Diallel cross analysis of filament length in the silkworm, Bombyx mori L.

Abstract

A diallel analysis for filament length in six varieties of silkworm, Bombyx mori L. having a wide range of variability has been genetically analysed by means of 6×6 diallel cross. The results indicated that both additive and non-additive genetic variations were important for determining the expression of this trait. Besides the dominance, deviation of genes present in this diallel existed predominantly in one direction and they were independent of reciprocal effect and some of the parents contained more dominant than recessive alleles in S-1 and S-3. The presence of specific dominance effect which were peculiar to individual crosses and a significant part of it was independent of reciprocal effect. The regression of filament length is deviated significantly from unity in majority of the seasons (except S-4) giving a contrasting result implying the presence of nonallelic interaction. The distribution of genes for two seasons (S-2 and S-3) was not symmetrical, while the rest two seasons (S-1 and S-4) showed symmetrical distribution of positive and negative among the parents. In narrow sense heritability was found to be medium to high and the broad sense heritability was high among the studied varieties.

DOI: http://dx.doi.org/10.3329/jasbs.v38i2.15616

J. Asiat. Soc. Bangladesh, Sci. 38(2): 247-255, December 2012