Marker Aided Incorporation ofSaltol, a Major QTL Associated with Seedling Stage Salt Tolerance, intoOryza sativa'Pusa Basmati 1121'.
Pusa Basmati 1121 (PB1121), an elite Basmati rice cultivar is vulnerable to salinity at seedling stage. A study was undertaken to impart seedling-stage salt tolerance into PB1121 by transferring a quantitative trait locus (QTL),Saltol, using FL478 as donor, through marker assisted backcrossing. Sequence tagged microsatellite site (STMS) marker RM 3412, tightly linked toSaltolwas used for foreground selection. Background recovery was estimated using 90 genome-wide STMS markers. Systematic phenotypic selection helped in accelerated recovery of recurrent parent phenome (RPP). A set of 51 BC3F2lines homozygous forSaltolwere advanced to develop four improved near isogenic lines (NILs) of PB1121 with seedling stage salt tolerance. The background genome recovery in the NILs ranged from 93.3 to 99.4%. The improved NILs were either similar or better than the recurrent parent PB1121 for yield, grain and cooking quality and duration. Biochemical analyses revealed significant variation in shoot and root Na+and K+concentrations. Correlation between shoot and root Na+concentration was stronger than that between root and shoot K+concentration. The effect of QTL integration into the NILs was studied through expression profiling ofOsHKT1;5, one of the genes present in theSaltolregion. The NILs had significantly higherOsHKT1;5expression than the recurrent parent PB1121, but lower than FL478 on salt exposure validating the successful introgression ofSaltolin the NILs. This was also confirmed under agronomic evaluation, wherein the NILs showed greater salt tolerance at seedling stage. One of the NILs, Pusa1734-8-3-3 (NIL3) showed comparable yield and cooking quality to the recurrent parent PB1121, with high field level seedling stage salinity tolerance and shorter duration. This is the first report of successful introgression ofSaltolinto a Basmati rice cultivar.
Division of Genetics, ICAR - Indian Agricultural Research Institute New Delhi, India.
N Naresh
NN
Babu
Division of Genetics, ICAR - Indian Agricultural Research Institute New Delhi, India.
S Gopala
SG
Krishnan
ICAR - Indian Agricultural Research Institute, Rice Breeding and Genetics Research Centre Aduthurai, India.
K K
KK
Vinod
ICAR - Central Soil Salinity Research Institute Karnal, India.
S L
SL
Krishnamurthy
Division of Genetics, ICAR - Indian Agricultural Research Institute New Delhi, India.
Vivek K
VK
Singh
Division of Plant Physiology, ICAR - Indian Agricultural Research Institute New Delhi, India.
Madan P
MP
Singh
ICAR - National Research Centre on Plant Biotechnology New Delhi, India.
Renu
R
Singh
Division of Genetics, ICAR - Indian Agricultural Research Institute New Delhi, India.
Ranjith K
RK
Ellur
ICAR - National Research Centre on Plant Biotechnology New Delhi, India.
Vandna
V
Rai
Division of Genetics, ICAR - Indian Agricultural Research Institute New Delhi, India.
Haritha
H
Bollinedi
Division of Genetics, ICAR - Indian Agricultural Research Institute New Delhi, India.
Prolay K
PK
Bhowmick
Division of Genetics, ICAR - Indian Agricultural Research Institute New Delhi, India.
Ashutosh K
AK
Yadav
ICAR - Indian Agricultural Research Institute, Rice Breeding and Genetics Research Centre Aduthurai, India.
Mariappan
M
Nagarajan
ICAR - National Research Centre on Plant Biotechnology New Delhi, India.
Nagendra K
NK
Singh
Division of Genetics, ICAR - Indian Agricultural Research Institute New Delhi, India.
Kumble V
KV
Prabhu
Division of Genetics, ICAR - Indian Agricultural Research Institute New Delhi, India.
Ashok K
AK
Singh
Basmati rice; OsHKT1;5 gene; Saltol; expression profiling; foreground selection; grain and cooking quality; marker assisted backcross breeding; salinity tolerance