ICARDA annual report 2004

ICARDA Annual Report 2004
52
Fig. 19. Collection sites of a subset of bread wheat accessions likely to contain valuable
drought-tolerance traits; the subset was identified using a new tool (‘FIGS’)
based on GIS and database technologies.
resolution map was extracted from
the FAO-UNESCO digital Soil Map
of the World which showed the
probability of saline soils recurrence.
This map was then overlaid
with collection-site coordinates.
Only accessions from sites with a
40% or higher probability of
encountering saline soils were chosen
for laboratory screening. Most
of these were in Central (47%) and
East Asia, mainly the Indian subcontinent
(31%); 16% and 5% came
from North Africa and West Asia,
respectively. Both the ‘Drought’
and ‘Saline’ subsets are currently
being evaluated for tolerance to
drought and salinity at Tel Hadya.
At the request of the University
of Zurich, the project also produced
a ‘best bet’ subset of material which
will be screened for resistance to
powdery mildew. Researchers compiled
collection-site information for
a set of 400 accessions known to be
resistant to powdery mildew in
addition to those landrace accessions
already included in the database.
Multivariate analyses identi-
fied 1350 accessions from collection
sites that closely matched those of
the resistant set. This ‘Mildew’ subset
will be screened for powdery
mildew resistance in Zurich during
the 2004/05 growing season.
This method of identifying sets
of material likely to contain valuable
traits is expected to make the
process of choosing germplasm for
screening far more efficient.
Creating global ‘composite
sets’ of chickpea and
barley germplasm
In 2004, ICARDA participated in a
System-wide program that aims to
explore the genetic diversity of the
CGIAR research centers’ global
germplasm collections. This project,
Subprogram 1 of the CGIAR’s
Generation Challenge Program, will
identify a composite set of
germplasm for individual crops.
These sets represent the range of
diversity of a crop and will be characterizes
using anonymous molecu-
lar markers. This will allow
researchers to study diversity across
a given genus and identify genes for
resistance to biotic and abiotic
stresses that can be used in cropimprovement
programs. ICARDA
was responsible for creating the
composite set for barley, and helped
to create the composite set for chickpea.
In 2004, a global composite collection
of 3000 chickpea accessions
was compiled from core collections,
trait-donor parental lines, landraces,
wild Cicer species, and elite
germplasm and cultivars. ICARDA
contributed 752 chickpea cultivars
to the set from its collection of
12,153 accessions.
The ICARDA accessions were
chosen by identifying material that
(i) had sufficient seed for distribution;
(ii) was unique to ICARDA;
and (iii) was FAO–designated, and,
therefore, owned by the global
community. The catalog and evaluation
data for these 5042 accessions
were then separated into five main
data sets which were further divided
into 29 data sets based on geographic
location and subjected to
hierarchical cluster analysis based
on 16 phenological, yield, and cropsize
characteristics. Approximately
10% of the accessions in each cluster
within a set were selected randomly
and included in ICARDA’s
contribution to the composite set.
To ensure that chickpea’s full
agroclimatological range was represented,
the entire set of 5042 accessions
was subjected to a two-step
cluster analysis using agroclimatological
data linked to the geographical
coordinates of the accessions’ collection
sites. Two hundred clusters
were produced, and one accession
was selected randomly from each.
Researchers also included an
additional 16 accessions known to
have resistance to certain diseases
and insects. Seeds from the 752