Abstract: 【Aim】 The Chinese citrus fly, Bactrocera minax, is a devastating pest of citrus. Our study aims to screen out the stably expressed endogenous reference genes in B. minax under specified conditions to assure the reliability of quantitative real-time PCR (qRT-PCR) analysis of target genes. 【Methods】 Ten candidate reference genes were selected for qRT-PCR, and five softwares were adopted to determine the stability of candidate reference genes in different developmental stages (low-instar larva, 3rd instar larva, 1 day-old pupa, 80 day-old pupa, 160 day-old pupa, male adult, and female adult) and body parts of male and female adults (head, thorax, abdomen, and whole body) by analyzing the Ct value. 【Results】 In different developmental stages and body parts of adults of B. minax, the Ct values of candidate reference genes were between 15 and 30. The disparity of the Ct value indicated that the expression levels of genes were different. Based on the comprehensive analysis of stability ranking of candidate reference genes with the five softwares and the optimal reference gene number calculated by geNorm, UBQ, GAPDH and GST were recommended as the reference genes for different developmental stages, and TUB, GAPDH and GST for different body parts of adults. 【Conclusion】 To obtain the precise expression patterns of target genes under specified conditions, the combination of reference genes is suggested to use. Our study is conducive to investigating the target gene expressions in B. minax under specified conditions.

Key words: Bactrocera minax, endogenous reference genes, expression stability, gene expression analysis, quantitative real-time PCR (qRT-PCR)