家蚕标记基因位点与数量性状基因位点重组参数的最大似然估计法

利用分离世代群体（ＢＣ＿１或Ｆ＿２），估算家蚕标记基因位点与数量性状基因位点重组参数的最大似然估计法，求解似然方程组的ＥＭ迭代算法。通过１２０次计算机模拟和一个生产实例验证了方法的可行性。     

中国粳稻春江06抗白背飞虱的遗传

分析了高抗白背飞虱、对白背飞虱的抗性表现为拒取食性和杀卵作用的中国粳稻春江06和感虫籼稻品种TN1正反交获得的F1和F2代拒取食性和杀卵作用的遗传方式.所有的F1稻株都具有拒取食和杀卵作用.两种抗性在F2代中以3∶1的抗感比例独立分离. 具有拒取食和杀卵抗性的不同组合的4种表现型以9∶3∶3∶1分离.表型分离说明春江06中的拒取食性和杀卵抗性分别受一个显性基因控制.采用常规的杂交方法可以容易地将春江06中的拒取食抗性导入日本粳稻品种日本晴、北陆-153和越光中.     

家系间数量性状主基因效应的分析

具有主基因差异的纯系杂交，其后代家系按主基因型表现为不同类型。本文以似然函数法分析Ｆ３家系资料，提出家系主基因型鉴别，主微基因效应和互作以有主基因显性度的估计和测试方法。应用于籼稻株高和直链淀粉含量两组资料的分析，结果表明，家系间的分离比均符合一对主基因的理论比。两对主基因的增值基因均表现不完全显性，高杆基因对半矮杆基因的显性度估计为０．６７，高直链淀粉含量基因对低直链淀粉含量基因估计为０．３２。     

Fine mapping of quantitative trait loci using linkage disequilibrium in inbred plant populations

Linkage disequilibrium (LD)-based methods capitalize on the number of generations that occurred since the appearance of a mutation at a QTL and can produce extremely accurate estimates of the QTL position. Here, we describe a regression methodology to estimate the effect of marker haplotypes on a quantitative trait for the case of inbred plant populations. The method builds upon probabilities of being 'Identical by Descent' that are obtained via a gene-dropping simulation, where inbreeding is assumed to be due to a single seed descent process. The method was empirically tested via Monte Carlo simulation and results showed that the power to detect the true QTL position depended on the age of the QTL mutation, effective population size and marker distances. Also, increased marker polymorphism dramatically improved power and the method seemed fairly robust to differences in genetic and population assumptions. This revised version was published online in July 2006 with corrections to the Cover Date.     

柳树纤维性状遗传变异的研究

柳树的纤维长与纤维素含量在苗期即有显著差异，其纤维长的遗传变异，无论是在杂种（家系）间，还是在杂种（家系）内无性系间都是显著的。纤维直径和长径比尽管在苗期的差异不显著，但在林期与纤维长一样，无性系间的差异是极显著的。通过杂交组合和无性系选择改良柳树的纤维性状是可行的。无性系内不同年龄间纤维性状的差异是显著的，这为确定纸浆林的轮伐期提供了参考依据。     

撒坝猪繁殖性状的表型和遗传参数分析

对 6个世代共 2 31头撒坝母猪的繁殖性能数据资料进行了分析。在建立混合线性模型的基础上 ,采用HARVEY程序估计了总产仔数、活产仔数、初生窝重、 2 0日龄窝重、 60日龄断奶仔数和断奶窝重等 6个繁殖性状的表型和遗传参数。结果表明 ,撒坝猪繁殖性能在选育过程中有一定程度的提高 ,但速度平缓 ;上述 6个性状的遗传力分别为 0 0 37,0 0 75,0 1 1 1 ,0 1 55 ,0 1 0 3和 0 31 0 ,多为低遗传力性状 ;各性状间的遗传相关介于 0 532～ 0 773之间 ,表型相关和环境相关分别在 0 30 3～ 0 946和 0 442～ 0 972之间     

The presence or absence of the soybean Kunitz trypsin inhibitor as a quantitative trait locus for seed protein content

Numerous quantitative trait loci (QTL) for various characters have recently been reported in different crop plants. However, information is limited about the molecular mechanisms behind QTL, because most of them have only been detected at a statistical level. Therefore, progeny from a cross between two soybean genotypes segregating for the presence vs. absence of the Kunitz trypsin inhibitor, a 21.5 kDa protein, have been analysed for possible effects of that protein on agronomic and seed quality characters. Protein content was reduced by, on average, 4.5 g/kg in segregants lacking the Kunitz protein, whereas oil content and other characters remained unaffected. This finding can be interpreted as a ‘model QTL’ for variation in seed protein content, because the molecular and genetic backgrounds of the soybean Kunitz trypsin inhibitor are well understood.     

闽南火鸡生长特性的研究

本试验观测了闽南火鸡的生长发育特性。应用三种非线性生长模型对闽南公，母火鸡生长曲线进行拟合，估测生长参数，以Von Bertalanffy模型的拟合度最高，公、母火鸡拟合度分别为0．999和0．996，说明此模型较好地反映了闽南火鸡的生长特点，结果表明，公火鸡生长速度明显快于母火鸡，公、母火鸡最大日增重分别为32．99g和19．34g，从60日龄开始公、母火鸡体重差异显著，210日龄公，母火鸡体重分别为5746.5g和2964．3g。成年火鸡体尺性状与体重经相关分析表明，公火鸡的体斜长，胸深，胸宽，龙骨长和体重呈极显著正相关；而母火鸡的体斜长，胸深，胸宽，骨盆宽，胫长和体重呈极显著正相关，以上结果为闽南火鸡的选择育和生长预测提供了科学依据。     

根据麻茎外部特征进行苎麻单蔸选择的回归方程

选择“黑皮蔸”、“芦竹青”种子繁殖后代共20蔸,测定单蔸茎数(x_1)、茎高(x_2)、中部茎径(x_3)、茎上下部粗细均匀度(x_4)、梢径衰减率(x_5)及茎顶粗壮度(x_6)。分别建立了这些参数与单蔸产量(y_1)或单纤维支数(y_2)的回归方程。结果表明,x_1、x_2和 x_3与 y_1为极显著正相关,但与 y_2无关,而 x_5/x_6是作用于单纤维支数的决定性参数。对于育种材料的初步筛选有应用价值。