genetic resource in agriculture
so what are we going to learn? let me share.. :))
- Centre of origin
- Germplasm
- Biological diversity :1) Genetic diversity, 2) Species diversity ,3) Ecosystem diversity
- Genetic resource application
- Conservation of genetic resources
- Threat to diversity & genetic resources
*GERMPLASM AND BIODIVERSITY
A little story of theory~~
- The term germplasm was first used by the German biologist August Weismann (1834–1914).
- The germplasm theory states that multicellular organisms consist of germ cells that contain and transmit heritable information, and somatic cells which carry out ordinary bodily functions.
- Inheritance in a multicellular organism only takes place by means of the germ cells: the gametes, such as egg cells and sperm cells.
keywords:
- Germplasm
⇒ a collection of genetic resources for an organism
⇒ DNA of an organism through collection of materials
For your information, a worldwide had been collected various of germ of the existing plant. Collections of plant, animal & bacterial
germplasm for use in breeding new organisms and the
conservation of existing species.
This seed had to be store in a cold place. Therefore, there were a place which is situated deep in a mountain. the seed even arranged exactly like in a library.
(Biodiversity)
• Variability among living organisms
• Plant or animal diversity
• Terrestrial or marine
• Within species or between species
This biodiversity has 3 aspects:
i) Genetic diversity
ii) Species diversity
iii) Ecosystem diversity
i) GENETIC DIVERSITY
- The total of all the genetic information carried by individual organisms.
- some are obvious to the human eye, but others are more subtle
- eye colour, colour of skins, susceptibility to cancer
- This term refers to the variation of genes within a species.
keywords:
DNA = carries the genetic information of a cell
Genes = contains basic information of a species
ii) SPECIES DIVERSITY
- The diversity among the species.
iii) ECOSYSTEM DIVERSITY
- Ecosystem = an area that contains organisms (e.g: plants, animals, bacteria) interacting with one another and their non-living environment
- Ecosystem diversity = Different diversity in variety of habitats, topography, elevation, natural vs agroecosystem
*GENETIC RESOURCES APPLICATIONS
- Agriculture production is increased through the use of improved genetic resources (new variety) created by altering the genetic constitution.
- Increase in yield. for example:
- a) Genes from wild relatives - resistance to at least 32 major tomato diseases - Insect resistant genes
- b) Foreign genes such as from Bacillus - Bacillus thuringiensis (Bt), which produces an insect killing toxin, into maize
3. Ecological tolerance
- E.g: Genes tolerant to temperature extremes
⇒Drought
⇒ Waterlogging
!! ADD ON KNOWLEDGE: !!
6 categories of genetic
resources :
1. Wild relatives
- species in the wild from the same genus of the crop or
livestock.
2. Weedy relatives
- bridge between wild relatives and domesticated
species (neglected varieties, evolved to adapt the
natural growing environment.
3. Primitive cultivars/landraces
- the cultivated varieties during earlier times.
4. Modern cultivars
- improved strains bred from primitive cultivars.
5. Advanced breeding lines
- superior germplasm selected from modern cultivars.
6. Genes from other species
- advanced lines which contain specific desired genes
from other species. For example, 90% of the genes
in rice could also be found in corn, wheat and barley
*TECHNIQUE TO CONSERVE GENETIC RESOURCES
- In situ conservation
- on-site conservation e.g., botanical reserves, forest reserves
- It is the process of protecting an endangered plant or animal species in its natural habitat
- Off-site conservation
- From a threatened habitat to a new location, which may be a wild area or within the care of humans Ø In gene banks, long-term storage as seed.
- Many important tropical species are recalcitrant (difficult or impossible to store for long periods )
- Tissue culture, cryopreservation
*THREATS TO DIVERSITY & LOSS OF GENETIC
Dying species:
- Domestication and use of modern varieties
2. Wanton (intentional damage)
- Irresponsible and thorough wide spread, and often concentrated habitat destruction.
- Natives species often lost and habitat invaded by exotic weeds.
3. Natural extinctions as a result of competition
and natural disasters
THAT ALL FOR NOW.. nice to share with you.. XOXO.
