Construction of genetic linkage map and QTL analysis for foliar disease resistance, nutritional quality and productivity traits in groundnut (Arachis hypogaea L.)
Loading...
Files
Date
2009
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
UAS Dharwad
Abstract
Groundnut (Arachis hypogaea L.) is an important oilseed and food crop of the world.
Breeding for disease resistance, improved nutritional quality and productivity are the major
challenges in groundnut breeding. Conventional breeding has had limited success for
improvement of these traits. Advent of molecular markers provides useful way to map and
tag for the desired traits in any crop. An attempt has been made to construct the linkage map
for identification of QTLs for foliar disease resistance, nutritional quality and productivity
traits using 53 polymorphic SSR markers in 146RILs (TG-26xGPBD-4).
Genetic variability components revealed higher magnitude of variation for all the
traits. Heritability was high for disease and nutritional quality but lower for productivity
traits. All the traits showed normal distribution except rust which had bimodal distribution
indicating the complex and simple nature of inheritance, respectively. Correlation between
LLS and rust, protein and oil, oleic and linoleic was negative whereas, number of pods
correlated positively with pod yield.
A partial linkage map with the total distance of 657.9cM (8LGs) and an average
intermarker distance of 14.62cM was constructed using 45 markers (23% genome). Single
marker and QTL analysis identified a total of 23 markers and 5QTLs for disease resistance,
35 markers and 17QTLs for nutritional quality and 34 markers and 13QTLs for productivity
traits. Among them QTL near XIP103 on LG3 for rust (24.10–48.90%), oil content (7.90–
9.10%), number of pods (4.41–6.10%), pod yield (6.60–11.20%), a QTL near TC3A12 on
LG8 for plant height (12.60–17.50%) and a QTL near TC1B02 for test weight (8.20–14.0%)
showed consistent results across the seasons with substantial contribution and the favorable
allele was contributed by GPBD-4 parent. From the study one major QTL (XIP103) has been
identified which could be employed in MAS for identification of rust resistant genotypes