Seed germination and seedling growth parameters of rice (Oryza sativa) varieties as affected by salt and water stress

Rice (Oryza sativa L.) is a staple food for more than half of the world's population. Globally, rice is grown on 161 million hectares, with an average annual production of 678.7 million tonnes. Drought and salinity are two major abiotic determinants due to high magnitude of their impact and wide occurrence. In the present study rice varieties were analyzed for water and salt stress tolerance at germination and early seedling growth stage. Seeds of three rice varieties (Narendra 1, Sabarmati and Hybrid 312) were collected and kept under four water stress and six salt stress levels. Seed germination, seedling length, dry weight, seed vigor and other parameters were recorded. The results showed that with increasing water stress, germination in all the varieties was delayed and decreased from 68.8% in control to 4.4 % in highest stress (-15 bar) level. Dry weight of shoot and root, shoot and root length, fresh weight of stem and root decreased in all rice varieties with the increase in water stress level. Narendra 1 and Sabarmati showed better response while Hybrid 312 failed to germinate in all water stress levels. The increase in salt stress also reduced every measured trait significantly in all the varieties. Seed germination decreased from 100% in control to 65 % in highest (20 ds/m) salt stress level. Maximum germination percentage (100%) was observed in Hybrid 312 under all the salt stress levels. These results could be helpful in identification of the tolerant varieties which can be studied further and economically exploited.