卷丹百合远缘杂交及杂种后代的鉴定

为培育抗性强、观赏性优良的卷丹百合新种质,采用液体培养基悬滴法测定3个观赏百合品种‘Black stone’‘Tresor’‘Sorbonne’ 的花粉生活力;用蕾期授粉、正常授粉、延迟授粉、切割柱头授粉方式分别与母本卷丹百合进行杂交,对获得的杂交后代进行胚珠培养及增殖扩繁,采用SSR分子标记的方法鉴定杂种的真实性。结果表明：‘Sorbonne’的花粉萌发率总体高于‘Black stone’和‘Tresor’;蕾期授粉的结实率最高,为14.44%;卷丹בBlack stone’ 组合获得蒴果数量最多,共得到了17个蒴果;对杂交蒴果进行胚珠培养,得到9株F1代杂种苗;筛选杂种苗增殖扩繁的较适培养基为MS+30 g/L蔗糖+0. 1 mg/L NAA+1 mg/L 6–BA+8 g/L琼脂;鳞茎膨大生根较适培养基为MS+80 g/L蔗糖+0.1 mg/L NAA+ 0. 05 mg/L 6–BA+0.75 g/L活性炭+6.5 g/L琼脂,最适培养环境为黑暗培养;通过4对引物鉴定证实卷丹בTresor’的2个杂种株系为真实杂种。     

243份云南普通小麦地方品种抗条锈病鉴定及分子标记检测

【目的】小麦条锈病由条形柄锈菌小麦专化型（Puccinia striiformis. f. sp. tritici,Pst）引起的气传性真菌病害,是世界范围内最具破坏性的小麦病害之一。发掘抗病资源和培育抗病品种是防治条锈病最经济有效的措施。通过鉴定和评价云南小麦地方品种对中国当前流行的条锈菌生理小种的抗性水平,综合分析可能携带的抗条锈病基因,为小麦抗病育种提供理论依据。【方法】利用当前中国小麦生产上毒性强、流行频率高的条锈菌生理小种CYR32和CYR34对243份云南小麦地方品种进行苗期抗病性鉴定,成株期使用CYR32、CYR33、CYR34和贵农致病类群等混合生理小种进行抗性鉴定,并利用小麦生产上重要抗条锈病基因Yr5、Yr10、Yr15、Yr18、Yr26、Yr28、Yr29、Yr30、Yr36、Yr39、Yr41、Yr48、Yr65、Yr67、Yr80和Yr81的紧密连锁标记对供试材料进行分子检测。【结果】在243份小麦材料中,18份种质对CYR32表现苗期抗性,32份种质对CYR34表现苗期抗性,对CYR32和CYR34均表现苗期抗病的有8份,占3.29%。结合苗期和成株期抗性鉴定,174份地方种质表现为稳定的成株期抗性,占71.6%,其中105份种质高抗条锈病。分子检测结果显示,携带Yr10、Yr18、Yr29、Yr30、Yr65和Yr81抗性基因的材料分别有48、44、4、6、4和101份。同时携带2、3和4个抗性基因的材料各有34、4和1份。所有供试材料均未检测到Yr5、Yr15、Yr26、Yr28、Yr36、Yr39、Yr41、Yr48、Yr67和Yr80。此外,74份地方种质未检测到以上所有抗性基因,其中58份具有成株期抗性,可能携带其他已知或新的条锈病抗性基因。【结论】云南小麦地方品种作为中国特有的小麦种质资源,具有优良的条锈病抗性。243份供试小麦品种对当前条锈菌流行小种抗性水平整体偏高,筛选得到174份具有稳定抗性的地方种质,同时有74份可能携带其他已知或未知的抗性基因,可作为进一步挖掘抗条锈病新基因或QTL的亲本来源。     

基于新遗传连锁图谱的豇豆抗豆象QTL定位

【目的】豆象是危害豇豆最主要的仓储害虫。发掘豇豆抗豆象基因为抗性品种的选育,以及减少豆象对豇豆生产的危害奠定基础。【方法】以中豇1号（感）和Pant-lobia-1（抗）为亲本构建的包含282个株系的RIL群体为研究材料,利用人工接种法分别对282个株系接种绿豆象和四纹豆象,进行抗豆象表型鉴定,并利用两亲本对3 992个来源于绿豆、小豆和豇豆的SSR标记进行多态性筛选,然后利用筛选到的多态性标记对282个株系进行基因型分析,最后结合RIL群体各株系抗豆象表型鉴定数据和基因型分型数据,采用完备区间作图法（ICIM-ADD）进行抗豆象QTL定位分析,在此基础上构建遗传连锁图谱,并定位豇豆抗豆象基因。【结果】中豇1号和F₁籽粒的被害率均为100%,Pant-lobia-1籽粒的被害率分别为22.5%和42.5%。推测Pant-lobia-1对绿豆象和四纹豆象的抗性均为隐性遗传;筛选到182个多态性标记,利用这些多态性标记构建了一个包含11个连锁群的豇豆遗传连锁图谱,图谱总长1 065.23 cM,相邻标记间平均遗传距离为5.85 cM;经2种豆象处理,分别在连锁群1和连锁群5上检测到2个稳定的QTL位点,暂定名为vubr1-1和vubr5-1,其中vubr1-1位于标记XD11-44和HAAS_VR_2274之间,标记间的遗传距离为7.6 cM,在2种豆象处理中分别可以解释表型变异的7.16%和6.92%;vubr5-1位于标记XD1-14和CP185之间,标记间的遗传距离为2.90 cM,在2种豆象处理中分别可以解释表型变异的6.96%和6.37%。【结论】构建了一个包含11个连锁群、182个多态性标记的豇豆遗传连锁图谱,检测到2个与抗豆象相关的QTL位点。     

基于SSR标记对65份大白菜自交系的聚类分析

以65份自育的大白菜自交系为试验材料,进行多样性分析和类群划分。利用26对SSR分子标记分析供试材料遗传多样性,并利用SSR分子标记聚类方法进行大白菜自交系的组群划分研究。SSR标记多样性分析表明,平均Nei基因多样性指数为0.541 5,平均Shannon多态性指数为0.913 5,说明供试材料有较高的遗传多样性。SSR分子标记聚类将65份大白菜自交系划分为5个类群。SSR标记聚类结果真实地反映了种质资源内在基因组的多样性,可以将系谱来源相同的材料聚类在同一类群,对于杂种优势预测和亲本选择均有指导意义。     

基于 SSR 标记的广东含笑等 11 个 含笑属物种亲缘关系研究

【目的】含笑属植物是我国南方地区重要的园林绿化和用材树种,但目前种间的遗传关系尚不明确,以开发高效的基因分型手段进行各物种亲缘关系研究,可为含笑属的保护和开发利用提供理论和技术支撑。【方法】以广东含笑等11个物种为研究材料,筛选高多态性SSR引物,利用基于M13序列的荧光标记方法获取基因分型数据,计算遗传多样性参数,并利用Neighbor-Joining(NJ)方法构建进化树,分析种间的亲缘关系。【结果】12对SSR引物均具有较高的多态性,扩增成功率为90.9%,可以高效地完成基因分型,12个标记的平均等位基因数为8.17;Shannon多样性指数(I)平均值为1.836;观测杂合度(Ho)、期望杂合度(He)和多态信息含量(PIC)的平均值分别是0.365、0.839和 0.796。聚类分析结果显示,分属不同亚属的物种在NJ进化树上可以被明显区分开来,其中后生含笑亚属物种被聚类在两个主要分支上,含笑亚属的3个物种被聚类在一个主要分支上,亲缘关系分析结果与以往的分类学研究结果一致。【结论】SSR标记基因分型体系可以较好地完成广东含笑等11个物种的基因分型,在未来的杂交亲本评选、亲本选配和杂交子代亲缘关系鉴定等方面均可以发挥重要作用。     

Identification of Co-dominant SSR Markers Associated with Genes Controlling α′-and α-subunit-null β-conglycinin Phenotypes in Soybean (Glycine max (L.) Merr.)

Studies have shown that the three subunits of β-conglycinin are the main potential allergens of soybean sensitive patients.And β-conglycinin has adverse effects on nutrition and food processing.So solation and production of lines with lower β-conglycinin content has been the focus of recent soybean breeding projects.Soybean lines with deficiency in one or all subunits of β-conglycinin have been obtained.An effective and rapid system to identify such mutations will facilitate genetic manipulation of the β-conglycinin subunit composition.Here,two segregating F_2 populations were developed from crosses between Cgy-1/cgy-1 (CC),an α′-lacking line (Δα′),and DongNong 47 (DN47),a wild-type (Wt) Chinese soybean cultivar with normal globulin components,and Cgy-2/cgy-2 (CB),an α-lacking line (Δα),and DN47.These populations were used to estimate linkage among the cgy-1 (conferring α′-null) and cgy-2 (α-null) loci and simple sequence repeat (SSR) markers.Seven SSR markers (Sat_038,Satt243,Sat_307,Sat_109,Sat_231,Sat_108 and Sat_190) were determined to co-segregate with cgy-1,and six SSR markers (Satt650,Satt671,Sat_418,Sat_170,Satt292 and Sat_324) co-segregated with cgy-2.Linkage maps being composed of seven SSR markers and cgy-1 locus,and six SSR markers and the cgy-2 locus were then constructed.It assigned that the cgy-1 gene to chromosome 10 at a position between Sat_307 and Sat_231,and the cgy-2 gene to chromosome 20 at a position between Satt650 and Satt671.These markers should enable map-based cloning of the cgy-1 and cgy-2 genes.For different subunit-deficiency types[α′-null,α-null and (α′+α)-null types],the two sets of SSR markers could also detect of polymorphism between three normal cultivars and seven related mutant lines.The identification of these markers is great significance to the molecular marker-assisted breeding of soybean β-conglycinin subunits.     

豫玉22玉米杂交种子纯度的SSR和SNP分子比较鉴定

为研究豫玉22玉米杂交种子的SSR和SNP两种分子标记纯度鉴定方法,为快速有效鉴定玉米种子纯度提供依据。采用SSR荧光标记法和SNP分子标记的KASP技术对豫玉22玉米杂交种子进行基因组DNA提取、引物筛选、基因型分析、纯度鉴定。豫玉22的SSR特异性引物为umc2007y4和bnlg161k8,纯度鉴定结果为97.92%。SNP特异性引物MaSNP64和MaSNP245纯度鉴定结果是98.44%。SSR和SNP分子标记鉴定豫玉22玉米杂交种子纯度的最佳方法,为拓展玉米杂交种纯度鉴定方法具有指导意义。     

Prevalence of antimicrobial resistance in enteric Escherichia coli from domestic pets and assessment of associated risk markers using a generalized linear mixed model

Antimicrobial resistance (AMR) is a growing global public health problem, which is caused by the use of antimicrobials in both human and animal medical practice. The objectives of the present cross-sectional study were as follows: (1) to determine the prevalence of resistance in Escherichia coli isolated from the feces of pets from the Porto region of Portugal against 19 antimicrobial agents and (2) to assess the individual, clinical and environmental characteristics associated with each pet as risk markers for the AMR of the E. coli isolates.     

A Polymorphism in the Melanocortin 4 Receptor Gene (MC4R:c.92C>T) Is Associated with Diabetes Mellitus in Overweight Domestic Shorthaired Cats

Background

Feline diabetes mellitus (DM) shares many pathophysiologic features with human type 2 DM. Human genome‐wide association studies have identified genes associated with obesity and DM, including melanocortin 4 receptor (MC4R), which plays an important role in energy balance and appetite regulation.

Hypothesis/Objectives

To identify single nucleotide polymorphisms (SNPs) in the feline MC4R gene and to determine whether any SNPs are associated with DM or overweight body condition in cats.

Animals

Two‐hundred forty domestic shorthaired (DSH) cats were recruited for the study. Of these, 120 diabetics were selected (60 overweight, 60 lean), along with 120 nondiabetic controls (60 overweight and 60 lean). Males and females were equally represented.

Methods

A prospective case‐control study was performed. Genomic DNA was extracted from blood samples and used as template for PCR amplification of the feline MC4R gene. The coding region of the gene was sequenced in 10 cats to identify polymorphisms. Subsequently, genotyping by restriction fragment length polymorphism (RFLP) analysis assessed MC4R:c.92C > T allele and genotype frequencies in each group of cats.

Results

No significant differences in MC4R:c.92C>T allele or genotype frequencies were identified between nondiabetic overweight and lean cats. In the overweight diabetic group, 55% were homozygous for the MC4R:c.92C allele, compared to 33% of the lean diabetics and 30% of the nondiabetics. The differences between the overweight diabetic and the nondiabetics were significant (P < .01).

Conclusions and Clinical Importance

We identified a polymorphism in the coding sequence of feline MC4R that is associated with DM in overweight DSH cats, similar to the situation in humans.     

DNA Testing in Neurologic Diseases

DNA testing is available for a growing number of hereditary diseases in neurology and other specialties. In addition to guiding breeding decisions, DNA tests are important tools in the diagnosis of diseases, particularly in conditions for which clinical signs are relatively nonspecific. DNA testing also can provide valuable insight into the risk of hereditary disease when decisions about treating comorbidities are being made. Advances in technology and bioinformatics will make broad screening for potential disease‐causing mutations available soon. As DNA tests come into more common use, it is critical that clinicians understand the proper application and interpretation of these test results.