Performance Evaluation of Economic Traits of Crossbreeds of Nistari Lines, Improved through Selective Breeding

Abstract

Selective breeding is one of the strategies employed to improve desired traits in silkworm. Cross breeds are developed for enhanced silk productivity. The usage of genetically improved parental lines in crossbreeding programs can enhance raw silk production by enhancing key economic traits—such as cocoon yield, filament length, and silk quality in the resulting cross breed progeny. In West Bengal, crossbreds derived from Nistari lines, predominate the commercial sericultural belts, reflecting their adaptability and superior performance under local rearing conditions. The present study has made an attempt to enhance silk productivity of crossbreeds of Nistari lines, with SK6.7 by employing improved Nistari parental lines. The cocoon weight and filament length of parental Nistari lines were improved by selective breeding coupled with cold reeling for five generations. Crossbred lines derived from improved Nistari lines and SK6.SK7 exhibit enhanced expression of targeted economic traits (cocoon weight, shell weight and filament length), indicating improved performance relative to the crossbreed of unimproved Nistari lines in four different seasons.