Genomic assisted breeding and holistic management of abiotic and biotic stress in silkworm host cultivation: A review

Silk is a high-value, low-volume product, produced by an important insect commonly known as the silkworm. Sericulture serves as a source of livelihood for farmers besides being an important source of economy for many countries including India. Sustainable production of premium silk depends on continuous production of quality foliage as feed for silkworms obtained from host plants. The production of silk is significantly hampered when host plants are subjected to biotic and abiotic stresses. The foliage harvest could be enhanced when these constraints are efficiently managed by the development of stress-resistant host cultivars. Improved stress-resistant cultivars have been developed using conventional breeding strategies and used in commercial cultivation. However, the highly heterozygous genetic nature of the hosts makes it difficult to understand the inheritance and expression of these quantitative traits. Adoption of appropriate conventional breeding strategies along with genomics tools such as genome-wide association studies, transcriptomics, proteomics, metabolomics and advanced OMICS approaches could prove handy in the development of improved and stress-resistant cultivars. Deeper understanding of the mechanism of tolerance to various stress is required in breeding for improved cultivars. The number of stress-tolerant cultivars is scanty and therefore, holistic management of these stresses through an inter-disciplinary approach could be the most suitable strategy. Adoption of appropriate cultural practices and control measures is necessary for sustainable production under stress regimes. This comprehensive review holds great importance in improving silkworm host cultivation and to researchers in the field of sericulture.