Fast-track introgression of “QTL-hotspot” for root traits and other drought tolerance trait in JG 11, an elite and leading variety of chickpea (Cicer arietinum L.)

A “QTL-hotspot” containing QTLs for several root and drought tolerance traits was transferred through marker assisted backcrossing (MABC) into JG 11, a leading variety of chickpea in India from the donor parent ICC 4958. Foreground selection with up to 3 SSR (simple sequence repeat) markers namely TAA170, ICCM0249 and STMS11 and background selection with up to 10 AFLP (amplified fragment length polymorphism) primer combinations was undertaken. After undertaking three backcrosses with foreground and background selection and two rounds of selfing, 29 BC3F2 plants homozygous for two markers (ICCM0249 and TAA170) were selected and referred as introgression lines (ILs). Root trait phenotyping of these ILs showed higher rooting depth (RDp, average 115.21±2.24 cm) in all 29 ILs, better root length density (RLD, average 0.41±0.20 cm cm-3) in 25 ILs and higher root dry weight (RDW, average 1.25±0.08 g cyl-1) as compared to the recurrent parent, JG 11 (RDp- 111.70 cm, RLD- 0.39 cm cm-3 and RDW- 1.10 g cyl-1) as well as the donor parent, ICC 4958 (RDp- 114.20 cm, RLD- 0.45 cm cm-3 and RDW- 1.25 g cyl-1). These ILs, developed in 3 years, after multi-location field trials may be released as improved variety with enhanced drought tolerance.