HETEROSIS EXPRESSION AND F1 INHERITANCE OF BIOLOGICAL CHARACTERS IN SILKWORM BOMBYX MORI L. SEX LIMITED FOR LARVAL MARKING BREEDS

Diana Arkova-Pantaleeva,, Panomir Tzenov, Jolanta Vasileva

Abstract: A study of hybrids, obtained from four silkworm sex-limited for larval markings breeds (Vratsa 2003, Vratsa 2006, Vratsa 2007 and Vratsa 2012) and two ordinary breeds - Vratsa 54 and Vratsa 55 has been carried out. It was found out that the hybrid Vratsa 2007 x Vratsa 2012 was the best – having high pupation rate and its reciprocal cross Vratsa 2012 x Vratsa 2007 was characterized with the highest egg hatchability. The hybrids Vratsa 2003 x Vratsa 54, Vratsa 2006 x Vratsa 2003 and Vratsa 2006 x Vratsa 55 manifested a fresh cocoon yield by a box of eggs over 40 kg. The hybrids tested exhibited a positive heterosis in F1 for the characters pupation rate and fresh cocoon yield by a box of eggs, compared both to the mid and higher-parent values /MP and HP/. The inheritance in F1 of the characters pupation rate and fresh cocoon yield by a box of eggs is of the type of positive overdominance.

Keywords: biological characters; heterosis; hybrids; sex-limited breeds; silkworm

Date published: 2023-02-01