Some Characteristics of Bivoltine Silkworm Hybrids Heritability

Abstract

Heritability of cocoon filament production in bivoltine silkworm hybrids was studied using full diallel crossed among PH2, PH3, PH5, PH8, PH9 and PH10. Thirty selected silkworm hybrids and 6 parental lines were assigned in the randomized complete block design with 3 replications. Genetic analysis was done using Griffing (1956) method 1 model 2 and broad and narrow sense heritability. Three consecutive experiments were conducted at Chiang Mai Sericultural Experiment Station in three periods: June-July 1996, September-October 1996 and January-February 1997. Broad sense heritability of sound pupa percentage, good cocoon percentage, single cocoon weight and single cocoon shell weight in period I, II and III was 16.51-44.94, 33.77-50.00 and 46.95-88.91 percent, respectively, and narrow sense heritability was 3.97-33.32, 6.79-24.92 and 12.49-30.41 percent, respectively. One high heritability was found among three experimental periods in terms of broad sense heritability in period III. Therefore, silkworm improvement using some characteristics as indicators should be considered.