Physiological characterization for abiotic stress tolerance in rice (Oryza sativa) genotypes

Abiotic stresses in rice restrict the growth and potential of the crop hampering the production and productivity. Screening for abiotic stress tolerance was conducted for salinity and water stress (1% and 2%) during Kharif 2019 at Regional Agricultural Research Station, Maruteru, Andhra Pradesh, India. The physiological characterization of selected genotypes showed that among all treatments, seed germination, root length, shoot length and seedling vigour index was greater under control followed by 1% mannitol, 2% mannitol and salinity stress. The entries IET 27773, IET 27750 and IET 26861 performed well under moderate water stress (1% mannitol and 2% mannitol induced stress) and hence can be identified as relatively tolerant. Under salinity stress AC 1303 followed by IET 27750, IET 27772 and IET 27773 performed well. The above cultures can be used as physiological donors for respective stresses. The seedling vigour was highest in IET 27773 under all the stress treatments. IET 27750 and IET 27773 showed tolerance to both salinity and water stress. In the field experiment, IET 26961 (6230 kg/ha), IET 27768 (6060 kg/ha) and IET 27773 (6050 kg/ha) recorded the highest grain yield. Among all the genotypes tested, IET 27773 was found to be a good performing genotype as it exhibited tolerance to abiotic stress in lab conditions and recorded higher yields under field conditions.