Abstract: : The objective of this study was to investigate the effects of polymorphisms or haplotypes in the 5′ regulatory region (-496~-1 bp) of the vasoactive intestinal peptide type I receptor (VIPR1) gene on broodiness in Qingyuan Partridge chicken, and then to look for the genetic marker inhibiting broodiness. The polymorphisms in the 5′regulatory region of the VIPR1 gene were detected by directly sequencing in 498 Qingyuan Partridge chicken under cage condition. The association between mutation sites and broodiness was analyzed by the least square mean analysis. The PHASE software was used for haplotype association analysis. A total of 12 SNPs were found in -496-1 bp region of the VIPR1 gene. Significant associations (P<0.05) were found between G359T, G266T, A134G, A94G, C72G and duration of broodiness from 18 to 43weekold. A94G was significantly associated with broody frequency (%) from 18 to 54weekold (P<0.05). Haplotypes based on 12 polymorphism sites in -496-1 bp of VIPR1 gene significantly associated with duration of broodiness from 18 to 54weekold (P<0.01). The least square analysis showed that the birds with CCTGGGAAGCAG/TTGGGGAAGCAC had significantly longer duration of broodiness than those with other haplotypes (P<0.01). Markertrait association analysis indicated that genetic marker for chicken broodiness in the 5′ regulatory region of VIPR1 gene may be exist. The individuals with CCTGGGAAGCAG/TTGGGGAAGCAC had a great genetic effect on broodiness in Qingyuan Partridge chicken, which can be a candidate marker for molecular markerassisted selection.

Key words: chicken, VIPR1 gene, 5′ regulatory region, polymorphism site, haplotype, broodiness