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Filoviruses (family Filoviridae) are nonsegmented, negative-strand RNA viruses belonging to 3 genera: Marburgvirus, Ebolavirus, and Cuevavirus. Marburgvirus comprises 1 species, Marburg marburgvirus, which includes Marburg virus (MARV) and Ravn virus. [...]

Abstract: Rice stripe disease caused by rice stripe virus (RSV) is vectored by the small brown planthopper (Laodelphax striatellus Fallen). The resistance gene Stv-bi has been fine mapped on chromosome 11 of rice (Oryza sativa L.). The objective of this study was to develop a practical marker-assisted method with the help of molecular markers closely linked to Stv-bi . A total of 26 pairs of markers were tested, of which 8 pairs were polymorphic between the parents Shengdao 13 and Zhendao 88. These polymorphic markers consisted of 3 pairs of simple sequence repeat (SSR) markers and 5 pairs of sequence-tagged site (STS) markers. Three markers, H21, H11-8, and H11-12, were subsequently used in marker-assisted selection. The individual seedlings from 3 compound breeding populations, F30718 (Shengdao 13/Zhendao 88), F50701 (Wuyou 34/T022//Shengdao 806), and F60702 (V6/T022//Zhendao 88), were genotyped with the 3 markers. The resistant lines examined by marker-assisted selection were also investigated in field. The consistency between field performance and the marker genotypes was 99.3%, 87.7%, and 91.8% in the 3 compound breeding populations, respectively. These results indicate that the molecular markers can be applied for selecting candidate lines with resistance to RSV. [Copyright &y& Elsevier]

A series of typical abandoned croplands in the regions of Ruanliang and Yingliang in the Ordos Plateau, China, were selected, and dynamics of the surface litter, biological soil crust and soil bulk density, soil texture, and soil moisture in different soil layers were investigated. The results showed that in the abandoned cropland in Ruanliang, the clay particle content and surface litter of the surface soil layer (0-10 cm) increased during the restoration process, while that of soil bulk density substantially decreased and soil water content slightly increased in the surface soil. In the medium soil layer (10-30 cm), the clay particle content increased and the soil water content slightly decreased. In the deep soil layer (30-50 cm), there was a relatively large variation in the physical properties. In the abandoned cropland in Yingliang, the coverage of litter and the coverage and thickness of the biological soil crust increased during the abandonment process. The surface soil bulk density, soil clay particle content and soil water content remained constant in 0-10 cm soil layer, while the physical properties varied substantially in 10-40 cm soil layer. The shallow distribution of the soil water content caused by the accumulation of the litter and clay particles on the soil surface might be the key reason of the replacement of the semi-shrub Artemisia ordosica community with a perennial grass community over the last 20 years of the abandoned cropland in Ruanliang. The relatively high soil water content in the shallow layer and the development of the biological soil crust might explain why the abandoned cropland in Yingliang was not invaded by the semi-shrub A. ordosica during the restoration process.

Gene expression profiling using microarray has contributed significantly to heterosis studies. Using the Affymetrix rice genome array, we investigated gene expression profiles in the flag leaves of the japonica hybrid rice Huayou14 and its parental cultivars Shen9A and Fan14 at the booting stage. A total of 2057 genes differentially expressed (fold change ≥2 or ≤0.5) between Huayou14 and its parents were identified. Functional classification of the differentially expressed genes by Gene Ontology (GO) analysis indicated the differentially expressed genes were significantly enriched in photosynthesis-related cellular component categories (e.g. photosystem Ⅰ, chloroplast membrane and chloroplast envelope), and biological process categories (e.g. chlorophyll catabolic, chlorophyll biosynthetic and carotenoid biosynthetic processes). These results suggest that the changes in the photosynthetic ability of the japonica hybrid rice Huayou14 may be related to heterosis. Metabolic pathway analysis indicated that differentially expressed genes were significantly enriched in photosynthesis-antenna proteins and starch and sucrose metabolic pathways, instead of photosynthesis and carbon fixation pathways as reported previously. These results suggest that different genes or metabolic pathways might contribute to the heterosis of different hybrid combinations.

Objective: To understand the epidemiologic characteristics of endemic typhus in Baoshan city., Methods: Epidemiological data were collected and characteristics were analyzed. IgG antibody (Ab) of Rickettsia mooseri and Orientia tsutsugamushi in serum of patients were tested using both Weil-Felix and IFA method. The Rickettsia mooseri gltA gene, Rickettsia prowazekii gltA gene, Orientia tsutsugamushi 56 kDa protein gene, SFGR ompA gene, Ehrlichia sp. 16S rRNA gene and Anaplasma sp. 16S rRNA gene in spleen of mice were examined by PCR., Results: Fifty-eight endemic typhus cases were found in Longyang district of Baoshan city, during July to August, 2009. Among them, 48 cases were confirmed by clinical diagnosis and 10 cases by laboratory tests. The Ab of Orientia tsutsugamushi Karp serotype was detected in 3 cases from laboratory diagnosis. The spleen samples from 85 Rattus flavipectus were tested using PCR. Of them, 3 samples for Rickettsia mooseri gltA gene showed positive (positive rate was 3.5%), and the homology of 3 Rickettsia mooseri and Rickettsia mooseri Wilmington strain (GenBank U59714.1) was 100% through comparing gene sequence. The results of PCR for detecting Rickettsia prowazekii, Orientia tsutsugamushi, SFGR, Anaplasma sp. and Ehrlichia. sp were all negative., Conclusion: The outbreak of endemic typhus was confirmed in Longyang district of Baoshan city through epidemiological data, clinical diagnosis and laboratory tests. Rickettsia mooseri DNA was detected in the dominant Rattus flavipectus, suggesting that endemic typhus did exist in the local areas.

Objective: To determine the hosts of hantavirus (HV) and its molecular epidemiological characteristics, to provide evidence for prevention and control on hemorrhagic fever with renal syndrome (HFRS)., Methods: Rodents were captured by a special trap within the residential area. The antigens of HV in lung tissues were detected by direct immuno-fluorescence assay (DFA). Nucleotide sequences of HV were amplified by RT-PCR with HV genotype-specific primer. The amplified genes were then sequenced. Phylogenetic tree were built on nucleotide sequence with ClustalX 1.83 software., Results: 1421 rodents were captured and classified into 8 species of 4 Genera in the epidemic area within 10 counties of Chuxiong prefecture, Yunnan province, between 2005 and 2006. Out of the 1421 rodents, 1056 (74.31% ) of them were Rattus norvegicus and 280 (19.70%) belonged to Rattus flavipectus. The antigens of HV were detected by DFA in lung tissues and the total positive rate of HV was 5.15% (53/ 1029). After applying the sequencing nucleotide method to the 53 positive specimens, data showed that 21 specimens were positive and all of them belonged to Seoul type (15 samples were from Rattus norvegicus, 4 samples Rattus flavipectus, 2 samples Rattus nitidus). The partial S segments from 12 specimens were sequenced which appeared homologic with R22, L99 and HLD65 from GenBank in relatively high level (87.1% -99.7%). When compared to 76-118 strain of Hantaan type, their homologic degree was only 64.4%-69.1%. Results from Phylogenetic analysis showed that 12 specimens belonged to Seoul type. As for their homology, they were significantly similar to Seoul type and could be tentatively divided into two subtypes S1 and S3., Conclusion: It was confirmed that the Seoul type virus, as HFRS's pathogenetic agent mainly carried by rats, prevailed widely in Chuxiong prefecture. Owing to the local ecological environment, we also noticed the characteristics of different HV subtypes among Seoul type.

Objective: Explore the genotype of the epidemic Japanese encephalitis virus (JEV) in Yunnan Province from molecular level and to understand the molecular differences of the virus isolated from Yunnan at different time, locality and host., Methods: Three-day suckling mice were inoculated with viruses continuously and when the disease developed and the mice were dying, the brain was taken and DNA was extracted from the supernatants of the brain after grinding; then the gene fragments of Prm-C region were amplified by RT-PCR. The viral gene sequences were compared with those of other 72 strains of JEV originated from both China and abroad at different times. Finally the genotypes were analyzed with the method which was established by Woan-Ru Chen., Results: All the 3-day suckling mice which were inoculated with the virus died within 78 h. The results of the nucleic acid-sequence analysis showed that 17 strains of the experimental virus belonged to genotype 1 and 2 strains belonged to genotype 3. The difference between genotype 1 and type 3 were more than 15%. While the difference between 17 strains of genotype 1 which were separated at different time, location and hosts were only 3.8%-5.2%., Conclusion: The above results suggest that the genotype of the epidemic JEV in Yunnan Province are type 1 and 3 and the latter is the main type.