• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.490-494
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• 2003

To understand flowering response under diverse day-length condition and the movement of floral stimulus, we used six perilla accessions which showed diverse days to flowering. Though the growth phase was reported as irreversible between vegetative and reproductive stage, perilla showed reversible growth phase according to day length increase in May and June. When it sowed in March, flowering response was started in early May and vegetative and reproductive phase was coexisted in late June. When a part of a perilla plant was treated under short day condition, only apical buds on main stem or branches were flowered but other long day conditioned apical buds were not flowered. With this result it is suggested that the floral stimulus can not be transferred to other part of perilla.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.97-102
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• 2000

This experiment was conducted to investigate the changes of harvest index and the relationship between harvest index and yield determination factors by different planting times in the determinate soybean cultivars, Shinpaldal and Danbaeg. Optimum planting were 23 May in 1995 and 1996. Late planting were 13 June in 1995 and 6 June in 1996. Growth period from planting to physiological maturity (R7) was shortened as planting time was delayed in two cultivars due to shortening of reproductive growth period in Shinpaldal, and of vegetative growth period in Danbaeg. Stem weight was distinctly decreased in late planting compared to optimum planting, but seed weight of both cultivars was not different between planting times. Also, seed number per pod and harvest index were significantly increased in late planting and the high correlation was found between two factors. It was suggested that increase of harvest index in late planting would be related with high assimilate use efficiency due to increase of sink capacity. The results of correlation and principal component analysis for yield determination factors showed that main factor on yield determination was pod number per plant at R5 stage associated with dry matter accumulation during early reproductive growth period, seed number per pod and harvest index were the second factor, and one hundred seed weight was the third factor. The result of this experiment indicated that yield determination in soy-bean was dependent mainly on pod number per plant related to dry matter accumulation by early reproductive growth period, and the increase of seed number per pod and harvest index could compensate for yield decrease by shortening of vegetative growth period in late planting. Such result suggests that optimum planting date can be delayed from mid May to early June in improved soybean cultivars in Korea.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.1
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• pp.20-25
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• 1988

This experiment was conducted to find out the effects of the different cutting height on the chemical composition, energy production and relation of yields of Italian ryegrass, tall fescue and perennial ryegrass swards. It was carried out on the experimental field of Livestock Experiment Station, in Suweon, from Sept. 1986 to May 1987. The results obtained are summarized as follows: 1. Chemical composition and Van Soest fiber contents were slightly different among grasses. But were not same trend with cutting heights. At the late vegetative stage, crude protein and crude fiber content were much more in tall fescue, Ash in perennial ryegrass, E.E. and NFE in Italian ryegrass respectively. NDF, ADF, Hemicellulose, Lignin, Cellulose and Silica contents were much more in tall fescue than the others. 2. DM, DCP, TDN, StE, ME and NEL productions were appeared to high in line with Italian ryegrass, perennial ryegrass and tall fescue. In addition 6 cm cutting height was the most production in Italian ryegrass, 15 cm cutting height was the most production in perennial ryegrass and tall fescue. 3. The much more content of crude protein, the less nonstructural carbohydrate content. The less content of NDF, the much more nonstructural carbohydrate content. Green and dry matter yield before wintering were not influence the green and dry matter yield of the late vegetative stage, but green yield before wintering influenced total green yield.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.384-396
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• 2014

Vegetative compatibility groups (VCGs) are determined for many fungi to test for the ability of fungal isolates to undergo heterokaryon formation. In several fungal plant pathogens, isolates belonging to a VCG have been shown to share significantly higher genetic similarity than those of different VCGs. In this study we sought to examine the relationship between VCG and genetic similarity of an important cool season turfgrass pathogen, Sclerotinia homoeocarpa. Twenty-two S. homoeocarpa isolates from the Midwest and Eastern US, which were previously characterized in several studies, were all evaluated for VCG using an improved nit mutant assay. These isolates were also genotyped using 19 microsatellites developed from partial genome sequence of S. homoeocarpa. Additionally, partial sequences of mitochondrial genes cytochrome oxidase II and mitochondrial small subunit (mtSSU) rRNA, and the atp6-rns intergenic spacer, were generated for isolates from each nit mutant VCG to determine if mitochondrial haplotypes differed among VCGs. Of the 22 isolates screened, 15 were amenable to the nit mutant VCG assay and were grouped into six VCGs. The 19 microsatellites gave 57 alleles for this set. Unweighted pair group methods with arithmetic mean (UPGMA) tree of binary microsatellite data were used to produce a dendrogram of the isolate genotypes based on microsatellite alleles, which showed high genetic similarity of nit mutant VCGs. Analysis of molecular variance of microsatellite data demonstrates that the current nit mutant VCGs explain the microsatellite genotypic variation among isolates better than the previous nit mutant VCGs or the conventionally determined VCGs. Mitochondrial sequences were identical among all isolates, suggesting that this marker type may not be informative for US populations of S. homoeocarpa.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.752-757
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• 2009

In the last decade, many methods such as greet chamber, reservoir, or debris barrier, have been utilized to manage and prevent muddy water problem. The Vegetative Filter Strip (VFS) has been thought to be one of the most effective methods to trap sediment effectively. The VFS are usually installed at the edge of agricultural areas adjacent to stream or drainage ditches, and it has been shown that the VFS effectively removes pollutants transported with upland runoff. But, if the VFS is installed without any scientific analysis of rainfall-runoff characteristics, soil erosion, and sediment analysis, it may not reduce the sediment as much as expected. Although Soil and Water Assessment Tool (SWAT) model has been used worldwide for many hydrologic and Non-Point Source Pollution (NPSP) analysis at a watershed scale. but it has many limitations in simulating the VFS. Because it considers only 'filter strip width' when the model estimates sediment trapping efficiency, and does not consider the routing of sediment with overland flow option which is expected to maximize the sediment trapping efficiency from upper agricultural subbasin to lower spatially-explicit filter strip. Therefore, the SWAT overland flow option between landuse-subbasins with sediment routing capability was enhanced with modifications in SWAT watershed configuration and SWAT engine. The enhanced SWAT can simulate the sediment trapping efficiency of the VFS in the similar way as the desktop VFSMOD-w system does. Also it now can simulate the effects of overland flow from upper subbasin to reflect the increased runoff volume at the receiving subbasin, which is what is occurring at the field if no diversion channel is installed. In this study, the enhanced SWAT model was applied to small watershed located at Jaun-ri in South Korea to simulate diversion channel and spatially-explicit VFS. It was found that approximately sediment can be reduced by 31%, 65%, 68%, with diversion channel, the VFS, and the VFS with diversion channel, respectively.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.5
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• pp.155-163
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• 2004

The objectives of this study were to characterize the wastewater flow through the VFS, and relate this to the P removal in the VFS. A total of 68 subsurface wells (20∼40 cm below the soil surface) and 35 surface wells (0~5 cm), and the application of chloride tracer were used to investigate flow paths and soluble reactive P (SRP) removal from the 21 m wide and 33 m long VFS receiving dairy milkhouse waste. The early chloride breakthroughs in wells in the center of the VFS showed that the milkhouse waste flows preferentially down in the center of the hillslope. The locally saturated area created near the discharge pipe in the center of the VFS accelerates surface flow that contributed to rapid transport of P to the down slope area. Although VFS of 33m long eventually reduced SRP to lower than 0.2 mg/L in most cases, SRP is less effectively removed in the areas where soil saturation occurred. It is suggested that the effort to distribute the wastewater uniformly to avoid soil saturation and reduce the flow velocity need to be considered in new designs.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.115-120
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• 2004

A Gram (-), rod-shaped bacterium in size of 1.3∼$1.8{\times}0.35{\mu}m$ inhibiting the growth of cyanobacterium (Ana-baena cylindrica) was isolated and designated NG-2 in this manuscript. This isolate showed positive reactions for catalase and oxidase, and optimal growth conditions of 35∼TEX>$40<^{\circ}C$ and pH 9.0. In a mixed-culture of A. cylindrica and the isolate, each microorganism grew inverse-proportionally, and the cyanobacterial vegetative cells almost completely disappeared within 24 hours. NG-2 lysed A. cylindrica only under light, which means that lytic activity of NG-2 was dependent on the photosynthetic activity of host. When observed under phase contrast microscope, the isolate lysed vegetative cells of A. cylindrica in scattered state in a liquid medium, whereas het-erocysts have not been lysed. When cyanobacterial cell walls have been lysed partly, NG-2 attatched around A. cylindrica filament and formed colony, then encouraged complete lysis of cyanobacterial cells. The isolate showed similar lytic activity in natural water as in an artificial medium. And lytic activity of NG-2 was enhanced when attached on expandable polystyrene bead.

• The Plant Pathology Journal
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• v.28 no.3
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• pp.227-238
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• 2012

Mitogen-activated protein kinase (MAPK) cascades are conserved signaling modules in the eukaryotic cells. They are involved in many major cell processes in fungi such as stress responses, vegetative growth, pathogenicity, secondary metabolism and cell wall integrity. In this review, we summarized the advances of research on the MAPK signaling pathways in Alternaria species. As major phytopathogenic fungi, Alternaria species reduce crop production. In contrast to the five MAPK pathways known in yeast, only three MAPK pathways as Fus3/Kss1-type, Hog1-type, and Slt2-type have been characterized in Alternaria. The Fus3/Kss1-type MAPK pathway participates in regulation of vegetative growth, conidiation, production of some cell-wall-degrading enzymes and pathogenicity. The Hog1-type pathway is involved in osmotic and oxidative stress, fungicides susceptibility and pathogenicity. The Slt2-type MAP kinases play an important role on maintaining cell wall integrity, pathogenicity and conidiation. Although recent advances on the MAPK pathways in Alternaria spp. reveal many important features on the pathogenicity, there are many unsolved problems regarding to the unknown MAP kinase cascade components and network among other major signal transduction. Considering the economic loss induced by Alternaria spp., more researches on the MAPK pathways will need to control the Alternaria diseases.

• Microbiology and Biotechnology Letters
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• v.2 no.3
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• pp.127-131
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• 1974

Inhibition of over-oxidation of prednisolone in the fermentation has been studied by using vegetative cells as enzyme source. firstly, A. simplex (ATCC 6946) was demonst.ated to degrade p.ednisolone in the vegetative culture of the microorganism. Over 72％ of hydrocortisone was transformed into prednisoloneby 3 hours of the fermentation. However, the prednisolone produced was considerably oxidized forming over-oxidation product in 8hours of fermentation period with the intact cells. Secondly, in order to depress the over-oxidation and the breakdown of the steroid skeleton of prednisolone, chelating agents such as $\alpha$$\alpha$'-dipyridyl, o-phenanthroline and 8-hydroxyruinoline were added to the fermentation broth. Conseauently, the breakdown of prednisolone by the iutact cells was able to be remarkably retatded and an intermediate regarded as an oxidized product derived from prednisolone was accumulated, by the addition of $\alpha$$\alpha$'-dipytidyl in the fermentation.

• Journal of Microbiology and Biotechnology
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• v.26 no.10
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• pp.1774-1780
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• 2016

Vegetative insecticidal proteins (Vips) are insecticidal proteins synthesized by Bacillus thuringiensis during the vegetative stage of growth. In this study, Vip3Aa protein, obtained by in vitro expression of the vip3Aa gene from B. thuringiensis WB5, displayed high insecticidal activity against Spodoptera litura aside from Spodoptera exigua and Helicoverpa armigera. Bioassay results showed that the toxicity of Vip3Aa protein against S. litura larvae statistically decreased along with the increase of the age of the larvae, with LC₅₀ = 2.609 ng/cm² for neonatal larvae, LC₅₀ = 28.778 ng/cm² for first instar larvae, LC₅₀ = 70.460 ng/cm² for second instar larvae, and LC₅₀ = 200.627 ng/cm² for third instar larvae. The accumulative mortality of 100% larvae appeared at 72 h for all instars of S. litura larvae, when feeding respectively with 83.22, 213.04, 341.40, and 613.20 ng/cm² of Vip3Aa toxin to the neonatal and first to third instar larvae. The histopathological effects of Vip3Aa toxin on the midgut epithelial cells of S. litura larvae was also investigated. The TEM observations showed wide damage of the epithelial cell in the midgut of S. litura larvae fed with Vip3Aa toxin.