Artificial Seed Production
General procedure for the production of artificial seeds
- Somatic embryogenesis or callus culture
- Somatic embryo maturation or shoot bud formation
- Encapsulation of above with suitable matrix
- Evaluation of the resulted artificial seeds
- Mass production
- Open field / green house planting
Artificial seed production methods
Synthetic seed production methods can be of two types
- Desiccated system
- Hydrated system
Desiccated system for artificial seed production
Prior to encapsulation, somatic embryos are first hardened to withstand desiccation. Then these hardened embryos are encapsulated artificially with the use of appropriate growth medium.
Hydrated system for artificial seed production
The gel used to enclose somatic embryo remains hydrated. Various water soluble gels can be used for the purpose of encapsulation, like alginate, gel rite, locust bean gum, sodium alginate with gelatin. However, alginate is the most suitable gel.
Methods for artificial seed encapsulation
There are two methods for encapsulation listed as follows.
- Dropping method
- Molding method
- Somatic embryos are dipped in hydrogel, this step encapsulate SEs.
- Hydrogel used may be any of the following.
- alginate – sodium alginate, agar from see weeds
- seed gums like guar gum, locust bean gum
- Here we have considered sodium alginate solution (1 – 5%), prepared in MS basal medium solution. SEs are dipped in this solution.
- These coated beads are added one by one with the help of pipette (5mm) into a complexation solution flask kept on magnetic stirrer and kept such for around 20-30 minutes. Here we considered calcium nitrate solution (100mM) as complexation solution.
- Embryos get covered by calcium alginate which is a stable complex due to ionic bond formation, become harder. Seeds become harder. Then gelled embryos are washed with water or MS basal medium.
- The synthetic seeds are ready.
- Alternatively, a burette is filled with sodium alginate solution (1 – 5%), dripped into a calcium nitrate solution (100mM) drop by drop. Somatic embryo is inserted into the drop formed at the burette tip. Sodium alginate drop along with SE falls into the solution of calcium nitrate.
- Useful adjuvants like growth regulators, herbicides, insecticides, fungicides and mycorrhizae such can be supplied to the SE while encapsulation along with the matrix.
- This method is applicable for embryo / auxiliary / apical / adventitious buds.
- This method follows simple procedure of mixing of embryos with temperature dependent gel (e.g. gel rite, agar).
- Cells get coated with the gel at lowering of the temperature.
To know uses and advantages of artificial seeds visit link advantages and uses of artificial seeds. The page enlists those.