Pre-breeding to Genetic Engineering

Wheat ( Triticum aestivum L.) is among the most dominant of food crops, and is cultivated and consumed worldwide. Fulfilling 20% of the global calories, it is a complete source of nutrition providing carbohydrates, proteins, fats, minerals, and vitamins required for healthy life on a daily basis. Wheat output reached its highest at 787.4 million metric tonnes (MMT) worldwide, but this crop was still facing challenges to its sustainable production stemming from biotic and abiotic stresses including heat, drought, salinity, rusts, and insect attacks during 2023–24. Due to the significant role of wheat in global food security, economic stability, and international trade, any decline in its yield is a direct threat to stability and peace. The population projection of 9–10 billion people by 2050 requires wheat production to rise by 132 MMT more than current levels annually. This review assesses in-depth strategies from the pre-breeding level to genetic engineering for the development of climate-resilient cultivars tolerant against biotic and abiotic stresses. Pre-breeding with huge potential for integrating useful genes from crop wild-type relatives and exotic germplasm has enabled broadening of genetic diversity as well as improving tolerance against various stress factors. In addition to conventional breeding programs, molecular approaches like QTL mapping, GWAS, and genomic selection, are playing promising roles in introducing climate-resilient characteristics with more accuracy and less time. Unlike other molecular approaches, genetic engineering techniques such as TALENs, ZFNs, and CRISPR-Cas9, for crop breeding are still in the developmental phase and facing regulatory issues. However, it has contributed a lot to gene characterization. A number of genes and DNA sequences have been identified with promising potential to uplift the yield and ensure stable crop production.