Published in Scientific Papers. Series D. Animal Science, Vol. LVII
Written by Valentina CEBOTARI, Ion BUZU
The aim of the research was to identify the degree of heritability of main biological morph-productive characters of Apis mellifera carpatica bees family to streamline the process of genetic improvement of bee populations. The research was performed on the population of experimental bee apiary of the Institute of Zoology of the Academy of Sciences located stationary in a forest glade in the center of the country. It was studied heritability of major morpho-produtive characters such as queen prolificacy, family strength, brood viability, resistance to disease and the amount of honey gathered in the nest. The heritability coefficient of morpho-productive characters was calculated by the method h2 based on determining the genotype correlation of the above mentioned characters at 20 pairs of mother-daughter families. Research results have shown that between homologous characters of mother families and daughter families exist a genotypic correlation at different levels, from below average until strong, depending on selected character and the amplitude of the phenotypic variability of character. It was found that the genotypic correlation between mothers and daughters characters is enough strong at characters with narrow phenotypic variability, such as: disease resistance, queen prolificacy and family strength, and lower at characters with wider phenotypic variability, such as brood viability and the amount of honey gathered in the nest. The amount of genotypic correlation coefficients (rmf) of characters from the first group varies within the limits of rmf = 0.78 ± 0.05 and rmf = 0.85 ± 0.03. The coefficient of heritability (h2) of these characters being also at a high level, in the range of 0.61 to 0.72 having a certitude of the highest threshold of the theory of probability forecasts without error after Student (P < 0.001). At the morpho-productive characters from the second group, such as, the brood viability and the amount of honey gathered in the nest, the genotypic correlation had an average level, comprised within the limits of 0.60 ± 0.09 and 0.56 ± 0.09 with enough high certitude, and the coefficients of heritability of these characters were at below average level, in the range of 0.36 0.31 (P < 0,01). The obtained results of researches of heritability of principal biological morpho-productive characters have been used to elaborate the plan for genetic improvement of bee families and prediction selection effect, calculated by the formula Es = h2 · d, where: Es - selection effect of selected character obtained in a generation; h2- heritability coefficient of selected character; d - the differential of selection, calculated by the formula: d = Mlp - Mst, where: Mlp the average value of selected character on families of bees from the breeding stock; Mst- the average value of the selected character on the bee families from whole apiary. The selection effect of bee families by morph-productive biological characters from first group, with the heritability coefficient (h2) over average, was bigger than the effect achieved in selection of bee families by the characters in the second group, the coefficient of heritability (h2) below average.
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heritability
