This document discusses the maintenance of germplasm at a seed bank. It involves monitoring seed viability every 5-10 years, monitoring seed quantity annually, and regenerating accessions when viability or quantity is low. Regeneration involves sowing seeds of cereals with tractors or legumes by hand. Care is taken to avoid cross-contamination and maintain genetic integrity. Seed from individual plants is bulked and species not producing seed are maintained as live plants.

1. Sept 2012
Germplasm Maintenance
Maintenance of germplasm
includes
Monitoring seed viability
™™ Seed viability of conserved germplasm
is tested at regular intervals, five years
for medium-term storage and ten years
for long-term storage
Monitoring seed quantity
™™ Seed quantity in medium-term store is
recorded every year
Testing the viability of conserved
germplasm in the seed biology laboratory.
Regeneration of germplasm
™™ Accessions are regenerated when
seed viability and seed quantity
are critical (<85% viability or <1/4
of total quantity).
™™ Regeneration is carried out in the
postrainy season for securing high
quality seed.
™™ Cereals are sown using tractor
mounted 4-cone planters, while
legumes are hand sown.
™™ Maintaining genetic integrity of
accessions during regeneration
is an important activity in cross-
pollinated crops.
™™ Maximum care is taken to
avoid admixtures while sowing,
harvesting, threshing, seed
processing and transfer. Sowing cereal germplasm for regeneration.
Preparing for tractor planting of cereal
germplasm. Field view of sorghum germplasm
regeneration.
Clasping craft paper bag to identify plants.
Field view of pearl millet germplasm
regeneration.
Field view of chickpea germplasm
regeneration.
Harvesting and threshing of individual
plants of chickpea while regeneration.
Perennial chickpea species grown for
regeneration in glasshouse.
Pigeonpea accessions grown for
regeneration under insect proof cages.
Wild relatives of pigeonpea grown for
regeneration in the field genebank.
Field view of groundnut germplasm
regeneration.
Poor pod producing groundnut
germplasm regenerated in glasshouse.
Self-pollinated small millets grown for
regeneration.
Special facility created to regenerate
wild relatives of groundnut by growing
in RCC rings.
™™ Pollination control to avoid
contamination due to foreign pollen is
important in cross pollinating crops.
™™ Equal quantity of seeds from each
plant is bulked to reconstitute the
accession.
™™ Species that do not produce seeds
are maintained as live plants in
glasshouse or in a field genebank.
™™ A special facility of reinforced
cement concrete (RCC) rings has
been created to regenerate wild
relatives of groundnut.
Cluster bagging in pearl millet germplasm.