GENETIC IMPROVEMENT AND MOLECULAR EVALUATION OF BACILLUS THURINGIENSIS TO CONTROL SOME MAJOR INSECT PESTS IN EGYPT

Abstract

The insecticides cause mammalian toxicity, the appearance and spread of resistant insect pest species, the ground water contamination and environmental pollution, that restrict their use. Therefore, the moment towards the use of entomotoxin producing by bacteria such as Bacillus thuringiensis as a microbial control agent must be encouraged. Bacillus thuringiensis (Bt) is a spore-forming bacterium well-known for its insecticidal properties associated with its ability to produce crystal inclusions during sporulation. These inclusions are proteins encoded by cry genes and have shown to be toxic to a variety of insects and other organisms like nematodes and protozoa. Lepidoptera and Coleoptera are of the most devastating insect pests for important crops in Egypt; their control is a priority as well as a necessity. In this context, use of environmentally safe technology to reduce crop damage would be extremely valuable. Consequently, this study was planned to establish the genetic improvement of Bacillus thuringiensis strains to control potato tubers moth; (Phthorimea operculella) and cotton leaf worm (Spodoptera litoralis) using protoplast fusion technique The obtained results can be summarized as the following: 1- Identification and characterization experiments were done on the two