【作者】 宣凤苓；

【导师】 李祥龙；

【作者基本信息】 河北农业大学 ， 动物遗传育种与繁殖， 2010， 硕士

【摘要】 河北柴鸡具有体型小、耐粗饲、适应性强、抗病力高、遗传性能稳定等品种特征,是河北省宝贵的地方品种资源。本研究利用软件SPASS15.0对河北柴鸡的产蛋性能、屠宰性能以及蛋品质进行了多重比较和相关分析,目的在于检验河北柴鸡的选育效果。同时,以MHC B-G基因作为影响家禽生产性能的候选基因,采用PCR直接测序的方法,对河北柴鸡的黑羽、灰麻、黄麻和白羽四个色系,以及海兰褐和罗曼褐两个配套系红羽鸡B-G基因的外显子2和部分内含1序列进行了单核苷酸多态性（SNP）筛查、遗传多样性分析和氨基酸多态性分析,以探讨B-G基因在河北柴鸡中的变异情况,从而为河北柴鸡选育提供参考依据。河北柴鸡一世代43周龄产蛋量遗传力估计和合并选择指数制定结果表明,河北柴鸡一世代43周龄产蛋量的遗传力估计值为0.132,显著性检验结果不显著；计算得到合并选择指数公式为I=P+7.44Pf,求出每个个体的指数范围在50.314～105.857之间,为种母鸡的选留提供了依据。产蛋率和蛋重比较结果表明,经过三个世代的选育,河北柴鸡二、三世代的产蛋高峰维持时间明显延长、羽色间生产性能更趋于一致。开产日龄、开产体重、300日龄蛋重、300日龄产蛋量和6周龄的比较结果表明,300日龄产蛋量有了极显著提高（P<0.01）；三世代的开产体重明显高于一、二世代。在体尺和屠宰性能的因子分析结果中,经相关系数矩阵的特征根比较,共提取了5个公因子,分别为factor-1（屠体重、活体重、胸深、胫围、体斜长、龙骨长和胸宽）、factor-2（全净膛率和半净膛率）、factor-3（骨盆宽、翅膀率、腹脂率和胫长）、factor-4（胸角）和factor-5（腿肌率和胸肌率）,这五个公因子共解释了原始变量的87%的方差；利用最小二乘法分析固定效应对上述各因子的影响结果显示,羽色对屠宰性能影响不显著（P>0.05）,但在公母鸡间差异极显著（P<0.01）；通过人工选育后,体尺和屠宰性能的各指标较零世代均有了极显著提高,为今后柴鸡育种工作提供了可靠的理论依据。蛋品质的相关分析结果显示,血肉斑与蛋壳强度和蛋壳厚度呈极显著的正相关,与哈氏单位和蛋壳比率呈极显著的负相关；蛋黄颜色与蛋壳厚度和蛋壳强度呈极显著的负相关（P<0.01）,与哈氏单位呈极显著的正相关（P<0.05）；蛋壳比率与蛋重和蛋形指数呈显著负相关（P<0.05）,与蛋比重呈极显著的正相关（P<0.01）。蛋品质的比较结果显示,经过人工选育后,河北柴鸡三世代的蛋壳强度和哈氏单位较二世代都有了极显著（P<0.01）提高,血肉斑明显减少,极大地增强了柴鸡蛋的市场竞争力。利用PCR产物直接测序法,在所有分析的鸡B-G基因片段中共筛查到36个SNPs,其中,有两个SNPs位点（g.863C>A和g.957C>A,相对于序列号NC₀06103）只存在于河北柴鸡中,在两个配套蛋鸡中没有发现；各群体遗传多样性分析结果表明,河北柴鸡各色系的单倍型多样性（0.928～0.949）、核苷酸多样性（0.024～0.027）和平均核苷酸差异数（10.716～13.061）都明显高于海兰褐（0.806、0.022、10.345）和罗曼褐（0.711、0.024、10.947）,表明河北柴鸡具有丰富的遗传多样性。根据210个个体的氨基酸序列比对发现了20个鸡B-G基因的非同义替换位点,即位点36、37、48、59、61、65、68、69、75、76、78、81、89、92、95、96、106、109、116和122（相对于序列号NP 001025844.1）。其中,在所研究的6个群体中都发生了Iie48Asn、Arg68Ser、Leu69Ser、Leu75Gln、Val89Glu、Gly92Glu、Gly96Glu、Tyr109Ser的突变；位点36、81、106和116的突变只发生在河北柴鸡中,在两个配套系蛋鸡群体中没有发现,同时,位点78在河北柴鸡中的突变率显著（P<0.05）高于两个配套系品种。更多还原

【Abstract】 As one excellent indigenous breed from Hebei province, Hebei Domestic chicken has many good characteristics, such as small size, remarkable adaptability to rearing under rudimentary conditions, stable heredity, excellent meat flavor, high nutritional value, and especially robust resistance to disease. In order to inspect the selection effect on Hebei Domestic chicken, SPASS15.0 was used to do multi-comparison and association analysis on its laying performance, slaughter performance and egg quality. Meanwhile, as a candidate gene affecting poultry production performance, MHC B-G gene was analyzed in this study. With the method of PCR amplification and directly sequencing, screening of Single Nucleotide Polymorphism （SNP）, genetic diversity analysis and amino acid polymorphism analysis were done in exon 2 and partial intron 1 of MHC B-G gene of Hebei Domestic chicken with four plumage color strain （black, gray plumage color with black spots, yellow plumage color with black spots and white） and two red plumage color commercial chicken （Hy-Line Variety Brown and Lohmann Brown）, so the variation of B-G gene in Hebei Domestic chicken could be enunciated as one reference for breeding of Hebei Domestic chicken new strain.Study on egg production heritability and combined selection index for forty-three week-old egg number of Hebei Domestic Chicken showed that that the egg production heritability of forty—three week—old of Hebei domestic chicken was 0.1323, without significant difference. The formula of combined selection index of the first generation was I=P+7.44Pf. And the combined selection index of each chicken was ranged from 50.314 to 105.857, providing the basis for selection and mating of Hebei domestic chicken.Comparison of laying performance showed that after selection of three generations, Hebei domestic chicken presented significant difference in laying performance:obvious extension of laying peak duration, more uniform production performance among different plumage color strain, significant increase of egg production at day 300 （P<0.01）.In factor analysis for body size and slaughter production, a total of 5 common factors were extracted via comparison of characteristic roots of correlation coefficient matrix or covariance matrix. Factor-1 included carcass weight, live weight, chest depth, shank girth, body steep length, keel length and chest width; factor-2 included whole net carcass rate and semi net carcass rate; factor-3 included width of pelvis, wing percentage, fat ratio and shank length; factor-4 was chest angle; factor-5 included leg muscle rate and breast muscle rate. These five factors accounted for 87% of primitive variance. With the help of least square method, we analyzed the fixed effects on each of the aforementioned factor, which showed that plumage color had no significant effect on slaughter production （P>0.05）, but there was extremely significant difference between cocks and hens （P<0.01）. After artificial selection, each index for body size and slaughter production got one extremely significant improvement, providing reliable theoretical basis for future breeding of Hebei domestic chickens.Comparison and correlation analysis of the egg quality showed that flesh and blood spots had extremely significant positive correlation with eggshell strength and eggshell thickness, and had extremely significant negative correlation with haugh unit and eggshell ratio; yolk color had extremely significant negative correlation with eggshell thickness and eggshell strength （P<0.01）, but had significant positive correlation with haugh unit （P< 0.05）. Eggshell ratio had significant negative correlation with egg weight and egg shape index （P<0.05）, had extremely significant positive correlation with egg ratio （P<0.01）. Comparison of the egg quality showed that after artificial selection, the third Hebei domestic chicken generation got an extremely significant improvement （P<0.01） in eggshell strength and haugh unit, and a significant decrease in flesh and blood spots, bringing them tremendous competitiveness in domestic egg market.36 SNPs were detected within the partial B-G gene （encompassing exon2 and partial intron 1） in all analyzed populations by direct sequencing of PCR amplification product, and only 2 novel SNPs （g.863C>A and g.957C>A, based on NC₀06103） were found in Hebei Domestic Chicken. The genetic diversity analysis indicated that the haplotype diversity （0.963～0.995）, the nucleotide diversity （0.024～0.027） and the average number of nucleotide differences （10.716～13.061） within each color strain of Hebei Domestic Chicken were all significantly greater than that of Hy-Line Variety Brown （0.942、0.022、10.345） and Lohmann Brown （0.873、0.024、10.947）, indicating their rich genetic diversity.Alignment of the amino acid sequences form 210 individuals detected 20 nonsynonymous substitutions in total （site 36、37、48、59、61、65、68、69、75、76、78、81、89、92、95、96、106、109、116 and 122, based on NP₀01025844.1）. Among the 20 substitutions mentioned above, eight （Iie48Asn、Arg68Ser、Leu69Ser、Leu75Gln、Va189Glu、Gly92Glu、Gly96Glu、Tyr109Ser） existed in each of the six analyzed populations. Except for substitutions at site 36,81,106 and 116, which only existed in Hebei Domestic chicken, the rest ones were found in all the analyzed populations. Meanwhile, variation rate of site 78 in Hebei Domestic chicken was higher than that in the two commercial chickens, with significant difference under chi-square test （P<0.05）.更多还原