ICARDA annual report 2004

ICARDA Annual Report 2004
24
Institute submitted the high-yielding,
Ascochyta blight resistant line
FLIP 94-24C for registration in 2004
under the name ‘Janalik.’ This cultivar
is suitable for general cultivation
in southern Kazakhstan. In
2001 the Kazakh Research Institute
of Crop Husbandry submitted
FLIP 97-137C to the SVTC under
the name ‘ICARDA-1.’ Over the
last three years ‘ICARDA-1’ has
yielded more seed and shown better
disease resistance than the local
check ‘Kamila.’
Several promising lines are
being evaluated in Tajikistan by the
Tajik Research Institute of Crop
Husbandry. Of these, ILC 3279 outperformed
the already-released
variety ‘Muktadir,’ growing taller,
yielding 20% more, and showing
greater Ascochyta blight resistance.
It was recently submitted for registration
and release for general cultivation
under the name ‘C3-80.’
In Turkmenistan, researchers identified
several promising chickpea
lines, including FLIP 98-131C, FLIP
82-150C, and FLIP 98-41C. All
exhibit Ascochyta blight resistance,
and heat and drought tolerance.
The new cultivars identified will
increase chickpea production and
help alleviate poverty and malnutrition
in CAC countries. Growing
chickpea in rotation with cereals
will also help to overcome the soildegradation
problems caused by
widespread continuous cereal cropping
in the region.
Breeding chickpea for leaf
miner resistance
The leaf miner insect pest causes
serious crop losses in chickpea,
which is traditionally grown in
spring in Mediterranean environments
in WANA. Chemical control
methods are available, but are
expensive and environmentally
unfriendly. A better alternative is
host-plant resistance, but resistance
breeding programs require reliable
germplasm screening techniques.
ICARDA recently developed an
efficient screening technique for
use in the field, which involves
sowing chickpea in mid-April, one
month later than usual. This
ensures high humidity and moderate
temperatures—conditions
which promote leaf miner populations
to develop faster. Limited irrigation
is used to encourage germination,
crop growth, and leaf miner
development. Susceptible lines are
planted after every nine test entries
Breeding for leaf miner resistance.
Above: susceptible line; Below: resistant
line.
and around the perimeter of the
experimental area to indicate infestation
and ensure that high numbers
of insects spread quickly
through the field.
Plants are evaluated using a
scale of 1 to 9, where 1 = no visible
damage by leaf miner (leaf-miner
free); 5 = less than 50% of leaflets
damaged by leaf miner (tolerant);
and 9 = almost all leaflets damaged
by leaf miner (highly susceptible).
When the susceptible check plants
in a single row score 9, observations
are recorded for all experimental
materials.
Using this screening technique,
researchers identified two leaf
miner resistant lines: ILC 5901 and
ILC 3805. However, these lines
have narrow leaflets and small
seeds. To understand how leaf
miner resistance is inherited, and to
develop large-seeded, resistant cultivars,
researchers hybridized the
resistant line ILC 5901 with the
larger-seeded but leaf miner susceptible
ILC 3397.
Parent lines and subsequent
generations were grown in
ICARDA’s Leaf Miner Nursery
using the new screening regime.
Observation of the parents and the
F1, F2, and F3 generations showed
that leaf miner resistance is dominant
over susceptibility and is simply
inherited.
Using the pedigree method of
selection, researchers identified a
large number of leaf miner resistant
lines in the F6 generation, which
produced seeds of various sizes.
Some seeds were larger (45 g/100
seeds) than those of the resistant
parent ILC 5901 (20-24 g/100
seeds). Seed from visually homogenous
F6 lines showing the same
level of leaf miner resistance will be
multiplied at Tel Hadya, evaluated
agronomically, and then shared
with NARS.