1) Researchers from India, Australia, and the US collaborated to study resistance to pod-boring Lepidoptera (moths) in chickpea. 2) They screened over 150 accessions of wild chickpea relatives for resistance to major pest moths (Helicoverpa spp.) in different regions. 3) They found high levels of resistance in some perennial and annual wild chickpea species, including C. reticulatum, offering potential to breed resistance into cultivated chickpea.

1. Confronting the Lepidoptera Pod-Borer Problem
on Chickpea Through International
Collaboration and Research
Dec 2009
HC Sharma1
, J Ridsdill-Smith3
, SL Clement2
and G Pampapathy1
For more information, contact: HC Sharma, Principal Scientist (Entomology), e-mail: h.sharma@cgiar.org
1
International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru 502 324, Andhra Pradesh, India.
2
USDA, ARS Plant Germplasm Introduction and Testing Research Unit, Washington State University, Pullman, WA 99164-6402 USA.
3
Commonwealth Scientific and Industrial Research Organization (CSIRO), Entomology, Private Bag 5, Wembley 6913, Australia.
Funding: U.S. Agency for International Development (U.S.) and Grains Research and Development Corporation (Australia).
Introduction
Pod-boring Lepidoptera (Helicoverpa spp.) are serious
constraints to chickpea (Cicer arietinum) production in India
and Australia, and occasional pests (Spodoptera) of chickpea
in the US. In India, the widespread use of insecticides to
control H. armigera on cotton, high value vegetables, and grain
legumes has led to high levels of resistance to conventional
insecticides.
Host plant resistance is an effective management option, but
cultivated chickpea has low to moderate levels of resistance to
Helicoverpa and Spodoptera. In the absence of good genetic
variation for pod-borer resistance in the Cicer primary gene
pool, searches for resistance have been expanded to wild
relatives (secondary and tertiary gene pools).
Plants and Insects
Germplasm repositories at ICRISAT (India), Australian
Centre for Legume Improvement Program at Tamworth, New
South Wales, and the USDA-ARS Western Regional Plant
Introduction Station, Pullman, Washington (US) provided seed
of Cicer accessions.
Perennial species: C. canariense, C. macracanthum,
C. microphyllum, C. pungens.
Annual species: C. bijugum, C. cuneatum, C. echinospermum,
C. judaicum, C. pinnatifidum, C. reticulatum, C. yamashitae.
Cultivated chickpea: (C. arietinum) genotypes ICC 506
(moderately resistant check), ICCC 37 (susceptible check), and
Annigeri (commercial landrace cultivar).
Helicoverpa cultures were maintained at ICRISAT (H. armigera)
and CSIRO, Perth, Australia (H. punctigera) laboratories
using standard methods. Larvae for screenings in Pullman,
Washington will be reared from eggs of Spodoptera exigua
purchased from a commercial supplier.
Resistant Screening Methods
Detached leaf assay:
Branches from potted plants embedded in agar-agar medium in
plastic cups and infested with larvae (Fig. 1).
Caged larvae on potted glasshouse plants (Fig. 2)
Exposure of field plants to natural infestations.
Data were recorded on leaf damage, larval survival and larval
weights.
Results
To date, we have screened over 150 accessions of wild
Cicer for resistance to H. armigera, and high levels of
resistance identified in the accessions of perennial (Table 1)
and annual species (Fig. 3). Also, resistance to Australian
native budworm H. punctigera exists in some, but not all wild
Cicer accessions.
Table 1. Evaluation of perennial wild Cicer for resistance to
H. armigera.
Accession Species
Resistance
index (RI)1
(Detached
leaf assay)
Damage
rating2
(Open
field trial) Status
ICC 17138 C. pungens 1.71 3.0 Resistant
ICC 17202 C. canariense 0.73 1.0 Highly resistant
ICC 17230 C. microphyllum 1.04 4.0 Resistant
ICC 17238 C. microphyllum 0.71 2.0 Highly resistant
ICC 17243 C. microphyllum 0.52 1.5 Highly resistant
ICC 17244 C. microphyllum 0.30 1.0 Highly resistant
ICC 17247 C. microphyllum 0.29 1.0 Highly resistant
ICC 17248 C. microphyllum 0.09 2.0 Highly resistant
ICC 17249 C. microphyllum 0.18 2.0 Highly resistant
Annigeri C. arietinum 2.63 8.5 Landrace line
ICC 506 C. arietinum 3.75 9.0 Desi cultivar3
ICCC 37 C. arietinum 3.40 9.0 Susceptible
check
1
RI = leaf damage rating x larval weight / (100-percentage survival).
2
Damage rating (1=<10% leaf area damaged; 9=>80% leaf area damaged).
3
Resistant.
High levels of Helicoverpa resistance have also been
detected in wild annual C. reticulatum, which is noteworthy
because hybridizations of cultivated chickpea with this wild
species are readily obtained and the progenies are fertile.
Thus, it should be possible to endow cultivated chickpea
with pod-borer resistance genes from wild Cicer.
Cicer reticulatum
Cicer echinospurmum
Cicer bijugum
Cicer arietinum
Kabuli chickpea cv. Sierra
C. pinnatifidum Collecting Cicer microphyllum in India, and inspecting and conducting insect bioassay in Pullman, USA. Cicer cuneatum Fig. 2. No-choice cage
technique.
Fig. 1. Detached leaf assay.
0
10
20
30
40
50
60
70
80
90
100
IG69948
IG70032
IG70033
IG72931
IG70039
IG70002
IG70010
IG69947
IG69980
IG70019
IG70003
IG69979
ICC506
Annigeri
ICCC37
Accessions
Larvalweight(mg)
Wt. (mg) 10 DAR
C. arietinum
C.pinnatifidum
C.judaicum
C.judaicum
C.judaicum
C.pinnatifidum
C.bijugum
C.bijugum
C.bijugum
C.judaicum
C.bijugum
C.bijugum
C.cuneatum
Spodoptera exigua
Helicoverpa armigera
Helicoverpa punctigera
Helicoverpa on cultivated
chickpea
Spodoptera on cultivated
chickpea
Fig. 3. Weights of Helicoverpa armigera larvae at 10 days after
releasing the larvae on leaves of wild relatives of chickpea.