Artificial Seed Production

8/4/2019 Artificial Seed Production

1/17

ARTIFICIAL SEED

PRODUCTION

Presented by Joshua SamuelI M.Sc. BiotechnologyDR.G.R.D.C.S


2/17

ARTIFICIAL SEEDS

What is a seed?A seed is a small embryonic plant enclosed in a coveringcalled the seed coat, usually with some stored food. It is theproduct of the ripened ovule of gymnosperm and angiospermplants which occurs after fertilization and some growth withinthe mother plant.(According to Wikipedia)

What are artificial seeds?Synthetic or artificial seeds have been defined as somatic

embryos engineered for use in the commercial propagation ofplants (Gray and Purohit, 1991; Redenbaugh, 1993).


3/17

Artificial Seeds

Types of synthetic seeds : Typesof synthetic seeds Hydratedsynthetic seeds (Redenbaugh et.al., 1986) Desiccated syntheticseeds (Kitto and Janik, 1985)

Natural Seeds (Lotus

seeds)


4/17

Why artificial seeds over natural ??

Storage Life

Much longer, seed viability remains good for longer timeperiod.

Product uniformity

As somatic embryos used are genetically identical.

Large scale propagationVery much suitable for large scale monoculture.

Germplasm conservationImportant in germplasm conservation.

Permits direct field use


5/17

Facilitates studyOf seed coat formation, function of endosperm in embryodevelopment and seed germination, somaclonal variation.Supply of beneficial adjuventsbeneficial adjuvants like plant nutrients, plant growthregulators, microorganisms, fungicides, mycorrhizae,antibiotics can be made available to the developing plant

embryo as per the requirement as these can be added into the matrix.

Hybrid production

synthetic seed production technology can be used forproduction of hybrids which have unstable genotypes orshow seed sterility. It can be used in combination withembryo rescue technique. The rescued embryo can beencapsulated with this technique.


6/17

Artificial Seeds production (Summary)

Induction of somatic embryogenesis.

Maturation of somatic embryos.

Encapsulation of somatic embryos.

Evaluation of embryoids and

Conversion Planting in fields / green house.


7/17

Somatic embryogenesis

Somatic cellsSomatic or vegetative cells are derived from the Greek

word for body. Somatic cells are diploid in nature.

EmbryogenesisFormation of an embryo

Somatic EmbryogenesisIs the process by which the somatic cells or tissues

develop into differentiated embryos and each fullydeveloped embryo is capable of developing into plantlet. Invitro process , by which somatic cells develop into somaticembryo without gametic fusion

Types of Somatic Embryogenesis

Direct and Indirect Embryogenesis.


8/17

Stages of Somatic Embryo

Globular Stage or phase.

Heart shaped stage or phase.

Torpedo stage or phase.

Cotyledonary stage or phase.


9/17

Gelling agents used in artificial seed production

Several agents like agar, alginate, plyco2133(Bordon Co.),carboxy mathyl cellulose, carrageenan, gelrite(Kelko Co),

guargum, sodium pectate, tragacanth gum etc

Out of these gelling agents alginate was found to be moresuitable for artificilal seed production

Why alginate gel ?Alginate hydrogel is frequently selected as a matrix forsynthetic seed because of its moderate viscosity and lowspinnability of solution, low toxicity for somatic embryos andquick gellation, low cost and bio-compatibility characteristicsAlginate was chosen because it enhances capsule formation

and also the rigidity of the alginate beads provides betterprotection to encased somatic embryos against mechanical

injury


10/17

Principle and Conditions for encapsulation with Alginate matrix

BiochemistryAlginate is a straight chain, hydrophilic, colloidal poluronic acidcomposed primarily of hydro-beta-D-mannuronic acid residues with 1-4linkages.

PrincipleThe major principle involved in the alginate encapsulation process is

that the sodium alginate droplets containing the somatic embryos whendropped into calcium chloride solution form round and firm beads due toion exchange between Sodium in sodium alginate and Calcium incalcium chloride solution.

The hardness and rigidity of the capsule mainly depends upon thenumber of sodium ions exchanged with calcium ions.

In general 3% sodium alginate upon complexation with 75mM calciumchloride for half an hour gives optimum bead hardness and rigidity for

the production of viable synthetic seed


11/17

Artificial Endosperm:Somatic embryos lack seed coat (testa) and endosperm

that provides nutrition and protection for zygotic embryos indeveloping seeds.

To augument these deficiencies, addition of nutrients andgrowth regulators to the encapsulation matrix is desired,

which serves as an artificial endosperm.

Addition of nutrients and growth regulators to the artificialmatrix results in increase of germination and viability of

encapsulated somatic embryos.

These synthetic seeds can be stored for a longer period oftime even up to 6 months without losing viability, especiallywhen stored at 4C.


12/17

Addition of Adjuvents to the matrixIn addition to prevent the embryo from desiccation andmechanical injury, a number of useful materials such asnutrients, fungicides, antibiotics and microorganisms maybe incorporated into the matrix.

Incorporation of activated charcoal improves the

conversion and vigour of the encapsulated somaticembryos

Why charcoal ?

Charcoal breaks up the alginate and thus increasesrespiration of somatic embryos.

Charcoal retains nutrients within the hydrogel capsule andslowly releases them to the growing somatic embryo.


13/17

Utilization of artificial seeds

Multiplication of non-seed producing plants

The artificial seed system can also be employed in thepropagation of male and female sterile plants for hybridseed production.

Cryopreserved artificial seeds may also be used ingermplasm preservation particularly in recalcitrant species.


14/17

Terminology

Germplasm conservation: The sum total of all the genespresent in a crop and its related species constitutes itsgermplasm. It is ordinarily represented by a collection ofvarious strains and species.

Somaclonal variation:It is the term used to describe thevariation seen in plants that have been produced by planttissue culture. Chromosomal rearrangements are animportant source of this variation.

Spinnability of a solutionthe capacity of a viscous liquid to be drawn out into a strandor blown up into a bubble.


15/17

References

http://en.wikipedia.org/wiki/Seed http://www.uoguelph.ca/plant/research/embryo/synse

eds.htm http://theagricos.com/tissue-culture/artificial-

seeds/advantages-of-artificial-seeds/

http://www.wiziq.com/tutorial/57248-synthetic-seed http://biobasics.gc.ca/english/View.asp?x=799


16/17

COLLAGE


17/17

THANK YOU

Artificial Seed Production

Documents

Transcript of Artificial Seed Production