Drought tolerance in recombinant inbred lines (RILS) derived from the cross of BPT-5204/Sahbhagi dhan

Drought stress is a major constraint for rice (Oryza sativa L.) production and yield stability in rainfed ecosystems. Higher probability and greater spatial covariance of drought and less diversified farming systems with rice accounting for a larger share of household income are likely to be the main reasons for this higher cost of drought in eastern India. Farmers deploy various coping mechanisms but such mechanisms are largely unable to prevent a reduction in income and consumption, especially in eastern India. Therefore, identifying drought tolerant genotypes will help to develop rice cultivars suitable for water-limiting environments through markerassisted breeding. F4 progenies derived from the cross of BPT 5204 and Sahbhagi dhan were used to generate the RILs (Recombinant Inbred Lines) by advancing the F4 generation to F6. Eight hundred ten RILs were screened for drought tolerance in the rainout shelter. Scoring for leaf rolling, leaf drying and recovery was based on the 0-9 scale of SES (Standard Evaluation System) of IRRI. The screening results showed one hundred forty recombinant inbred lines were found highly resistant to drought (scale 0-3). Further confirmation of drought tolerance was based on the use of polymorphic microsatellite markers RM 3825, RM 1349, RM 24, RM 232, RM 212 and RM 3 linked to different drought related characteristics such as plant height, panicle length, test weight and grain yield.

Author : Sonali Kar and DN Singh*