Introgression of disease resistance genes from Arachis kempff-mercadoi into
N. Mallikarjuna, S. Pande, D. R. Jadhav, D. C. Sastri and J. N. Rao
International Crops Research Institute for the Semi-Arid Tropics, Patancheru 502 324, Andhra Pradesh, India; E-mail:
Received May 16, 2003/Accepted June 4, 2004
Communicated by A. Ashri
Arachis kempff-mercadoi is a wild species from the section Arachis. All
kempff-mercadoi accessions originate from the Santa Cruz province of
Bolivia and they represent Arachis species with the A genome. From
molecular analysis it was found that although cultivated A. hypogaea
is made up of A and B genomes, A. kempff-mercadoi may not be as
closely related to it as are some of the other A genome species. Arachis
kempff-mercadoi is of interest because it has multiple disease
resistance. It was crossed with a Spanish A. hypogaea cultivar which
is susceptible to foliar diseases and to the insect pest Spodoptera litura.
The success rate of the cross A. hypogaea (2n ¼ 40) · A. kempff-
mercadoi (2n ¼ 20) was very low, but it could be increased by
culturing immature seeds in vitro. Although the hybrids were triploids,
a few fertile pollen grains were obtained due to the formation of
restitution nuclei in the F1 plants. Interspecific derivatives at the
BC2F2generation were scored for early leaf spot, late leaf spot and to
Spodoptera damage. Screening results showed that 29% of the
derivatives had both early and late leaf spot resistance and that less
than 5% of the derivatives had resistance to both the foliar diseases
and to Spodoptera.
Key words: Arachis hypogaea — Arachis kempff-mercadoi —
Cercospora arachidicola — Phaeoisariopsis personata —
Spodoptera litura — interspecific hybrids
The genus Arachis, a native of the Brazil-Paraguay region of
South America (Simpson et al. 2001), is made up of nine
sections (Krapovickas and Gregory 1994). The cultivated
species Arachis hypogaea L. belongs to the section Arachis.
Many wild species from the section Arachis such as A. villosa,
A. correntina, A. diogoi (¼A. chacoense), A. stenosperma,
A. cardenasii, A. duranensis and A. batizocoi have been
successfully crossed with cultivated species (Stalker 1985,
Singh 1986, Stalker and Simpson 1995) with pod formation
ranging from 0 to 30%. It is not known if all the pods were
mature and the seeds germinated under in vivo conditions.
Transfer of rust resistance to the cultivated species has been
reported from A. duranensis (Singh 1986). Simpson et al.
(1993) reported the successful transfer of nematode resistance
from A. cardenasii and A. diogoi. Stalker et al. (2002) reported
a leaf spot-resistant population from the cross A. hypogaea ·
A. cardenasii. The population also had resistance to root knot
nematode and southern corn root worm. Milla (2003) has
reported the transfer of tomato spotted wilt virus resistance
from A. cardenasii.
Arachis kempff-mercadoi (2n ¼ 20, PI 468331; ICG 8959;
Coll no. 30085) is a perennial species and a native of the Santa
Cruz province in Bolivia, South America. It belongs to the
section Arachis with the A genome (Milla 2003). Based on
molecular and cytogenetic analysis, A. hypogaea is made up of
A and B genomes (Singh and Moss 1984, Gimenes et al. 2002).
Based on RAPD-molecular analysis it was found that
A. kempff-mercadoi may not be as closely related to
A. hypogaea as some of the other A genome species
(Mallikarjuna et al. 2003). Although A. kempff-mercadoi has
published report of transfer of disease resistance and the nature
of seed set in the crosses using A. kempff-mercadoi.
Surveys at ICRISAT have shown that A. kempff-mercadoi
has resistance to foliar diseases (Subrahmanyam and Moss
1983, Subrahmanyam et al. 1985, Pande and Narayana Rao
2001) and to the insect pest, Spodoptera litura (Stevenson et al.
1993). Although wild species from the section Arachis have
been recognized by Stalker and Simpson 1995) as cross-
compatible with cultivated groundnut (A. hypogaea L.), not all
wild species from this section cross readily with A. hypogaea
(Ozias-Akins et al. 1992). The success rate of the cross
A. hypogaea · A. kempff-mercadoi is very low. Very few mature
seeds (2%) are produced and a large number of them contain
well-developed embryos that have still not reached maturity.
These seeds do not germinate in vivo but can do so in vitro. A
small number of pods also had small aborted seeds (3–4 mm).
To obtain hybrid plants from aborted seeds, embryo rescue
techniques have had to be used (Mallikarjuna and Sastri
Early leaf spot (ELS) caused by Cercospora arachidicola
Hori and larly leaf spot (LLS) caused by Phaeoisariopsis
personata (Berk and MA Curtis) are economically significant
and widely distributed diseases of groundnut (Waliyar 1991).
The incidence and severity of the diseases vary with location,
year and cultivar and both diseases cause severe yield losses.
Although management options are available, they may not
be the best options because of the high costs of fungicides,
the possibility of obtaining fungicide-resistant strains and
environmental degradation due to the use of chemicals. Hence,
the best option to combat these diseases is to obtain disease-
The tobacco caterpillar, Spodoptera litura (Fab.) is a
polyphagous noctuid moth of high reproductive capacity, with
the ability to migrate over long distances. These characteristics
have resulted in its becoming a pest of many agricultural crops
throughout South Asia and South East Asia. Groundnut yield
losses up to 71% have been reported in India (Amin 1988).
High yield losses of groundnuts have been directly associated
with increased larval density of S. litura, and the intensity of
defoliation (Panchbhavi and Nethradani Raj 1987). With the
Plant Breeding 123, 573—576 (2004)
? 2004 Blackwell Verlag, Berlin
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