Evaluation of recombinant inbred lines for low soil phosphorous tolerance derived from Rasi - a low soil phosphorous tolerant variety

Rasi is a P efficient genotype identified by ICAR-IIRR, Hyderabad, lacking Pup1, the known major low soil P tolerance QTL-. In the present study, a set of 214 recombinant inbred lines (RILs) developed from cross Rasi x Improved Samba Mahsuri was evaluated in a low soil P plot (available P < 2 kg ha⁻¹) and normal soil P plot (available P >18 kg ha⁻¹) at ICAR- IIRR along with known tolerant and the sensitive checks. The RILs showed high genetic variability for the traits associated with low soil P tolerance. Stress indices were calculated based on the yield and the RILs were grouped into highly tolerant, tolerant and sensitive lines. Thirty-six RILs performing better than the tolerant checks and exhibiting excellent tolerance to low P and a yield reduction of < 40% were identified. These RILs can serve as donors for the new novel source for low soil P tolerance.