Nazima Batool

Drought mitigation potential of Azospirillum inoculation in Canola ( Brassica napus )

Azospirillum is considered to be a most effective Plant Growth Promoting Rhizobacteria (PGPR), which is responsible for various modifications in plants to cope with stress conditions. Therefore, the present research was planned to evaluate the effect of Azospirillum lipoferum (GQ 255949) inoculation on growth, biochemical, yield attributes of canola grown under drought conditions. Two different modes of inoculation were used; i.e., inoculation of seeds directly and exposure of planted seed in the rhizosphere. Drought stress was imposed at flowering stage. Azospirillum seed inoculation was helped mitigate stress effects by improving germination percentage up to 12.49%. Root area was increased up to 18.5% and 11.38% with seed and rhizosphere inoculation in drought stress respectively. Chlorophyll contents and water potential were increased 12.21%, and 11.0% in seeds inoculated under drought conditions. Superoxide dismutase activity was decrease up to 24.6% and 12.5% in seed and rhizosphere inoculated plants under well watered conditions. Seed inoculation was most effective, as number of seeds per pod and seed weight per plant was significantly increased up to 25%, and 14.28% as compared to the control. In conclusion, Azospirillum can mitigate deleterious effects of drought stress in canola under water deficiency conditions.

Application of biochar in mitigation of negative effects of salinity stress in wheat (Triticum aestivum L.)

ABSTRACT Salinity is a major abiotic stress that affects crop production throughout the world. Biochar is an activated carbon soil conditioner that can alleviate the negative impacts of salinity. The research was conducted to evaluate the ameliorative effect of 1% and 2% of biochar application on wheat seed germination and growth attributes under salinity. Both levels of biochar improved the germination and growth conditions under salinity; however, 2% biochar level was more effective compared to 1% level. Root and shoot length increased up to 23% and11% with 2% biochar, respectively. The maximum increase of 16% and 10% in leaf water potential and osmotic potential was noted with 2% biochar at 150 mM salt. The decrease in proline content and soluble sugar at 2% biochar was 51% and 27%, respectively. Decrease in superoxide dismutase activity was 15.3% at 2% level of biochar under stress biochar mitigates the negative effects of salinity and improved wheat productivity.

Contribution of Nitrogen Fixed by Mung Bean to the Following Wheat Crop

ABSTRACT Crop rotation is a supportive management practice in which legumes greatly improve the growth and yield of subsequent cereal crops, particularly wheat. In this study, effects of mung bean (Vigna radiata) on the yield and quality of grains of following wheat crop were determined. An experiment was carried out with two sets of wheat (Triticum aestivum) crops: one grown following mung bean (Vigna radiata) crop and the other grown after a fallow period. Concentrations of macronutrients, sugar, protein, amino acids, and phytohormones of wheat were determined. The grain protein concentration of wheat was improved if cultivated after mung bean, and nitrogen and other macronutrients of wheat were increased significantly. In case of phytohormone contents in the wheat crop, abscisic acid concentration showed no change, but the concentrations of gibberellin increased significantly by 41% and indole acetic acid by 30% as a result of crop rotation. Sugar content in wheat cultivated after mung bean BRM-318 showed 10% increase and wheat protein content increased by 17% and 20%, respectively. The present study demonstrated that crop rotation simulated yield and improved the nutritional value of wheat grain compared to wheat which followed the fallow period.

Amelioration of drought stress in wheat by combined application of PGPR, compost, and mineral fertilizer

ABSTRACT Among various abiotic stresses, global drought reduces global growth and yield of wheat. Present research has been designed to ameliorate the adverse effects of drought stress on wheat by combined application of plant growth-promoting rhizobacteria (PGPR), compost, and mineral fertilizers. In this experiment, the role of fertilizer, compost, and PGPR inoculation to ameliorate drought stress was studied in two wheat varieties at vegetative stage. Water stress adversely affects morphology, physiology, and biochemistry of the wheat plant. Inoculated seed with compost and mineral fertilizer grown in drought condition showed 43% increase in relative water content (RWC) of 9.39% in Membrane Stability Index and 82.20% in chlorophyll as compared to control. Drought affected the accumulation of osmolytes, but PGPR in combination with compost and mineral fertilizer under drought stress triggered higher accumulation of soluble sugar and proline content, i.e., 28.96% and 73.91%, respectively. It is concluded from this research that PGPR in combination with compost and mineral fertilizer considerably reduces the effect of drought on wheat by enhancing the physiological (RWC, membrane stability, chlorophyll content, and water potential) and biochemical (proline and sugar) aspects of the plant.