Challenges Imposed By Abiotic Stresses On The Plant And Productive Traits In Rice And Strategies For Their Mitigation

Abstract

In recent years, agricultural crops, especially cereals are facing immense pressure of feeding ever increasing world population and climate induced negative impacts of abiotic stresses on their productivity. Rice is cultivated as a staple food in various parts of the world and delivers food to 50% of the populace. Its productivity also depends on and is affected by climatic factors and investigations on rice plant response to different abiotic stresses including drought, heat and salinity are reported. Rice plant is highly sensitive in terms of yield towards lower salinity levels (NaCl 3 dSm−1), threshold temperature 37ᴼC and drought occurrence for a period of 7 days. Pre-flowering vegetative, flowering and post flowering reproductive responses of rice plants were studied under adverse impact of abiotic stresses on these specific stages. Rice plant yield is compromised under these harsh climatic conditions through germination losses, impaired seedling growth, yellowing of leaves, leaves curling and wilting, delayed or early flower initiation, loss of fertilization process resulting from poor performance of anther dehiscence, pollen number, viability, germination on stigma and pollen tube formation. Further, shortening of grain filling span with deformed floral parts, infertile spikelets, reduced grain size and weight with low assimilation movement from source to sink are the plants traits which are key indicators of abiotic stress onset during grain filling period in rice. New cultivars with improved and stress tolerant traits are needed of this global warming era to withstand harsh climatic for sustainable productivity in crops. Foreseeing the future threats to food security through the agricultural system requires our breeding programs to be aligned with advanced strategies and techniques to overcome these challenges. This review covers potential threats imposed by abiotic factors to productive traits of rice plant, their physiological basis and strategies to ameliorate these effects. This work will provide scientific basis to design and amend breeding lines for researchers to improve rice crop productivity under adverse abiotic conditions.