This document discusses ex situ conservation methods for plant genetic resources, focusing on field gene banks and seed banks. Field gene banks involve growing plant collections in artificial ecosystems for study and comparison. Seed banks preserve seeds at low temperatures and moisture levels for long-term conservation, though only seeds from orthodox species can be stored this way. Cryopreservation allows storage of seeds, pollen, or embryos in liquid nitrogen for even longer preservation periods. Both methods have advantages like easy access to materials and large storage capacity, but field gene banks are costly to maintain and exposed to threats, while seed banks cannot store recalcitrant species.

1. FIELD GENE BANK
AND
SEED BANK

2. CONTENT
• Introduction
• Field Gene Bank
• Seed Bank
• Scope of the Seed Bank
• Cryopreservation

3. INTRODUCTION
• Ex situ conservation of plant genetic
resources can be achieved through
different methods such as seed banks, field
gene banks, in vitro storage methods,
pollen banks and DNA banks.
• The major consideration for long term
conservation of germplasm collection is the
determination of the seed behavior of each
individual species to be preserved during
storage under dry conditions and cold
temperatures.

4.  If the seeds can be dried to a low
percentage humidity such as below 8%
,in the majority of cases the seeds will
then withstand very cold temperatures.

5. FIELD GENE BANK
 This is a method of planting plants for the
conservation of genes.
 For this purpose, an ecosystem is created
artificially.
 Through this method one can compare the
difference among plants of different species
and can study it in detail.
 It needs more adequate soil, weather, etc.

7.  Field gene banks provide an easy and
ready access to the plant genetic
resources for characterization, evolution
or utilization.
 While the same material conserved in the
form of seeds, in vitro or cryo must be
germinated or regenerated and grown
before it can be used.

8. PRINCIPLES
 Field gene bank also called plant gene
banks are areas of land in which
germplasm collection of growing plants
are assembled.
 This also ex situ conservation of
germplasm.
 Those plant species that have recalcitrant
seeds or do not produce seeds readily
are conserved in field gene bank.

9.  In field gene banks, germplasm is
maintained in the form of plants as a
permanent living collection.
 Field gene banks are often established to
maintain working collection of living plant
for experimental purpose.

10. CONSERVATION
 Plant genetic material in a ‘gene bank’ is
preserved at -196 °C in liquid nitrogen as
mature seed (dry).
 Germ plasma if important crops are
conserved through this method.
 42,000 varieties of rice are conserved in
the central rice research institute in
Orissa.

11. ADVANTAGES
 Field Genebank has many advantages
e.g., crop diversity conservation,
production and income generation,
sources of propagating material, making
healthy environment, resources for
research and study, providing diversity
options and selection opportunity.
 It provides opportunities for continuous
evaluation for various economic
characters.

12.  It can be directly utilized in the breeding
programmes.
 Field Genebank may be of different types
e.g., crop specific park, crop specific field
Genebank, community field Genebank,
village level field Genebank, etc.
 More than 5,00,000 accessions of crops are
being globally maintained in the field
Genebank of 103 countries.

13. DISADVANTAGES
 The germplasm in field gene banks is
exposed to pathogen and insects and
some times is damaged by natural
disasters such as bushfires, foods etc.
 Maintenance of germplasm in the field
gene banks is costly affair.

14. SEED BANK
 A seed bank preserves dried seeds, by
storing them at a very low temperature.
 Spores and pteridophytes are conserves
in seed banks, but other seedless plants
such as tubercrops can not be preserved
this way.
 A place where germplasm is conserved
in the form of seed is called seed gene
bank.

16.  Seed are very convenient for storage
because they occupy smaller space than
whole plants.
 However, seeds of all crops can not be
stored at low temperature in the seed
banks.
 The germplasm of only Orthodox species
can be conserved in seed banks

17. COLLECTION OF SEED STORED AT CONSTANT
LOW TEMPERATURE AND MOISTURE
 In the seed banks, there are three types
of conservation.
(1) Short term
(2) Medium term
(3) Long term.
 Base collection are conserved for long
term (50 years or more ) at 18 or 20 °C.
 Working collection is stored for short
term (3-5 years ) at 5-10 °C.

18.  A seedbank stores seeds as a sources for
planting in case seed reserves elsewhere
are destroyed.
 It is a type of gene bank.
 The seeds stored may be good crops or
those of rare species to product
biodiversity.

19.  The reasons for storing seeds may be
varied.
 Many plants that were used centuries ago
by humans are used less frequently now
and seed banks offer a way to preserve
that historical and cultural value.

20. SCOPE OF THE SEED BANKS
 Common Varieties :- Members states will
collaborate with each other in the
development of a list of common variety.
 Maintaining seed quality :- Member State
will develop a common minimum seed
quality standard and seed testing
producers.
 Seed reserve :- The seed reserve to be
maintained shall consists of quality seeds
of rice, wheat, pulses and oilseeds.

21. • CRYOPRESERVATION :-
 The storage of seeds, pollen tissue or
embryos in liquid nitrogen.
 This method can be used for virtually
storage of material without deterioration
over a much greater time- period
relative to all other methods of ex situ
conservation.
 Cryopreservation is also used for the
conservation of the liver stock genetics
through conservation of animal genetic

23. ADVANTAGES
 Large number of germplasm samples or
entire variability can be conserved in a
very small space.
 In seed banks handling of germplasm is
easy.

24. DISADVANTAGES
 Seeds of recalcitrant species can not be
stored in seed banks.
 Failure of power supply may lead to loss
of viability and there by loss of
germplasm.

25. REFERENCES
 BIODIVERSITY AND PLANT RESOURCES
By K. Jagan Mohan Reddy and S.Veeraiah
 www.field gene bank and seed bank images.in