ICARDA annual report 2004

Global database on wheat
wild relatives updated
The Wild Wheat Global Database,
developed by ICARDA and IPGRI
and maintained by ICARDA,
records the accessions of Aegilops,
Amblyopyrum, and wild Triticum
species held in major genebanks
worldwide. This database helps
researchers plan collecting missions,
conduct research into species
distributions, and locate samples of
germplasm.
In 2004, the database was updated
by adding records of the samples
collected worldwide since
1990. ICARDA’s collecting missions
alone yielded around 2000 accessions
and additional data was
obtained from published catalogs
and the internet sites of major
genebanks. The update also georeferenced
collection sites to allow
researchers to use GIS and link climatic
data to the sites. The database
was made completely compatible
with ICARDA’s main
germplasm database, allowing it to
be continuously updated; it now
cross-references accessions that are
duplicated in different genebanks.
Researchers also developed a
new database that registers only
‘unique’ accessions. This records
almost 18,000 accessions: 4800
accessions of wild Triticum (four
species), 13,000 of Aegilops (22
species) and 100 of Amblyopyrum
(one species). These were collected
from 6300 sites between 1948 and
2004, and represent 88% of the
world collection. The latitude and
longitude of collection sites are
available for nearly 15,000 (83%) of
these accessions. Figure 18 shows
the distribution of samples registered
in the database.
Technologies to improve
the use of ex-situ
germplasm collections
To allow ex situ collections to be
used more efficiently, ICARDA is
developing a ‘focused identification
of germplasm strategy’ (FIGS).
Using databases and GIS, FIGS
links environmental data to the
geographical coordinates at which
individual accessions were collected.
Researchers can then filter the
data and extract subsets of accessions
most likely to contain the
traits breeders require to enhance
productivity. For example, accessions
collected from very dry areas
that have evolved under those conditions
are highly likely to contain
useful drought-tolerance traits and
can be identified using FIGS.
The FIGS concept is being developed
further as part of a project
funded by Grains Research and
Development, Australia. This aims to
identify and utilize useful traits in
the bread wheat germplasm held
within VIR, ICARDA, and the
Australian Winter Cereals Collection.
These three institutions hold more
than 17,000 bread wheat landrace
Theme 3
accessions, many of which were collected
early in the 20th century from
a diverse range of environments to
which they were adapted.
The project has now captured the
geographical coordinates of more
than 6000 collection sites by reviewing
written accounts of past collecting
missions. The coordinates were
checked using GIS software that
incorporated road maps and a digital
elevation model. Each accession
was then linked to a range of agroclimatic
and edaphic data generated
by ICARDA’s GIS Unit, which
extended its continuous surface coverage
from CWANA to the whole of
Eurasia to do this.
In 2004, the project identified a
subset of accessions likely to contain
drought-tolerance traits by filtering
the records in the combined
collection using a number of criteria.
Only accessions from sites that
received 180-300 mm of precipitation
per year in agroclimatic zones
where moisture limits the growing
period were included. Accessions
from irrigated sites or sites with
dubious geo-coordinates were
excluded. A hierarchical cluster
analysis of the site data was then
used to produce 750 clusters of
accessions. One accession was then
chosen at random from each cluster
to make up the final ‘Drought’ subset
(Fig. 19).
ICARDA researchers also selected
a subset of 422 bread wheat landrace
accessions to be used for
salinity tolerance screening. A 1-km
Fig. 18.
Collection sites
of the Aegilops
and wild
Triticum species
held in the Wild
Wheat Global
Database
developed by
ICARDA and
IPGRI and
maintained by
ICARDA.
ICARDA Annual Report 2004
51