Identification of several small main-effect QTLs and a large
number of epistatic QTLs for drought tolerance related traits
in groundnut (Arachis hypogaea L.)KRaviauthorVVadezauthorSIsobeauthorR RMirauthorYGuoauthorS NNigamauthorM V CGowdaauthorTRadhakrishnanauthorD JBertioliauthorS JKnappauthorR KVarshneyauthorCultivated groundnut or peanut (Arachis hypogaea
L.), an allotetraploid (2n = 4x = 40), is a self pollinated
and widely grown crop in the semi-arid regions of
the world. Improvement of drought tolerance is an
important area of research for groundnut breeding programmes.
Therefore, for the identification of candidate
QTLs for drought tolerance, a comprehensive and refined
genetic map containing 191 SSR loci based on a single
mapping population (TAG 24 9 ICGV 86031), segregating
for drought and surrogate traits was developed. Genotyping
data and phenotyping data collected for more than
ten drought related traits in 2–3 seasons were analyzed in
detail for identification of main effect QTLs (M-QTLs)
and epistatic QTLs (E-QTLs) using QTL Cartographer,
QTLNetwork and Genotype Matrix Mapping (GMM)
programmes. A total of 105 M-QTLs with 3.48–33.36% phenotypic variation explained (PVE) were identified
using QTL Cartographer, while only 65 M-QTLs with
1.3–15.01% PVE were identified using QTLNetwork. A
total of 53 M-QTLs were such which were identified using
both programmes. On the other hand, GMM identified 186
(8.54–44.72% PVE) and 63 (7.11–21.13% PVE), three and
two loci interactions, whereas only 8 E-QTL interactions
with 1.7–8.34% PVE were identified through QTLNetwork.
Interestingly a number of co-localized QTLs controlling
2–9 traits were also identified. The identification of
few major, many minor M-QTLs and QTL 9 QTL interactions
during the present study confirmed the complex and
quantitative nature of drought tolerance in groundnut. This
study suggests deployment of modern approaches like
marker-assisted recurrent selection or genomic selection
instead of marker-assisted backcrossing approach for
breeding for drought tolerance in groundnut.Groundnut2011Springer VerlagArticle