Key principles for breeding spring-and-autumn using silkworm varieties: from our experience of breeding 873×874

The successfully breeding of the hybrids 873×874 had settled the problem that the yield was not uniform to the silk quality in silkworm varieties. In this paper, we illuminated the key technology, principle, hints and methods for selection in breeding spring-and-autumn rearing silkworm varieties were analyzed using the procedure of breeding the hybrid of 873×874 as example.