Biotechnology:
It is defined as genetic modification and manipulation of living organisms through the novel technologies such as tissue culture and genetic engineering resulting in production of improved or new organisms that can be used in variety of ways.
APPLICATION OF BIOTECHNOLOGY IN PLANT DISEASE MANAGEMENT:
- Diagnosis of plant diseases :
a) Diagnostic kits helps in identification of plant diseases at an early stage of development and helps in devising suitable management practices.
b) Polymerase Chain Reaction (PCR):
- Detection of very small amount of pathogen in a sample by amplifying the pathogen sequences to a detectable level.
- Strain improvement of biocontrol agents:
It has the following advantages :
a) Expanding the range of target species
b) Restricting the range of non-target species
c) To improve the survival ability or rhizosphere competence
d) Expanding the bio-agents environmental range beyond its congenial habitat
e) Development of fungicide tolerant strains.
- Transgenics for plant disease management :
a) Coat protein mediated resistance for papaya ring spot virus in Hawaii islands
b) Cloning of resistance genes,viz., Xa 21, bacterial blight resistance gene isolated from African rice, Oryza longistaminata was introduced into cultivable rice, Oryza sativa
- Determination of biochemical nature and the signals involved in plants reaction to pathogen invasion and disease development. Ex: Host-pathogen interaction has been studied in rice blast disease incited by Magnaporthe grisea.
- Manipulation of resistance of host by expression of PR-proteins, antifungal peptides, etc. Ex: Expression of multiple PR-proteins (Chitinases and β-1,3 glucanases) in rice enhanced disease resistance to rice sheath blight pathogen, Rhizoctonia solani.