不同来源花生品种的ISSR分析及亲缘关系研究

利用13对ISSR引物对28个栽培种花生品种进行PCR扩增,研究这些品种的DNA多态性及其亲缘关系。结果表明,有7对引物检测到明显的多态性,从28个花生品种中扩增出90条带,其中多态性带达到79条,多态性比率为87.8%,平均每个引物可扩增出12.86条带,11.29条为多态性条带。品种间的遗传相似系数值在0.411~0.800之间,平均为0.620。在UPGMA聚类分析简单匹配系数值为0.57处,可把28个花生品种分成3个品种群。由此表明,这些不同来源的花生品种具有较高的DNA多态性,亲缘关系不同。     

柑橘CHS基因序列多态性及表达水平对类黄酮生物合成的影响

查尔酮的合成是类黄酮生物合成途径中的一个关键节点。从10个柑橘种质中克隆了查尔酮合成酶(chalcone synthase,CHS)基因,并对其不同时期的果实和叶片中的类黄酮含量进行了测定,分析了CHS基因的序列多态性与类黄酮含量之间的关系;同时通过qRT-PCR检测了CHS基因在不同种质之间以及同一种质的不同组织间的表达差异。结果表明,柑橘CHS基因的核苷酸序列高度保守,相似度达98%以上。聚类分析表明,CHS氨基酸序列的多态性有物种特异性,而且与类黄酮含量有一定的相关性。CHS基因的表达水平在不同种质、部位及生长发育时期有显著差异,这些差异与类黄酮的含量有显著的相关性,说明CHS基因对类黄酮的生物合成有明显影响。     

结球甘蓝抽薹性遗传规律和QTL定位分析

以早抽薹‘S-1’与晚抽薹‘G-1’为亲本，构建F1、BC1、BC2和F2群体，采用植物数量性状主基因 + 多基因混合遗传模型分析法对结球甘蓝抽薹性状进行遗传分析，并采用SLAF-BSA方法对抽薹时间进行QTL定位分析。结果显示，结球甘蓝抽薹性状是由2对加性—显性—上位性主基因 + 加性—显性多基因遗传控制；主基因 + 多基因平均遗传率是93.41%。共检测到2个QTL，分别为2号染色体上的2.31 ~ 3.09 Mb和33.57 ~ 34.40 Mb，总长度为1.61 Mb。     

Relationship of Icelandic cattle with Northern and Western European cattle breeds,admixture and population structure

ABSTRACT

Icelandic cattle is believed to have been brought from Norway during the settlement of Iceland around AD 870-930. Previous research on genetic relationships has indicated that Icelandic cattle is most related to northern Nordic indigenous breeds. Using single nucleotide polymorphism genotype data from Icelandic cattle and 29 Northern and Western European cattle breeds, we studied relationships and admixture among these breeds, and assessed population structure in Icelandic cattle. Population structure analysis through principal component analysis, estimation of ancestry, and analysis of patterns of population splitting and mixing revealed that Icelandic cattle are most related to three Finncattle breeds (Eastern, Northern and Western Finncattle), and Swedish Mountain cattle. Icelandic cattle has very low levels of admixture. We observed very limited population structure in Icelandic cattle. The observed structure was due to variable sire contributions. Over 1000 years of almost complete isolation has made Icelandic cattle highly genetically distinct from other cattle breeds.     

胡萝卜根中主要类胡萝卜素含量相关QTL的精细定位

以白色的野生胡萝卜‘松滋野生’(Ws)和橘色的栽培胡萝卜品种‘Amsterdam’(Af)为亲本构建的回交重组自交系(BIL)为试材,基于低倍重测序技术开发SNP标记,构建了由1 976个Bin标记组成,包含29 435个SNP标记的遗传图谱。图谱总距离834.28 c M,平均图距0.42 c M。通过对胡萝卜肉质根中类胡萝卜素含量相关QTL分析,在连锁群LG04和LG08中检测到调控α–胡萝卜素、β–胡萝卜素、ζ–胡萝卜素、叶黄素、玉米黄质和总类胡萝卜素含量的主效QTL(M-QTL)2、2、3、2、2和2个,表型贡献率为11.47%~19.18%;另检测到调控α–胡萝卜素、β–胡萝卜素、ζ–胡萝卜素、玉米黄质和总类胡萝卜素含量的上位性QTL(E-QTL)1、1、2、1和1个,表型贡献率为2.50%~3.66%。在M-QTL显著区间内共检索到36个有功能注释的预测基因,其中Dck018297为ζ–胡萝卜素脱氢酶2基因,与调控β–胡萝卜素合成和总类胡萝卜素含量有关;Dck008006为乙烯响应因子2.2的同源基因,与调控α–胡萝卜素、ζ–胡萝卜素合成有关;Dck029898为转录因子b HLH135的同源基因,与调控玉米黄质合成有关。     

Analysis on Genetic Diversity and Phyletic Evolution of mtDNA Cytb Gene in Zhongdian Yak

In order to investigate the genetic diversity and the origin of evolutionary relationship of Zhongdian yak,we analyzed the complete sequence of 15 individuals Cytb gene,its sequence polymorphism was analyzed,and the phylogenetic tree was constructed.The results showed that the length of the nucleotide sequence were 1 140 bp,with nucleotide frequencies of 26.3%,31.8%,13.1% and 28.8% for T,A,G and C,respectively.Three haplotypes were identified of 15 individuals,with 3 polymorphic sites,including two conversions,one transversion,haplotype diversity was 0.2571 and nucleotide diversity was 0.00035.Phylogenetic analysis suggested that Zhongdian yak and Bos mutusc clustered firstly,then gathered with Bison bison,which indicated that there were high genetic similarity and closer genetic relationship,genetic similarity with other cattle genus was relatively low.Combining with the proof of molecular biology and paleontology,the result supported the point that Bos grunniens and Bos mutus were classified as an alone genus in Bovinae.     

2017-2018年吉林部分地区规模化猪场猪细环病毒的遗传变异分析

为了解猪细环病毒（Torque teno sus virus, TTSuVs）在吉林部分规模化猪场的流行及其遗传变异情况。本研究对2017-2018年间，来自吉林地区10家规模化猪场的574份血清样本进行TTSuVs流行情况调查。并根据收地点，对20株TTSuVs进行ORF1全基因序列扩增及遗传变异性分析。结果显示：TTSuV1感染率为35.0%；TTSuV2感染率为63.2%；TTSuV1与TTSuV2混合感染率为30.3％；10株TTSuV1测序株之间的核苷酸同源性为75.7%-94.7%，氨基酸同源性为48.1%-88.2%；10株TTSuV2测序株之间的核苷酸同源性为77.5%-93.7%，氨基酸同源性为70.6%-87.4%；且吉林地区流行的TTSuV1均属于TTSuV1-lb型，而TTSuV2流行情况较为复杂，各种亚型均有涉及。     

Over 40% of 450 registered wheat cultivars (Triticum aestivum) worldwide are composed of multiple biotypes

Many of 450 common wheat cultivars bred and registered during the twentieth century in 12 countries were proved, due to seed-by-seed analysis, to be composed of two or more biotypes differing in their alleles at the gliadin (Gli) loci. These multiple biotypes may be regarded as authentic progeny of the respective parent lines, as evidenced by the gliadin composition of the respective parents. Therefore, the official claim for each cultivar to be uniform is commonly not maintained in practice. The most frequent was a non-uniform cultivar composed of two biotypes differing at one Gli locus, but there were cultivars represented by a large set of related genotypes differing at several Gli loci. The proportion of the multi-biotype cultivars was never less than 15% for a country collection, exceeding 50% in other countries. This proportion differed significantly between neighbouring countries. In Australia, all multi-biotype cultivars were found in eastern states; in the state of Victoria, their frequency was statistically higher than in the rest of the country. The proportion of multi-biotype cultivars among newly-released cultivars decreased with time in Australia and the UK. Thus, the non-uniformity of registered cultivars represents a general and important phenomenon of common wheat as a crop.