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Chitosan is a natural biopolymer modified from chitins which act as a potential biostimulant and elicitor in agriculture. It is non-toxic, biodegradable and biocompatible which favors potentially broad application. It enhances the physiological response and mitigates the adverse effect of abiotic stresses through stress transduction pathway via secondary messenger(s). Chitosan treatment stimulates photosynthetic rate, stomatal closure through ABA synthesis; enhances antioxidant enzymes via nitric oxide and hydrogen peroxide signaling pathways, and induces production of organic acids, sugars, amino acids and other metabolites which are required for the osmotic adjustment, stress signaling, and energy metabolism under stresses. It is also known to form complexes with heavy metals and used as tool for phytoremediation and bioremediation of soil. Besides, this is used as antitranspirant compound through foliar application in many plants thus reducing water use and ensures protection from other negative effects. Based on such beneficial properties, chitosan is utilized in sustainable agricultural practices owing to changing climates. Our review gathers the recent information on chitosan centered upon the abiotic stress responses which could be useful in future crop improvement programs.

Agriculture in the Central Himalayan Region depends on the availability of suitable germplasm as well as natural conditions. Due to extreme weather conditions, food and nutrition security is a major issue for communities inhabiting these remote and inaccessible areas. Millets are common crops grown in these areas. Foxtail millet (Setaria italica(L.) P. Beauv) is an important crop and forms a considerable part of the diet in this region. The aim of the present study was to explore, collect, conserve and evaluate the untapped genetic diversity of foxtail millet at the molecular level and discover variability in their nutritional traits. A total of 30 accessions having unique traits of agronomic importance were collected and molecular profiling was performed. A total of 63 alleles were generated with an average of 2.52 alleles per locus and average expected heterozygosity of 0.37 ± 0.231. Significant genetic variability was revealed through the genetic differentiation (Fst) and gene flow (Nm) values. Structure-based analysis divided whole germplasm into three sub-groups. Rich variability was found in nutritional traits such as dietary fibre in husked grains, carbohydrate, protein, lysine and thiamine content. The collected germplasm may be useful for developing nutritionally rich and agronomically beneficial varieties of foxtail millet and also designing strategies for utilization of unexploited genetic diversity for food and nutrition security in this and other similar agro-ecological regions.

SUMMARYThe mountain ecosystem of the Central Himalayan Region is known for its diversity of crops and their wild relatives. In spite of adverse climatic conditions, this region is endowed with a rich diversity of millets. Hence, the aim of the present study was to explore, collect, conserve and evaluate the diversity of barnyard millet (Echinochloa frumentacea) to find out the extent of diversity available in different traits and the traits responsible for abiotic stress tolerance, and to identify trait-specific accessions for crop improvement and also for the cultivation of millets in the region as well as in other similar agro-ecological regions. A total of 178 accessions were collected and evaluated for a range of morpho-physiological and biochemical traits. Significant variability was noted in days to 50% flowering, days to 80% maturity, 1000 seed weight and yield potential of the germplasm. These traits are considered to be crucial for tailoring new varieties for different agro-climatic conditions. Variations in biochemical traits such as lipid peroxidation (0·552–7·421 nmol malondialdehyde formed/mg protein/h), total glutathione (105·270–423·630 mmol/g fresh weight) and total ascorbate (4·980–9·880 mmol/g fresh weight) content indicate the potential of collected germplasm for abiotic stress tolerance. Principal component analysis also indicated that yield, superoxide dismutase activity, plant height, days to 50% flowering, catalase activity and glutathione content are suitable traits for screening large populations of millet and selection of suitable germplasm for crop improvement and cultivation. Trait-specific accessions identified in the present study could be useful in crop improvement programmes, climate-resilient agriculture and improving food security in areas with limited resources.

In the present piece of work the effects of seed priming with KNO3 on late sown sesame crop (Sesamum indicum) var. T-4 (V1), T-12 (V2) and Shekhar (V3) in respect of germination, physiomorphological, biochemical and yield parameters were observed. The treatments comprised of KNO3 [10 mM (T1), 15 mM (T2)] and distilled water (DW) primed sets (T0). The results showed that the KNO3 treatment promoted germination percentage, root and shoot length, fresh and dry weights of seedling, catalase, peroxidase and proline content as well as yield attributes like number of capsules plant−1, number of seeds capsule−1, test weight (1000 seed weight in g) and yield plant−1 (g). After 80 h, the highest germination percentage was recorded in 15 mM KNO3 (T2) primed seeds of Sesamum indicum var. T-4, T-12 and Shekhar. The average of root length, shoot length, fresh weight, and dry weight was recorded highest in treatment T2 in comparison to distilled water primed seeds (control) at 25 DAS in all varieties i.e., T-4, T-12 and Shekhar respectively. Yield attributes like number of capsules plant−1, number of seeds capsule−1, test weight and yield plant−1 were also highest in treatment T2 in all varieties V1, V2 and V3 respectively. Variety V1 and treatment T2 recorded the highest values of catalase, peroxidase and proline content followed by variety V3 and V2 and treatment T1 and T0 at 45 DAS respectively. It had been found that seed priming with KNO3 ameliorate the effect of late sowing.

Biopolymer “Chitosan” has received much interest for potential wide application in agriculture due to its excellent biocompatibility, biodegradability and bioactivity. This naturally occurring molecule with interesting physiological potential has been getting more attention in recent years. Chitosan enhanced the efficacy of plants to reduce the deleterious effect of unfavorable conditions as well as on plant growth. Chitosan affects various physiological responses like plant immunity, defense mechanisms involving various enzymes such as, phenylalanine ammonium lyase, polyphenol oxidase, tyrosine ammonia lyase and antioxidant enzymes viz., activities superoxide dismutase, catalase and peroxide against adverse conditions. Recent studies have shown that chitosan induces mechanisms in plants against various biotic (fungi, bacteria, and insects) and abiotic (salinity, drought, heavy metal and cold) stresses and helps in formation of barriers that enhances plant's productivity. This paper takes a closer look at the physiological responses of chitosan molecule.

The present investigation was carried out to examine the role of exogenously applied ascorbic acid which mitigates the deleterious effects of salt stress in mungbean (Vigna radiata L.) genotype HUM-1. Plants grown under induced salinity stress at 150 mM NaCl were treated with different concentration of ascorbic acid, i.e., 0.5 mM, 1.0 mM and 2.0 mM. To study the effects of treatments of salt stress on chlorophyll content, proline content, nitrate reductase activity, superoxide dismutase activity and yield attributes data were recorded at 20, 40, 60 day after sowing. Nitrate reductase activity and chlorophyll content with 1.0 mM ascorbic acid under salinity (150 mM NaCl) while the activities of superoxide dismutase get reduced up to 43.71% at 40 days after sowing. In plant treated with combined treatment of 150 mM NaCl and 1.0 mM foliar applied ascorbic acid caused a decline in the level of proline, which was 3.38 mg, 3.35 mg and 6.30 mg at 20, 40 and 60 days after sowing. The threshold level of ascorbic acid was 150 mM NaCl along with 1.0 mM ascorbic acid, that improved the yield attributes under salinity. Ascorbic acid inhibits the adverse effect of NaCl for growth and development of plants. So ascorbic acid may be a promising treatment to ameliorate the deleterious effects of salt stress in crops.

The experiment was conducted in stressed and non stressed condition during kharif season 2014 at Department of Plant Physiology, Banaras Hindu University, Varanasi, India. Mungbean seeds were treated with different concentrations of brassinolide (BL) 0.01 mM and 0.05 mM in combination with sodium chloride (NaCl) 100 mM, BL 0.05 mM alone with control. The whole experiment was done in Petriplates and pots in growth chamber and net house, and was laid out in complete randomized design. The results of experiment revealed that plant growth regulator brassinolide (BL 0.05 mM) with salinity stress increased the germination percentage by three folds, root length by two folds, shoot height by two folds, SPAD value by one fold, nitrate reductase activity by seven folds and proline content by one fold when compared with salinity stressed condition (NaCl 100 mM) in both HUM-16 and HUM-12 genotypes at 30 days after sowing (DAS). The increase in above parameters was found at par with BL 0.01 mM concentration. Stressed plants exhibited poor growth and biochemical parameters were significantly reduced. However, the follow up application of BL (0.01 mM and 0.05 mM) neutralized the damaging effects of the salinity on the plants.

Application of Plant Growth Promoting Rhizobacteria in Promising Agriculture: An Appraisal Gradually agriculture is facing struggle to meet the various threaten of producing more food for an increasing world population food security. Large quantities of synthetic fertilizers and pesticides are necessitated for high productivity which can smash up bionetwork structures and functions, including the soil microbial community which plays imperative function in agriculture sustainability. Soil is an excellent niche of growth of many bacteria in rhizosphere. Many rhizospheric bacterial strains possess plant growth-promoting mechanisms. These bacteria can be applied as biofertilizers in agriculture and forestry, enhancing crop yields. Plant growthpromoting rhizobacteria can improve plant growth through several different mechanisms: (a) the synthesis of plant nutrients or phytohormones (Indole acetic acid and cytokinin), which can be uptake by plants, (b) the mobilization of soil compounds like phosphorous and metals, making them available for the plant to be used as nutrients, (c) the protection of plants under stressful conditions, thereby counteracting the negative impacts of stress, or (d) defense against phytopathogens, reducing plant diseases or death by producing antibiotics and HCN. Several plant growth-promoting rhizobacteria have been used worldwide as biofertilizers, contributing to increasing crop yields and soil fertility and hence having the potential to contribute to more sustainable agriculture and forestry. Scientific researchers involve various moves towards for identification of plant growthpromoting rhizobacteria adaptation, upshot on physiological and growth aspects on plants and induced systemic resistance, biocontrol and biofertilization in agriculture.

Current soil management strategies are mainly dependent on inorganic chemical-based fertilizers, which caused a serious threat to human health and environment. Plant growth-promoting rhizobacteria (PGPR) are naturally occurring soil bacteria that aggressively colonize plant roots and benefit plants by providing growth promotion. Inoculation of crop plants with certain strains of PGPR at an early stage of development improves biomass production through direct effects on root and shoots growth. The major groups of PGPR can be found along with the phyla actinobacteria, bacteroidetes, firmicutes, and proteobacteria. Inoculation of agricultural crops with PGPR may result in multiple effects on early-season plant growth, as seen in the enhancement of seedling germination, plant health, vigor, height, shoot weight, nutrient content of shoot tissues, early bloom, chlorophyll content, and increased nodulation in legumes. PGPRs are reported to influence the growth, yield, and nutrient uptake by an array of mechanisms. They help in increasing nitrogen fixation in legumes, help in promoting free-living nitrogen-fixing bacteria, increase supply of other nutrients, such as phosphorus, iron and produce plant hormones that enhance other beneficial bacteria or fungi. Now a day’s an increasing number of PGPR being commercialized for various crops. Subsequently, there has been much research interest in PGPRs. Several reviews have discussed specific aspects of growth promotion by PGPRs. Therefore, PGPRs can help to generate wealth cooperatively in local communities, reducing the need for more expensive manufactured products, such as nitrogenous fertilizers and use of PGPR in world has the potential to provide valuable insight.

Flooding stress is one of the major obstacles which hamper plant growth and development in various ways. Two screened mungbean genotypes, HUM-16 (flooding tolerant) and HUM-12 (flooding susceptible), were selected to evaluate the effect of paclobutrazol @10ppm and 25ppm along with its combinations through pre-seed soaking and foliar spray at pre-flowering stage. The flooding stress shock was imposed for seven days at pre-flowering stage. Paclobutrazol (PBZ) treatments significantly enhanced chlorophyll, soluble sugar, starch, MSI, APX, and SOD in both HUM-16 and HUM-12 genotypes under flooding stress. Among all the treatments, PBZ @10ppm seed treatment + 10ppm foliar spray revealed higher chlorophyll (2.47 and 1.97 mg g-1 FW), soluble sugar (24.57 and 20.53 mg g-1 FW), MSI (49.16% and 38.67%), APX (16.13 and 6.50 Units mg-1 protein min-1) and SOD (38.00 and 18.30 Units mg-1 protein min-1) in both tolerant and susceptible genotype, respectively, while it minimized the production of MDA (18.30% and 49.00%) and H2O2 (19.05% and 25.06%) in both tolerant and susceptible genotype, respectively, under flooding stress as compared to control. Paclobutrazol treatments, as evident, minimized the flooding stress damage in tolerant genotype as compared to susceptible genotype by enhancing chlorophyll, soluble sugar and antioxidant enzymes activity (APX and SOD) and by reducing the generation of H2O2 and MDA contents under flooding stress.

Significant differences in the antioxidant system of the leaves of four chickpea (Cicer arietinum L.) genotypes differing in tolerance to drought were observed in a pot experiment. Drought stress was imposed at pre- and post- anthesis stage (50 and 65 days after sowing). We studied the effect of drought stress on hydrogen peroxide (H2O2) content, lipid peroxidation and antioxidant enzyme activities in four chickpea genotypes viz., Tyson, ICC 4958, JG 315 and DCP 92-3. Drought treatment significantly increased hydrogen peroxide accumulation and lipid peroxidation, which indicated the extent of oxidative injury posed by stress conditions. Enzyme activities of Superoxide Dismutase (SOD), Peroxidase (POX), Catalase (CAT) and Ascorbate Peroxidase (APX) increased in chickpea leaves as a consequence of drought conditions and all the enzyme activities were significantly higher in drought stressed genotypes i.e., Tyson and ICC 4958 than in JG 315 and DCP 92-3. Relationship between Lipid Peroxidation (LPO), Hydrogen peroxide (H2O2), Superoxide Dismutase (SOD), Catalase (CAT), Peroxidase (POX) and Ascorbate Peroxidase (APX) was determined in order to find out whether these parameters can be used as selection criteria for drought tolerance in this crop. Early drought stress (pre-anthesis drought) was found to be more damaging than the late drought stress (post-anthesis drought).