Genetic analysis and fine mapping of the pubescence gene GL6 in rice (Oryza sativa L.)

The pubescence of the leaf blade surface is an important agronomic characteristic for rice morphology and significantly influences rice growth as well as physiological characteristics. This characteristic was analyzed in F1 and F2 plants derived by crossing cultivar 75-1-127 with the indica cultivar Minghui 63, as well as the glabrous cultivar Lemont and indica cultivar 9311. Results indicated that the pubescence of the leaf blade surface was a dominant trait and controlled by a single gene. The GL6 gene was primarily mapped on rice chromosome 6 with recessive F2 population derived from 75-1-127/Minghui 63 by combining bulked segregation analysis and recessive class analysis using the Mapmaker3.0/MapDraw software. The genetic distances between the simple sequence repeat markers RM20491 and RM20547 were 7.2 and 2.2 cM, respectively. The GL6 gene was fine mapped in the interval between InDel-106 and InDel-115 at genetic distances of 0.3 and 0.1 cM, respectively. The large, recessive F2 population was derived from 75-1-127/Minghui 63. A high-resolution genetic and physical map of GL6 was constructed. Derived from the map-based sequences published by the International Rice Genome Sequencing Project, the GL6 gene was localized at an interval of 79 (japonica) and 116.82 kb (9311) bracketed by InDel-106 and InDel-115 within the BAC accession numbers AP008403 and AP005760. Seven annotated genes (japonica) and eight annotated genes (9311) were present. The basis was further set for GL6 cloning and function analysis.     

Isolation and characterization of rl（t）, a gene that controls leaf rolling in rice

Moderate leaf rolling is one of the most important morphological traits in rice breeding for plant ideotype. Previous studies have shown that the rl（t） gene has a high breeding potential for developing hybrid-rice varieties with an ideal ideotype, because it leads to an appropriate leaf rolling index （LRI） of about 30 % in the heterozygous state, and had a positive effect on grain yield. In this study, we isolated rl（t） and performed a preliminary investigation of its function in regulating leaf rolling in rice. DNA sequencing identified a single base change （G to T） in the finely mapped region （11 kb） containing rl（t）, and this is located in 3′-untranslated region （3′-UTR） of the only predicted gene, Roc5 （Rice outermost cell-specific）. The expression level of Roc5 is significantly higher in the rl（t） mutant than in the wild-type. Using RNAi and overexpression analysis, we found that the expression level of Roc5 correlated with LRI and leaf bulliform area, and wasalso associated with leaf abaxial or adaxial rolling. These results confirmed that Roc5 controls leaf rolling in a dosagedependent manner. Bioinformatics analysis revealed a conserved 17-nt sequence （called the GU-rich element） in the 3′-UTR of HD-GL2 （Homeodomain-Glabra2） family genes including Roc5. Based on the model of this element in regulating mRNA stability in mammals, we speculate that the single nucleotide change in this element accounts for the higher expression level of Roc5 in the rl（t） mutant compared to the wild-type, which ultimately leads to adaxial rolling of the leaf. This discovery further enhances our knowledge of the molecular mechanisms underlying leaf rolling in rice.     

Genetic analysis and gene mapping of a narrow leaf mutant in rice ( Oryza sativa L.)

A narrow leaf mutant was obtained after T-DNA transformation conducted on a rice variety Zhonghua 11. Several abnormal morphological characteristics, including semi-dwarf, delayed flowering time, narrow and inward rolling leaves, and lower seed-setting, were observed. The rate of net photosynthesis (under saturate light) of flag leaves in the mutant was significantly lower than that of the wild type. Moreover, the leaf transpiration rate and stomatal conductance in the mutant flag leaf were lower than those of the wild type at the grain filling stage. It was found that the mutant phenotype was not caused by the T-DNA insertion. Genetic analysis showed that the mutant was controlled by a single recessive gene, designated as nal3(t). A genetic linkage map was constructed using a large F₂ mapping population derived from a cross between nal3(t) and an indica variety Longtefu B with 6 polymorphic markers on chromosome 12 identified from 366 SSR markers by the BAS method. Gene nal3(t) was mapped between the markers RM7018 and RM3331. Fine mapping of nal3(t) locus was conducted with 22 newly developed STS markers based on the sequence diversity around the region harboring nal3(t) between Nipponbare and 93–11, and nal3(t) was finally mapped to a 136-kb region between the STS markers NS10 and RH12-8. Supported by National High Technology Research and Development Program of China (863 Program) (Grant No. 2006AA10A102), National Natural Science Foundation of China (Grant No. 30600349) and Natural Science Foundation of Zhejiang Province (Grant No. Y306149)     

Genetic analysis and fine mapping of an enclosed panicle mutant esp2 in rice （Oryza sativa L.）

The phenomenon of panicle enclosure in rice is mainly caused by the shortening of uppermost internode.Elucidating the molecular mechanism of panicle enclosure will be helpful for solving the problem of panicle enclosure in male sterile lines and creating new germplasms in rice.We acquired a monogenic recessive enclosed panicle mutant,named as esp2 (enclosed shorter panicle 2),from the tissue culture progeny of indica rice cultivar Minghui-86.In the mutant,panicles were entirely enclosed by flag leaf sheaths and the uppermost internode was almost completely degenerated,but the other internodes did not have obvious changes in length.Genetic analysis indicated that the mutant phenotype was controlled by a recessive gene,which could be steadily inherited and was not affected by genetic background.Apparently,ESP2 is a key gene for the development of uppermost internode in rice.Using an F 2 population of a cross between esp2 and a japonica rice cultivar Xiushui-13 as well as SSR and InDel markers,we fine mapped ESP2 to a 14-kb region on the end of the short arm of chromosome 1.According to the rice genome sequence annotation,only one intact gene exists in this region,namely,a putative phosphatidylserine synthase gene.Sequencing analysis on the mutant and the wild type indicated that this gene was inserted by a 5287-bp retrotransposon sequence.Hence,we took this gene as a candidate of ESP2.The results of this study will facilitate the cloning and functional analysis of ESP2 gene.     

Gracefulness of several unconnected graphs with wheel

In the paper, we study the gracefulness of several unconnected graphs related to wheel. For natural number p ≥1,t ≥1, let n =2t +3, 2t +4, which proved W_n∪K_(p,t)~(1)∪K_(p,t)~(2) is graceful; for p ≥1, t ≥1,let n=2t+3,2t+4, then W_(n,2n+1)∪K_(p,t)~(1)∪K_(p,t)~(2) is graceful and for m≥1,r ≥1, let n =2m +5, W_(n,2n+1) ∪( C_3∨K m) U St( r)is graceful.     

Formation age and tectonic environment of the Gantaohe Group, North China Craton: Geology, geochemistry, SHRIMP zircon geochronology and Hf-Nd isotopic systematics

The Gantaohe Group is an important early Precambrian unit in the Trans-North China Orogen,North China Craton,and is mainly composed of greenschist-facies metabasalt,meta-sandstone and dolomitic marble.We report whole-rock geochemical compositions and SHRIMP zircon ages as well as LA-ICP-MS Hf-in-zircon isotopeic analyses for metabasalts from the Gantaohe Group.SHRIMP dating yielded a weighted mean 207Pb/206Pb age of 2087±16 Ma(MSWD=1.3) for magmatic zircons,but there are also abundant ca.2.5 Ga inherited zircon xenocrysts.The magmatic zircons shows a large Hf(t) variation in Hf(t) from 7.17 to +0.45,suggesting an isotopically highly heterogeneous source for the metabasalt.Chemically all samples show no distinct Zr or Hf anomalies,and some samples show no Nd or Ta anomalies in a primitive mantle-normalized trace element variation diagram,and their whole-rock Nd(t) values range from 4.0 to 0.8.We suggest that the basalt is formed by partial melting of a depleted mantle source,followed by significant crustal contamination.Field observations,the presence of abundant inherited zircon,as well as isotope and trace elements geochemistry support formation of the Gantaohe Group on top of a continental basement.These data and the regional geology lead us to conclude that the Trans-North China Orogen constituted an intracontinental rift during the Paleoproterozoic that was connected to the Eastern Block since the end of the Archean.     

Genetic analysis and mapping of rice （Oryza sativa L.） male-sterile （OsMS-L） mutant

A rice male-sterile mutant OsMS-L of japonica cultivar 9522 background, was obtained in M4 population treated with ^60Co γ-Ray. Genetic analysis indicated that the male.sterile phenotype was controlled by a single recessive gene. Results of tissue section showed that at microspore stage, OsMS-L tapetum was retarded. Then tapetal calls expanded and microspores degenerated. No matured pollens were observed in OsMS-L anther locus. To map OsMS-L locus, an F2 population was constructed from the cross between the OsMS-L (japonica) and LongTeFu B(indica). Firstly, the OsMS-L locus was roughly mapped between two SSR markers, RM109 and RM7562 on chromosome 2. And then eleven polymorphic markers were developed for further fine fine-mapping. At last the OsMS-L locus was mapped between the two lnDel markers, Lhsl0 and Lhs6 with genetic distance of 0.4 cM, respectively. The region was delimited to 133 kb. All these results were useful for further cloning and functional analysis of OsMS-L.     

Electrical conductivity optimization of the Na3AlF6-Al2O3-Sm2O3 molten salts system for Al-Sm intermediate binary alloy production

Metal Sm has been widely used in making Al-Sm magnet alloy materials. Conventional distillation technology to produce Sm has the disadvantages of low productivity, high costs, and pollution generation. The objective of this study was to develop a molten salt electrolyte system to produce Al-Sm alloy directly, with focus on the electrical conductivity and optimal operating conditions to minimize the energy consumption. The continuously varying cell constant (CVCC) technique was used to measure the conductivity for the Na₃AlF₆-AlF₃-LiF-MgF₂-Al₂O₃-Sm₂O₃ electrolysis medium in the temperature range from 905 to 1055℃. The temperature (t) and the addition of Al₂O₃ (W(Al₂O₃)), Sm₂O₃ (W(Sm₂O₃)), and a combination of Al₂O₃ and Sm₂O₃ into the basic fluoride system were examined with respect to their effects on the conductivity (κ) and activation energy. The experimental results showed that the molten electrolyte conductivity increases with increasing temperature (t) and decreases with the addition of Al₂O₃ or Sm₂O₃ or both. We concluded that the optimal operation conditions for Al-Sm intermediate alloy production in the Na₃AlF₆-AlF₃-LiF-MgF₂-Al₂O₃-Sm₂O₃ system are W(Al₂O₃) + W(Sm₂O₃)=3wt%, W(Al₂O₃):W(Sm₂O₃)=7:3, and a temperature of 965 to 995℃, which results in satisfactory conductivity, low fluoride evaporation losses, and low energy consumption.     

Structural investigation and luminescent properties of BaZr(BO<Subscript>3</Subscript>)2:Eu<Superscript>3+</Superscript> phosphors containing Si

Si⁴⁺-doped BaZr(BO₃)₂:Eu³⁺ phosphors are prepared by a conventional solid-state reaction. The influence of Si⁴⁺ addition on the charge transfer state of Eu³⁺-O^2– and photoluminescence (PL) properties of BaZr(BO₃)₂:Eu³⁺ are discussed. Room temperature PL spectra indicated that efficient emission is obtained by Si doping. Increased values for the peak-peak ratio (PPR) of BaZr(BO₃)₂:Eu³⁺ at higher Si doping concentrations implied that the Eu³⁺ ion is located in a more asymmetric environment in BaZr_0.8Si_0.2(BO₃)₂:Eu³⁺ than in the undoped samples. The Judd-Ofelt parameters Ω_λ (λ=2,4) were calculated from the PL data, giving results that were consistent with those from the PPR. The maximum radiative quantum efficiency was achieved at a Si doping concentration of 20 mol%.     

The periodic solution for a kind odd order delay differential equation

In this paper, we use the coincidence degree theory to research the odd order delay differential equation a(t)χ(2n+1)(t)+b(t)χ(t)+g(t,-τ(t)))=p(t), and we obtain the sufficient conditions for the existence of periodic solutions, which improves and generalizes some related results in the literatures.     

Late Paleozoic magmatism in South China:Oceanic subduction or intracontinental orogeny?

A gneissic granite with an U-Pb age of 313±4 Ma was found in northeastern Fujian Province,South China.It is an S-type granite characterized by high K2O,Al2O3 and low SiO2,Na2O contents with high A/CNK ratio of 1.22 for the whole rock.Zircons with stubby morphology from the gneissic granite yield 206 Pb/238 U ages ranging from 326 to 301 Ma with a weighted average age of 313±4 Ma,and negative εHf(t) values from -8.35 to -1.74 with Hf model ages (TCDM) of 1.43 to 1.84 Ga.This S-type granite probably originated from late Paleoproterozoic crust in intracontinental orogeny.Integrated with previous results on paleogeographic reconstruction of South China,the nature of Paleozoic basins,Early Permian volcanism and U-Pb-Hf isotope of detrital zircons from the late Paleozoic to early Mesozoic sedimentary rocks,we suggest the occurrence of a late Paleozoic orogeny in the eastern Cathaysia Block,South China.This orogenic cycle includes Late Carboniferous (340-310 Ma) orogeny (compression) episode and Early Permian (287-270 Ma) post-orogenic or intraplate extension episode.Therefore,the late Paleozoic magmatism in the southeastern South China probably occurred during the intraplate orogeny rather than the arc-related process.     

Tunable tribological properties in water-based lubrication of water-soluble fullerene derivatives via varying terminal groups

In this paper,three kinds of water-soluble fullerene derivatives were synthesized via electrophilic addition reaction and cycloaddition reaction,respectively.The chemical composition characterizations of these derivatives indicated the successful preparation of C60(OH)x,C60(C(COOH)2)x and C60(OH)x(NHCH2COOH)y fullerene derivatives.The aggregation and morphology characterizations showed that the three kinds of derivatives had an ideal spherical aggregating structures and excellent dispersibility in water,especially C60(OH)x and C60(C(COOH)2) x.The lubrication performance of the fullerene derivatives acted as lubricant additives were investigated at different concentrations in the range of 0-1 wt%.The results indicated that the addition of polyhydroxyl and carboxylic derivatives could improve the lubrication properties,which led to the reduction of wear to about 40% at most.It is attributed that the optimized substitutions of fullerene molecules may be of benefit to their distribution properties and lubricating behaviors in water based lubrication.     

Acylation of nitriles to β-ketonitriles catalyzed by a heterometallic alkoxide cluster of neodymium and sodium： NdNa8（O^tBu）10（OH）

Catalytic acylation of nitriles with esters in the presence of 10 mol% NdNa8(OtBu)10(OH) is developed.The procedure is suitable for both enolizable and nonenolizable esters and affords β-ketonitriles in moderate to high yields.The heterometallic alkoxide cluster NdNa8(OtBu)10(OH) is structurally characterized by X-ray diffraction,and a mechanism for the production of β-ketonitriles using the cluster is proposed and verified.     

Identification of a novel tillering dwarf mutant and fine mapping of the TDDL（T） gene in rice （Oryza sativa L.）

Rice plant architecture is an important agronomic trait that affects the grain yield. To understand the molecular mechanism that controls plant architecture, a tillering dwarf mutant with darker-green leaves derived from an indica cultivar IR64 treated with EMS is characterized. The mutant, designated as tddl（t）, is nonallelic to the known tiilering dwarf mutants. It is controlled by one recessive nuclear gene, TDDL（T）, and grouped into the dn-type dwarfism according to Takeda＇s definition. The dwarfism of the mutant is independent of gibberellic acid based on the analyses of two GA-mediated processes. The independence of brassinosteroid （BR） and naphthal-3-acetic acid （NAA） of the tddl（t） mutant, together with the decreased size of parenchyma cells in the vascular bundle, indicates that the TDDL（7） gene might participate in another hormone pathway. TDDL（T） is fine mapped within an 85.51 kb region on the long arm of rice chromosome 4, where 20 ORFs are predicted by RiceGAAS （http：//ricegaas.dna.affrc. go.jp/rgadb/）. Further cloning of TDDL（T） will benefit both marker assisted selection （MAS） of plant architecture and dissection of the molecular mechanism underlying tillering dwarf in rice.     

Zircon U/Pb dating and Hf-O isotopes of the Zhouan ultramafic intrusion in the northern margin of the Yangtze Block, SW China: Constraints on the nature of mantle source and timing of the supercontinent Rodinia breakup

The Zhouan ultramafic intrusion in the northern margin of the Yangtze Block is mainly composed of lherzolite.Zircon grains selected from lherzolite are irregular in shape with distinct oscillatory and sector zoning and have Th/U ratios ranging from 0.8 to 10.6,indicating a magmatic origin.The weighted average 206 Pb/238 U age is 637±4 Ma (2σ,n=15),which can be considered as the crystallization age of the Zhouan intrusion.Zircon grains have δ18O values ranging from 5.2‰ to 7.0‰,with an averaged value of 5.8±0.4‰ (1σ,n=33),similar to the mantle δ18O value of zircon.Their 176Hf/177Hf(t) ratios range from 0.282410 to 0.282594 with εHf(t) values ranging from 1.3 to 7.6,lower than the corresponding value of the depleted mantle (～15),indicating an enriched mantle source.The enriched mantle source may have generated from a metasomatized lithospheric mantle with subducted slab.A number of ～635 Ma mafic-ultramafic intrusions in the Suizao basin are associated with coeval bimodal volcanics of the Yaolinghe Formation,indicating a continental rift setting.The ～635 Ma magmatic event in this region may represent the product of the last breakup of the Rodinia supercontinent in the northern margin of the Yangtze Block at Neoproterozoic.     

An Sm-Nd isotopic dating study of the Archean Kongling Complex in the Huangling area of the Yangtze Craton

Sm Nd isotopic compositions of associated amphibolites, TTG gneisses and granitic gneisses from the Archean Kongling Complex of the Yangtze Craton, South China are systematically analyzed. The results show that the amphibolites and TTG gneisses have a similar age of ca. 2 700 Ma, which well agrees with zircon U Pb dating of previous studies. However, their ε Nd ( t ) are different, suggestive of possible dissimilarity in source composition.     

Opening of the Longmu Co–Shuanghu–Lancangjiang ocean:constraints from plagiogranites

This paper reports new zircon U-Pb ages,and Hf isotope and whole-rock major and trace element data for Cambrian plagiogranites from the Tuobeiling ophiolite in central Qiangtang,Tibetan Plateau.Zircon SIMS and LAICP-MS U-Pb dating of the plagiogranites yield weighted mean ages of 504.8±4.2 and 491.6±1.5 Ma,respectively.The zircons from plagiogranites exhibit positive eHf(t)values(ranging from 11.46 to 15.16),indicating that the plagiogranites are derived from depleted mantle.These plagiogranites are characterized by high SiO2and Na2O,low K2O,low REE contents,and flat REE distribution patterns.These rocks have geochemical compositions typical of oceanic plagiogranite and,considered along with their petrography and field relationships,are interpreted to have derived from anatexis of hydrated amphibolites by ductile shearing during transports of the oceanic crust.The formation age of such type of plagiogranite is slightly younger than that of the associated section of oceanic crust.Thus the new results from these plagiogranites suggest that the Longmu Co–Shuanghu–Lancangjiang ocean had probably opened before the Middle Cambrian.     

球面稳定同伦群的一族新元素G0(B1)4Γs

利用May谱序列的E₁^s,t,*项收敛于群E_A^s,t(Z_p,Z_p)以及Adams谱序列的E₂^s,t项收敛于球面稳定群π_t-s(S)_p的方法, 并结合谱的上纤维序列导出Ext群的正合序列, 发现了谱V(2)稳定同伦群中的一个非零元素g₀(b₁)⁴, 并且发现它在Adams谱序列中是一个永久循环. 运用Yoneda乘积, 得到了球面稳定同伦群中的一个非零元素g₀(b₁)⁴γ_s.     

Isolation and genetic characterization of a fragile plant mutant in rice (itOryza sauva) L.

The fragile rice mutant was isolated from an M₂ population of indica variety Shuang Ke Zao (SKZ) treated with g-rays, and designated as fp1 (fragile plant 1) because of its fragile leaves and culms. To map FP1 locus, an F² mapping population was derived from a cross between the fp1 and C-bao, a polymorphic japonic variety. The primary mapping result places the FP1 locus in an interval between two molecular markers, microsatellite marker RM16 (3.1 cM proximal to FP1) and STS marker G144a (9.1 cM distal to FP1) in the centromere region of chromosome 3. A CAPS marker C524a was further developed between RM16 and G144a, with 0.4 cM genetic distances to the FP1locus, providing a practical starting point for constructing a BAC contig spanning the FP1 locus and cloning the fp1 gene. Allelism test demonstrated that fp1 is allelic to bc1, a fragile rice mutant reported previously.     

A Large Deviation Principle for the Risk Process with Varying Premium

Let u ∈ R ,for any ω 〉 0, the processes X^ε = {X^ε（t）; 0 ≤ t≤ 1} are governed by the following random evolution equations dX^ε（t）= b（X^ε（t）,v（t））dt-εdSt/ε, where S={St; 0≤t≤1} is a compound Poisson process, the process v={v（t）; 0≤t≤1} is independent of S and takes values in R^m. We derive the large deviation principle for{（X^ε,v（.））; ε〉0} when ε↓0 by approximation method and contraction principle, which will be meaningful for us to find out the path property for the risk process of this type.