水稻对稻瘟病抗性的分子生物学研究进展

 介绍了水稻对稻瘟病抗性的分子生物学研究进展,主要包括：用于定位作图的分子标记的种类和特点、稻瘟病抗性基因的分子标记定位、稻瘟病抗性基因的等位性比较研究、稻瘟病菌生理小种无毒基因的克隆以及稻瘟病抗性基因克隆研究进展等。     

Introgression of Gene for Non-Pollen Type Thermo-Sensitive Genic Male Sterility to Thai Rice Cultivars

For the two-line hybrid rice system, pol en sterility is regulated by recessive gene that responds to temperature. The recessive gene controlling thermo-sensitive genetic male sterility （TGMS） is expressed when the plants are grown in conditions with higher or lower critical temperatures. To transfer tgms gene（s） control ing TGMS to Thai rice cultivars by backcross breeding method, a male sterile line was used as a donor parent while Thai rice cultivars ChaiNat 1, PathumThani 1, and SuphanBuri 1 were used as recurrent parents. The BC2F2 lines were developed from backcrossing and selfing. Moreover, the simple sequence repeat （SSR） markers were developed for identifying tgms gene and the linked marker was used for assisting selection in backcrossing. The identification lines were confirmed by pol en observation. The results showed the success of introgression of the tgms gene into Thai rice cultivars. These lines will be tested for combining ability and used as female parent in hybrid rice production in Thailand.     

茶多糖化学及生物活性的研究

近年的研究发现茶叶多糖有多种生理作用,非常具有开发前景。它具有降血糖、降血脂、抗血栓、降血压及增强机体免疫力等生理功能,可作为功能保健食品用于糖尿病人、心脑血管病人的辅助治疗。本文就茶多糖的提取纯化方法、纯度测定、分子量测定、化学组成、生理作用等进行综述。     

现代生物技术在油菜遗传改良上的应用和进展

总结了小孢子培养技术在油菜新品种选育和材料创新、群体构建、复杂性状的遗传分析和转基因等上的应用,概述了转基因技术在油菜品质改良、抗性提高、雄性不育系的选育等方面的进展,综述了DNA分子标记在油菜遗传图谱构建和基因定位、指纹图谱和分子标记辅助选择等各个方面的进展,并对这三大现代生物技术的应用前景进行了展望。     

27株嗜水气单胞菌致病性及ERIC—PCR指纹图谱分析

从福建省淡水养殖鱼类体内分离到27株嗜水气单胞菌,根据嗜水气单胞菌16SrDNA基因和气溶素基因（aerolysin）的保守序列,设计2对引物,对所分离到的27株嗜水气单胞菌进行双重PCR扩增,扩增结果表明,其中18株为含有Aer毒力基因的潜在致病性嗜水气单胞菌,占总菌数的66．67％。应用ERIC-PCR分型技术对27株嗜水气单胞菌菌株进行分析,以相似度54．00％为限,所有菌株可分为Ⅰ和Ⅱ两大聚类,以76．00％相似度为界,27株嗜水气单胞菌可分为11个聚类,同一个聚类中菌株分离区域基本相同。分析结果表明,分离的嗜水气单胞菌基因型的多样性和分离地域具有一定的关联,也表明ERIC-PCR可以有效应用于嗜水气单胞茵分子流行病学调查。     

5个尼罗罗非鱼群体遗传关系的ISSR分析

采用ISSR分子标记技术,对吉富尼罗罗非鱼群体(GF)、尼罗罗非鱼群体Ⅰ(NLⅠ)、尼罗罗非鱼群体Ⅱ(NLⅡ)、尼罗罗非鱼群体Ⅲ(NLⅢ)和尼罗罗非鱼群体Ⅳ(NLⅣ)的遗传多样性进行分析。用81个ISSR引物对5个尼罗罗非鱼群体进行扩增,15个ISSR引物获得多态片段。根据Nei’s遗传距离矩阵构建了5个尼罗罗非鱼群体的遗传关系树状图。UPGMA聚类图表明:NLⅢ群体和NLⅣ群体最先聚在一起;其次二者再与GF群体聚在一起;NLⅠ群体与NLⅡ群体聚在一起。分析结果显示:GF群体与其它4个罗非鱼群体区分较明显;用UBC835扩增的500 bp片段为GF所特有,可作为区别GF和其它尼罗罗非鱼的分子标记。     

斑节对虾细胞周期蛋白Y基因克隆与原核表达

为了研究细胞周期蛋白Y(cyclin Y)在斑节对虾(Penaeus monodon)卵巢发育中的作用,从斑节对虾转录组数据中筛选获得cyclin Y基因部分序列,采用SMART-RACE方法克隆得到斑节对虾细胞周期蛋白Y(Pm-cyclin Y)基因c DNA全序列。Pm-cyclin Y基因c DNA全长1576 bp,其中包含108 bp的5′非编码区(5′UTR)和439 bp的3′非编码区(3′UTR)以及1029 bp的开放阅读框(ORF),可编码342个氨基酸。生物信息学分析显示,其编码的氨基酸序列有1个保守的周期蛋白框(cyclin box)同源结构域(172~257 aa),预测的分子量约为37.6 k D,理论等电点6.64。实时定量PCR显示其m RNA在卵巢的表达量显著高于其他组织(P0.05);并且在卵巢5个不同发育期都有表达,在III期卵巢中的表达量最高。本研究通过原核表达方法对Pm-cyclin Y进行重组表达,为其蛋白质功能方面的研究奠定了基础。     

Fractionation of soil humic acids by preparative polyacrylamide gel electrophoresis in the presence of concentrated urea

To separate soil humic acids (HAs) into their constituents and characterize them, polyacrylamide gel electrophoresis (PAGE) was carried out in the presence of 7 M urea using a preparative electrophoresis system. Two types of soil HAs were fractionated into nine fractions by PAGE. The dark-colored constituents were recovered from the electrophoretic fractions by precipitation on acidification, and the brown-colored constituents dissolved in the acidic solution of fast-moving fractions were recovered by adsorption onto DAX-8 resin. High-performance size-exclusion chromatography (HPSEC) confirmed that the constituents of the HAs were separated based on their molecular size by PAGE. The dark-colored constituents exhibited higher degrees of humification than did the corresponding unfractionated HAs, except for the constituents remaining in the electrophoretic gels at the end of electrophoresis. Diffuse reflectance infrared spectroscopy revealed that the chemical properties of the dark-colored constituents changed regularly: the content of carboxyl groups decreased and the proportions of proteinous, aliphatic and polysaccharide moieties increased with increasing molecular size. The humification degrees of the constituents adsorbed onto DAX-8 resin were considerably lower than those of the corresponding unfractionated HAs. The chemical properties of the DAX-8-adsorbed constituents were different from those of the dark-colored constituents. Observation of electrophoretic fractions under blue light (470 nm) and HPSEC with fluorescence detection at an excitation wavelength of 460 nm and an emission wavelength of 520 nm showed that green fluorescent substances were largely concentrated in the smallest molecular size fractions and were partitioned into both the dark-colored precipitates and DAX-8-adsorbed fractions. The proportion of organic carbon recovered by precipitation and adsorption onto DAX-8 resin was 45–63%, indicating that substantial parts of the HA constituents were missing. The unrecovered constituents were considered to be acid-soluble, nearly colorless substances. The dissociation of the acid-soluble constituents from the acid-insoluble dark-colored constituents during the preparative PAGE of soil HAs was ascribed to disruption of hydrogen bonding and hydrophobic interactions caused by concentrated urea.     

利用分子标记辅助选择技术改良三系不育系荃9311A稻瘟病抗性的研究

为了提高三系不育系荃9311A的稻瘟病抗性,以含广谱稻瘟病抗性基因Pigm的水稻品种9311为供体,保持系荃9311B为受体和轮回亲本,通过分子标记辅助选择技术筛选抗性基因、剔除恢复基因和遗传背景筛选,在稻瘟病病区进行抗性鉴定,人工接种鉴定以及田间农艺性状考查,于BC2F2代获得有Pigm基因并剔除了恢复基因的改良株系,其后再与荃9311A杂交和连续回交,育成了农艺性状与荃9311A无显著差异而稻瘟病抗性明显增强的三系不育系K9311A及其保持系K9311B。     

中国台湾番茄曲叶病毒侵染引起广东番茄黄化曲叶病

广东汕头番茄(Lycopersicon eseulentum)上发生的黄化曲叶病毒病,田间症状表现为病株明显矮化、病叶褪绿黄化、叶小且卷曲和叶质较脆硬。对该病毒代表分离物(BS)基因组DNA-A克隆和测定结果表明,其全长为2740nt(GenBank acces-sion No.DQ237918),具有菜豆金色花叶病毒属(Begomovirus)病毒基因组典型特征,为闭合环状单链DNA,有6个ORFs,分别位于病毒链上的AV1、AV2及位于互补链上的AC1、AC2、AC3和AC4;在基因AV2与AC1之间有269nt的非编码区。BLAST结果显示,BSDNA-A与Begomovirus中来自亚洲的病毒同源性较高,而与美洲、非洲等地的相对较低;其中与中国台湾番茄曲叶病毒(Tomato leaf curl Taiwan virus,ToLCTWV)DNA-A全序列同源性最高,为97.7%,而二者的AV1、AV2、AC1、AC2、AC3和AC4基因及IR的同源性分别为98.6%、98.0%、98.0%、97.5%、96.3%、98.6%和96.6%,推导编码的6个蛋白的氨基酸序列同源性分别为97.7%、99.1%、97.5%、95.6%、91.8%和99.0%%。全序列系统进化关系树显示,BS与ToLCTWV的亲缘关系最近,并形成一个独立分支,再与广东番茄曲叶病毒G2(Tomato leaf curl Guangdong virus G2,ToLCGDV-[G2]和广东番茄曲叶病毒G3(Tomato leaf curl Guangdong virus G3,ToLCGDV-[G3]形成一个大的分支,而与其它33种Begomovirus病毒的亲缘关系均相对较远。这些结果表明,BS应是ToLCTWV的一个分离物。