SSCP Marker Development and Analysis of Candidate Restorer Gene Rf1 for Cotton Cytoplasmic Male Sterility

[Objective] Locating the cotton cytoplasmic male sterility (CMS) restorer gene Rf₁ is important for investigating restorer gene mechanisms and improving restorer lines. In our previous study, a gene cluster, with nine Pentatricopeptide repeat(PPR) genes and nine other genes, was found within the 160-kb Rf₁ target region in Scaffold 333. The objective here was to improve the density of Rf1-linked markers in the target region and determine the expression profiles of candidate genes. [Method] Using the sequences of the 18 genes, we designed 155 single-strand conformation polymorphism (SSCP) primers covering all of the gene sequences to identify the polymorphic SSCP markers between the fertile and sterile pools. Additionally, real-time polymerase chain reaction(PCR) was performed to analyze the expression profiles of eight candidate genes in the four developmental stages of buds of sterile, maintainer and restoring lines, respectively. [Result] In total, 15 polymorphic primers were identified. A genotype analysis of the F₂ population was conducted using the 15 primers and 3 other polymorphic simple sequence repeats (SSR) markers. The markers were distributed in a 4.8 cM range. In addition, owing to the influence of sterile cytoplasm or restorer genes, most of the genes showed different expression patterns in the four developmental stages of the three lines' buds. [Conclusion] SSCP markers tightly linked to Rf₁ were identified and the expression profiles of candidate genes were determined. This study provides a basis for the further fine mapping of restorer genes and for candidate gene screening.     

中国新疆小反刍兽疫病毒F基因序列分析

为分析中国新疆小反刍兽疫病毒(PPRV)毒株分子演变特点和疫情传播路线,从GenBank数据库下载所有国家全部的PPRVF基因全序列,应用DNAStar软件,结合疫情毒株时空分布进行序列分析。结果显示,中国新疆PPRV株F基因全序列,与2014年小反刍兽疫情中河南和北京毒株核苷酸的同源性最高,为99.8%~99.9%,与中国西藏3个毒株核苷酸的同源性为97.7%,与中国采用的疫苗株核苷酸同源性为92.9%,核苷酸同源性最低的是肯尼亚毒株,与国外毒株核苷酸同源性最高的是印度毒株。F基因系统进化关系分析显示,中国新疆PPRV株属于基因Ⅳ系。F蛋白氨基酸同源性结果显示,除与科特迪瓦1989年毒株ICV89氨基酸同源性最低外,与其他氨基酸同源性比对结果均与核苷酸的比对结果一致。中国新疆PPRV株存在一定程度的变异,可能是由周边国家传入。     

PPR‐B‐31: a new maintainer allele in the male‐fertility restorer gene of radish (Raphanus sativus) Ogura cytoplasm

The PPR‐B gene is responsible for male‐fertility restoration of the Ogura‐type male‐sterile radish plants, and it is located in the complex Rfo locus in the vicinity of similar PPR‐A gene and PPR‐C pseudogene. The aim of this study was to identify PPR‐B alleles and understand the structure of the Rfo locus in radish breeding lines. Five lines of radish with normal male‐fertile cytoplasm were tested. The entire PPR‐B gene was amplified, sequenced and allelic PPR‐B sequences were identified. The results indicated that the maintainer lines 7, 15 and 21 contained a non‐restoring form of PPR‐B protein. A unique PPR‐B was found in lines 24/15 and 31 that are restorer and maintainer lines, respectively. The substitutions might be responsible for the loss of a restoring function of the PPR‐B‐31 allele. Amplification of the PPR‐A/PPR‐B and PPR‐B/PPR‐C intergenic regions allowed to identify rearrangements within Rfo locus. Obtained results confirm the wide allelic variation within the Rfo locus, as well as high genetic complexity of the fertility restoration mechanism in radish.     

Utilization of protein-A in immuno-histochemical techniques for detection of Peste des Petits Ruminants (PPR) virus antigens in tissues of experimentally infected goats

This paper constitutes the first record of utilizing the S. aureus protein-A (PA), conjugated to peroxidase enzyme, for the detection of the Peste des Petits Ruminants (PPR) virus antigens in tissues of experimentally infected goats. The goats were experimentally infected with a virulent PPR virus, which was previously isolated from a severe natural disease outbreak in gazelles, during 2002 in Saudi Arabia. The technique is rapid, and has the superiority over the peroxidase –anti-peroxidase (PAP) test in that, inactivation of the indigenous peroxidase in the tissues is not required and that it can be used against a wide range of animal species. An advantage over the other immunolabelled conjugates is that PA attaches specifically to the crystalizable fraction (Fc) of the IgG molecule, thus allowing the antigen binding fraction (Fab) of the molecule, free to interact specifically with the antigen. So, it doesn't actually compete with the antigen for the Fab portion of the IgG molecule. In the present study, PA conjugate detected the PPR virus antigens in various tissues of the experimentally infected goats.     

小反刍兽疫(PPR)和生物安全

从小反刍兽疲(PPR)的流行情况、临床症状和病理变化、传播途径、PPRV基因组的结构、PPRV的理化特征等方面进行了阐述,简要介绍了生物安全对控制PPR的意义,从外部生物安全和内部生物安全两方面提出了预防和控制措施,以期为养羊生产者提供参考.     

单翼迷宫式滴灌带的关键参数与灌水均匀度的响应关系

为探究单翼迷宫式滴灌带坡度、进水压力和铺设长度对灌水均匀度的影响,以3种单翼迷宫式滴灌带为研究对象,以灌水均匀度作为评价指标,采用UL₉(3⁴)均匀正交设计试验,比较了3种不同流量的单翼迷宫滴灌带在进水压力、铺设长度和坡度作用下的灌水均匀度的变化规律。经直观分析、方差分析和多重比较进行综合评价,再由SPSS和PPR对试验数据进行数学建模。结果显示,3种单翼迷宫式滴灌带灌水均匀度的外界因素排序均为压力>坡度>长度,相比于SPSS、PPR所建立的模型具有更高的精度。研究成果不仅为灌水均匀度计算与预测提供了理论依据,还对各学科试验优化设计、高维数据建模分析提供了有效的解决方案。     

棉花2个新的PPR基因的克隆及表达模式分析

【目的】从棉花中克隆2个新的PPR基因,分析其序列结构、基因表达和亚细胞定位,为深入研究这2个基因在棉花中的功能提供依据。【方法】利用棉花EST库,通过RT-PCR从陆地棉徐州142中克隆得到2个PPR基因：GhPPRH1和GhPPRH2;应用生物信息学方法对2个基因编码蛋白序列进行预测分析,利用半定量RT-PCR和实时荧光定量PCR的方法分析目的基因在不同组织及纤维不同发育时期的表达模式;利用棉花子叶瞬时表达系统对上述2个基因编码的蛋白进行亚细胞定位。【结果】GhPPRH1和GhPPRH2均属于PPR基因家族的PLS亚家族;GhPPRH1和GhPPRH2的开放读码框的长度分别为1 917和2 556 bp,编码638和851个氨基酸;GhPPRH1蛋白有18个PPR基序,包含1个E+结构域和1个DYW结构;GhPPRH2蛋白有17个PPR基序,包含1个E结构域,1个E+结构域和1个DYW结构;将GhPPRH1和GhPPRH2蛋白的氨基酸序列与GenBank数据库中的9条同源蛋白以及棉花中已经报道的5个PPR蛋白的氨基酸序列进行比对,构建系统进化树,结果显示,GhPPRH1与水稻RF1b蛋白亲缘关系较近,推测其可能与胞质雄性不育的育性恢复相关,而GhPPRH2与玉米PPR5蛋白亲缘关系最近,推测可能会影响细胞器一些转录本的RNA编辑;半定量RT-PCR和实时荧光定量PCR的结果表明,GhPPRH1和GhPPRH2在根、茎、叶、花及纤维发育不同时期均有表达,GhPPRH1在根中表达较高,而GhPPRH2在根、叶及15 d的纤维中表达较高;亚细胞定位结果显示,GFP标记的GhPPRH1蛋白的绿色荧光与线粒体Marker的红色荧光重叠,表明该蛋白可能定位于线粒体,GFP标记的GhPPRH2蛋白的绿色荧光与叶绿体自发的红色荧光重叠,表明GhPPRH2可能定位在叶绿体。【结论】从棉花中获得2个新的PPR基因,均属于PLS亚家族成员,亚细胞定位显示可能在线粒体和叶绿体中,推测其功能可能与细胞器中RNA的加工、修饰等过程有关。     

利用投影寻踪回归技术进行草地产量预报的研究

本文利用1991～1992年在新疆阜康县不同类型草地上观测的牧草产量、环境因子和卫星遥感资料运用投影寻踪回归（PPR）技术，探讨了草地产量预报的原理与方法，建立了产量预报综合模型，其预报精度达到83．5％以上，并克服传统预报方法的一些不足，科学地提示其内在关系，进而对影响产量预报精度和产量形成的因素进行分析与实验验证。因而研究结果表明利用PPR技术基本实现了科学预报草地产量的目的。     

投影寻踪回归模型在大豆食心虫虫食率预测中的应用

大豆食心虫的虫食率受越冬基数、气象条件等多种因素的影响,是一个复杂的非线性非正态系统,文章采用投影寻踪回归新技术,建立了大豆食心虫虫食率的预测模型,对历史值的拟合和对预留值的预测效果均令人满意,可以作为大豆虫害预测的一种新手段。     

云冷杉天然林林分年龄预测——以金沟岭林场为例

应用BP神经网络模型、PPR神经网络模型以及多元逐步回归模型,依据林分因子预测了金沟岭林场云冷杉天然林林分年龄。对比分析了人工神经网络计算模型算法与多元逐步回归分析模型预测结果的精度以及稳定性。结果表明:3种模型均可用于天然林林分年龄的预测,BP神经网络模型的预测平均相对误差为0.04,模型稳定性差;PPR神经网络模型的预测相对误差为0.06,模型稳定性好;多元逐步回归模型的预测相对误差为0.08,模型稳定性好。