Differential levels of antioxidants in paraquat-resistant and -susceptible Erigeron canadensis biotypes in Korea

To characterize the biochemical differences in paraquat-resistant and -susceptible biotypes of Erigeron canadensis L. collected from Korea, we investigated the constitutive levels of various antioxidants such as antioxidant enzymes and low molecular weight antioxidants in leaves, as well as after paraquat treatment. The activities of superoxide dismutase, peroxidase, ascorbate peroxidase, and catalase were higher in the paraquat-resistant biotype than in the paraquat-susceptible biotype. Reduced ascorbic acid content was higher in the resistant biotype, but the content of reduced glutathione was higher in the susceptible biotype. These results indicate that one of the paraquat-resistant mechanisms in E. canadensis in the present study might be related to protecting the activities of antioxidant enzymes, such as superoxide dismutase, peroxidase ascorbate peroxidase, and catalase, as well as the contents of low molecular weight antioxidants such as ascorbate and glutathione.     

台州市区绿化现状分析与对策研究

文章分析台州市区绿化的现状,指出绿化建设存在的问题,提出了市区绿化的总体思路、目标和对策措施。       

Herd prevalence and genotypes of Coxiella burnetii in dairy cattle bulk tank milk in Gyeongsang provinces of South Korea

Coxiella burnetii is the causative agent of the zoonotic Q fever, and its reservoirs include ticks and livestock, which are key sources of transmission to humans. Although there have been several studies on the prevalence of C. burnetii antibodies in dairy cattle bulk tank milk (BTM), there is a lack of information on the molecular detection of C. burnetii in BTM in South Korea. Thus, this study was designed to assess milk shedding of C. burnetii in BTM from dairy cattle herds. Among the 607 BTM samples collected from 41 counties in Gyeongsang provinces in 2015, 108 (17.8%) from 23 (56.1%) counties tested positive for C. burnetii by PCR. Because the 16S rRNA sequences of C. burnetii from all 108 PCR-positive samples were identical, two representative samples (BTM-GB-10 and BTM-GN-63) are described in this paper. These sequences showed high identity (96.9–100%) to other C. burnetii sequences deposited in GenBank. Phylogenetic analysis showed that these two sequences were clustered with existing C. burnetii strains. The relatively high prevalence rates of C. burnetii in BTM detected in this study suggest that C. burnetii is prevalent among dairy cattle herds in South Korea. Thus, implementation of continuous monitoring and control strategies for domestic animals is needed to prevent disease transmission and protect public health.

     

Stochasticity dominates assembly processes of soil nematode metacommunities on three Asian mountains

Nematodes play an important role in ecosystems; however, very little is known about their assembly processes and the factors influencing them. We studied nematode communities in bulk soils from three Asian mountain ecosystems to determine the assembly processes of free-living nematode metacommunities and their driving factors. On each mountain, elevations span a range of climatic conditions with the potential to reveal assembly processes that predominate across multiple biomes. A phylogenetic nu...     

大陈岛森林公园旅游资源及其开发前景探讨

论述了浙江省大陈岛森林公园现有的旅游资源──即生物资源、自然景观及人文景观等，同时提出了开发利用的一些设想。     

Evidence of Toxoplasma gondii Exposure among Horses in Korea

The present study investigated the seroprevalence of Toxoplasma gondii (T. gondii) antibodies by ELISA in horses reared in Korea. Serum samples were collected from 2009 through 2013 from 816 horses reared in Korea. Analysis was performed using a commercial toxoplasmosis ELISA kit to detect anti-T. gondii antibodies. Overall, 24 out of 816 horses (2.9%) were seropositive for T. gondii. The result was analyzed by age, gender, breed and region. Significant differences were observed according to breed and region (P<0.05). This is the first nationwide serological investigation of T. gondii in horses reared in Korea. The study results reveal that T. gondii occurs nationwide in Korean horses.     

Real-time intraocular pressure measurement during phacoemulsification in dogs ex vivo

This study was performed to evaluate changes in intraocular pressure (IOP) during standard coaxial phacoemulsification using 4 different bottle heights (BHs) and 2 different incision sizes. Coaxial phacoemulsification was performed with a venturi-based machine in 8 enucleated canine eyes through 3.0 and 3.2 mm clear corneal incisions (CCIs). A pressure transducer inserted in the peripheral cornea monitored the IOP in real-time. The surgery was subdivided into 4 stages: sculpt-segment removal, irrigation/aspiration, capsular polishing and viscoelastic removal. The mean IOP and the difference between the maximum and minimum IOPs were calculated at each stage and compared. The ultrasound time and volume of irrigation fluid used were recorded. The mean IOP increased with an elevation in the BH. The mean IOP in the irrigation/aspiration stage was significantly higher than that in the sculpt-segment removal stage at the same BH. The difference between the maximum and minimum IOP at each stage was greater in the 3.2 mm than the 3.0 mm CCIs, although the mean IOP was lower with the 3.2 mm than the 3.0 mm CCIs. The ultrasound time and irrigation fluid volume were greater with the 3.2 mm than the 3.0 mm CCIs. Therefore, fluidic parameters during each stage could be reassessed and adjusted to reduce complications arising from an elevated IOP. Phacoemulsification with 3.0 mm CCIs at a lower BH might lead to less stress on the eye from IOP fluctuations, ultrasound energy and irrigation fluid.     

Biological characterization and genetic diversity analysis of two species of Pestalotiopsis causing twig dieback of Myrica rubra

Chinese bayberry (Myrica rubra Siebold & Zucc) is an evergreen fruit tree with high ecological and economic values in China. In recent years, a new twig dieback disease caused by Pestalotiopsis mangiferae and P. vismiae was observed in major M. rubra-producing areas of Zhejiang and Fujian Provinces, causing serious economic losses. In this study, 16 isolates of P. mangiferae and 27 isolates of P. vismiae were obtained from diseased leaves, roots and branches of M. rubra from different regions. The optimum growth temperature of the two species of Pestalotiopsis was determined to be 20–25 °C, while the optimum temperature for the germination of conidia was 25–35 °C. The two species of Pestalotiopsis showed rich genetic diversity. Inoculating the conidial suspension of one or both of the two species of the Pestalotiopsis on detached leaves or branches of M. rubra could cause lesions surrounding the inoculation sites with the frequency of 100 %. Moreover, necrotic lesions could be observed on inoculated potted plants with the frequencies of 33.3 % for P. mangiferae, 25 % for P. vismiae and 50 % for a mixed inoculum.