ICARDA annual report 2004

ICARDA Annual Report 2004
12
other with very low virulence, in a
controlled environment.
Researchers found that 47% of the
accessions were resistant to the
high-virulence pathotype and 57%
to the low-virulence pathotype;
12% of the accessions showed combined
resistance to both pathotypes.
Separate tests using the
detached-leaf testing method
showed that 86% of the accessions
were resistant to Syrian isolates of
net blotch.
New sources of resistance
to Russian wheat aphid
Host-plant resistance is the most
economical and practical method of
controlling Russian wheat aphid
(Diuraphis noxia), an important pest
of barley in Algeria, Ethiopia,
Morocco, Tunisia, Turkey and
Yemen. ICARDA screened
thousands of barley entries from
different origins for resistance to
this pest at its Tel Hadya research
station.
Entries were first screened in
the field in hill plots (10 seeds per
hill), with a susceptible check being
planted after every tenth entry. At
the tillering stage, each plant was
infested with 10 aphids. Once
symptoms were clearly visible on
the susceptible checks, entries were
evaluated for leaf rolling using a
scale of 1-3, and for leaf chlorosis
using a scale of 1-6. Promising
entries were then grown in a
greenhouse for confirmation.
Individual plants were infested
with 10 aphids at the one-leaf stage
and then evaluated.
Forty-five entries scored 1 on
the leaf-rolling scale and less than 3
on the leaf-chlorosis scale, which
indicated a good level of resistance.
Of these resistant entries, 18 were
H. spontaneum accessions from
Jordan and 22 landraces from
Afghanistan. The final five were
landraces from Armenia,
Kyrgyzstan, Russia, Turkmenistan,
and Uzbekistan. These resistant
lines will be used to widen the
genetic base of resistance to the
aphid and develop new resistant
varieties.
Improved barley varieties
for Iraq
ICARDA is working with the
national program of Iraq to rebuild
the country’s agricultural sector,
improve rural livelihoods, and
reduce the country’s dependence
on imported food. Since the early
1990s, several barley varieties have
been tested and released in Iraq.
‘Rihane-03’ was particularly successful,
and within three years of
its release in 1993 was being grown
on 250,000 hectares. In 2004,
‘Rihane-03’ was further tested for
its performance against a local
check and an improved variety
‘Furat-1,’ which was released in
Syria. ‘Rihane-03’ outyielded the
local check by 58% and the Syrian
variety by 37%, proving its usefulness
in Iraq’s moderate-rainfall
areas. Nineveh’s State Board of
Agricultural Research began disseminating
‘Rihane-03’ more widely
in Iraq.
Screening barley
lines for resistance
to Russian wheat
aphid (RWA). Lines
showing poor
growth are susceptible
to RWA.
In 2004, two other ICARDA barley
varieties, ‘Tadmor’ and
‘Zanbaka,’ performed well in Iraq’s
driest areas. Both these lines are
descendents of the black-seeded
Syrian landrace Arabi Aswad,
which is widely cultivated in most
of northeast Syria and is similar to
Iraqi Black, the landrace traditionally
grown in Iraq. Both ‘Tadmor’
and ‘Zanbaka’ proved to be welladapted
to the dry areas of
Nineveh province, outyielding the
local check by 47% and 26%,
respectively, under a wide range of
stress conditions (Fig. 3). Both these
varieties are now being distributed
by Nineveh’s State Board of
Agricultural Research.
Increasing water
productivity in Eritrea
through participatory
plant breeding
War, droughts, and famine in
Eritrea have caused food production
to fall by around 60% over the
last decade. In 1997, two-thirds of
the population was undernourished
and 40% of children under
the age of five suffered from malnutrition.
With the support of the
CGIAR’s Challenge Program on