Bombyx mori L. (silkworm) is of high commercial importance as a silk producer and is also widely used for implementation of basic and applied research. Silkworm are distributed both in temperate and tropical countries. The tropical genotypes (non diapausing) are hardy and can withstand adverse eco-climatic conditions but produce very small quantities of silk of poor quality while the genotypes of temperate origin (diapausing) produce higher quantities of good quality silk. Evaluation of genetic resources is an essential prerequisite for their effective utilization. The presently available linkage map is based on morphological and bio-chemical markers. Biochemical markers resulted in the identification of only one enzyme -amylase. The development of molecular markers will be extremely useful in silkworm improvement programme. The molecular markers such as RFLP, RAPD, SSR, ISSR and AFLP have been successfully used for identification and genetic diversity in silkworm
