Unveiling The Hidden Half: Root Phenotyping of Rice for Enhanced Drought Tolerance under Rainfed Conditions

Drought is a major abiotic stress that reduces crop productivity and weaken the global food” security. Rice (Oryza sativa L.) is a semi-aquatic plant and it requires an adequate amount of water but drought has a detrimental effect on crop growth factors and caused a 25.4% decreased in rice output. It is therefore, imperative to understand the mechanism of plant responses to water deficit conditions and finding the rice germplasm that can withstand intermittent water stress in order to support crop development initiatives for periods of intermittent drought. The present investigation entitled “Unveiling The Hidden Half: Root Phenotyping of Rice for Enhanced Drought Tolerance under Rainfed Conditions” was carried out with the objective to quantify the variations existed among the genotypes. The planting materials used in the experiment consisted of 28 genotypes in which 27 rice genotypes obtained from IIRR, Hyderabad under the AICRP on rice program and 01 check variety from IGKV, Raipur. To understand the root dynamics, the root phenotyping study was conducted in rainout shelter of IGKV research farm using glass mini-rhizotron and root morphology scanning was done in Department of Plant Molecular Biology and Biotechnology lab. The root studied was carried out following the completely randomized design with three replication and two water treatments (watering regularly and watering after 2 days of interval). The field experiment was laid out in randomized block design with three replications under two water regimes (irrigated and rainfed) for two years (2020 and 2021) during kharif season. The results of analysis of variance revealed that the presence of greater diversity among the genotypes for all the observed root traits. Based on mean performance, the highest root length was observed in DT-127, genotype high total root length (DT-127), total root surface area (DT-127), root average diameter (DT-108), root volume (DT-127) and root anatomy (DT-122) in root phenotyping. Similarly, the genotypes were identified for higher total root length (DT-122), total root surface area (DT-122), root average diameter (DT-114), root volume (DT-111), root anatomy (DT-122) under rainfed conditions. The most of genotypes were showed variability across the genotypes for various attributes and genotypes were decreased under rainfed condition as compared to irrigated conditions. The variations among the genotypes and checks i.e., Indira Barani for each trait were noticed under irrigated and rainfed condition.