Lecture 30 : BIOTECHNOLOGY IN PEST MANAGEMENT
Use of molecular biology techniques for the management of insect pests. The
following are some strategies.
1. Wide hybridization: This technique involves transfer of genes from one species
to other by conventional breeding. The genes for resistance are transferred from a
different species. e.g. WBPH resistant gene has been transferred to Oryza sativa
from O.officinalis.
2. Somaclonal variability: The variation observed in tissue culture derived
progeny. e.g. Somaclonal variants of sorghum resistant to Spodoptera litura has
been evolved.
3. Transgenic plants: Transgenic plants are plants which possess one or more
additional genes. This is achieved by cloning additional genes into the plant
genome by genetic engineering techniques. The added genes impart resistance to
pests.
Transgenic plants have been produced by addition of one or more following
genes.
a. Bt endotoxin from Bacillus thuringiensis
b. Protease inhibitors
c. -Amylase inhibitors
d. Lectins
e. Enzymes
c. Bt endotoxin gene: The gram positive bacteria Bacillus thuringiensis produces a
crystal toxin called (delta) endotoxin.
The endotoxin is a stomach poison and kills the lepidopteran insects if
consumed.
The gene (DNA fragment) responsible for producing endotoxin is isolated
from Bt and cloned into plants like cotton, potato, maize, etc. to produce Transgenic
cotton, etc.
Transgenic Bt plants Target insect pests
1. Cotton Bollworms, S. litura
2. Maize European corn borer
3. Rice Leaf folder, stem borer
4. Tobacco, Tomato Cut worms
5. Potato, Egg plant Colarado potato beetle
Use of molecular biology techniques for the management of insect pests. The
following are some strategies.
1. Wide hybridization: This technique involves transfer of genes from one species
to other by conventional breeding. The genes for resistance are transferred from a
different species. e.g. WBPH resistant gene has been transferred to Oryza sativa
from O.officinalis.
2. Somaclonal variability: The variation observed in tissue culture derived
progeny. e.g. Somaclonal variants of sorghum resistant to Spodoptera litura has
been evolved.
3. Transgenic plants: Transgenic plants are plants which possess one or more
additional genes. This is achieved by cloning additional genes into the plant
genome by genetic engineering techniques. The added genes impart resistance to
pests.
Transgenic plants have been produced by addition of one or more following
genes.
a. Bt endotoxin from Bacillus thuringiensis
b. Protease inhibitors
c. -Amylase inhibitors
d. Lectins
e. Enzymes
c. Bt endotoxin gene: The gram positive bacteria Bacillus thuringiensis produces a
crystal toxin called (delta) endotoxin.
The endotoxin is a stomach poison and kills the lepidopteran insects if
consumed.
The gene (DNA fragment) responsible for producing endotoxin is isolated
from Bt and cloned into plants like cotton, potato, maize, etc. to produce Transgenic
cotton, etc.
Transgenic Bt plants Target insect pests
1. Cotton Bollworms, S. litura
2. Maize European corn borer
3. Rice Leaf folder, stem borer
4. Tobacco, Tomato Cut worms
5. Potato, Egg plant Colarado potato beetle
