Mapping QTL(s) for drought tolerance in Indian mustard (Brassica juncea L. Czern & Coss.)
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Date
2015
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
CCSHAU
Abstract
The present investigation on studies on Mapping QTL(s) for drought tolerance in Indian mustard (Brassica
juncea L. Czern & Coss.) was conducted with the objective to identify QTL(s) for drought tolerance in RB50 x
Kranti derived F
2
and F2:3
populations of Brassica juncea (RB50-Drought tolerant, Kranti-Drought sensitive)and to
evaluate both generations for various phenological traits, growth related traits, physiological traits along with yield
and its component traits under irrigated and drought conditions. RB50 × Kranti derived F
2
and F2:3
population
showed significant variation for various observed agronomic traits. 200 SSR primers from various Brassica
species were used to screen parental genotypes (RB50, Kranti) and 51 markers were found polymorphic. These
polymorphic SSR primers were used to screen F2
population and were used to construct linkage map of Brassica
juncea using MapmakerExp3.0 covering 10 linkage groups, 2 SSR markers did not show linkage with any of the
marker groups and hence did not map to any of the linkage group. Composite interval mapping (CIM) analysis
revealed a total of 30 QTLs in F
2
generation under irrigated conditions for various drought related, yield and other
traits in Brassica juncea out of which four QTLs were identified for drought related physiological trait (Electrolyte
leakage). A total of 19 QTLs were identified in F
2:3
under irrigated conditions for various drought related, yield
and other traits in Brassica juncea including 4 QTLs for physiological trait (Relative water content). QTL analysis
revealed a total of 7 QTLs accounting for different phenotypic variance in F
2:3
generation under drought conditions
for various drought related, yield and other traits in Brassica juncea with one QTL identified for drought related
physiological trait (Electrolyte leakage). There was clustering of QTLs on many LGs in linkage map. Most
prominent clustering signifying multifunctional QTL region was observed in the LG 5 and 10. This multifunctional
QTL region on the LG 5 contains at least one major QTL for various traits. Linkage groups 5 and 10 have been
suggested to have major QTLs affecting drought tolerance. QTLs identified in the present study firstly needs to be
validated in other populations and then fine mapping of these drought related QTLs have to be carried out them in
marker assisted selection and breeding for drought tolerant genotypes in Brassica juncea.
Description
Keywords
Indian mustard, Drought tolerance, QTLs, linkage map, Physiological traits