遗传同型交配下母子间基因型联合分布的信息熵性质

定义了遗传同型交配下一对等位基因群体的基因库信息熵和基因型信息熵，给出并讨论了世代交替中母子间基因型联合分布及其信息熵性质。并从信息角度加以解释；最后，应用Matlab软件进行数据模拟，验证了所得结论的正确性。     

Genetic Structure of Melampsora Epitea Populations in Swedish Salix Viminalis Plantations

Amplified fragment length polymorphism (AFLP) was used to study the genetic structure of populations of the willow leaf rust, Melampsora epitea, in Swedish willow plantations. In total, 197 isolates collected from Salix viminalis clones in three locations in Sweden were analysed. AFLP profiles based on 83 markers were used to compute genetic distances between pairs of individuals. High levels of gene and genotypic diversity were detected in all populations, with 96% of the AFLP loci being polymorphic and with normalized Shannon's diversity indices ranging from 0.977 to 1.0. Analysis of molecular variance (AMOVA) showed small significant differences among locations, although most of the molecular variability was found within locations (97.5%). Five isolates from one willow clone in one location differed markedly from the common pattern. When these five exceptional isolates were excluded, no significant differences among willow clones were found with AMOVA. Sexual reproduction and spore migration appear to be important factors for the population genetic structure of this pathogen.     

西林水牛群体的RAPD遗传多样性分析

【目的】了解西林水牛群体的遗传变异和遗传结构,为其辅助标记育种、遗传资源保护及利用提供参考依据。【方法】从广西西林县的8个乡（镇）采集184份西林水牛血样,采用优化后的RAPD技术检测其多态性DNA,统计多态性条带数,并应用Popgene32软件对西林水牛群体的有效等位基因数、Nei氏基因多样性指数及Shannon多样性指数进行分析。【结果】从18条RAPD引物中筛选出8条扩增产物稳定、条带清晰可辨的引物,扩增出的DNA片段分子量为100-1000 bp;从184个样本中共扩增出4968个多态性条带,平均每条引物可扩增出621个多态性条带,多态性频率达60.0%-100.0%,平均为89.7%。西林水牛群体的平均有效等位基因数为1.6745,平均Nei氏基因多样度指数为0.3583,平均Shannon多样性指数为0.5510。【结论】西林水牛群体的遗传变异、遗传分化及遗传多样性均较高,但选育程度较低,育种潜力较大,有待进一步保种和开发利用。     

以湖南和湖北大豆[Glycine max（L.）Merr.]为例分析影响遗传多样性评价的因素

以不同来源大豆种质为材料进行基因组SSR分析，探讨大豆遗传多样性研究方法，旨在为科学评价大豆种质资源提供参考。当取样比例相同时，湖北大豆的遗传丰富度显著高于湖南大豆，但两省大豆遗传多样性指数之间没有显著差异。当取样量相同时，利用随机取样法比较，湖南大豆的遗传多样性显著高于湖北，而利用聚类取样比较，两省大豆的遗传多样性没有显著差异。在遗传多样性指数相同情况下，湖北大豆的遗传丰富度显著高于湖南大豆。取样数与三个遗传多样性评价参数（等位变异数、Shannon指数、He）之间均达到显著和极显著相关。以湖南大豆为例，估算出在大豆SSR遗传多样性分析中，至少需要50~60个样本，即占总体9.0%~10.8%的取样比例，才能代表总体的遗传变异。提出在评价大豆遗传多样性时，应用大豆样本数对其遗传多样性指数计算公式进行修正，建议将Shannon指数计算公式改为H＝－lnN ∑P_i lnP_i (N为样本数)。根据修正公式分析，结果表明，湖北大豆的遗传多样性高于湖南大豆。     

表型同型交配群体的Shannon信息熵和互信息

应用信息论方法研究了在表型同型交配下一对等位基因群体的基因型信息熵和互信息。在表型同型交配下,从随机交配下的平衡状态开始,群体的基因型信息熵逐代减少,但这种减少的趋势越来越慢,最终趋向于零。随着基因型信息熵的减少,群体的遗传多样性程度也越来越小。在表型同型交配下,群体的配子间互信息逐代增加,但这种减少的趋势越来越慢,最终趋向于零。配子间互信息的增加说明,配子间的信息交流程度逐代增加,两性配子间的信息关联程度越来越密切,而这用表型信息关联系数反映会更好。最后应用Matlab软件进行了数学模拟,直观验证了所得的结论。     

Low cost measurement setup based on a piezoelectric microphone for estimating apple bruising using Shannon entropy

This study presents a low cost measurement setup for estimating apple bruise volume during drop impact tests. The proposed measurement system consists of three main stages namely recording impact sound, signal processing, and estimating bruise volume. In the recording stage, the impact sound occurred when striking the apple on the surface was recorded by a piezoelectric microphone into computer. The impact sound was converted into Shannon entropy signals based on the Kernel density approach, and two measurable quantities namely entropy peak and pulse-width time were extracted from Shannon entropy signals in the signal processing stage. In the bruise volume estimating stage, the regression curves that map entropy peak and pulse-width features into bruise volume are estimated using measurements data. To evaluate the performance of the proposed method, we conducted several drop experiments with six different drop heights and two different temperatures (1 and 19 °C). Experimental results showed that bruise volume was exponentially proportional to the entropy peak and it was inversely proportional to pulse-width time as power functions, and all the curves were fitted with coefficients of determination of more than 0.98. Moreover, it was found that colder apples developed less bruise volume then warmer ones.     

云杉天然群体表型性状频率分布及多样性研究

为探索云杉天然群体表型性状的频率分布特征,及其在频率水平上的表型多样性,根据性状值大小分组统计频率,绘制频率分布图,应用频率数据计算各群体的多样性指标值：表型多样度（Dp）和表型Shannon信息指数（Ip）,用多重比较与PCA主成分分析对10个群体分类。频数分布分析结果显示：云杉群体的表型性状数据基本符合正态分布;根据DP和IP对群体排序,按群体多样性从大到小依次为阿坝、卓尼、林坡、铁布、热务沟、黑水、巴西、川盘、大录、小金。多重比较与PCA主成分分析结果表明,云杉10个天然群体可分为3类,其中第1类的小金、热务沟群体的表型频率多样性较低,但性状值较大,位于云杉分布区的南部;第2类的7个群体表型频率多样性较大至中等,性状值较小至中等,位于云杉分布区的中部和北部;第3类的阿坝群体表型频率多样性最大,性状值偏小;DP和IP相关极显著（r=0.995）。     

养殖刀鲚与生长环境菌群PCR-DGGE指纹图谱及多样性分析

为了分析养殖刀鲚体内与生长环境菌群结构,利用PCR-DGGE技术,对养殖刀鲚鳃、胃、肠壁及肠内容物和养殖水体菌群结构进行了初步分析。PCR-DGGE指纹图谱分离显示,42条清晰条带,其中养殖水体(27)、鳃(9)、胃(13)、肠道壁(19)、肠道内容物(18)的香农指数分别为3.037、1.883、2.193、2.825、2.683;养殖水体与刀鲚鳃、胃、肠道壁及肠道内容物分别具有6、9、11、8共有带。UPGMA聚类分析显示,样品3个重复相似度都在95%以上,差异不明显;不同样品之间,养殖刀鲚鳃和胃聚为一支,具有较高的相似度(76%),同时与养殖水体相似度达29%;养殖刀鲚肠道壁和肠道内容物聚为一支,相似度为38%。回收测定所有显示条带,主要包含变形菌、放线菌、拟杆菌、柔膜菌、蓝藻细菌、厚壁菌、梭杆菌及少量未定义菌种。研究表明,PCR-DGGE技术能区分养殖刀鲚主要部位及水体微生物的结构差异和多样性,澄清养殖刀鲚及生长水体微生物区系,可为定植益生菌的开发提供参考。     

相邻位点碱基突变的熵性质

为了在分子水平上探讨2相邻位点碱基突变的熵性质,在双参数模型下建立有限长DNA序列2相邻位点碱基突变的微分方程模型,得出了16种碱基组成的概率随世代变化的函数关系式,证明2相邻位点碱基突变具有保熵性,生物是朝着熵增方向即多样性增加的方向进化的;阐明了在单参数模型下相邻位点碱基突变的熵性质亦是如此;该结论也适用于3个相邻位点以及更多相邻位点碱基突变的情况。并利用Matlab软件进行2相邻位点碱基突变的计算机模拟,直观地验证了所得的理论结果。