis to increase its productivity and realize earliness and alteration in genetic architecture. Sodium Azide was used as a chemical mutagen in the present study. Nine sesame varieties viz., TMV 3, TMV 4, TMV 5, TMV 6, TMV (Sv) 7, CO 1, VRI 1, VRI(Sv) 2 and Paiyur 1 released from Tamil Nadu Agricultural University, Coimbatore, India were subjected to mutation at three different concentrations of Sodium Azide viz., 5 mM, 10 mM and 15 mM. An extra early mutant that matured on 70 DAS was identified in M4 generation of TMV 5 at 15 mM. This mutant (TVS 1401) was forwarded to subsequent generations with confirmed earliness. After confirming the superior performance of the mutant TVS 1401 for yield attributes in station trials, it was evaluated in MLT for two seasons. During Rabi 2017 MLT, it recorded 521 kg/ha of seed yield with the duration of 72 days. During Kharif 2018, it recorded 683 kg/ha of seed yield which was 21.96% higher yield than the popular check TMV 7 and matured 16 days earlier. This extra early mutant has white seed coat colour with 1000 seed weight of 3.22 g. Dissection of fatty acid profile of this mutant also confirmed its superiority. Distinctness of TVS1401 in molecular level was also established through RAPD markers viz., OPC03550 and OPA04550.

Effects of different concentrations of sodium azide and chloramphenicol on the preservation of raw milk samples

ABSTRACT: The preservation of milk samples for microbiological analyses by the Brazilian Network of Milk Quality Control Laboratories requires the addition of preservatives to maintain the microbiota from the time of sample collection to the moment of analysis. The number of microorganisms can change as a result of the active ingredients and concentration of the preservative, as well as due to interactions between the preservatives, incubation time, and packaging temperature. The objective of this research was to evaluate the conservation potential of different concentrations of sodium azide and chloramphenicol on the analytical shelf life of milk samples. Two farms were selected, one with a low bacterial count and one with a high bacterial count. The milk was dispensed into sterile vials and tested after the addition of the usual concentrations of sodium azide and chloramphenicol, doubled concentrations, tripled concentrations, and as a control, without preservatives. The samples were incubated at 3 ± 1 °C, 6 ± 1 °C, and 9 ± 1 °C for 14 days and analyzed daily for their bacterial count by flow cytometry. The tripled preservative concentrations improved conservation, increasing the timespan of the analytical viability of the samples without altering the results.

Assessment of Genetic Divergence in Mutant Lines of Tomato (Solanum lycopersicum L.)

Introduction: Mutation breeding is the process of exposing seeds to chemicals or radiation in order to generate mutants with desirable traits. Aim: This study is aimed at assessing the genetic variability among mutant lines of tomato (Solanum lycopersicum L.) generated from a variety of tomato (Roma VF) using two different chemo-mutagens. Materials and Method: The collected seeds were exposed to different concentrations of Sodium azide and Colchicine with varied period of exposure. The seeds were planted and selected 49 positive mutant lines were assessed for morphological genetic variability and yield. 18 mutant lines that produced fruits were tagged and selected. The fruits of the selected mutants were harvested and the seeds (M2 seeds) were subsequently planted for divergence analysis. Ten quantitative characters and twenty qualitative characters were scored using IPGRI standard tomato descriptor. The potted experiment was laid out in the Green House, using Randomized Block Design (RBD) with three replications. Result: The results of this study revealed a high genetic divergence among the mutant lines in both quantitative and qualitative characters. There was significant LSD (0.05) for Germination percentage (7.66), Plant height at maturity (7.05) and Number of leaves at maturity (4.56). The yield (fresh fruit weight) varied significantly, ranging from 10.00g for LeMT29 to 319.70g for LeMT7 respectively. Fruit and plant qualitative characters equally exhibit variation. Conclusion: These observations suggest the existence of genetic variability among the different mutant tomato lines. Further selection and field trials is recommended to identify suitable and desirable lines for possible variety release. To Keywords: Mutant, Tomato, Colchicine, Sodium azide, genetic variability.

Mutagenic effects of Sodium azide (NaN<sub>3</sub>) on morphological characteristics on two varieties of tomato (<i>Solanum lycopersicum</i> Mill)

The Impact of Sodium Azide on the Germination and Growth of Two Varieties of Tomato was investigated with the aim of inducing variability that could be exploited in the improvement of some quality traits in tomato plants. The seeds of two varieties of Tomato (Roma and UC82B) were treated with three different concentrations of Sodium Azide (0.1mM, 1.0 mM, 2.0 mM and 0.0 mM as control). The result obtained revealed a highly significant differences (P≤0.01) in the effects of Sodium Azide on seedlings heights, Height at maturity, fruit weight, pericarp thickness, number of leaves and pH(Potential of Hydrogen) Significant improvement (P≤0.05) was also recorded in fruit diameter, while no significance difference was found on Root dry weight. The result revealed that Sodium Azide improve important quality traits in tomato. However, the response of variety UC82B to Sodium Azide was higher. More so, significant differences were observed between the seasons except in the number of leaves, fruit number, pericarp thickness and fruit diameter. It was concluded that 0.1 mM of Sodium Azide improve some quality traits of tomato that could be utilized in the improvement of tomato.Key Words: Sodium Azide, Tomato, Mutation, Varieties, Morphology, UC82B, Roma.

Induced-growth and yield responses to seasonal variation by sodium azide in tomato (Lycopersicon esculentum Mill.)

The mutagenic effect of various concentrations of sodium azide on some selected quality traits of three varieties of tomato was investigated with the aim of improving the quality and quantity of the traits of economic importance. The seeds of three tomato varieties namely: Roma, UC and a Local variety were treated with four different concentrations of sodium azide (0.1mM, 1.0 mM, 2.0 mM and 0.0 mM as control) via pre-soaking during both the wet and dry seasons. The results obtained revealed highly significant difference (P≤0.01) in the effects of various concentrations of sodium azide on the number of leaves, leaf area, number of fruits, fruit weight, pericarp thickness, number of seeds/fruit and pH of the fruit juices. Significant improvement (P≤0.05) was recorded on fruit diameter. More so, significant differences were found in the interactions of the varieties to the mutagenic treatments during the rainy season than the dry season. The interaction showed that all the mutants treated with 0.1mM concentration have the highest response in all the selected traits during rainy season except fruit diameter. Similarly, all the 1.0mM treated mutants showed highest response during rainy season except in leaf area where highest response was found in dry season. Similar result was found in 2.0 mM treated mutants. We therefore concluded that 0.1Mm sodium azide concentration improves important quality traits of tomato more especially variety UC as it responds significantly to sodium azide and that, the mutant tomato could be grown both during the rainy and dry seasons.Key Words: Concentrations, Mutation, Sodium Azide, Tomato

Anatomical Variations Caused by the Exposure of Sodium Azide and Potassium Chromate to the Accessions of Colocasia esculenta (L.) and Xanthosoma maffafa (L.) in Nigeria.

The anatomical variations of the mid ribs and petioles of five accessions of Colocasia esculenta L. and three accessions ofXanthosoma maffafa L. exposed to different concentrations of sodium azide and potassium chromate were carried out. Graded quantities of 2.5, 5, 7.5 and 10 mg/kg of sodium azide and potassium chromate were applied to each accession while the control experiment lacked the oil-field chemical additives. Results showed some variations in the shape of epidermal cells, thickness of cuticle and number of vascular tissues among others. The petioles were observed to have more vascular tissues than the mid ribs for both the control and treated accessions. Statistical evidence showed that differences in the number of vascular tissues between various accessions and treatments were highly significant at 5 % probability. Between these two oilfield chemicals, it was observed that sodium azide treatments induced formation of more vascular tissues in both the mid ribs and petioles than potassium chromate treatments. These observations add to the literature and the understanding of this species’ mechanism in withstanding environmental stress

Phenotypic and biochemical profile changes in calendula (Calendula officinalis L.) plants treated with two chemical mutagenesis

Chemical mutagenesis is an efficient tool used in mutation-breeding programs to improve the vital characters of the floricultural crops. This study aimed to estimate the effects of different concentrations of two chemical mutagens; sodium azide (SA) and diethyl sulfate (DES). The vegetative growth and flowering characteristics in two generations (M1 and M2) of calendula plants were investigated. Seeds were treated with five different concentrations of SA and DES (at the same rates) of 1000, 2000, 3000, 4000, and 5000 ppm, in addition to a control treatment of 0 ppm. Results showed that lower concentrations of SA mutagen had significant effects on seed germination percentage, plant height, leaf area, plant fresh weight, flowering date, inflorescence diameter, and gas-exchange measurements in plants of both generations. Calendula plants tended to flower earlier under low mutagen concentrations (1000 ppm), whereas higher concentrations delayed flowering significantly. Positive results on seed germination, plant height, number of branches, plant fresh weight, and leaf area were observed in the M2-generation at lower concentrations of SA (1000 ppm), as well as at 4000 ppm DES on number of leaves and inflorescences. The highest total soluble protein was detected at the concentrations of 1000 ppm SA and 2000 ppm DES. DES showed higher average of acid phosphatase activity than SA. Results indicated that lower concentrations of SA and DES mutagens had positive effects on seed germination percentage, plant height, leaf area, plant fresh weight, flowering date, inflorescence diameter, and gas-exchange measurements. Thus, lower mutagen concentrations could be recommended for better floral and physio-chemical performance.

English

Plants of Browallia speciosa were treated with different concentrations of sodium azide (0, 200, 400, 600 and 800 ppm) as a soil drench. The concentration of 800 ppm had simulative effect on the most studied traits. It increased the number of branches and leaves, chlorophyll content, fresh weights of vegetative growth and roots, dry weights of vegetative growth and roots and root length in the M1 (2011/ 2012) and  M2 (2012/ 2013). All the concentrations of sodium azide produced changes in the flower colour, flower shape and leaf form in both generations. Peroxidase isozyme pattern indicated that seven loci produced of peroxidase are shown in B. speciosa.  In addition, different peroxidase profiles among mutants were found. The phylogenetic tree indicated that mutant 4 was the most genetically distinct mutant from the control followed by mutant 3.   Key words: Browallia speciosa, mutation, sodium azide, isozyme.

Fate of Bulk Organic Matter, Nitrogen, and Pharmaceutically Active Compounds in Batch Experiments Simulating Soil Aquifer Treatment (SAT) Using Primary Effluent

Reduction of bulk organic matter, nitrogen, and pharmaceutically active compounds from primary effluent during managed aquifer recharge was investigated using laboratory-scale batch reactors. Biologically stable batch reactors were spiked with different concentrations of sodium azide to inhibit biological activity and probe the effect of microbial activity on attenuation of various pollutants of concern. The experimental results obtained revealed that removal of dissolved organic carbon correlated with active microbial biomass. Furthermore, addition of 2 mM of sodium azide affected nitrite-oxidizing bacteria leading to accumulation of nitrite-nitrogen in the reactors while an ammonium-nitrogen reduction of 95.5 % was achieved. Removal efficiencies of the hydrophilic neutral compounds phenacetin, paracetamol, and caffeine were independent of the extent of the active microbial biomass and were >90 % in all reactors, whereas removal of pentoxifylline was dependent on the biological stability of the reactor. However, hydrophobic ionic compounds exhibited removal efficiency >80 % in batch reactors with the highest biological activity as evidenced by high concentration of adenosine triphosphate.

Inhibition of mitocondrial complex IV in cell death and the influence of light.

AbstractPurpose Characterise the mechanism by which the mitochondrial complex IV poison sodium azide kills RGC‐5 cells (cell line with certain ganglion cell properties) in the dark and determine the influence of white and red light.Methods RGC‐5 cell cultures in 96‐ or 12‐well plates were exposed to different concentrations of sodium azide in the dark or under white (400‐700nm, 1000 lux) or red (625‐635nm, 1000lux) light. Cells were analysed 24‐96 hours later for production of reactive oxygen species (ROS), cell viability (MTT procedure) and for apoptosis (staining for phosphatidylserine and DNA breakdown). Also, cultures were subjected to immunocytochemistry for the localisation of certain antigens or their proteins extracted and subjected to electrophoresis and western blotting for various proteins involved in cell death.Results Sodium azide (5mM)‐induced apoptosis of RGC‐5 cells is characterised by positive membrane staining for phosphatidylserine, breakdown of DNA, a generation of ROS production, the activation of p38 MAPK and by inhibition with the caspase inhibitor z‐VAD‐fmk. Sodium azide also caused p38 MAPK to be translocated from the nucleus to the cytoplasm and the stimulation of alpha fordrin and caspase‐3 content. White light exacerbated and red light reduced the effects of sodium azide that occurred in the dark.Conclusion Red light as opposed to white light acting directly on the retina might protect neurones from dying by apoptosis where their mitochondria are affected.

관류 랫드 장관모델에서의 케토프로펜의 흡수기전 연구

The aim of this study was to investigate the absorption properties of ketoprofen. The in-situ perfusion model has advantages over in vitro models as it provides intact lymphatic and blood flow circulation. The absorption properties of six different concentrations of ketoprofen have been studied in single pass in-situ rat intestine model. 4000 was used as a permeability marker and the possibility of an energy dependent contribution to ketoprofen absorption was also Investigated using the metabolic inhibitor sodium azide. Three different concentrations of sodium azide were studied to examine its effect on absorption of ketoprofen from the rat intestine. The findings of this study suggest that mono-carboxylic type drugs like ketoprofen cause permeability changes in the intestine. This is shown by the increase in absorption of 4000 as the concentration of ketoprofen is increased. However, the trend for ketoprofen permeability is to decrease over the concentration ranges. It was observed that the Papp values for ketoprofen with sodium azide shows a trend towards reduction in the amount of ketoprofen absorbed from the rat intestine which was significantly different (p by the buffering capacity of the small intestine secretions. The results suggest that mechanisms other than passive diffusion may be involved in ketoprofen absorption. This would be consistent with the involvement of active transport or saturatable processes in the absorption of drugs containing monocarboxylic acid group, as has been previously suggested from in vitro data.

Effects of sodium azide on yield parameters of groundnut (Arachis hypogaea L.)

The mutagenic effects of different concentrations of sodium azide (0.01 – 0.05%) on groundnut (Arachis hypogaea L. cv SS1145B and RMP 91) were investigated. The characters studied include; plant height, number of branches per plant, pods/plant, seeds/pod, seeds/plant and 100 seed weight in the M1 and M2 generations. Both negative and positive shifts in mean values were recorded as a result of the chemical treatment. The most effective dosage for inducing mutation/morphological aberration was established at 0.03%. Increases in genetic parameters of variation, heritability and genetic gain under the chemical treatment indicate the possibility of evolving higher yield variants through proper crop selection. Thus, economic traits like pods/plant, seeds/plant with high heritability and genetic gain values in the M3 generation offer good scope for selection and improvement.

Azide resistant mutants of Acetobacter diazotrophicus and Azospirillum brasilense increase yield and nitrogen content of cotton

Evolution of symbiotic plant-microbe interactions has provided mankind a powerful and environment-friendly means to increase yield of agricultural crops. Here, we report that some azide resistant mutants of two microbial strains can significantly enhance the productivity of cotton varieties, as an attractive and cheap biological substitute of chemical fertilizers, for improved yield of an important cash crop, without any untoward impacts. Sodium azide resistant mutants were isolated from each strain of Azospirillum brasilense and Acetobacter diazotrophicus on different concentrations of sodium azide ranging from 5–60µg/ml. These azide resistant mutants were assessed for their performance on cotton (varieties H-117, HD-123) for various parameters. Inoculation of cottonseeds with mutants obtained better results than inoculation with their respective parental strains. Azide resistant mutants, when used as biofertilizers, showed increased plant height, early flowering, more yield, and high biomass and total nitrogen content. They also increased, in cotton genotypes, the indole acetic acid production and ammonia excretion due to high nitrogenase activity.