Germplasm is the living resource for genetic information in a plant. pass from one generation to another. Germplasm conservation is the preservation of these genetic information.
Genetic erosion – Decline in the genetic variation in cultivation or natural population.
Causes of genetic erosion.
- Crop domestication and spread of superior variations.
- Exploitation of the natural environment: deforestation.
- Natural hazards
- Pests, weeds, diseases.
- Economy
- selection of the very narrow range of traits,neglect the traditional variations: most genes are lost from the population.
- plant breeders are only concern with few desirable characters therefore it has a narrow genetic base.
- plant breeders are mainly focus on uniformity and stable harvest, available genetic traits will be loose from the population.
Crop wild relatives (CWRs) are wild, undomesticated relatives of cultivated plants, these plants are evolved in natural habitats. These plants are important genetic resourse in plant breeding. because these genes are useful when introducing the new traits, uplift the crop resilience, developing new varieties, and preservation of the genetic resources.
Centers of diversity of crop plants. – The geological region where crop species originated and exhibit the highest genetic diversity.
Importances of knowing the centers of diversity of crop plants.
- Understanding of the genetic diversity of the cultivated crop and their wild relatives.
- Crop improvements and ensure the food security: by understanding the genetic diversity. important to develop more resilience and sustainable agricultural systems
- Food sovereignty – the authority that nations and communities have over their own food systems. They decide how they want their food to be produced and what kind of crops they want to grow, they can used various traditional methods, selecting the crops for desired environments.
Gene bank
Collection of plant or planting material that act as repository to store and conserve plant genetic resources. there are two type of gene banks : in vivo gene banks, in vitro gene banks
- In vivo gene banks – use conventional methods to preservation of genetic resources. (seeds, vegetative propagules)
- in vitro gene banks – use non conventional methods to preservation of germplasm (cell and tissue culture)