摘要
Higher crop productivity in a sustainable manner is being perceived as one of the most crucial factors to ensure food security in light of the shrinking arable land resources and limiting fresh water resources. Soil salinity is the chief climatic constraint to agricultural productivity, restricting the suitability of agricultural land and affecting both biomass and grain yields in crops, including rice. The objective of this study was to screen a collection of rice mutants (O. sativa L. cv IR64) produced by γ-ray irradiation, for their higher yield and biomass under saline conditions. The initial screening was carried out at seedling stage employing hydroponics system, followed by screening in saline microplots under standard agronomic practices. Mircoplots were maintained at three different saline levels i.e., low salinity (EC ∼ 6 dS/m), moderate salinity (EC ∼ 10 dS/m) and high salinity (EC ∼ 14 dS/m). Based on screening carried out for various yield and related parameters i.e., plant height, tiller number, shoot and root weight, total biomass, panicle length, and harvest index, four ideotypes were observed to be performing significantly better than the wild type plants. Most importantly, selected mutants, such as D100-211 and D100-209 showed an increase of 18 and 34% in yield as compared to WT plants under moderate saline conditions (EC = 10 dS/m). These results suggest that regulated genetic modulation can improve crops to get optimum biomass and yield despite environmental vagaries. Further, detailed genetic and molecular characterization of these mutants will help to identify and characterize the key genes regulating the traits for high biomass and yield under salinity stress in rice.