Improvement of Resistance to Rice Blast in Zhenshan 97 by Molecular Marker-aided Selection

Fungi blast is one of the most serious diseases of rice worldwide. Breeding resistant varieties have been proved to be the most effective and economical means to control the disease. This paper describes the molecular marker-assisted selection (MAS) procedure for a broad-spectrum blast resistant gene Pi1 integrated into an elite hybrid maintainer line, Zhenshan 97. A simple sequence repeat (SSR) based on molecular marker-aided selection system for Pi1 segment was established. Using a backcross population and a blast isolate F1829, Pi1 gene was mapped on the top of chromosome 11 between markers RZ536 and RM144, with a distance of 9.7 cM and 6.8 cM, respectively. Seventeen families derived from the recurrent parent Zhenshan 97 were obtained with homozygous Pi1 gene. The background of the 17 families was identified with inter simple sequence repeat (ISSR) amplification, the highest recovery of the Zhenshan 97 genetic background was 97.01% after the assay of 167 polymorphic bands.

Mapping of S-b Locus for F_1 Pollen Sterility in Cultivated Rice Using PCR Based Markers

In cultivated rice ( Oryza sativa L.), F-1 pollen sterility is controlled by at least 6 loci of the F, pollen sterility genes. To map S-b, one of loci, rice variety Taichung 65 (T65) carrying S-b(j)/S-b(j) and its near-isogenic line TIST2 carrying S-b(i)/S-b(i) were used to develop the mapping population. One hundred and fifty-eight microsatellite markers were selected to survey T65 and TISL2. RM13 on chromosome 5 was found to be polymorphic between them. Cosegregation indicated that RM13 was closely linked with locus S-b. Eleven RFLP markers were selected on the corresponding region from the genetic map of Rice Genome Research Program (RGP) of Japan to convert into sequence-tagged site (STS) markers. Amplicon length polymorphism (ALP) was carried out, but none of them was found to be polymorphic between T65 and TISL2. Then PCR-based RFLP (PBR) was done using six 4-nucleotide recognizing restriction endonucleases. Polymorphism was detected when PCR products of R830STS and R2213SSTS were digested with Taq I. Genetic analysis indicated that the distance between locus S-b and markers, R830STS, RM13 and R2213SSTS were 3.3 cM (centi-Morgan), 5.2 cM and 5.5 cM, respectively. These PCR-based markers could be directly used in marker-assisted selection. The technical system combining genetic mapping and PCR-based marker-assisted selection will facilitate the development of molecular breeding.

Segmental Duplications Are Common in Rice Genome

Segmental duplications on rice (Oryza sativa L.) chromosomes 8, 9, 11, and 12 were studied by examining the distributions of sequences resolved by 13 probes detecting multiple copies of DNA sequences. Four of the hybridization bands detected by a repetitive sequence probe, rTRS, were mapped to the ends of all the four chromosomes. Two or three of the bands detected by each of the other 12 probes were also mapped to different chromosomes. The bands detected by the same probe usually occurred in similar locations of different chromosomes. Loci detected by different DNA probes were often similarly arranged on different chromosomes. Chromosomes 8 and 9 showed colinearity of marker loci arrangement indicating a possible common origin. A segment on chromosome 9 was also very similar to the previously reported duplicated fragments on the ends of chromosomes 11 and 12 which were also detected in this study, indicating a likely common origin. Moreover, the various degrees of distributional similarity of the segments suggest a complex relationship among the chromosomes in the evolution of the rice genome. These results support the proposition that chromosome duplication and diversification may be a mechanism for the origin and evolution of the chromosomes in the rice genome.

天津地铁积水区段行车组织措施分析

针对积水线路积水没过轨面情况,现有规定“积水没过轨面的停止列车通过”,参考其他地铁行车措施,尝试进行修订。以车辆最大涉水能力作为硬性约束条件,利用线路最大坡度对称形式下作为最差工况,计算此时积水没过轨面的水平距离,取各条线路积水没过轨面的水平距离的最小值作为限速依据阈值。验证积水没过轨面时水平距离的合理性:最差工况下积水没过轨面的水面距离阈值反向求得各条线路积水没过轨面高度,均小于车辆最大涉水能力;考虑到地铁正线车站横截面以梯形形式存在的情况,计算获得出现积水没过轨面深度值刚好达到人为设定列车最大涉水深度时坡底水平距离在各正线中不存在。根据积水距离调整积水区段的限速措施,为提升现场执行,配合设置水位标线综合判断后采取行车措施,以期达到积水区段运营安全与运营效率平衡双优。

怀洪新河小型涵闸设计

怀洪新河安徽段小型涵闸共110多座,通常单个造价在40～100万元之间。目前已完成并通过总指挥部验收的有43座,尚有规划数量的一半待设计施工。已实施的工程,有的是由水利行业甲级设计院完成,有的是由乙级设计院完成,其结构型式则大同小异,基本类似。

Comparative Physical Localization of Rice Pib Gene and Its Linked RFLP Markers in Oryza sativa, O. officinalis and Zea mays

Comparative genetic studies have shown that there are widespread synteny and colinearity of the genes among different species within grass family. Rice ( Oryza sativa L.) is a model plant, and analysis of its genome allows us to reveal the common features and the evolutionary rules of the gramineous genomes and accumulate the data for establishment of a common genetic system in the Poaceae. In this study, a rice gene Pib ( 10.3 kb), a map-based cloned gene, and RFLP markers linked with it are used as the tested probes to investigate their homology and physical location among the tested species. Southern blotting analysis showed that there were sequences homologous to Pib in maize genome. Further, Pib was localized onto the chromosomes of O. sativa ssp. indica cv. Guangluai 4, O. officinalis Wall ex Watt and the inbred line of Zea mays cv. Huangzao 4. The results of fluorescence in situ hybridization (FISH) and double-color FISH indicated that a synteny of Pib and RFLP markers linked with Pib existed among the genomes of the three tested species.

A Scheme of Fragile Watermarking Based on SVD and 2D Chaotic Mapping

This paper proposed a novel fragile watermarking scheme based on singular value decomposition (SVD) and 2D chaotic mapping. It obtains chaotic initial values from the image blocks singular value decomposition and the user’s key, then uses the chaotic mapping to get the chaotic sequence and inserts the sequence into the LSBs of the image blocks to get the watermarked image blocks. The paper reconstructed the watermarked image from all the embedded blocks. The analysis and experimental results show that the scheme is pretty fragile to tampering, and it can localize the tampering position accurately, reach 3×3 blocks.

A robust watermarking algorithm based on significant-tree in Contourlet domain

An adaptive algorithm operating in the Contourlet domain is presented. Contourlet is a new image sparse representation, which is better than a wavelet for piecewise smooth images with smooth contours. Because of flexible multiresolution, local and directional sensitivity of Contourlet transform, our approach also defines significant-tree in the Contourlet domain. By analyzing the relation of the Contourlet coefficients, we embed the watermarking into all the coefficients of each significant-tree. Then referring to the statistical properties of the coefficients, the masking characteristics of texture are defined for adaptively controlling the embedding strength. Experimental results show that the proposed algorithm is highly robust to various attacks, such as JPEG compression, medium filtering, cropping and rotation. Furthermore, comparisons with a classical method in the wavelet domain prove the validity of the new algorithm.

Image-based Water Level Measurement Method under Stained Ruler

This paper propoes the water level measuring method based on the image, while the ruler used to indicate the water level is stained. The contamination of the ruler weakens or eliminates many features which are required for the image processing. However, the feature of the color difference between the ruler and the water surface are firmer on the environmental change compare to the other features. As the color differeaces are embossed, only the region of the ruler is limited to eliminate the noise, and the average image is produced by using several continuous frames. A histogram is then produced on the height axis of the produced intensity average image. Local peaks and local valleys are detected, and the section between the peak and valley which have the greatest change is looked for. The valley point at this very moment is used to detect the water level. The detected water level is then converted to the actual water level by using the mapping table. The proposed method is compared to the ultrasonic based method to evaluate its accuracy and efficiency on the various contaminated environments.

He,Ne and Ar isotope compositions of fluid inclusions in hydrothermal sulfides from the TAG hydrothermal field,Mid-Atlantic Ridge

Helium, neon and argon isotope compositions of fluid inclusionshave been measured in hydrothermal sulfide samples from the TAG hydrothermal field at the Mid-Atlantic Ridge. Fluid-inclusion 3He/4He ratios are 2.2-13.3 times the air value (Ra), and with a mean of 7.2 Ra. Com-parison with the local vent fluids (3He/4He=7.5-8.2 Ra) and mid-ocean ridge basalt values (3He/4He=6-11 Ra) shows that the variation range of 3He/4He ratios from sulfide-hosted fluid inclu-sions is significantly large. Values for 20Ne/22Ne are from 10.2 to 11.4, which are significantly higher than the atmospheric ratio (9.8). And fluid-inclusion 40Ar/36Ar ratios range from 287 to 359, which are close to the atmospheric values (295.5). These results indicate that the noble gases of fluid inclu-sions in hydrothermal sulfides are a mixture of mantle- and seawater-derived noble gases; the partial mantle-derived components of trapped hydrothermal fluids may be from the lower mantle; the helium of fluid inclusions is mainly from upper mantle; and the Ne and Ar components are mainly from seawater.