Advanced breeding strategies for combating rice salinity stress in Ghana: A critical review and future perspective

Abstract

Rice is a staple crop and the second most consumed food in Ghana; however, only 48 % of what is consumed. Rising soil salinity, driven by changing climatic conditions, presents a substantial challenge to rice cultivation in Ghana, especially in coastal and delta regions where rice is a crucial staple crop. The application of advanced breeding tools is essential to developing salt-tolerant rice varieties as a mitigation strategy. This review examines the application of cutting-edge techniques for developing resilient rice cultivars tailored for Ghana's saline environments. Here, we explored the effectiveness of marker-assisted selection, genomic selection, genetic modification, and genome editing as potential approaches to accelerate the breeding of salt-tolerant rice. Marker-assisted selection, utilising high-density Single Nucleotide Polymorphism markers, has enabled rapid identification and incorporation of salt tolerance traits. Advances in low-cost, high-density DNA marker technologies have made genomic selection, a method that uses genome-wide markers to predict performance without extensive phenotyping, a promising approach to accelerate genetic gains in rice salinity tolerance. Genetic modification techniques, including Agrobacterium-mediated transformation, have been used to introduce novel traits to enhance resilience to salinity. Genome editing, particularly CRISPR-Cas9, enables precise gene modifications to enhance tolerance to various abiotic stressors, including salinity. Additionally, the application of double haploid technology has streamlined the breeding process to achieve homozygosity for salinity tolerance within one generation. This review highlights the application of these tools as potential solutions to sustain rice production and food security in Ghana and elsewhere. Future research should focus on developing regulatory frameworks to safely test, validate, adopt and integrate the technologies, complemented with traditional agricultural practices to maximise their impact in farms with saline soils.