About Lesson
Types of resistance
1.Vertical resistance:
- Resistant to same race of pathogen.
- Governed by single gene and is unstable.
- Horizontal resistance:
- Resistant to all races of pathogen.
- Also called generalization / non-specific / field/ qualitative resistance.
- Monogenic resistance:
- Defense mechanism controlled by single pair of gene.
- Oligogenic resistance
- Defense mechanism governed by few gene pairs.
- Polygenic resistance
- Governed by many genes or more group of supplementary genes.
Cross protection
- Organism infected by mid strain become resistant to severe strain of same virus.
- Used in management of citrus tristeza virus.