Effect of Phosphate Dissolving Bacteria on Physiological Behavior of Some Sesame Cultivars under Saline Conditions at Sahle Eltina- North Sinai

Abstract

Four highly efficient halotolerant phosphates solubilizing bacteria (PSB) were investigated for their activities under saline conditions. Increasing salinity over 3% NaCL concentration had a negative effect on both phosphatase activity and pH reduction resulting a net reduction in their phosphate solubilization activity. The four strains could secrete multiple organic acids under saline condition. Both Pseudomonas geniculata and Alcaligenes faecalis had achieved the maximum phosphate solubilization at 3% NaCL . Green house experiment was conducted for evaluation of four sesame cultivars (Sohag ,Giza 32, Shandaweel and Zail Elgamal) and two phosphates solubilizing bacteria (Alcaligenes faecalis and Pseudomonas geniculata) and mixture of them under saline conditions. The results revealed that Giza 32 was the most resistant cultivar to salinity while Zail Elgamal cultivar was the lowest one, at the same time, mixture of two PSB was more efficient than single bacterial inoculation. Two growing seasons were conducted at Sahle El-Tina, North Sinai to study the potential of PSB mixture and KCL foliar application on the growth and productivity of sesame cultivar Giza 32. The highest significant increase in sesame yield, oil content and chemical constituents of sesame seeds were recorded by the interaction of biofertilizer and foliar application in both seasons. Gas liquid chromatography analysis indicated that the unsaturated fatty acid constituents in sesame oil were oleic, linoleic and linolenic acid while the predominant saturated acids were palmitic and stearic acids. Dual inoculation of biofertilizer and foliar applications recorded the the highest bacterial counts and phosphatase enzyme activity in the rhizosphere regions.