Leaf rust, caused by Puccinia arachidis, is one of the major devastating diseases in peanut (Arachis hypogaea L.). After validating a major QTL (82.62% phenotypic variation) for resistance to rust, it was introgressed in three susceptible varieties.. 17 Sep 2013

1. Inclusive Market-Oriented Development (IMOD) –
our approach to bringing prosperity in the drylands.
ICRISAT is a member of the CGIAR Consortium.
1International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, India
2CGIAR Generation Challenge Programme, c/o CIMMYT, Mexico DF, Mexico
3The University of Georgia, Tifton, USA; *Address for correspondence: r.k.varshney@cgiar.org
Three elite peanut cultivars improved for rust resistance
by introgressing a QTL genomic region through marker-
assisted backcrossing (MABC) approach
QTL introgressed through MABC approach into the genetic background of three elite cultivars (ICGV 91114, JL 24 and TAG 24)
using four linked markers (Theor Appl Genet 2013, under review)
A total of 81 promising introgression lines identified with high rust resistance i.e., with disease score of <2.0 on 1.0-9.0 scale
At present, promising lines are grown in replication for yield assessment and superior lines will be selected for multilocation
evaluation in target areas of SAT region
Improved varieties with enhanced disease resistance will provide better yield and higher income, and, sustain the livelihood of
resource poor farmers of the semi-arid regions of the world
Leaf rust, caused by Puccinia arachidis, is one of the major devastating diseases in peanut (Arachis hypogaea L.). After validating a
major QTL (82.62% phenotypic variation) for resistance to rust, it was introgressed in three susceptible varieties namely ICGV 91114, JL 24 and TAG
24 using GPBD 4 variety as donor through MABC approach. A total of 81 introgression lines developed from 2 to 3 backcrosses with high level of rust
resistance were selected with disease score of <2.0 on 1.0-9.0 scale as par the donor. Screening of 43 promising lines with 13 markers present on the
carrier linkage group showed introgression of only target genomic region from resistant donor in 11 lines. Multi-location field evaluation of most
promising lines should provide entries for possible release of the improved varieties with enhanced disease resistance that will eventually provide
better yield and higher income to resource poor farmers of the semi-arid regions of the world. Further, this study highlights the utility of four markers
for improving rust resistance in any peanut molecular breeding programme of the world.
Abstract
Acknowledgements
Summary
Rajeev K Varshney1,2*, Manish K Pandey1,3, Pasupuleti Janila1, Shyam N Nigam1, Hari Sudhini1,
MVC Gowda1, Manda Sriswathi1, T Radhakrishnan1, P Nagesh1
This work has been undertaken as part of the CGIAR Research Program on Grain Legumes. Financial
support from Bill & Melinda Gates Foundation through CGIAR Generation Challenge Programme
(GCP) is gratefully acknowledged. Thanks are also due to Bryan J Moss and V Papaiah for their help.
Disease screening during rainy 2012
ICGV 91114 ICGV 91114 + QTL GPBD 4
JL 24 JL 24 + Rust QTL
Replicated yield assessment of improved lines, rainy 2013
Disease symptom at harvesting stage
Post rainy 2008-09
Disease screening of BC2F3 progenies
and BC3F2 plants, selection of 75
homozygous BC3F2 plants based on MAS
Screening of homozygous resistant BC3F3
progenies for agronomic performance and
seed multiplication from BC2F4 plants
Rainy 2011
Post rainy 2011-12
Rainy 2012
Marker assisted introgression of rust QTL
Foregroundmarkers:IPAHM103,
GM2079,GM1536,GM2301
Post rainy 2010-11
183 plants screened for MAS, 53 plants
selected
186 BC3F1 and 498 BC2F2 plants screened
for MAS, 55 heterozygous BC3F1 &
158 homozygous BC2F2 plants selected
Crosses made between GPBD 4 with
ICGV 91114, JL 24 and TAG 24
Rainy 2009
True hybrids selected based on SSR
markers
Post rainy 2009-10
186 plants screened for MAS, 52 plants
selected
Selfing Rainy 2010
Selfing
Selfing
Selfing
ICGV 91114,
JL 24,
TAG 24
GPBD 4
F1
BC1F1
BC2F1
BC3F1 BC2F2
BC3F2 BC2F3
BC3F3 BC2F4
BC3F4 BC3F5
x
A major QTL contributing up to 82.96% PVE for rust resistance identified and linked SSR markers (IPAHM103,
GM2079, GM1536 and GM2301) validated (Theor Appl Genet 2010, 121:971-98; Mol Breed 2012, 32:773-788)