Gametoclonal variation in Plant tissue culture - Variation in gametes clones # Origin # Production # Application of Gametoclonal Variation in plants with their examples. Please watch the slides and don't forget to follow our channel to getting more updates.

1. Dr. Divya Sharma
Assistant Professor
GAMETOCLONAL VARIATION

2. GAMETOCLONAL VARIATION
Gameto ---- Gametic cells
Clones ---- Generations
GAMETOCLONAL VARIATION ---- GAMETOCLONES
(variation in gametes clones)

3.  The variations observed while culturing the gametic
cells are regarded as gametoclonal variations. This is in
contrast to the somaclonal variations detected in the
cultures of somatic tissues.
 The term Gametoclones (in place of somaclones) is
used for the products of Gametoclonal variations.
 By mitosis, somatic cells are divide, the genetic
material is equally distributed to the daughter cells.
In contrast, the gametes, being the products of meiosis,
possess only half of the parent cell genetic material.
Origin of Gametoclonal Variation

4. Gametoclonal Variation
 If the somatic-issue derived variants have a gametophytic origin such
as pollen or egg cell, then its known as “Gametophytic variation”.
 It introduced for variation observed among plants regenerated from
cultured gametic cells.
 It can be developed by culturing male and female gametic cell (anther
culture).

5. The
Gametoclonal
variations
differ from
somaclonal
variations by
three distinct
features:
 Mutants obtained from gametoclonal
variations give rise to haploid plants since a
single set of chromosomes are present.
 Meiotic crossing over is the recombination
process observed in gametoclonal variations.
 The gametoclones can be stabilized by
doubling the chromosome number.

6. Production of Gametoclones
 Gametoclones can be developed by culturing male or
female gametic cells. The cultures of anthers or
isolated microspores are widely used.
 Improvements have been made in several plant
species through development of gametoclones.
Eg., Rice, Wheat, and Tobacco.

7. Crop Common name Characteristics
Oryza sativa Rice Plant height; time of flowering; seed
size and protein content; level of
tillering; waxy mutant; chloroplast
content
Nicotiana tabacum Tobacco Plant size; leaf shape; number of
leaves; alkaloid content; virus
resistance; time of flowering
Brassica napus Rapeseed Leaf shape and color; time to flower;
type of flower; glucinolate content;
pod size and shape
Hordeum vulgare Barley Plant height; days to maturity;
grain yield; fertility
Selected list of plants regenerated from
Gametoclonal variations

8. Applications of
Gametoclonal Variations
• Suitable for breeding
• Crop improvement
• Disease, herbicides, toxin resistance
• Abiotic resistance (cold, high temperature, ph)
• Biotic resistance (insect, bacteria etc)

9. Sources of Genetic Variations
in the Gametoclones
 Cell culture technique may induce genetic variations.
 Variations may be induced while doubling the haploid
chromosomes.
 Genetic variations may occur due to heterozygosity of
the diploids.

10. Gametoclonal variations differ
from somaclonal variations
Somaclonal Variation Gametoclonal Variation
Somaclonal variation involves fusion of
somatic cells.
Gametoclonal variation involves fusion of
male and female gamete.
It involves the production of
allotetraploid plants happens.
It results on production of the diploid
plant.
In Somaclonal variation, there is equal
contribution of cytoplasm from both the
plants.
Cytoplasm contribution is more from
female parent.
Segregation does not occurs in
Somaclonal variation.
Leads to occurrence of segregation.
Wide crosses can be made easily Wide crosses are associated with sexual
problem.

11. Sharma’s Classes - Dr. Divya Sharma