冰草的遗传多样性研究

利用根尖压片法,从细胞水平对来自6个不同居群的冰草的遗传多样性进行了研究.结果表明各居群染色体数目恒定(2n=28),均为同源四倍体;居群间存在核型多型性,主要表现在核型类型、随体及B染色体的有无等;A、E居群核型为1B型,其余种群为1A型;C、E居群的染色体有随体,E居群细胞核中有B染色体存在.     

冰草的遗传多样性研究

利用根尖压片法。从细胞水平对来自6个不同居群的冰草的遗传多样性进行了研究。结果表明：各居群染色体数目恒定(2n=28)。均为同源四倍体；居群间存在核型多型性。主要表现在核型类型、随体及B染色体的有无等；A、E居群核型为1B型，其余种群为1A型；C、E居群的染色体有随体，E居群细胞核中有B染色体存在。     

不同类型苏丹草染色体数目及核型分析研究

本文对苏丹草[Sorghumsudanense（Piper）Stapf]种内的黑壳（黑颖）、红壳（红颖）、白壳（白颖）3种类型进行染色体数目及核型研究，结果表明3种不同类的苏丹草染色体数目均为2n＝20，核型公式均为Zn＝4x=18m＋2SAT，其染色体均为中部染色体，均具有一时带随体染色体，核型类型均为1A型，属于较对称性核型。苏丹草在种内其染色体及核型特征无明显差异。苏丹草与同属植物高梁的染色体、数目及核型特征有明显的属内一致性。     

扇穗茅不同居群染色体数目及核型分析

为了探讨扇穗茅(Littledalea racemosa)不同居群的染色体核型特征和进化关系，本研究采用染色体常规压片技术对分布于青藏高原6个自然地理居群的扇穗茅核型特征及进化趋势进行了分析。结果表明：扇穗茅6个居群的染色体数目均为2n=2x=28；染色体有中部着丝粒(m)型和亚中部着丝粒(sm)型，中部着丝粒型占比更高；平均臂比介于1.27~1.44之间，长度比为1.95~2.56，核不对称系数处于55.64%~57.88%之间；核型类型有1B，2A和2B三种；所有居群中，居群83的染色体核型进化程度最高，居群67的进化程度最低；当遗传距离为1时，居群119和120优先聚为一支，亲缘关系最近。本研究首次报道了扇穗茅的染色体核型数目、特征和进化趋势，为今后进一步探明扇穗茅的系统进化关系提供了有力的细胞学佐证。     

苏丹草与高粱染色体核型比较研究

采用去壁低渗火焰干燥法对4个苏丹草和6个高粱品种的核型进行比较研究。结果表明,苏丹草和高粱体细胞染色体数均为20(2n=20);苏丹草品种均为1A核型,并具有1对随体染色体,其中1、2号品种的第2对染色体为近中间着丝点染色体,3、4号品种为中间着丝点染色体;高粱品种除5号为1A核型、中间着丝点染色体外,其余的5个品种为2A或2B核型,且都有1或2对近中间着丝点染色体,9号品种还出现1对近顶端着丝点染色体;高粱8、9号品种各观察到1对随体染色体。染色体数量分析表明,第1到第10对染色体长短臂的绝对长度、相对长度以及绝对全长在苏丹草和高粱2类间的差异均不显著(P>0.05)。因此,苏丹草和高粱的遗传差异不在染色体长度上。     

六种基因型草坪草的染色体核型分析(简报)

对禾本科羊茅属和黑麦草属6种基因型草坪草的染色体核型进行了分析,结果表明,6个种的染色体数均为2n=2x=14,都为中部着丝粒或近中部着丝粒染色体,所有染色体中均未见随体。核型公式显示高羊茅品种“自豪”为2n=14=8m 6sm、“家园”为2n=14=12m 2sm、“猎狗5号”为2n=14=14m、“羊茅极品”为2n=14=14m;多年生黑麦草品种“绅士”为2n=14=8m 6sm、“黑麦王子”为2n=14=10m 4sm。羊茅属4个品种具有3种核型:2B、2A和1B;黑麦草属2个品种核型也不相同,分别为2A和2B。表明同一属下不同品种间染色体核型存在差异,而不同属下某些品种却有相同的核型类型,为通过草坪草不同属间远缘杂交进行遗传改良创造了条件。     

串叶松香草染色体核型分析

对串叶松香草根尖细胞进行染色体常规制片,并进行核型分析。结果表明,串叶松香草染色体数为2n=14,,核型公式为K（2n）=2x=14=4m＋6sm＋4st,其中中部着丝粒染色体（m）为2对,近中部着丝粒染色体（sm）为3对,近端部着丝粒染色体（st）为2对。核型类型为3B。     

燕麦I-D品系及其亲本的染色体核型分析

为了解燕麦杂交新品系I-D（A.sativa L.I-D）与其亲本间的遗传关系,本研究采用染色体压片法,从细胞遗传学水平比较分析其与亲本在染色体形态特征和核型上的差异,为燕麦杂交育种和遗传改良提供科学依据。结果表明,燕麦I-D品系的核型为2n=6x=42=12m+30sm（4SAT）,核不对称系数为66.62%,属3B型;两亲本的核型为2n=6x=42=24m+18sm（4SAT）,核型为2B型;母本‘青海444’核不对称系数为63.60%;父本‘青海甜燕麦’为62.84%。燕麦I-D品系具有双亲染色体的一些特有形态,其中部着丝点染色体所占比例（28.57%）和核不对称系表明,其是较亲本更为进化的种群。可见,燕麦杂交能够整合两个亲本的优良特性,对创造新型种质具有重要意义。     

热研4号王草和桂闽引象草的核型分析

采用常规压片法,对热研4号王草(Pennisetum purpureum×P.americanum cv.Reyan No.4)和桂闽引象草(P.purpureumcv.Guiminyin)的染色体数目和核型进行分析,以期为狼尾草属种质资源多样性保护利用和遗传育种研究提供理论依据。结果表明,两者染色体基数均为x=7。其中,热研4号王草为三倍体,有21条染色体,核型公式2n=3x=21=21m(3SAT),染色体相对组成I.R.L=9S+3M1+3M2+6L,3条染色体含有随体;桂闽引象草为四倍体,有28条染色体,核型公式2n=4x=28=18m(2SAT)+10sm(2SAT),染色体相对组成I.R.L=10S+6M1+4M2+8L,4条染色体含有随体。热研4号王草和桂闽引象草核型不对称系数分别为60.15%和62.19%,属于1B型和1C型,其核型都属于比较原始的类型。     

山西白羊草染色体核型分析

选用山西白羊草(Bothriochloa ischaemum)种子为材料,采用根尖压片法进行细胞染色体核型分析,为白羊草的种质资源利用及育种提供细胞学依据。观察统计了30个完整的中期分裂相确定染色体数目,并选其中5个分裂相进行核型分析。结果表明,白羊草染色体数为2n=40,核型公式为K(2n)=4x=40=34m+6sm,其中中部着丝粒染色体(m)为17对,近中部着丝粒染色体(sm)为3对,核型类型为1B。核型不对称系数为58.32%。     

28个中国紫苏属种质资源的染色体核型分析

为了探明我国紫苏属（Perilla Linn.）植物的染色体特点,本研究采用常规压片法对我国紫苏属的28份材料的染色体核型进行分析研究。结果表明：供试的28份紫苏属材料,染色体基数均为x=20,其中3个为四倍体,2n=80,其余25份皆为二倍体,2n=40;28份材料中均有发现至少一个随体,染色体类型包含m,sm,st 3种,核型有2A,3A,2B,3B 4个类型,最长染色体/最短染色体值1.50~2.80,臂比大于2的染色体占染色体总数的百分比为10%~65%,核型不对称系数59.69%~68.52%;通过核型分析,回回苏和多倍体紫苏类型可能具有更高的进化地位,而野生紫苏与之相反。这些数据表明了我国紫苏属植物资源在细胞学方面具有较为丰富的多样性,同时本研究也对我国紫苏属植物的分类、鉴定等提供了理论参考。     

长白山3种橐吾的核型研究

采用常规压片法对长白山主产的复序橐吾、全缘橐吾、狭苞橐吾进行了核型研究。结果表明,3种橐吾的染色体数目均为2n=58,核型除全缘橐吾为2A外,其他2种均为2B。核型不对称系数介于59.22%～62.89%,核型公式分别为2n=2x=58=42m+16sm,2n=2x=58=44m+12sm+2st,2n=2x=58=32m+26sm。从染色体相对组成来看,复序橐吾为2n=58=2L+20M₂+30M₁+6S、全缘橐吾为2n=58=28M₂+28M₁+2S、狭苞橐吾为2n=58=2L+28M₂+26M₁+2S,供试的3种橐吾的染色体数和核型均为首次报道。     

Influence of biotic and abiotic factors on the distribution and abundance of Culicoides imicola and the Obsoletus Complex in Italy

Culicoides imicola Kieffer (Culicoides, Diptera: Ceratopogonidae) is the principal vector of bluetongue virus (BTV) to ruminant livestock in southern Europe. The secondary potential vectors are Culicoides obsoletus (Meigen) and Culicoides scoticus Downes and Kettle of the Obsoletus Complex, Culicoides pulicaris (Linnaeus) of the Pulicaris Complex and Culicoides dewulfi Goetghebuer of the subgenus Avaritia Fox. Between 2000 and 2004 >38,000 light-trap collections were made for Culicoides across Italy including the islands of Sardinia and Sicily. Mapping of the 100 largest collections of C. imicola and of the Obsoletus Complex showed them to be disjunct overlapping in only 2% of the 200 municipalities selected. For each municipality the average values were calculated for minimum temperature, aridity index, altitude, terrain slope, normalised difference vegetation index (NDVI) and percentage forest cover. A factor analysis identified two principal factors (‘biotic’ and ‘abiotic’) and explained 84% of the total variability; a discriminant analysis classified correctly 87.5% of the observations. The results indicate adult populations of C. imicola to occur in more sparsely vegetated habitats that are exposed to full sunlight, whereas species of the Obsoletus Complex favour a more shaded habitat, with increased green leaf density. Heliophily and umbrophily, by shortening or lengthening the respective adult life cycles of these two vectors, will likely impact on the ability of each to transmit BTV and is discussed in the light of the current outbreak of BTV across the Mediterranean Basin.     

基于线粒体控制区的鸡不同杂交组合遗传多样性研究

旨在探讨鸡不同杂交组合线粒体控制区（mtDNA D-loop区）的遗传多样性和单倍型特性。选取固始鸡和隐性白羽鸡及其正、反交F1代、藏鸡以及F2代等6个群体共387个个体的mtDNA D-loop区进行测序,分析其遗传规律和单倍型特性,并与不同红色原鸡亚种进行聚类,分析其母系起源。结果显示,6个群体D-loop区全序列大小为1 231 bp,共检测到28个多态位点和1个C碱基缺失,共构成19种单倍型,分为A、B、C和E 4个单倍型群,其中,固始鸡和反交F1代主要为A、C单倍型,固始鸡A、C单倍型比例分别为53.42%和46.58%,反交F1代A、C单倍型比例分别为50.75%和49.25%;隐性白羽鸡、正交F1代和F2代优势单倍型均为E单倍型,占比分别为48.89%、48.84%和50.00%。6个鸡群体单倍型多样度（Hd）在0.496~0.729之间,核苷酸多样度（Pi）在0.003 40~0.005 41之间,Hd值和Pi值最大的均为正交F1代,其次为隐性白羽鸡和F2代,固始鸡和反交F1代群体遗传多样性接近。聚类分析显示,A、B单倍型群与滇南亚种交叉聚为一枝;E单倍型群与印度亚种交叉聚为一枝;C单倍型群与印度亚种、指名亚种、印尼亚种以及滇南亚种聚为一枝。结果提示,mtDNA D-loop区遵循严格的母系遗传,后代的遗传多样性和单倍型比例与其母本基本一致;我国家鸡群体具有多个红色原鸡母系起源,且主要起源于原鸡滇南亚种。     

灵空山采伐干扰下油松林林间草地物种多样性分析

采用记名样方,对不同采伐方式油松林林间草地群落的草本植物区系及其生态生活型和物种多样性进行了比较分析。结果表明,皆伐后林间草地的草本植物科、属、种数均高于间伐,不同时间间伐的物种数变化不大。在种水平上的区系地理成分都是以温带分布为主和植物生活型以地面芽、隐芽植物为主。皆伐方式下的各生长型种数比间伐方式下多,一年生草本所占比例也较大。不同采伐方式下的水分生态型差异不明显,以中生和旱中生植物为主。重要值统计结果表明,不同采伐方式下草本群落除共优种大披针苔草(Carex lanceolata)、小红菊(Chrysanthemum chanetii)外,均存在不同的优势种。物种多样性指数随采伐方式和时间不同呈现出皆伐＞间伐、采伐晚的＜采伐早的。     

Construction of SRD5A2 Gene Interference Vector and Its Effect on the Expression of Lambing Related Genes in Qianbei Ma Goats

The purpose of this study was to investigate the effect of SRD5A2 gene on the expression of genes related to goat lambing traits. In this study, 3 healthy (2-3 years old) and female Qianbei Ma goat with a weight of approximate 32 kg were selected. Ovary tissue was collected and granulosa cells were successfully cultured. Four pairs of siRNA interference sequence of SRD5A2 gene sequence and a pair of negative control sequence were designed by online software. After connecting pGPH1/GFP/Neo vector, the constructed interference vectors were transfected into ovarian granulosa cells of Qianbei Ma goats. The interference vector with optimal interference efficiency was screened by qRT-PCR, and its effect on the expression of SRD5A2 gene was detected. The effects of silencing SRD5A2 gene on the expression of bone morphogenetic protein 15 (BMP15), growth differentiation factor 9 (GDF9), bone morphogenetic protein-1B (BMPR-1B) and follicle-stimulating hormone lactin (FSHβ) were investigated. In this experiment, the interference vector of SRD5A2 gene was successfully constructed on the basis of cultivating ovarian granulosa cells of Qianbei Ma goats. shRNA-SRD5A2-1 interference vector with the optimal interference efficiency was screened out (P<0.01). After inhibiting SRD5A2 gene expression, the expression levels of BMP15, BMPR-1B, GDF9 and FSHβ were significantly reduced. The expression level of BMP15 was extremely significantly lower than that in shRNA-NC control group (P<0.01), and the expression levels of BMPR-1B, GDF9 and FSHβ were significantly lower than those in shRNA-NC control group (P<0.05). In this study, the constructed SRD5A2 gene interference vector was successfully transfected into ovarian granulosa cells. The silencing of SRD5A2 gene can inhibit the expression of genes related to lambing traits, which indicate that SRD5A2 gene is closely related to lambing traits of Qianbei Ma goats, the result will provide a basis for further studies on the regulatory mechanism of SRD5A2 gene on lambing traits in Qianbei Ma goats.     

Phenotypic and genotypic traits of Staphylococcus aureus strains isolated from pig carcasses

A total of 142 S. aureus strains isolated from pig carcasses from abattoirs A (n = 98) and B (n = 44) were characterized by phenotypic and genotypic traits. Phenotypically, 96% showed yellow-pigmented colonies, 63% β/δ hemolysis, 85% were egg yolk-positive and 99% were positive for clumping factor/protein A. Only 25% of the strains were resistant to the antimicrobials tested (abattoir A: 19%; abattoir B: 39%), especially to penicillin and ampicillin. None of the strains harbored the mecA gene, which is conserved in methicillin-resistant S. aureus. The biofilm associated genes icaA, icaD and bap were present in 100%, 100% and 0% of the strains. Genes for staphylococcal enterotoxin (SE) were detected in 51% (abattoir A) and 14% of the strains (abattoir B). Among strains harboring SE genes (n = 56), 63%, 31%, 4% and 2% tested positive for seg/sei, seg, sei and sec, respectively. The amplification of the 3′ end of the coagulase gene (coa) yielded amplicons of 400, 436, 602, 682 or 776 bp. Coa restriction profile (CRP) analysis using HaeIII resulted in seven patterns (a–d, e1–e3). CRP (c) was detected most frequently at both abattoirs, whereas CRP (a) was restricted to abattoir A and CRP (e3) to abattoir B. In the slaughter process (abattoir B), (i) two CRPs (b and d) were only found before dehairing/singeing, and (ii) four CRPs (c, e1–e3) were identified throughout the process. The genotyping revealed a remarkable homogeneity in S. aureus strains from the two different abattoirs and the slaughter process stages. These results may be explained by the distribution of a limited number of S. aureus genotypes in the pig population. Moreover, as the predominant CRPs (c, e1–e3) persisted throughout the slaughter process in abattoir B, it may be hypothesized that these types are characterized by colonization advantages.     

黔北麻羊SRD5A2基因干扰载体构建及其对产羔相关基因表达的影响

旨在探究SRD5A2基因对山羊产羔性状相关基因表达的影响。本研究选择健康的（2~3岁）黔北麻羊经产母羊3只,体重约32 kg,采集卵巢组织并成功培养卵巢颗粒细胞。通过在线软件设计SRD5A2基因的4对siRNA干扰序列和1对阴性对照序列,连接pGPH1/GFP/Neo载体后,将构建成功的干扰载体转染至黔北麻羊卵巢颗粒细胞。利用qRT-PCR方法筛选出干扰效率最佳的载体,检测其对SRD5A2基因表达的影响。运用qRT-PCR检测沉默SRD5A2基因对山羊产羔性状相关基因骨形态发生蛋白15（BMP15）、生长分化因子9（GDF9）、骨形态发生蛋白1B（BMPR-1B）和卵泡刺激素β亚基（FSHβ）表达的影响。结果表明,本试验在培养黔北麻羊卵巢颗粒细胞的基础上,成功构建了黔北麻羊SRD5A2基因的干扰载体,并筛选出shRNA-SRD5A2-1干扰效果最佳（P<0.01）;抑制SRD5A2基因表达后,qRT-PCR检测产羔性状相关基因BMP15、BMPR-1B、GDF9和FSHβ的表达量均显著降低,BMP15的表达量极显著低于shRNA-NC对照组（P<0.01）,BMPR-1B、GDF9和FSHβ的表达量显著低于shRNA-NC对照组（P<0.05）。本研究成功构建了SRD5A2基因干扰载体并转染至卵巢颗粒细胞,发现体外沉默SRD5A2基因可抑制产羔性状相关基因的表达,提示SRD5A2基因与黔北麻羊产羔性状密切相关,本试验结果为进一步研究SRD5A2基因对黔北麻羊产羔性状的调控机制提供了基础。     

青藏高原东缘３种风毛菊属植物的核型研究

 本研究报道了产于青藏高原东缘３种风毛菊属植物的染色体数目和核型。研究结果表明,３个种的染色体数目和核型如下：甘肃风毛菊为２ｎ＝２ｘ＝３２＝１２ｍ＋１６ｓｍ＋４ｓｔ,核型属２Ｂ型;大耳叶风毛菊为２ｎ＝２ｘ＝２６＝１０ｍ＋１４ｓｍ＋２ｓｔ,核型属２Ａ 型;波缘风毛菊为２ｎ＝２ｘ＝２６＝６ｍ＋２０ｓｍ,核型属２Ｂ型;这３个种均为二倍体,并且在染色体中均未发现随体和Ｂ染色体。