RESEARCH CONCERNING THE ESTABLISHMENT OF THE BEST SIZE OF RACES POPULATIONS FROM THE GENE STOCK SP. BOMBYX MORI L.

Alexandra Matei, M. Androne, A. Popescu, D. Dezmirean, B. Vlaic

Abstract
The present technique utilized in sericultural genetic resources conservation, provides "in situ" silkworm conservation with the maintenance of small effectives as part of races using the selection based on mainly qualitative criteria (layings aspect and colour, larvae colour, cocoon shape and colour). Paper's aim is establishing the best size of gene stock populations based on quantitative parameters achieved in the conditions of different populations size, and on the other hand the estimation of an actual population size taking as criteria the increase of consanguinization by generation and the real number of males and females. As biological material 6 silkworm races were used: AC 29/T, AB, B1, AC/T, RG 90 si IBV. Adult free pairing was practiced. In the case of populations small actual size utilization, small values of quantitative parameters, conglomerate layings deposit, appearance of malformations at adults, are achieved. Minimum actual size of populations gene stock that allows a distant consanguinization (Df=0.50%) is of 100 individuals (50 females +50 males).

Key words: Bombyx mori L., population size, prolificacy, silk cocoons