Correlation Between Main Productive Traits and Possibilities for Predicting F1 Heterosis at Hybridization of Silkworm (Bombyx mori L.) Lines, Genetically Marked by Sex

D. GREKOV
Agricultural University, BG-4000 Plovdiv, Bulgaria

Abstract

GREKOV, D., 2003. Correlation between main productive traits and possibilities for predicting F1 heterosis at hybridization of silkworm (Bombyx mori L.) lines, genetically marked by sex. Bulg. J. Agric. Sci., 9: 381–384

In the period 2000–2002, a study was conducted at the Agricultural University in Plovdiv to establish the correlations between the main productive traits and the possibilities for predicting F1 heterosis at hybridization of Bombyx mori L. lines, genetically marked by sex at the egg- and larval stages. The new original F1 hybrids, involving lines genetically marked by sex at the egg- and larval stages, showed a relatively high heterosis effect in terms of cocoon weight, shell weight and cocoon filament length. The values of these traits in the F1 hybrids increased over the midparent lines by 7.84 %, 0.91 % and 2.35 %, respectively. A highly significant positive correlation (r = + 0.44–0.60) was found between the source lines and their F1 hybrids. Using regression analysis, prediction equations were developed for raw cocoon weight in F1 hybrids (y = 0.825x + 0.613), for cocoon shell weight (y = 0.623x + 0.209) and silk filament length (y = 0.881x + 198.6).

Key words: silkworm, Bombyx mori L., hybrids, heterosis