Buletinul USAMV-CN, 62/ 2006 (176-182) ISSN 1454-2382 ESTIMATION OF THE PERFORMANCES OF SOME SILKWORM BOMBYX MORY L. HYBRIDS REARED IN TRANSYLVANIAN CLIMATIC CONDITIONS BenŃea M., L. Al. Marghita, D Dezmirean, Alexandra Matei UNIVERSITY OF AGRICULTURAL SCIENCES AND VETERINARY MEDICINE (UASVM) 1-3 MANASTUR STREET, 3400 CLUJ-NAPOCA ROMANIA FAX +40-264-593792 email: mihaib78@yahoo.com Key words: Bombyx mori L., hybrid, heterosis, cocoon, incartment, silkwire Abstract. The analyze of some Bombyx mori L. (mono, tri and tetra) hybrids concerning five productive parameters weight of crude cocoon, weight of silk incartment, silk percent in cocoon, weight of dry cocoon and length of the silk wire is presented in this paper. In the end of the research the most valuable hybrids from production point of view could be identified. They can be reared in industrial system. The best results were obtained with monohybrids: B1x AC29, ABx AC and AC29x B1; trihybrids: ACx (ABx B1), (ABx B1)x AC and (ACx AC29)x B1 and tetrahybrids: (B75x AC29)x (B1x J90); (B1x J90)x (B75x AC29) and (ABx B1)x (ACx AC29). They were superior compared to other studied hybrids and we recommend these hybrid structures to be reared in both familial and industrial system. INTRODUCTION The mulberry silkworm belongs to Artropodae phylum, Tracheate under phylum, Insecta (Hexapoda) class, Pterigotae under class, Neopterae section, Metamorphae under section, Superior Lepidoptera ordin, Metaheterocerelor or Night Superior Lepidopterae series, Bombycidae family, Bombyx genus, Bombyx mori specie. Long years ago, when the Chineses discovered the natural silk, during domestication of this specie, humans begun to select those larvae capable to produce a higher silk quantity of superior quality. Those larvae were afterwards crossed, producing hybrids. The hybrids resulted from crossings between pure breeds, with other hybrids or from two hybrids are caracterized by variate heterosis, wich influences the quantity of silk from the cocoon. MATERIAL AND METHOD The comparative study of five productive traits (weight of crude cocoon, weight of silk incartment, silk percent in cocoon, weight of dry cocoon and lenght of silk wire) was performed on 6 breeds, four monohybrids, eight trihybrids and four tetrahybrids. brought to you by CORE View metadata, citation and similar papers at core.ac.uk