Effect of plant growth promoting rhizobacterial (PGPR) inoculation on growth in tomato (Solanum Lycopersicum L.) and characterization for direct PGP abilities in Morocco

Plant Growth promoting rhizobacteria are a heterogeneous group of bacteria that can be found in the rhizosphere, at root surfaces and in association with roots. They benefit plants through Production of plant hormones, such as auxins, asymbiotic N2 fixation, solubilization of mineral phosphates, antagonism against phytopathogenic microorganisms by production of antibiotics, siderophroes, Chitinase and other nutrients ability to effectively colonize roots are responsible for plant growth promotion. An experiment was conducted in the field of National Institute of Agronomic Research of Meknes. Morocco. The experiment was a completely randomized design with six replicates. There were four treatments viz. T1: (control; N0 -PGPR), T2: (N0 +2027-2), T3: (N0 +2066-7) and T4: (N0+2025-1). The results indicated that a remarkable increase in root growth, namely length, the diameter of the rod and the total chlorophyll. A total of three different bacteria colonies were isolated and proceed with in vitro screening for plant growth promoting activities; phosphate solubilization, nitrogen fixation, indole acetic acid (IAA), ammonia production and antimicrobial enzymes (cellulose, chitinase and protease) activity. Among the three bacterial strains, all bacterial strains are able to produce ammonia, IAA production and nitrogen fixation activity, one strain phosphate solubilizing activity, two strain are able to produce cellulase syntheses, Protease activity and Chitinase activity

Rapid and sensitive methods for detection of Allorhizobium vitis, causal agent of grapevine crown gall

A rapid method and sensitive methods for extraction of bacterial DNA from pure culture and directly from plant materiel were compared in polymerase chain reaction with specific primers VCF3/VCR3 to see the reliable method that can used in the detection of tumorigenic strain of Allorhizobium vitis causal agent of grapevine crown gall. From the three tested methods of DNA extraction from pure culture, the alkaline method is the most effective technique for the extraction presenting a high sensitivity with a detection threshold equal to 5.104 CFU/ml. Five different protocols for extracting bacterial DNA from plant tissues of infected tomato, based on the use of an extraction buffer, were tested to see its usefulness in detecting pathogenic strain of A. vitisS4. Two protocols based on the use of Triton X-100 and Tween 20 were efficient for detecting A. vitis S4 directly from tomato tumors with a sensitivity of 103 CFU/ml for the both protocols. Consequently, these protocols were proposed as specific protocols for the detection of tumorigenic strain of A. vitis from symptomatic and asymptomatic plants