Application of molecular and biotechnological techniques in plant disease management: A review

Plant diseases are a major challenge in crop production. They are caused by nematodes, bacteria, fungi, viruses as well as plant nutritional factors. Diseases interfere with the normal physiological and metabolic processes of plants. This results in various effects including wilting, stunting, yellowing and death of plant tissues and organs. Crop losses due to diseases manifest in form of reduced yield, poor quality produce, and reduced post-harvest storage. Past research has brought to the limelight the continuous capacity of pathogens to revert to new pathotypes and strains, some that break resistant varieties or are less sensitive to chemical control products. Currently, farmers are advised to combine several plant disease management practices, a strategy known as integrated plant disease management. Such strategies include crop rotation, use of disease free planting materials, field sanitation, and chemical methods as well as use of resistant varieties. However, some of these methods are expensive and substantially increase the cost of production. Development in molecular biology and biotechnology found application in plant disease management. This ranges from identification, diagnosis to control through gene transfer, mutation breeding and RNA interference, among others. In this paper, the current developments in the application of molecular techniques and biotechnology to manage plant diseases, outlining their possible future application and potential for enhanced plant disease management. Key words: Phytopathogens, genetics, molecular biology, plant transformation, control options.