Abstract:  【Aim】 The objective of this study is to investigate the effects of mixtures of brood pheromone esters on the queen quality of the Chinese honeybee, Apis cerana cerana, reared by queenrearing technology without larvae-grafting, and to find a way to rear high-quality queen. 【Methods】 Queen-rearing technology without larvae-grafting was employed to rear queen of A. cerana cerana. Using a micro sampling syringe injector, 1 μL of mixture of brood pheromone esters with the concentration gradients of 0, 0.1%, 1.0% and 10.0% was added into queen cells, respectively, when the queen larvae were 60-64 h old. The body weight, the weight and width of thorax, the number of ovarioles in one ovary of the newly-emerged queens were tested. And the gene expression levels of vitellogenin (Vg), hexamerin70b (hex70b) and hexamerin110 (hex110) were quantified by qPCR. 【Results】 The results showed that the body weight of the newly-emerged queens of A. cerana cerana was increased significantly (P＜0.05) in the treatments with the mixture of three brood pheromone esters (3E) (1.0% methyl linoleate, 16.0% methyl linolenate, and 35.0% methyl oleate) at all the three concentrations, while the width and weight of thorax of reared queens had no significant change as compared with the control (paraffin oil) (P＞0.05). The number of ovarioles in one ovary was increased significantly (P＜0.05) in 0.1% and 1.0% treatment groups. The expression levels of Vg and hex70b in all 3E treatment groups had no significant change, while that of hex110 in 1.0% and 10.0% 3E treatment groups increased significantly (P＜0.05) as compared with the control. When the queens were reared with the mixture of four brood pheromone esters (4E) (4.5% methyl palmitate, 1.0% methyl linoleate, 16.0% methyl linolenate, and 35.0% methyl oleate), the body weight of the newly-emerged queens and the number of ovarioles in one ovary significantly increased in 10.0% 4E treatment group (P＜0.05), while no significant difference of developmental indexes existed in 0.1% and 1.0% 4E treatment groups (P＞005). The expression levels of Vg in ovaries in 0.1% and 1.0% 4E treatment groups, hex70b in 10.0% 4E treatment group and hex110 in 1.0% and 10.0% 4E treatment groups all significantly increased as compared with the control (P＜0.05). When the queens were reared with the mixture of 10 brood pheromone esters (10E) (4.5% methyl palmitate, 2.5% methyl stearate, 35.0% methyl oleate, 1.0% methyl linoleate, 16.0% methyl linolenate, 3.5% ethyl palmitate, 1.5% ethyl stearate, 18.0% ethyl oleate, 0.5% ethyl linoleate, and 17.5% ethyl linolenate), the body weight of the newly-emerged queens, and the expression levels of Vg and hex110 in ovaries in all treatment groups significantly decreased as compared with the control (P＜0.05), while the number of ovarioles in one ovary and the thorax indexes showed no significant change (P＞0.05). The expression level of hex70b also reduced significantly in 10% 10E treatment group (P＜0.05). 【Conclusion】 To a certain extent, the 1.0% 3E and 10.0% 4E added in queen-rearing process of A. cerana cerana could improve the queen quality.

Key words: Apis cerana cerana, brood pheromone, vitellogenin gene, hexamerin gene, reared queen quality