Marker-assisted introgression of QTLs for yield under moisture stress into elite varieties of rice (Oryza sativa)

Rice production is severely constrained by the moisture stress. The present study was undertaken to transfer two important QTLsviz., (qDTY2.2andqDTY4.1), which controls yield under moisture stress (DTY) into two elite varieties, that is, MTU1010 and NLR34449 through marker-assisted breeding. Foreground and background selections of backcross generations, that is, BC1F1, BC(2)F(1)and BC(2)F(2)identified several promising introgression lines (ILs) with two QTLs and single QTLs with an appreciable level of recovery of recipient parent genome. In ILs, the recovery of MTU1010 genome content was estimated to be 83%-93% while the recovery of NLR34449 was 84%-92%. The two-QTL ILs of MTU1010 and NLR34449 backgrounds (qDTY2.2andqDTY4.1) have shown substantial yield advantage (32 to 84%) over the single-QTL ILs (eitherqDTY2.2orqDTY4.1) under moisture stress conditions. Among all, two ILs, MBC-124 and NBC-127 are the best high yielding lines under moisture stress conditions. These outyielded ILs have the potential to be released as varieties in rainfed ecosystem and also can be used as donors in the existing breeding programme in rice.