Question

1 Discuss three ways in which mutations in genetics can be used in agriculture

2 Can genetics in agriculture be solely responsible for global food security?

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Answer 1

Ans. 1. Mutation = sudden heritable change in phenotype of an individual.

Mutation occurs in many ways ::

1. By alteration in nuclear DNA ( point mutation )

2. By changing in cytoplasmic Dna ( cytoplasmic mutation )

3. By Uv- rays or some chemical mutagens .

Inducing desirable Mutation and exploiting them for crop improvement. Mutation breeding used to produce trait in crops such as large seed , new colour or pest resistant .

a. Selection of variety for mutation breeding

b. Part of plant to be treated

c. Dose of mutagen : which induce a high frequency of chromosomes changes . It is physical or chemical agent which enhances the frequency of Mutation.

Dna mutations are generally of the most interest to the breeders. However , Mutations that alter chromosome structure to increase the number of recombination events .

Physical mutagens most often result in chromosome changes and largerDna deletion while mutagenic chemicals typically cause point mutation .

Seeds or plant propagules typically treated with cobalt -60 source , or are irrediated in X- ray machine . Whole plant seedling can also be irradiated , either in gamma field . This process called chronic irradiation.

The major aim in mutation - based breeding is to develop and improve well- adapted plant varieties by modifying one or two major trait to increase their productivity or quality . Both physical and chemical mutagenesis is used in including mutations in seed and other planting .

# Main mutation work has been carried upon wheat, rice and barley varities . With the X- ray treatment semi - dwarf varities of rice has been produced . Gamma rays treatment in Indonesia of rice line pelita-1 produced a high yielding cultivar called atomita-2 . This is resistant to brown plant hopper and tolerates saline condition in soil.

# in mung bean( Vigna radiata) , resistance to yellow mosaic virus and powdery mildew were induced by mutations with the help of mutagens . So improved varieties are formed by Mutation .

# in case of wheat , mutant variety is sharbati sonara , NP 836 and parent variety is sonara -64, NP 799 and Mutation occurred by gamma - rays.

Ans 2 . Plant genetics remains a key component of global food security , prosperity for foreseeable future . Millions of lives depends upon the extent to which crop genetic improvement can keep pace with growing global population , changing climate and shrinking environment resources .

An important goal for genetic improvement of agriculture crops is to adapt our existing food crops to increasing temperature , decreasing water availability , rising salinity and changing pathogen and insects threat and development of a new generation of agriculture crop tolerance of diverse stress to improve food security .

Genetic manipulation in which genes of desirable characters are taken from a plant and transferred to another plant by technique of hybridization to improve the plant quality , so, we can say that genetics in agriculture responsible for global food security .