• Journal of Korean Society of Forest Science
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• v.77 no.1
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• pp.17-22
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• 1988

Inhibitory effect of L. leptolepis fallen leaf extracts on the germination of Pinus densiflora, ${\times}$ Pinus rigitaeda, Pinus rigida, Pinus thunbergii and Larix leptolepis was investigated. Germination of those seeds in culture room and in pot at field showed the highly significant inhibitory effects by the aqueous extracts from L. leptolepis fallen leaves. Among them L. leptolepis was the most severely inhibited by the aqueous extracts used. To identify allelopathic substances, thin-layer chromatography was employed. Gallic, ferulic, t-cinnamic and vanillic acids were identified from fallen leaves of L. leptolepis. From the results, it is assumed that autotoxicity of L. leptolepis may act as inhibitory factors on germination of the species in natural stands.

• Journal of Ecology and Environment
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• v.35 no.2
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• pp.123-129
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• 2012

Salt marsh is an important transitional zone among terrestrial, riverine, and marine ecosystems and is a productive habitat that interacts extensively with adjacent landscape elements of estuarine and coastal ecosystems. Nowadays, in addition to various human activities, a variety of natural processes induce changes in salt marshes. This study aims to provide background information to restore disturbed salt marshes and to propose their ecological restoration using seed banks. The study area is a prepared area for the Gwangyang Container Port located in the southern Korea. This area was formed by accumulating mud soils dredged from the bottom of the forward sea. This land was created in a serial process of preparing the Gwangyang container port and the salt marsh was passively restored by seeds buried in mud soil dredged from seabed. As a result of stand ordination based on vegetation data collected from the land, stands were arranged according to tolerance to salinity in the order of $Suaeda$ $maritima$, $Salicornia$ $europaea$, and $Phragmites$ $communis$ communities on the Axis 1. Landscape structure of the projected area was analyzed as well. Edges of the projected area were divided from the marginal waterway by the dike. Four types of vegetation appeared on the dike: $Alnus$ $firma$ plantation, $Robinia$ $pseudoacacia$ plantation, $Lespedeza$ $cyrtobotrya$ plantation, and grassland. In the more internal areas, two types of vegetation sequences appeared: $Aster$ $tripolium$ community-$Suaeda$ $glauca$ community-$Salicornia$ $europaea$ community sequence and $Aster$ $tripolium$ community-$Suaeda$ $maritima$ community-$S.$ $europaea$ community sequence. Mixed community showed the highest species diversity (H' = 0.86) and $S.$ $europaea$ community showed the lowest (H' = 0.0). Evenness is the highest in Mixed community (J' = 2.26) and the lowest in $S.$ $maritime-S.$ $europaea$ community (J' = 0.0). Several plant communities were successfully established on the land created by mud soil dredged from the bottom of Gwangyang Bay. Moreover, community diversity in this area approached a similar level with those from other studies involving natural salt marshes. Therefore, restoration effect based on community diversity obtained in our study can be evaluated as a successful achievement. In this respect, although most salt marshes in Korea and other places worldwide have been destroyed or disturbed by excessive land use, feasibility of seed bank as a restoration tool is greatly expected.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.390-394
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• 2004

The genetically modified glyphosate-tolerant soybean contains the following introduced DNA sequences: the EPSPS (5-enol-pyruvylshikimate-3-phosphate synthase) gene from Agrobacterium sp. strain CP4, the 35S promoter from the cauliflower mosaic virus, and the NOS terminator from Agrobacterium tumefaciens. In the present study, detection of these introduced DNAs was performed by amplification using the polymerase chain reaction (PCR). A multiplex PCR method was also applied to prevent false positive results. When primers for 35S promoter, nos3', CTP(chloroplast transit peptide), and CP4 EPSPS (EPSPS from Agrobacterium sp. CP4) were used, positive results were obtained in PCR reactions using DNA from genetically modified glyphosate-tolerant soybeans. There were no false positive results when using DNA from non-genetically modified soybeans. The CP4 EPSPS gene was detected when less than 125 pg glyphosate-tolerant soybean DNA was amplified. Lectin Lel and psb A were amplified from both non-genetically modified and genetically modified glyphosate-tolerant soybean DNA. Multiplex PCR was performed using different primer sets for actin Sacl, 35S promoter and CP4 EPSPS. The actin gene was detectable in both non-genetically modified and glyphosate-tolerant soybeans as a constant endogenous gene. Target DNAs for the 35S promoter, and CP4 EPSPS were detected in samples containing 0.01-0.1% glyphosate-tolerant soybean, although there were variations depending on primers by multiplex PCR. Soybean seeds from five plants of non-genetically modified soybean were co-cultivated for six months with those of genetically modified soybean, and they were analyzed by PCR. As a result, they were not positive for 35S promoter, nos3' or CP4 EPSPS. Therefore, these results suggest there was no natural crossing of genes between glyphosate-tolerant and non-genetically modified soybean during co-cultivation, which indicates that gene transfer between these plants is unlikely to occur in nature.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.240-249
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• 2011

The potential of juglone a plant naphthoquinone as a natural herbicide on new target, 7-keto-8-amino pelargonic acid synthetase (KAPAS) in the early step of biotin biosynthesis pathway, was performed in vitro and in vivo. Juglone effectively inhibited KAPAS activities in vitro and the $IC_{50}$ was $9.5{\mu}M$. Foliar application of juglone showed very good herbicidal activity to the eight-tested weed species. Among them, Solanum nigrum was completely controlled at a concentration of $250{\mu}g\;mL^{-1}$ with main symptoms of desiccation or burndown. Digitaria sanguinalis and Aeschynomene indica were also sensitive to juglone treatment. All eight weed species were controlled by 90~100% at a concentration of $500{\mu}g\;mL^{-1}$. However, soil application of juglone to Digitaria sanguinalis did not show any herbicidal symptoms. Cellular leakage from cucumber leaf squares treated with juglone increased depending on the concentrations increased from 6.25 to $100{\mu}M$ after 24 hours incubation with or without light. However, chlorophyll loss in cucumber leaf squares was negligible. Biotin supplements significantly rescued the inhibition of germination rate of Arabidopsis thaliana seeds previously inhibited by the juglone. Our results suggest that the juglone is a possible environmental friendly herbicide candidate with a new target KAPAS inhibiting activity.

• Journal of Korean Society of Forest Science
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• v.102 no.1
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• pp.1-6
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• 2013

This study was conducted to investigate the variation of fruit and seed morphology among populations and among individuals within population of Sorbus commixta Hedl. distributed in Korea. Fruits collected from 42 trees in six natural populations and their six fruit and four seed characteristics were analyzed. In all characteristics, there were significant differences among populations and among individuals within populations. Especially, number of fruits per fruit-bearing branch and number of seeds per fruit showed higher values among populations in total variance component. Coefficients of variation in the number of fruits per fruit-bearing branch and seed weight are relatively high (42.0~75.3%) compared to other traits (11.9~32.1%). As a result of simple correlation analysis, the number of fruits per fruit-bearing branch showed a significant positive correlation with latitude but showed a negative correlation with longitude. According to cluster analysis, geographically close populations showed the tendency of clustering into the same group. Three principal components (PC) were deduced from principal component analysis, which explain the 87% of total variance of fruit and seed characteristics. The highest contribution was seed length and seed weight in PC1, fruit width and seed index in PC2 and fruit length and number of fruits per fruit-bearing branch in PC3.

• Korean Journal of Plant Resources
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• v.24 no.1
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• pp.69-75
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• 2011

This study was conducted to investigate the variation of cone, seed and germination characteristics among populations and among individuals within populations of Picea jezoensis(Siebold & Zuccarini) Carriere distributed in Korea. Cone collected from 25 trees in two natural populations(Mt. Jiri and Mt. Dokyu) and their thirteen cone and seed characteristics as well as three germination behaviors were analyzed. Statistical analysis showed significant differences among populations and among individuals within populations in 9 traits except for seed breadth, seed weight, index of seed wing and mean germination time. Generally, morphological variation of cone and seed wings from Mt. Jiri population has smaller and longer than those of Mt. Dokyu population. Percentage of sound seeds and Tetrazolium test from Mt. Jiri population showed 1.79 and 1.87 higher values than Mt. Dokyu population, respectively. The maximum germination percentage was obtained at the optimum temperature of $20^{\circ}C$ and in this case, mean germination time and germination rate showed 7.5 days and 2.9 ea./day, respectively. In seed germination behaviors, percentage(40.7%) and rate(0.90 ea./day) of germination in Mt. Jiri population were more higher and faster than those of Mt. Dokyu population(17.7%, 0.37 ea./day). According to correlation analysis, P. jezoensis populations with small restricted distribution may have been reduced because seed qualities were correlated with increased levels of inbreeding and disproportion flowering.

• Korean Journal of Environment and Ecology
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• v.28 no.6
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• pp.705-714
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• 2014

This text was analyzed and investigated the aerial part plants and buried seed plants at coniferous forest and broadleaved forest in Yesan-gun, in order to offer the basic data of potential natural vegetation change on secondary forest. Plants of buried seed germination were consisted of 29 taxa in coniferous forest (28 species, 1 varieties, of 27 genus, 20 families) and 36 taxa in broadleaved forest (34 species, 2 varieties, of 32 genus, 18 families). Family classification of buried seed plant was the most in Compositae, and emergent plot frequency was the highest of Cyperus amuricus in coniferous forest and Crepidiastrum sonchifolium in broadleaved forest. The soil depth of the most plants appearance was 0~10 cm in coniferous forest and 0~5 cm in broadleaved forest, and the soil depth of the most population appearance was 0~2 cm in coniferous forest and broadleaved forest. Population of buried seed germination was decreased according as soil is deep. Crepidiastrum sonchifolium was a plant that population of buried seed germination is the most. Similarity index of the aerial part plants and buried seed plants was low as 0.22, and coniferous forest and broadleaved forest was 0.40.

• Weed & Turfgrass Science
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• v.4 no.2
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• pp.118-123
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• 2015

Metagenomics is a powerful tool to isolate novel biocatalyst and biomolecules directly from the environmental DNA libraries. Since the metagenomics approach bypasses cultivation of microorganisms, un-cultured microorganisms that are majority of exists can be the richest reservoir for natural products discovery. To discover novel herbicidal substances from soil metagenome, we established three easy, simple and effective high throughput screening methods such as cucumber cotyledon leaf disc assay, microalgae assay and seed germination assay. Employing the methods, we isolated two active single clones (9-G1 and 9-G12) expressing herbicidal activity which whitened leaf discs, inhibited growth of microalgae and inhibited root growth of germinated Arabidopsis seeds. Spraying butanol fraction of the isolated active clones' culture broth led to growth retardation or desiccation of Digitalia sanguinalis (L) Scop. in vivo. These results represent that the screening methods established in this study are useful to screen herbicidal substances from metagenome libraries. Further identifying molecular structure of the herbicidal active substances and analyzing gene clusters encoding synthesis systems for the active substances are in progress.

• Journal of Marine Life Science
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• v.3 no.1
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• pp.31-37
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• 2018

We investigated natural habitat of seagrass and created replacement habitat to monitor for restoration of the habitat which is expected to be damaged at Cheonseong harbor in Busan. Depth of water for natural seagrass habitat at Cheonseong harbor was 1.2~3.1 m and the water temperature was 7.4℃, salt concentration was 29.1 psu and pH was 8.05 in January, 2013. The density of seagrass was 167.1±16.4 shoots m^-2, the total length was 48.5±18.1 cm, the height of sheath was 9.1±2.8 cm and the width of leaf was 4.8±1.1 cm, respectively. We transplanted in December 2014 and monitored the habitat during 9 months after transplanted. In the beginning, the density of seagrass was decreased to 8.5 shoots patch^-1 in January and was increased to 19.0 shoots patch^-1 in April. The total height were 73.3±2.9~121.3±6.1 cm, the length of sheath were 9.6±0.6-21.0±1.2 cm, the width of leaf were 5.7±0.1~6.8±0.2 mm. It showed that all values were increased steadily until July and was decreased rapidly in August. Flowering shoot, which was not observed in the beginning of transplanting, started to be spotted in March and was continued to be seen during the monitoring period. We were able to observe seedling of germinated seagrass in seeds in the replacement habitat next year.

• Korean Journal of Weed Science
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• v.31 no.3
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• pp.260-270
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• 2011

This study was carried out to examine the effect of rice bran, barley bran, burned rice bran, and burned barley bran on the growth and yield of Chinese chive (Allium tuberosum Rottler), taro (Colocasia esculenta), and weed control. When the above 4 brans were examined 13, 27, 41 and 57 days respectively after application, the plant height of Chinese chive applied with burned barley bran was significantly higher than non-treated control, whereas the other brans did not have any distinct effect on the plant height or population number of Chinese chive. However, when examined 57 days after the application of the above 4 brans, all the plants applied with brans showed more than twice the improvement in shoot fresh weight compared with non-treated control. A chemical analysis of soil 57 days after the application of the above 4 brans showed that the soils were richer in available phosphate and organic matter. Shoot fresh weight of Chinese chive at 2 weeks after cutting was significantly higher in barely bran treated plot than in non-treated plot. In the case of taro, only taro plots transplanted when 10 cm tall and applied with barley bran showed an improvement in growth increment of both the underground and above parts. However, when sowed seeds after the application of the 4 brans, the yield of taro was reduced by the brans. Thus this research indicates that the effect of brans is differ based on the amount of bran application as well as crops. The effect of weed control on Echinochloa crus-galli, Digitaria clliaris, Chenopodium album, and Solanum nigrum as affected by brans was very low in pot conditions. Weed efficacy of the brans was also very low in field conditions. Growth of Chinese cabbage and garland chrysanthemum was inhibited 63% and 37% by rice bran at $4,000kg\;ha^{-1}$, respectively, but other crops such as maize, squash, cucumber, and Chinese chive were inhibited by 0-20%. These results were similar to that of barley bran except for Chinese cabbage.