二花脸和大约克猪产仔数主要组分性状的基因效应研究

STUDIES ON GENE EFFECTS OF MAIN COMPONENT TRAITS OF LITTER SIZE IN ERHUALIAN AND LARGE WHITE PIGS

利用二花脸、大约克及其Ｆ１、Ｆ２和回交世代的最小二乘均数，采用多元回归分析程序，对猪的产仔数主要组分性状的基因效应进行了研究。组分性状包括卵巢体积、总卵泡数、未成熟卵泡数、排卵数、卵泡成熟率和妊娠胚胎数。结果表明：加性效应是世代间遗传变异的主导因素。在卵巢体积、总卵泡数和未成熟卵泡数方面，大约克对二花脸加性效应值依次为５．３４８０ｃｍ３，５．３４０２枚和８．０５３９枚；在排卵数、卵泡成熟率和妊娠胚胎数方面，二花脸对大约克加性效应值依次为１．９７４６枚，６．８４１１％和２．６１１４个。大约克在４个性状上呈显性，即卵巢体积、总卵泡数、未成熟卵泡数和妊娠胚胎数，而二花脸仅在排卵数和卵泡成熟率方面呈显性。但显性度除卵巢体积（１．３０２０）和妊娠胚胎数（－０．４８９３）较大外，其余均较小。

Gene effects of main component traits of litter size in pigs were analysed by the least square mulitipleregression procedure, using generation least-squre means of Erhualian (EHL) (one of the strains of Taihu breed),Large White (LW) and their F1,F2 and beckcross (to Large White) pigs. The main comPOnent traits of hit.er size included are volume of ovaries (VO), total follicies (TF), visible follicles unmaturated (VFU), ovulation rate (OR,counts of corpora lutea), follicle maturation rate (FMR) and number of embryos (NE). The results showed that theadditive gene effects are the main factors to cause the genetic variation among these generations. In VO, TF and VFUtraits, LW pigs are superior to EHL by 5. 348 0 cm3, 5. 340 2 follicles and. 8. 0539 follicles in additive effects respectively, while in OR, FMR and acE traits, the additive gene effects of EHL are larger than those of LW by 1. 974 6eggS, 6. 841 1 % and 2. 6114 embryoes respectively. LW pigs are dominant in VO, TF, VFU and NE, and EHLpick are dominant in OR and FMR, but the degree of dominance in most cases is small except VO (1. 302 0) and NE(-0. 4893).