Effect of rhizospheric bacteria from Prosopis limensisBenth. on the development of Solanum lycopersicumL. under salt stress

The growth and development of the Solanum lycopersicum"tomato" crops is affected by salinity. The objective of the research was to determine the effect of rhizospheric bacteria of Prosopis limensisBenth. "carob" on the development of tomato under salinity. The approach was quantitative and the experimental design completely randomized with four treatments: control (non-inoculated, T1), chemical control with 180 kg<middle dot>ha-1N, 100 kg<middle dot>ha-1P, 120 kg<middle dot>ha-1K(T2),and two treatments of bacteria with 1-aminocyclopropane-1-carboxylate (ACC) deaminase enzyme activity (T3, T4)at 108cel<middle dot>mL-1. These were isolated from the rhizospheric soil of 37 carob trees and those with ACCD activity were selected. The two bacteria with the greatest increase on seed germination of an indicator plant (radish) irrigated with saline water(80mM NaCl) were inoculated on tomato cv. Rio Grande seeds and roots before transplanting in a substrate with electrical conductivity of 10.28 dS<middle dot>m-1.In the rhizosphere of carob trees, 388 Gram-positive (72.16 %) and Gram-negative (27.84 %) bacteria were isolated. The 4.12 % showed ACCD activity and achieved from 89.72to 100 % germination of radish seeds compared to 32.75 % in the non-inoculated seeds, in saline conditions. Bacillusspp. promoting germination rates of 34.66 and 33.0 day-1versus 32.11 day-1in the non-inoculated seeds in non-saline conditions, and 12.29 day-1in the non-inoculated seeds in saline conditions were identified and selected. These bacteria increased the height, chlorophyll content, potassium/sodium ratio, number and fruit weight of tomato plants compared to the control. It was concluded that Bacillusspp. can constitute biofertilizers to favor tomato cultivation under salinity.