CHAPTER 4 GENETIC RESOURCES IN AGRICULTURE

GENETIC RESOURCES

• Genetic resources (GRs) refer to genetic material of actual or potential value.
  
• Genetic material is any material of plant, animal, microbial or other origin containing functional units of heredity.
  
• Examples include material of plant, animal or microbial origin, such as  medicinal plants, agriculture crops and animal breeds.

Animals Genetic Resources

Plant Genetic Resources and Seeds

Collection of genetic resources called Germplasm.

Germplasm

• A collection of genetic resources for an organism.
  
• Germplasm is the living genetic resources such as seeds or tissue that is maintained for the purpose of animal and plant breeding, preservation, and other research uses.
  
• Germplasm collections can range from collections of wild species to elite, domesticated breeding lines that have undergone extensive human selection.

The National Germplasm Resources Lab facilitates the acquisition, exchange, and documentation of crop genetic resources important to world food security.

What is Biodiversity?

• Biodiversity is the variety of different types of life found on Earth and the variations within species.
  
• Within species or between species.

• The number and variety of plants, animals and other organisms that exist is known as biodiversity.

• Biodiversity is not evenly distributed; rather it varies greatly across the globe as well as within regions. Among other factors, the diversity of all living things (biota) depends on temperature, precipitation, altitude, soils, geography and the presence of other species. The study of the spatial distribution of organisms, species, and ecosystems, is the science of bio geography.

         There are 3 categories of Biodiversity.
         1. Ecosystem Diversity
         2. Species Diversity
         3. Genetic Diversity

               ECOSYSTEM DIVERSITY

• Different diversity in variety of habitats, topography, elevation, natural vs agro ecosystem.
• Refers to the variety of ecosystems in a given place.
• Within any broader landscape there is a mosaic of interconnected ecosystems.

              SPECIES DIVERSITY

• the number of different species that are represented in a given community (a dataset).
• defined as the number of species and abundance of each species that live in a particular location.
• There are numerous reasons why species diversity is essential. Each species has a role in the ecosystem.

• For example, bees are primary pollinators. Imagine what would happen if bees went extinct. Fruits and vegetables could be next, and subsequently the animals that feed off them - this chain links all the way to humans.
  
• Various species provide us not only with food but also contribute to clean water, breathable air, fertile soils, climate stability, pollution absorption, building materials for our homes, prevention of disease outbreaks, medicinal resources, and more.

               GENETIC DIVERSITY

• Genetic diversity refers to the diversity (or genetic variability) within species.
• Genetic diversity is the sum of genetic information contained in the genes of individual plants, animals, and micro-organisms.
• What is the significance of genetic diversity?
• The huge variety of different gene sets also define an individual or a whole population's ability to tolerate stress from any given environmental factor.

Genetic diversity in a species allows it to adapt to changing environments.