Pearl millet is an important cereal crop capable of growing in
semi-arid, arid and marginal regions of the world. Drought is a
major abiotic constraint affecting pearl millet production globally.
Previously identified and validated major linkage group 2
(LG2) drought tolerance (DT) QTL contributing to hybrid grain
and stover yield potential to terminal drought stress is being fine
mapped. The fine mapping population was generated by crossing
two near-isogenic lines (NILs) differing for the LG2 DT QTL. A
modified double digest restriction site associated DNA (ddRAD)
technique using SphI and MluCI enzyme combination was employed.
A total of 290 out of 6,067 F2 mapping population of the
cross (H77/833-2-P10 × ICMR 01029-P10), and parents were
genotyped on Illumina HiSeq2500. Out of 52,028 SNPs that were
identified from a total of 888.85 million reads at a read depth of
10 in the mapping population, a total of 6,821 SNPs were used for
mapping. The genotypic data of these SNPs were used in combination
with that of seven SSRs that had known linkage relationship
with LG2 DT QTL interval. Linkage map was constructed using
QTL IciMapping 4.1 software at a LOD threshold of 3.0. A total
of 189 SNPs anchored to seven SSRs were mapped to the LG2 DT
QTL. The length of linkage group (LG) was 639.72 cM (Haldane
units) with an average inter-marker distance of 6.73 cM. In order
to refine the fine mapping process, ddRAD technique is being further
employed for genotyping rest of the fine mapping population