Yield and yield contributing traits in eri silkworm, Samia ricini (Donovan) in different combinations

Abstract

Six strains of eri silkworm were isolated from Samia ricini (Donovan) on the basis of larval colour and body markings, that is, Yellow plain (YP), Yellow spotted (YS), Yellow zebra (YZ), Greenish blue plain (GBP), Greenish blue spotted (GBS) and Greenish blue zebra (GBZ). The strains were maintained in the germplasm bank up to fifth generation to get the homozygous characters. Finally crossings were conducted among the six strains of eri silkworm based on combining ability test following dialell technique and observed the combining ability effect and heterosis of parental genotype for different character of the seven crosses, viz., YP × GBZ, YZ × GBS, GBZ × YS, YS × GBS, YZ × YS, GBZ × YP, and GBS × GBZ. The obtained data of the above crosses reflected that YZ × YS and GBS × GBZ cross combinations are superior in terms of fecundity, hatching (%), larval weight (g), larval period, cocoon weight (g), shell weight (g), pupal weight (g), shell ratio %, effective rate of rearing %, and absolute silk yield/dfls (g).

Keywords: Eri silkworm, strains, development, combination.