Physical location ofHelminthosporium carbonum susceptibility gene hm1 by FISH of a RFLP marker umc119 in Maize

A fluorescencein situ hybridization (FISH) procedure was adopted to physically map a RFLP marker, umc119 near the centromere of the long arm of linkage group1 in maize. The hm1 gene (Helminthosporium carbonum susceptibility gene) was linked closely with the marker umc119. RFLP markers are very good landmarks for mapping genes. Therefore, we also determined the position of the gene hm1 on the chromosome based on the physical location of umc119. The disease induced by infection ofHelminthosporium carbonum is one of the serious maize diseases and it distributes in many countries including China. Hybridization sites were showed on 1 L (long arm of chromosome1) and 5 L. The percentage distance from centromere to the hybridization site was 22.86 on 1 L and 58.23 on 5 L the detection rate was about 12% for mitotic cells. In interphase nuclei five hybridized sites were detected. It demonstrated that umc119 was multiplicated sequences. FISH has more advantages overin situ hybridization (ISH) detected by DAB for increasing the detection ratio and contrast between chromosomes and hybridization signals. The ability to detect the hybridization signal of a small low copy DNA sequence is a very important key towards wide application of FISH for plant genome mapping. Supported by the National Natural Science Foundation and Doctorate Vesting Point Foundation of the Education Committee of China Li Lijia: born in 1967. Ph. D.     

Cytogenetic Mapping of Disease Resistance Genes and Analysis of Their Distribution Features on Chromosomes in Maize

0　IntroductionMaizeisamongthemostintensivelystudiedspeciesingeneticsandoneofagronomicallythemostimportantplants.Therearemanydis easemicrobesandpeststoattackmaize,whichre sultsinlowproductionandbadquality .Withthedevelopmentofverydensegeneticmapconstruc tion ,avarietyoftheimportantdiseaseresistancegenesofmaizeincludingHelminthosporiumtur ciumPassresistancegenesHt1,Htn1andHt2 ,HelminthosporiummaydisNisikresistancegenesRhm1andRhm2 ,maizedwarfmosaicvirusresis tancegeneMdm1,wheatstreakmosaicvi…     

牦牛(Bos Grunniens)染色体高分辨G带带型的研究

由麦洼牦牛(公26,母8)颈静脉采血,经Brdu处理,结合胰酶G显带法,制备牦牛染色体高分辨G带标本,绘制出牦牛染色体高分辨G带模式图,并进行染色体区带划分和命名。结果是牦牛常染色体均为近端点着丝粒染色体,X、Y染色体为亚中部着丝粒染色体。单套染色体的G带数(含X、Y染色体)为641条,划分为108个区,牦牛染色体高分辨G带带型同普通牛染色体G带带型以及高分辨R带带型相比较,其X染色体基本相似,而Y染色体和常染色体有较大差异,这对今后深入探讨牦牛的雄性不育是有意义的。     

A candidate spermatogenesis gene on the mouse Y chromosome is homologous to ubiquitin-activating enzyme E1.

The human X-linked gene A1S9 complements a temperature-sensitive cell-cycle mutation in mouse L cells, and encodes the ubiquitin-activating enzyme E1. The gene has been reported to escape X-chromosome inactivation, but there is some conflicting evidence. We have isolated part of the mouse A1s9 gene, mapped it to the proximal portion of the X chromosome and shown that it undergoes normal X-inactivation. We also detected two copies of the gene on the short arm of the mouse Y chromosome (A1s9Y-1 and A1s9Y-2). The functional A1s9Y gene (A1s9Y-1) is expressed in testis and is lost in the deletion mutant Sxrb. Therefore A1s9Y-1 is a candidate for the spermatogenesis gene, Spy, which maps to this region. A1s9X is similar to the Zfx gene in undergoing X-inactivation, yet having homologous sequences on the short arm of the Y chromosome, which are expressed in the testis. These Y-linked genes may form part of a coregulated group of genes which function during spermatogenesis.     

DEX1, a plasma membrane-localized protein, functions in microspore development by affecting CalS5 expression in Arabidopsis thaliana

Microsporogenesis in flowering plants plays important roles in sexual reproduction. It has been reported that DEFECTIVE IN EXINE FORMATION1 (DEX1) is essential for exine pattern formation in Arabidopsis thaliana. However, the functions of DEX1 in regulating microspore development are largely not understood. In this study, we show that DEX1 is strongly expressed in the tapetum by using RNA in situ hybridization. dex1 microspores were degenerated and aborted after release from the tetrads. The callose wall in tetrads was thinner in the dex1 mutant than in the wild type, suggesting that DEX1 affects callose formation at the tetrad stage during anther development. RT-PCR and real-time PCR analyses showed that CalS5, which plays an important role in callose synthesis during microspore development, was greatly down-regulated in dex1 plants. DEX1 encodes a membrane protein with one transmembrane domain, one intracellular domain and one extracellular domain. Collectively, our results demonstrate that DEX1 is essential for microspore development, possibly by regulating the expression of CalS5.     

Knob-associated tandem repeats on mitotic chromosomes in maize,Zea diploperennis and their hybrids

Knob-associated tandem repeats, 180-bp repeats and TR-1 elements, together with 45S rDNA were located on mitotic chromosomes of Zea diploperennis (DP),maize inbred line F102 and their hybrid. In DP, knobs on the short arm of chromosomes 1 and 4 and on the long arm ofthe chromosomes 4 and 5 are composed predominantly of the 180-bp repeats. In addition, 180-bp repeats existed together with TR-1 elements were also detected on the short arm ofchromosomes 2 and 5 and on the long arm of the chromosomes 2, 6, 7, 8 and 9. In maize inbred line F102, 180-bp repeats were present in chromosomes 7S and one homologue of chromosomes 8L. TR-1 elements appeared on satellite of chromosome 6 and no detectable hybridization site co-located with 180-bp repeats was observed in maize F102.Polymorphism of size, number, and distribution of 180-bp and TR-1 signals were revealed among different chromosomes in these two species and heteromorphism existed between some homologous chromosomes in the same species.Using these excellent landmarks, the interspecific hybrid of maize and DP were identified. The results suggest that comparative analysis of 180-bp repeats and TR-1 elements may help understand the genome organization and the evolution in Zea.     

Distribution of highly repeated DNA sequences in Haynaldia villosa and its application in the identification of alien chromatin

Haynaldia villosa (L.) is a wild relative species of common wheat that possesses many beneficial genes that can be used for wheat improvement. The accurate detection of H. villosa chromosomes in the genetic background of wheat is critical for transferring its beneficial genes to common wheat by chromosome engineering. The aim of the present study was to investigate the distribution patterns of two repeated DNA sequences, pSc119.2 and pAs1, as well as two rDNA multigene family sequences, 45S rDNA and 5S rDNA, in the individual chromosomes of H. villosa for the future precise identification of alien chromatin in germplasm development and breeding programs. A set of common wheat-H. villosa disomic addition 1V-7V lines was used to determine these specific signals on individual chromosomes of H. villosa. The results showed that two rDNA probes, pTa71 (45S rDNA) and pTa794 (5S rDNA), were located on 1VS and 5VS, respectively, and the signal could be discriminated exclusively in the common wheat background as effective markers of 1VS and 5VS. Furthermore, all seven chromosomes of H. villosa could be distinguished clearly by fluorescence in situ hybridization using pSc119.2 and pAs1 as probes in combination. The utilization of these cytogenetic markers of repetitive sequences, combined with other molecular markers sometimes, will make it possible for a precise identification of alien chromosomes with high efficiency.     

A statistical method for genetic mapping of sterility genes that exhibit epistasis in remote hybridization of plants using molecular markers in an F2 population

Estimation of the position and effect of sterility genes is an important problem to be solved to understand the sterility mechanism in remote hybridization in plants.In this study,a maximum likelihood (ML) method was used for estimation of the position and effect of sterility genes that exhibit epistasis in an F 2 population using the distorted segregation of markers.The ML solutions for recombination fraction and viability were obtained via an expectation-maximization algorithm.The results of Monte Carlo simulations showed that the estimates of recombination fraction and viability were consistent with their true values.The bias and standard deviation of parameters indicated that a larger sample size,closer linkage and lower viability of sterile genes led to better estimates of the parameters involved.A subset of marker data of the F 2 population derived from a single cross between the rice japonica cultivar Nipponbare and the indica cultivar Kasalath was analyzed using this method.Eight sterility genes were identified on chromosomes 1,3,6,8 and 10,and significant epistasis was detected among four pairs of sterility genes.     

玉米两个自交系及其杂交F_1染色体G-带带型的比较

对玉米两个自交系京7和华5及其杂交F_1的染色体G-带带型进行了比较研究。结果表明,两自交系的G-带中A型带之间的相似点很多,有的完全一致;而B型带在带的数目和分布位置上有差异。杂交F_1的G-带带型具有杂合性,B型带的杂合性尤为明显。文中讨论了G-带、C-带和N-带并存等问题。     

SRO1 regulates heavy metal mercury stress response in Arabidopsis thaliana

Heavy metals in the environment are harmful limiting factors for the normal growth and development of plants. Here, we isolated and identified an Arabidopsis thaliana T-DNA insertion mutant, named srol-1, which showed a hyper-sensitive response to HgCl2. The SRO1 protein contains a WWE domain that mediates proteinprotein interactions. Under HgCl2 treatment, when compared with the wild-type plants, the growth of srol-1 was repressed dramatically and the number of true leaves was reduced and etiolated. The electrolyte leakage rates showed that cell membrane integrity in srol-1 was damaged more severely than in the wild type. DAB （3,5-diaminobenzidine） staining and confocal microscopy showed that Hg2＋ stress induced more hydrogen peroxide accumulation in srol-1 than in the wild type. The qRT-PCR results indicated that the expression of some abiotic stress-induced genes, such as L-ascorbate peroxidase （APX1）, was reduced under oxidative or Hg2＋ stress. Transgenic plants containing a GFP：：SRO1 fusion protein showed that SRO1 was localized in the nucleus of the cells. SRO1 was shown to be expressed in various tissues, and was most highly expressed in the vigorous tissues. Our results suggest thatSRO1 may play an important role in the stress response of A. thaliana to heavy metals.     

Multiple transgenes Populus xeuramericana ''''Guariento'''' plants obtained by biolistic bombardment

A JERF36 regulation gene, a selection marker gene (NPT-II), and the foreign genes levansucrase (SacB), Vitreoscilla hemoglobin (vgb), and Binary coleopterus insect resistance (BtCry3A OC-I) were co-transferred into Populus xeuramericana 'Guariento' using biolistic bombardment; 25 kanamycin resistant plants were obtained. The results of PCR and Southern hybridization showed that the foreign genes had been integrated into the genome of P. xeuramericana 'Guariento' and 5 genes were all transferred into 7 poplar plants. The results of a BtCry3A ELISA experiment indicated that the BtCry3A gene was expressed in the 7 transgenic poplar plants, and these plants grew well on coastal saline land.     

Analysis of F1 hybrid and BC1 monosomic alien addition line plants from Brassica oleracea × Sinapis alba by GISH

Sterile and semi-fertile F₁ plants were obtained by intergeneric sexual hybridization between paternal Brassica oleracea var. alboglabra (genome CC, 2n=18) and maternal Sinapis alba (genome SS, 2n=24), BC₁ plants were obtained by backcrossing between paternal B. oleracea and maternal semi-fertile F₁ plants. Genomic in situ hybridization (GISH) combined with dual-colour fluorescence in situ hybridization (dcFISH) showed that sterile F₁ plants contained 21 chromosomes consisting of one B. oleracea chromosome set and one S. alba chromosome set, belonging to expected hybrids, and semi-fertile F₁ plants contained 30 chromosomes consisting of two B. oleracea chromosome sets and one S. alba chromosome set. It is obvious that the semi-fertile F₁ plants belong to unexpected hybrids. 1―3 trivalents were detected at meiotic metaphase I of semi-fertile F₁ pollen mother cells (PMCs). Different separation ratios of S chromosomes were detected at anaphase I. A monosomic alien addition line (MAAL) was identified by GISH-dcFISH from BC₁ plants; it contained 19 chromosomes consisting of 18 C chromosomes and 1 S chromosome. At meiotic metaphase I, 9 divalents from B. oleracea and one univalent from S. alba could be detected. Sometimes, one putative C-S trivalent could also be detected. The achievement of B. oleracea-S. alba monosomic alien addition lines lays a foundation for gene introgression, location and cloning.     

采用反向PCR技术优化适合毕赤酵母表达的截短型HPV58型L1基因

目的:探讨利用反向聚合酶链反应(反向PCR)技术根据毕赤酵母偏爱密码子优化截短型人乳头瘤病毒58型(HPV58)L1基因的研究.方法:设计PCR引物扩增截短型HPV58L1目的基因,将其克隆入毕赤酵母分泌表达载体pPICZαC;测序并对目的基因进行序列分析;根据毕赤酵母偏爱密码子利用反向PCR技术设计引物对目的基因进行扩增.结果:扩增了截短型HPV58L1基因并将其克隆入毕赤酵母分泌表达载体pPICZαC中;根据毕赤酵母偏爱密码子优化了截短型HPV58L1基因.结论:成功构建经密码子优化截短型HPV58L1基因的毕赤酵母分泌表达载体pPICZαC-HPV58L1.     

Isolation and identification of the three rice monotelosomics

In order to obtain rice monotelosomic, the progeny of 24 telotrisomics, derived from an indica rice variety, Zhongxian 3037, were screened. The variants that differed morphologically from the diploids and the original primary trisomics as well as the telotrisomics were collected for cytological identification. The variants with 24 chromosomes were selected according to the prometaphase chromosomes. From these variants, three monotelosomies with one chromosome arm deletion in each were verified by fluorescence in situ hybridization （FISH） using a rice centromeric BAC clone of 17p22 as a marker probe. The three monotelosomics were derived from telotrisomic 1S, 4L and 11L, respectively. Further identification was conducted on the prometaphase or pachytene chromosomes of the three variants, which were probed with the same centromeric BAC clone together with the corresponding chromosome arm specific makers, a0059H02 （on the short arm of chromosome 1）, a0034E24 （on the long arm of chromosome 4）, and a0071H11 （on the long arm of chromosome 11）. The results indicated that the telocentric chromosomes in the three monotelosom. ics were derived from their respective corresponding telotrisomics. According to the telocentric chromosomes of the variants, they were monotelosomic 1S （one long arm of chromosome 1 was lost）, monotelosomic 4L （one short arm of chromosome 4 was lost） and monotelosomic 11L （one short arm of chromosome 11 was lost）, respectively.     

青菜花粉管通道法导入外源DNA的研究初报

采用花粉管通道法，将青菜株系７５Ｆ５、１４号大白菜、紫阳等三个品种的总ＤＮＡ及质粒ｐＡｃｔ１－Ｄ ＤＮＡ导入青菜６０５品系，收获青菜种子。种子发芽后分别提取约两周苗龄的小苗总ＤＮＡ，并经ＥｃｏＲⅠ酶切，以ｇｕｓ基因片段为探针做子杂交，证实了外源ｇｕｓ基因已整合到青菜６０５品系中；田间观察还获得了一株与供体大白菜花形相似的变异株。     

大麻茎皮出麻率早期非破坏性预测技术研究

大麻(Cannabis sativa L.)是重要的"绿色纤维"之一.为了培育高纤维产量品种,需要建立茎皮出麻率的早期非破坏性评价技术以便在花前选留高出麻率材料作为杂交亲本或繁种群体.以3个大麻品种为材料,研究不同部位茎皮与整株茎皮出麻率的关系和生长过程中茎皮出麻率的变化式样,发现大麻植株的出麻率高低在生长前期已经确定,现雄蕾前30d植株3/5高度处或现雄蕾前20d植株2/5高度处宽1/5周径、长20cm茎皮出麻率可以很好地反映整株出麻率.结果表明,选择高出麻率大麻植株可在生长早中期现雄蕾前采用非破坏性方法进行.     

辣椒疫病生防菌对青海循化线辣椒的防病促生效果

采用L4(23)正交试验设计,在青海省循化县露地线辣椒生产基地,研究两种辣椒疫病生防菌和有机肥组合对辣椒疫病防治效果以及产量的影响。结果表明:各因素对辣椒疫病相对防效影响由大到小的顺序为生防放线菌A5生防细菌B2有机肥;对辣椒产量影响由大到小的顺序为有机肥生防放线菌A5生防细菌B2。综合辣椒疫病的防效和产量效益,制定出可在当地辣椒生产中推广的生防菌和有机肥配施的综合应用技术指标为:A5放线菌45 kg/hm2、B2细菌30 kg/hm2、有机肥900 kg/hm2,此时辣椒疫病的田间防效可达到87.19%,产量达到16 977 kg/hm2,新增产值14 450元/hm2,投入产出比为1∶6。生防菌和有机肥配施对线辣椒生产具有明显的防病增产作用。     

糯玉米苏玉(糯)1号叶片生长规律的研究

对 6 0万株 /hm2 和 7.5万株 /hm2 密度下的糯玉米苏玉 (糯 ) 1号叶片和植株生长特点、叶片功能期、叶面积和叶片光合势的动态变化进行了试验研究。结果表明 :两种密度下的出叶速度相近 ,各叶出叶速度大小依次是基部三叶 >顶部 >中上部 >中下部。穗叶组叶片生长速度较快 ,叶面积较大 ,其中第 1 6叶 (非穗位叶 )生长速度最快 ,1 5叶叶面积最大。高密度下叶长、叶宽都较小 ,两种密度下最宽叶是最长叶 (穗位叶 )以上二片叶即 1 5叶。高密度下叶面积和光合势较低 ,但高密度的中期稳定 ,后期下降平稳 ;叶面积指数在抽雄吐丝期最高 ,光合势在后期分配比例占 2 /3。植株生长的曲线符合Logistic方程 ,7.5万株 /hm2 比 6 0万株 /hm2密度下的株高低 ,群体株高整齐度也小 ,而产量高 493 .6kg/hm2 。试验表明 :7.5万株 /hm2 相对 6 0万株 /hm2 密度较适合于苏玉 (糯 ) 1号的生长。     

Sequence modification of merB gene and high organomercurial resistance of transgenic tobacco plants

Mercury pollution has caused severe damage to environment and great attention has been paid to its control. Phytoremediation may become one of the most efficient measures to recover the polluted soil since it is economical, highly efficient and friendly to environment. In this report, plant genetic engineering methods were employed to modify the DNA sequence of merB genes that catalyze the conversion of organomercurals into ionic mercury. The modified merBhe genes were introduced into tobacco by Agrobacterium, and the resultant transgenic plants were verified by Southern and Northern hybridization. High level of organomercurial resistance was detected on progenies of transgenic plants, some of which were resistant to PMA (phenyl mercury acetate) of 2.5 μmol/L whereas 0.1 μmol/L PMA killed the seedlings of wild-type tobacco in soiless culrure. With the increase of PMA concentration, the inhibition of the seedling growth became apparent. This result makes it possible to breed mercury-resistant tobacco for phytoremediation of mercury-polluted soil.     

宁夏平罗春小麦氮、磷、钾肥肥效及适宜用量

用“3414”实验方案研究宁夏平罗县春小麦施用氮、磷、钾肥料的效果和最佳用量．结果表明,与未施肥处理相比．不同施肥处理均显著提高了春小麦籽粒产量;氮、磷、钾肥对春小麦的增产率,氮肥显著高于磷、钾肥,而磷肥又高于钾肥．根据肥料效应方程,确定春小麦最高产量（5231．5kg／hm。）时的氮、磷、钾肥的最佳施肥量分别是258kg／hm^2（N）,173kg／hm^2（P2O3）,22kg／hm^2（K2O）;经济最佳产量（5220．7kg／hm。）时的施肥量是257·9kg／hm^2（N）,173．0kg／hm^2（P205）,21．6kg／hm^2（K20）,氮、磷、钾肥的施肥质量比为1：0．67：0．08．对于指导该地区农业的合理施肥具有重要的参考价值．