WEL COME

SYNTHETIC SEED PRODUCTION

Parvati Pujer

UHS11PGM123

INTRODUCTION

Many fruit crops are difficult to multiply by conventional propagation methods and improve through traditional breeding programmes

Among the innovative techniques of micro propagation, the concept of somatic embryogenesis with synthetic seed production or artificial seed technology is very promising

Synthetic seed is referred to as encapsulated somatic embryos, which functionally mimic seeds and can develop into seedling under suitable conditions

Contd……

Besides, research has also been focused on the use of vegetative propagules like axillary buds, adventitious buds, shoot-tips, cormels, bulbs and protocorms for production of synthetic seeds

In general, for seed propagated crops outstanding hybrids can be multiplied through tissue culture and propagated by using synthetic seeds rapidly

Advantages

Direct delivery of tissue cultured plants to the field

Propagation of desirable genotypes with genetic uniformity

Reduction in cost of vegetative propagated elite plants

Preservation of germplasm and convenience in germplasm exchange

Reduction in dormancy period

Large production identical embryos in short time

It can be produced through out the year

Synthetic Seeds

Synthetic seeds: It is living seed-like structure derived from somatic embryoids in vitro culture after encapsulation by a hydrogel.

Such seed are encapsulated by protective gel like calcium

alginate against microbes and desiccation

Fig 2: Flow diagram presenting the procedure of synthetic seed production

Fig 3: Different stage of embryo development

Embryos Form Germination%

Conversion%

Zygotic Non

encapsulated 100 100

Encapsulated 100 93.3

SomaticNon

encapsulated 93.3 93.3

Encapsulated 100 100

Table 1: Effect of endosperm and encapsulation on zygotic somatic embryo germination and conversion

Artificial seed coat

Artificial endosperm

Somatic embryo

Fig 4 : The concept of Artificial Seed

Table 2: Artificial seed production and plant conversion

In vitro propagules for encapsulation

Crop

Somatic embryosPapaya, Brinjal, Mango, Carrot, Sandalwood, Brassica, Alfalfa, Lettuce, Celery,

Auxiliary buds/Adventitious buds

Vitis, Eucalyptus, Citrus, Pineapple

Shoot tips Banana, Cardamom, Apple, Kiwifruit

Table 4: Encapsulation for Synthetic Seed

Gel (Concentration) (% w/v)

Complexing Agent

Concentration (µM)

Sodium alginate (0.5-5.0) Calcium Salts 30-100

Sodium alginate (2.0) with gelatin ( 5.0)

Calcium chloride 30-100

Carrageenan (0.2-0.8) Potassium chlorideAmmonium chloride

500

Locust Bean Gum (0.4-1.0)

Gelrite (0.25)

A) Dropping procedure

1) The most useful encapsulation system. Drip 2-3 % sodium alginate drops from at the tip of the funnel and the somatic embryos are inserted

2) Keep the encapsulated embryos complex in calcium salt for 20 min

3) Rinsed the capsules in water and then stored in a air tight container

Encapsulation methods for synthetic seed

B) Automate encapsulation processThis is the quick method of artificial

seed production

A) Alginate solution with embryo is feed from supply tank

B) Alginate capsules were planted in speeding trays using a vacuum seeder.

C) The capsules are planted in the field using a stanhay planter

D) A hydrophobic coating is required for mechanical handling

BRIEF RESEARCH WORK ON SYNTHETIC SEEDS

Fig 5: Various developmental stages during plant regeneration via artificial seed in Carica papaya L. A- Somatic embryos in liquid culture after 30 days in maturation

medium. B- Somatic embryo at the cotyledonary stage.

Castillo et al., 1998

C - Artificial seeds encapsulated in 2.5% sodium alginate. D - Germinating artificial seed.

Castillo et al., 1998

E - A plantlet germinated from an artificial seed on growth regulator- free basal MS medium.F - A plantlet showing normal development after germination from an artificial seed. Culture tubes were 2.2 cm in diameter.

Castillo et al., 1998

Fig.8 : Plant regeneration from encapsulated somatic embryos of banana cv. Rasthali.

A- Somatic embryos used for encapsulation. B- Encapsulated somatic embryos in 5% sodium alginate.

Ganapathi et al., 2001

C- Emergence of shoots after 2 week of culture from encapsulated somatic embryos. D- Plantlet development from encapsulated somatic embryos on MS basal medium after 6 week of culture.E-Two month old hardened plants derived from encapsulated somatic embryos growing in the polybags. Ganapathi et al., 2001

COFFEE

PEAR