Genetic Improvement of the Silkworm (Bombyx mori): From Conventional Breeding to Modern Biotechnology

Abstract

The silkworm, Bombyx mori, is one of the most economically important insects owing to its exclusive ability to produce high-quality silk fibres that support the global sericulture industry. Genetic improvement of silkworm has been a primary objective of sericulture research for decades to enhance economically important traits including cocoon yield, shell weight, shell ratio, filament length, disease resistance, stress tolerance, fecundity, and silk quality. Traditional breeding approaches based on selection, hybridization, and heterosis exploitation have significantly contributed to the development of high-yielding silkworm breeds. However, the increasing demand for superior silk production under changing climatic conditions necessitates the integration of advanced molecular and genomic technologies into conventional breeding programmes. Recent developments in molecular genetics, quantitative trait locus (QTL) mapping, marker-assisted selection, genome sequencing, transcriptomics, proteomics, and genome editing have considerably improved the understanding of the genetic architecture underlying economically important traits in Bombyx mori. The availability of the complete silkworm genome and advanced bioinformatics tools has accelerated the identification of candidate genes associated with silk protein synthesis, immunity, environmental adaptation, and reproductive performance. Furthermore, CRISPR/Cas9-mediated genome editing and transgenic technologies have opened new opportunities for precise genetic manipulation to improve silk productivity and resistance against pathogens. Despite these advances, challenges including maintenance of genetic diversity, genotype × environment interactions, ethical concerns regarding genetically modified organisms, and climate change continue to influence silkworm breeding programmes. Future research should emphasize the integration of genomics, artificial intelligence, precision breeding, and multi-omics technologies to develop climate-resilient and high-yielding silkworm breeds. This review discusses the principles, methodologies, recent advances, challenges, and future prospects of genetic improvement in silkworm and highlights their significance for sustainable sericulture and global silk production.