Genetic evaluation of protoplast fusion product between Serratia marcesnces and Pseudomonas Fluorscens A. A. Hassan 1 ; M. Magdy 2,4 ; Sabit H. H 3 and S. A. Ibrahim 4 1 Biotechnology English Program, Faculty of Agriculture, Ain Shams University, Cairo, Egypt 2 Plant Biology Department, Faculty of Biology, Murcia University, Campus of Espinardo, Murcia, Spain 3 College of Biotechnology, Misr University for Science & Technology, 6 th October, Egypt 4 Department of Genetics, Faculty of Agriculture, Ain Shams University Cairo, Egypt ABSTRACT Technical, economical and environmental factors are forcing to adopt new sustainable methods, such as the use of microbial antagonists for the control of soilbrone pathogens. Mycolytic enzymes (chitinases, proteases and glucanase) producing microorganisms like Serratia marcesnces and Pseudomonas Fluorscens have a main role in the biocontrol process as these microorganisms have ability to lyses the fungal cell wall and also have the potential to manage the chitinous waste by producing chitinases. Many chitinolytic microorganisms have potential to control fungal plant pathogens but they are not fully successful in all cases due to different geological and environmental conditions thus combining them together appear to be suitable way to find novel, highly chitinolytic microorganisms which help in developing potential biocontrol agent. Furthermore, to increase the survivability of biocontrol agents, the usage of combining methods like protoplast fusion may also be necessary. The use of the molecular genetic characterization techniques like specific PCR techniques (16S PCR) and random PCR techniques (RAPD and RFLP) is the best tool to estimate the relation between the obtained fusant (Seratomonas) and the parental strains and also characterize the fusant (Seratomonas). Keywords: Mycolytic enzymes, Serratia marcesnces, Pseudomonas Fluorscens, biocontrol, protoplast fusion, 16S-PCR, RAPD, RFLP. INTRODUCTION In recent years, biological control of plant pathogens has received increasing attention as a promising supplement or alternative to chemical control. Fungal plant diseases are one of the major concerns to agricultural production. It has been estimated that total losses as a consequence of plant diseases reach 25% of the yield in western countries and almost 50% in the developing countries. Of this, one third is due to fungal infections (Bowyer, 1999). So there is a pressing need to control fungal diseases that reduce the crop yield so as to ensure a steady and constant food supply to ever increasing world population. Microbial ecology principles will be important in any future efforts practice ecofriendly pest management. Presently, we lack a complete understanding to interactions between pests and crop plants as well as between pests and other microorganisms. A lack of understanding of these interactions limits our ability to understand the processes that occur during our efforts to implement ecologically crop management. Unless a more thorough understanding of the ecofriendly principles dictating microbial and plant interactions is obtained, efforts to restore ecological integrity will remain empirical and will lack transferability between systems. On the other hand, by understanding particular model systems in which ecological restoration can be successfully implemented, it should be possible to develop common strategies and practices by which pest management can be relied upon in the future. The important ecological principles that will need to be understood as well as recent attempts to obtain information in these areas will be presented. The general mechanism of biological control can be divided into direct and indirect effects of the biocontrol agent (BCA) on the plant pathogen. Direct effects include competition for nutrients or space, production of antibiotic and lytic enzymes, inactivation of the pathogen's enzymes that produce morphological and biochemical changes in the host plants.