The similarity between plant and microbial cells encourage the use of microbial metabolites of halophilic bacteria for the alleviation of salt stress in plants. In the current research work, a compatible solute ectoine extracted from a moderately halophilic bacteria Chromohalobacter salexigens KT989776 was used to enhance flax germination and primary seedling under different levels of salinity. Two successive experiments including germination in Petri plates under six levels of salinity (0, 3, 5, 7, 9 and 11 dS.m-1) and a pot experiment under three irrigating water salinity levels (2, 3 and 4) with two types of ectoine application (spray and soil addition) were conducted. Germination parameters were recorded for the first experiment while a fresh and dry weight of plants and peroxidase activity in addition to sodium-potassium ratio were estimated in the pot experiment. Also, ectoine accumulation in plants was detected using HPLC. Results of LC-MS proved the production of ectoine by C. salexigens KT989776 and ectoine enhanced significantly all germination parameters of flax seeds, decreased sodium accumulation in the plant, increased potassium content, and lowered peroxidase and phenoloxidase activity. Also, HPLC analysis proved that ectoine was detected in all treated samples while not detected in non-treated control.

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http://eajbsf.journals.ekb.eg/ Toxicological and Biochemical Aspects of Bacillus thuringeinsis var. kurstaki on Fall Armyworm, Spodoptera frugiperda (J.E Smith) (Lepidoptera: Noctuidae).

Fall armyworm, Spodoptera frugiperda (J.E Smith) (Noctuidae: Lepidoptera) has become a serious pest in maize. In our study, we evaluate the efficacy of Teflubenzuron (Nomolt ® 15% EC), Emamectin benzoate (Proclaim ® 5% SG) and Alfa-cypermethrin (Fastac ® 5% EC) on the fourth instar larvae of the fall armyworm (FAW), Spodoptera frugiperda (J.E Smith) (Lepidoptera: Noctuidae) both laboratory and field experiments. The results revealed that the LC50 values obtained were 0.18 ppm, 0.019 mg/ml, and 0.6046 mg/ml for S. frugiperda larvae treated with different concentrations of Teflubenzuron, Emamectin benzoate and α-cypermethrin respectively. The study, investigates the prolongation of larval duration, decreasing both pupation % and pupal duration. Field application of Teflubenzuron, Emamectin benzoate and α-cypermethrin against the fall armyworm (FAW), Spodoptera frugiperda was expressed as a percentage reduction of larval population and residual toxicity. Conclusion of our study that the insecticide Teflubenzuron, Emamectin benzoate and α-cypermethrin were efficient and can be recommended to control the fall armyworm (FAW), S. frugiperda.