Abstract: ObjectiveThe genetic variation of follicle stimulating hormone β subunit(FSHβ)gene in Leizhou black duck population was clarified to provide molecular markers for breeding of Leizhou black duck population.MethodThe polymorphisms of exon2 and intron 1(int1)of gene FSHβ in 200 Leizhou black ducks were detected by PCR-SSCP,and the polymorphic sites(SNPs)were found and sequenced.The correlation between different genotypes and egg production traits of Leizhou black ducks was analyzed.ResultA single nucleotide mutation site(A→T)was found at g.1103451A>T (int1)of gene FSHβ in Leizhou black duck.There were three genotypes(AA,AT and TT).The corresponding genotype frequencies were 0.538,0.359 and 0.103 respectively.The frequency of T allele(0.718)was higher than that of allele A (0.282),and g.1103451A>T locus was in Hardy-Weinberg equilibrium(P>0.05)in Leizhou black duck population.Age at first egg of TT genotype was the earliest,followed by AT genotype,which were 5.48 and 4.00 d earlier than AA geno-type respectively,and the difference reached significant level(P<0.05,the same below).In terms of weight at first egg and egg production at 300 day-age,TT and AT individuals were also significantly higher than those of AA individuals,and TT individuals were the highest(1299.31 g/feather and 134.37 eggs respectively).The rest of the egg production traits in each genotype were not significantly different between the individuals(P>0.05).ConclusionThere is a SNP lo-cus(g.1103451A>T)in int1 of Leizhou black duck gene FSHβ,which has significant correlation with its egg production performance.It mainly promotes early egg laying and growth,hence it may be assisted-selection molecular markers for Leizhou black duck breeding.