A molecular tool for parentage analysis in the Mediterranean mussel (Mytilus galloprovincialis)

Estimation of selection response and genealogical tracing in family mixtures require an appropriate tool for parentage analysis. In this study, we tested 19 marker loci for parentage analysis allocation in Mediterranean mussel (Mytilus galloprovincialis). To this aim, we reared families in tanks isolated from wild mussel seed, analysed them using the 19 marker loci and characterized their performances based on Mendelian rules. Probabilities of exclusion of a false parent were estimated for different groups of loci and contrasted to the real paternity assignment. Based on this, we chose nine microsatellites with the highest exclusion probabilities and a real paternity assignment of 99.6%. Next, we analysed 600 individuals reared as in the usual production process, where contamination from wild seed is likely. We obtained a real assignment of 94.7% and were able to identify individuals from the wild as the most likely hypothesis to explain the observed incompatibilities with candidate parents. This information was used to evaluate parental contribution in offspring obtained from gamete mixtures of several parents, which bestowed results of interest for future breeding programs of Mediterranean mussel.     

微卫星DNA技术用于中国对虾家系构建中的系谱认证

用6个微卫星标记对中国对虾（Fenneropenaeus chinensis）的5个家系进行系谱鉴别和遗传多样性研究。6个微卫星位点中有5个位点是多态的，并在所有家系中都显示了高度的遗传差异。5个家系中，5个多态微卫星位点共发现了30个等位基因，每个位点的等位基因数在5～8之间。实验中共发现了4个家系特异性等位基因：2^#家系及4^#家系各1个，5^#家系2个。根据已知亲本及子代基因型，可推断出5个家系中全部亲本的基因型，据此鉴别各家系。在EN0033位点，可将5#家系与其他4个家系相区别；在RS0859位点，可将3^#和4^#家系与其他3个家系相区分。因此，EN0033和RS0859标记可用于鉴别5^#、3^#和4^#家系的家系特异性标记。研究表明，用5个微卫星标记，且最少用2对微卫星标记即可鉴别5个中国对虾家系。     

利用STR位点进行牛亲子鉴定的研究

为利用STR分型技术进行牛亲子鉴定,运用PCR技术用TGLA227、BM2113、TGLA53、ETH10、SPS115、TGLA126、TGLA122、INRA23、ETH3、ETH225、BM1824共11个STR(短串联重复序列)基因座对争议小牛、1号嫌疑母牛、2号嫌疑母牛的DNA进行扩增,扩增产物经遗传分析仪检测,检测结果用GeneMapper片段分析软件分析。鉴定结果可以排除1号母牛与争议小牛间具有亲子关系,不排除争议小牛与2号母牛间具有亲子关系。结果表明:STR基因分型技术能够准确、快速地进行牛亲子鉴定,该研究所用的STR位点具有较高的鉴别效率。     

利用微卫星标记鉴定德州驴亲子关系

试验旨在建立一套适用于德州驴亲子关系的鉴定体系。选取13个微卫星基因座作为标记,采集了53头德州驴血液样本,其中子代驴驹16头,候选父本13头,候选母本24头,用酚-仿法抽提血液基因组进行PCR扩增和基因扫描,并利用Peak Scanner Software v1.0软件读取基因型分型结果。对微卫星基因座的遗传多样性进行分析,利用似然法（Cervus 3.0软件）和排除法对个体间的亲子关系进行了鉴定。结果显示,13个微卫星基因座的平均等位基因数、平均观测杂合度（Ho）、平均期望杂合度（He）和平均多态信息含量（PIC）分别为6.846、0.689、0.671和0.625。期望杂合度与观测杂合度之差在0.002~0.088之间,差值较小。13个微卫星基因座的累计排除概率（EP）达到0.990以上。微卫星基因座具有高度多态性和较高的排除概率,适用于遗传分析和个体鉴定。利用Cervus 3.0软件基于似然法分析得到了16头子代驴驹的最似亲本,结合排除法对这16头驴驹及其最似亲本进行基因型比对,最终在53头德州驴中确定了11个亲子对。本试验建立了以13个微卫星位点作为核心标记,将似然法和排除法相结合作为主要分析方法的德州驴亲子关系鉴定体系,为育种工作提供参考资料。     

建国以来山东省小麦品种及其亲本的亲缘系数分析

 【目的】探讨山东省小麦品种的遗传多样性。【方法】对山东省建国以来历经9次更换的66个小麦品种的2145个组合进行了亲缘系数(coefficient of parentage, COP)分析。【结果】67.44％品种组合间存在亲缘关系，所有品种COP值变异范围为0.00～0.8203，平均为 0.06249，系谱亲缘系数高于平均值的占21.53％。随着时间的推移，各个年代之内品种间亲缘系数有逐渐增大的趋势，到90年代有所降低，然后又再增大。各年代内品种的亲缘系数普遍高于年代间品种的亲缘系数。早期的品种与以后年代的品种间的亲缘系数较小，中期和近期品种与以后年代的品种间的亲缘系数较大。同一个年代的品种，对后代的遗传贡献率，则随着年代的推移而逐渐减小。对品种间COP值按WAP法进行了聚类分析，除徐州438、齐大195、烟农78在COP为0处单独聚在一起外，其余63个品种可以聚为6个大类群，大多是同一年代的品种聚在一起，体现了不同年代的特点。山东省历史上年种植面积较大或推广时间较长的17个小麦品种，大都是较早利用引进亲本进行组配选育而成，亲本的亲缘系数较小，遗传差异较大。从系谱上看，山东省小麦的种质资源可基本上追溯到碧玉麦、Villa Glori(中农28)、洛夫林系、蚰子麦等四大骨干亲本体系。【结论】自50年代以来，品种间的遗传差异日趋狭窄，遗传多样性逐渐降低。     

微卫星DNA标记在蓝狐单亲亲权鉴定中的应用

主要探讨微卫星DNA标记在蓝狐(Alopex lagopus)单亲亲权鉴定中的可行性,为蓝狐育种的系谱精确鉴定提供依据。选择15个多态信息含量较高的微卫星DNA位点,以6窝蓝狐(母本6只,子代61只)为试验材料,计算15个基因座位的等位基因频率、杂合度(H)、多态信息含量(PIC)、非父排除概率(EP)、累积非亲排除概率(CCE)、亲权指数(PI)和亲权相对机会(RCP)。结果表明:15个微卫星位点的累积非亲排除概率值(CCE)为0.999996。单亲鉴定的PI值为850.5213~966160,RCP为99.8826%~99.9999%。说明所选的15个微卫星位点可用于蓝狐单亲亲权鉴定,其判定成功率和准确率较高,结果可靠。     

DNA profiling of pineapple cultivars in Japan discriminated by SSR markers

We developed 18 polymorphic simple sequence repeat (SSR) markers in pineapple (Ananas comosus) by using genomic libraries enriched for GA and CA motifs. The markers were used to genotype 31 pineapple accessions, including seven cultivars and 11 breeding lines from Okinawa Prefecture, 12 foreign accessions and one from a related species. These SSR loci were highly polymorphic: the 31 accessions contained three to seven alleles per locus, with an average of 4.1. The values of expected heterozygosity ranged from 0.09 to 0.76, with an average of 0.52. All 31 accessions could be successfully differentiated by the 18 SSR markers, with the exception of ‘N67-10’ and ‘Hawaiian Smooth Cayenne’. A single combination of three markers TsuAC004, TsuAC010 and TsuAC041, was enough to distinguish all accessions with one exception. A phenogram based on the SSR genotypes did not show any distinct groups, but it suggested that pineapples bred in Japan are genetically diversed. We reconfirmed the parentage of 14 pineapple accessions by comparing the SSR alleles at 17 SSR loci in each accession and its reported parents. The obtained information will contribute substantially to protecting plant breeders’ rights.     

华南地区常规籼稻主栽品种间亲缘系数分析

品种间亲缘系数是研究作物品种间遗传关系和遗传多样性的重要方法.对华南地区不同年代育成的常规籼稻主栽品种的亲缘系数进行了分析.结果显示,近50年来华南地区基于亲缘系数的水稻品种遗传多样性呈"W"型变化,3个高点分别出现在1957年前、1970—1979年和2000—2008年,3个低点分别出现在1957—1969年和1980—1989年.基于亲缘系数的品种聚类结果较直观地反映了近50年来华南地区籼稻品种的遗传关系及其品种演变特点,与该地区不同时期主要围绕着少数几个骨干亲本进行品种改良的特点相吻合.本研究获得的华南地区近50年来水稻品种遗传多样性呈"W"型变化这一结果说明,基于品种间亲缘系数的华南地区品种遗传多样性未经历持续的下降或上升,而是在一定范围内波动.     

Parentage analysis of huyou (Citrus changshanensis) based on internal transcribed spacer sequences

Huyou (Citrus changshanensis K. S. Chen et C. X. Fu) citrus is a natural hybrid with unidentified parents. Previous studies have hypothesized that pummelo and sweet orange might be parents, which contradicts the higher freezing resistance of huyou citrus than both the assumed parents. In this study, the parental analysis was based on internal transcribed spacer (ITS) sequences of huyou as well as six candidate parents: three mandarins, one sweet orange, one sour orange and one pummelo. Two different ITS1 sequences, with eight variable sites within the 250 bp region, were observed for huyou, which were identical only to that of sour orange and pummelo, respectively. The results indicated that huyou is most likely a hybrid between sour orange and pummelo. In addition, the application of ITS1 sequences in the phylogenetic analysis of citrus was discussed.     

Comparison of molecular markers and coefficients of parentage for the analysis of genetic diversity among spring bread wheat accessions

The comparison of different methods of estimating genetic diversity could define their usefulness in plant breeding and genetic improvement programs. This study evaluates and compares the genetic diversity of 70 spring wheat accessions representing a broad genetic pool based on molecular markers and parentage relationships. The sample was composed of 32 accessions from the International Maize and Wheat Improvement Center (CIMMYT) and 38 from other breeding programs worldwide. Eight AFLP-primer combinations and 37 pairs of SSR primers were used to characterize the accessions and the Coefficients of Parentage (COP) were calculated from registered pedigrees. The average genealogical (COP) similarity (0.09 with a range of 0.0–1.0) was low in comparison to similarity calculated using SSR markers (0.41 with a range of 0.15–0.88) and AFLP markers (0.70 with a range of 0.33–0.98). Correlation between the genealogical similarity matrix (excluding accessions with COPs = 0) and the matrices of genetic similarity based on molecular markers was 0.34≤r≤0.46 (p <0.05). It is concluded that AFLP and SSR markers are generally in agreement with estimates of diversity measured using COPs, especially when complete pedigree data are available. However, markers may provide a more correct estimate due to some unrealistic assumptions made when calculating COPs, such as absence of selection. Furthermore, both COP and marker distances indicate that CIMMYT accessions are different from the worldwide group of accessions. This revised version was published online in July 2006 with corrections to the Cover Date.