Abiotic Stress Tolerance and Breeding Strategies in Rice: A Comprehensive Review

Abstract

Abiotic stresses such as drought, salinity, and temperature extremes, as well as their combinations, often occur during rice production, negatively affecting rice growth, yield, and quality. The impacts include reduced leaf area and photosynthesis, inhibition of spikelet formation and development, and oxidative stress. At the same time, tolerance is determined by the combination of germination capacity, root volume, root number, plant height, and tiller number. The latest research identifies genetic and epigenetic mechanisms of tolerance, including cold tolerance linked to DNA hypomethylation, which underlies acquired and heritable tolerance. The gene pool of wild, weedy, and pre-breed rice varieties can be used to improve cultivated rice’s yield potential and tolerance to multiple stresses. Studies on rice’s response to salt stress reveal the role of QTL Saltol and mechanisms of ion homeostasis and antioxidant defense that can be harnessed to improve tolerance. The authors conclude that combined physiological, genetic, molecular, epigenetic, and multi-omics approaches, along with the utilization of the wild rice gene pool, speed breeding technologies, genome editing, transgenics, marker-assisted selection, QTL mapping, and GWAS, could be used to develop novel varieties with increased tolerance to multiple stresses, stable yield, and improved grain quality.