Gene pyramiding is a plant breeding technique that uses molecular markers to select plants with multiple pest-resistance and yield-enhancing genes through iterative hybridization. It aims to enhance trait performance, remedy genetic deficits, and increase durability against pests. Strategies for gene stacking include iterative hybridization between plants containing different transgenes, re-transformation of a plant with additional transgenes, and co-transformation of a plant with multiple transgenes simultaneously. Gene pyramiding is an important strategy for improving germplasm and developing durable pest resistance using multiple genes.

1. GENE PYRAMIDING
Vimal priya subramanian

2. INTRODUCTION:
• The development of molecular genetics and technology
lead to the emergence of a new field in plant breeding-
Gene pyramiding.
• The term gene pyramiding is used in agricultural research
to describe a breeding approach to achive a pest control
and higher crop yield.

3. • The molecular markers in gene pyramiding aid in
selecting the best plants with which to proceed .
• Development of multi-stack hybrid occurs via iterative
hybridization.

4. GENE PYRAMIDING:

5. OBJECTIVES OF GENE PYRAMIDING:
• Enhancing trait perforance by combing two or more
complementary genes.
• Remedying deficits by introgressing genes from other
source.
• Increasing the durability.

6. TYPES OF GENE PYRAMIDING:
• Conventional technique
• Molecular technique

7. STRATEGIES FOR GENE STACKING /PYRAMIDING:
• Iterative Procedure/ Sexual Hybridization
• Re- Transformation
• Co- Transformation

9. Iterative Procedure / Sexual Hybridization:
• A plant harboring one or more transgenes in cross-
Hybridized with one another plant containing other
transgenes.
• Development of multi-stack hybrid occurs via iterative
hybridization.
• Eg: Maize: AgrisureTM VipteraTM3220

10. Re- Transformation:
• A plant harboring a transgene is transformed with other
transgenes.
• Examples of commercial stacks
• cotton : BollgardTM

11. Co-Transformation:
• A plant is transformed with two or more independent
transgenes. The trans genes in separate delivered to the
plants.
• Eg: Soybean : vistveTM Gold

12. MAIN FACTORS AFFECTING GENE PYRAMIDING:
1. Characteristics of the target traits /genes
2. Reproductive characteristic
3. A breeders capability to identify the desired genotypes
4. Operating capital

13. ADVANTAGES OF GENE PYRAMIDING:
• Widely used for combining multiple disease resistance genes for
specific races of pathogen.
• Important to develop durable disease resistance against different
races.
• Mainly used to improve existing elite cultivator.
• Control linkage drag.
• Reduces breeding duration.

14. CONCLUSION:
• Gene pyramiding is an important strategy for germplasm
improvement.
• Molecular marker genotyping can facilate the gene
pyramiding process by reducing the number of
generations that breeders must evaluate to ensure they
have to desired gene combination.