The growing global population and changing environmental conditions have intensified the demand for high-yielding, stress-resilient, and nutritionally enhanced crops. Conventional breeding, though historically impactful, is limited by dependence on phenotypic selection, long breeding cycles, and challenges in improving complex, low-heritability traits. Marker-assisted introgression (MAI) has emerged as a precise and efficient molecular breeding strategy to overcome these limitations. MAI enables the targeted transfer of genes or quantitative trait loci (QTLs) from donor lines into elite cultivars while retaining the desirable genetic background of the recurrent parent. The strategy relies on molecular markers, including functional markers, SNPs, SSRs, and multi-locus panels, to track alleles accurately, minimize linkage drag, and accelerate breeding cycles. MAI has been successfully applied across major crops, including rice, maize, wheat, and peanut, for improving disease resistance, abiotic stress tolerance, yield potential, and quality traits. Functional markers and multi-marker approaches have enhanced the precision of introgression, particularly for complex traits governed by multiple genes. Integration of high-throughput genotyping, phenotyping, and knowledge of marker-trait associations ensures reliable selection under diverse environmental conditions. This review highlights the concepts, methodologies, influencing factors, applications, and advantages of MAI, emphasizing its critical role in modern crop improvement programs aimed at developing climate-resilient and high-performing cultivars.

Marker-assisted selection, introgression, backcross breeding, QTL mapping, crop improvement

Marker-assisted introgression has emerged as a transformative strategy in modern plant breeding, bridging the gap between conventional phenotypic selection and molecular approaches. By enabling the precise transfer of target genes or QTLs from donor to elite cultivars, MAI speeds up genetic improvements while keeping the desirable traits of the recurrent parent. Its efficiency depends on factors as genetic map length, population size, backcross duration, marker type and polymorphism, trait complexity, and environmental conditions. Using multiple markers helps improve accuracy and reduces the chance of unwanted traits being transferred. MAI has shown effectiveness across major crops, including rice, maize, wheat, and peanut, for improving disease resistance, stress tolerance, yield, and quality traits. It contains introgression of Xa21 in rice for bacterial blight resistance, β-carotene and kernel sweetness alleles in maize, and high oleic acid alleles in peanut highlight its value in addressing challenges, improving nutrition, and supporting climate-resilient farming. It provides a precise and efficient way to develop improved crop varieties. Combining marker information with careful field evaluation allows breeders to produce high-performing, stress-tolerant, and nutritionally enhanced crops that meet the demands of a growing population (Suen et al., 2003).

Godwin Gilbert J., Jaya Anjana Sunil and K. Indira Petchiammal (2025). Marker Assisted Introgression to Develop New Generation Varieties in Crop Plants. Biological Forum, 17(10): 01-09.