Effect of water stress at reproductive stage on yield potential and stability of rice (Oryza sativa L.) genotypes grown in rainfed lowland conditions

  • Santosh Kumar*, Sharad Kumar Dwivedi and S S Singh
Keywords: Rice, drought, water stress, yield potential, yield stability.


The present study was conducted at ICAR research complex for eastern region, Patna during kharif 2012 and
2013 with objective to identify rice genotypes having high yield potential and stability under water stress
(drought) conditions. Fifteen rice (Oryza sativa L.) genotypes were grown under irrigated and water stress
conditions. Water stress was imposed at reproductive stage by withholding irrigation supply. Yield and yield
attributesof rice genotypes under water stress condition were recorded. The effects of water stress on various
physio-morphological traits associated with drought tolerance were also studied at reproductive stage. Results
revealed that, significant yield decline was observed in most of the genotypes grown under stress condition
compared to non-stress condition. Drought susceptibility index (DSI) and relative grain yield (RY) were used
to illustrate yield stability and yield potential, respectively. Significant variation in drought susceptibility index
and relative yield values within genotypes were observed. The DSI values ranged from 0.68 to 1.46 and the
mean RY values were 0.85 for irrigated plots and 0.77 for water stressed plots. The rice genotypes IR 83376-BB-24-2, IR 83373-B-B-24-3 IR 84895-B-B-127-CRA-5-1-1 and IR83387-B-B-27-4 showed high yield

potential and stability (i.e. DSI<1; and RY>mean RY). These drought tolerant genotypes were also superior in
terms of grain yield and higher content of desired physio-morphological traits in terms of plant biomass,
relative water content, soluble protein and proline content. These drought tolerant rice genotypes may be
adopted in large area in rainfed lowland ecosystem where drought is frequent, particularly at reproductive

Research Article