• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.3
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• pp.265-272
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• 1999

In this study in order to know the behavior of mineral nutrients from forage plant to soil in a grassland ecosystem, the leaching of minerals (K, Mg, Ca, N and P) from air-dried (dead) plant body was investigated by putting orchardgrass (Dactylis glomerata L.) hay on meadow during a month with seasonal changes. The results obtained were as follows; 1) The K content of the forage, not stable during the experimental seasons, tended to decrease in the summer of 1986, while the Mg and Ca contents increased in the summer. The reason might be a different response (solubility or leaching liability) of the monovalent mineral (K) and divalent ones (Mg and Ca) in the forage to rainfall. 2) The percentage of P to the initial amount in the forage showed larger decrease in a rainy period (Feb.~Mar., 1986) and during the rainy summer (May to July). The P component of the forage might be easily leached with water. 3) The percentage of the four minerals (Ca, N, Mg, K) remained the least in the period of (Jun.~Jul., 1986), 4) Though the percentage of remained Mg and N of the forage varied very similarly, the percentage of remained N was higher than that of Mg during periods before summer (January to May), while after the period the ratio of the Mg seemed to be higher than that of the N (June to December), 5) During the periods until (May~Jun., 1986) the percentage of remained K and P of the forage varied in very similar pattern, and the order of remained mineral was as follows; $Ca>N{\geq}Mg>P=K$. But from the period of (Jun-Jul) the ratio of P remained in the forage increased nearly up to the ratio of N, and the order was as follows; $Ca>Mg{\geq}N{\geq}P>K$.

• Journal of Korean Society of Forest Science
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• v.102 no.1
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• pp.38-58
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• 2013

The existence of endemism in many parts of the world is an important factor for conservationists. Conservation can only be carried out under national legislation, and national endemics, which have very limited ranges, fully depend on the effort and success of conservation. A total of 523 vascular plant taxa were listed in the latest national checklist by Ministry of Environment in 2005, while the 'Creation and Furtherance of Arboretums Act' including a national endemic list (appendix 4-1) was established by Korea Forest Service and was legislated as a law in late 2011. This legislation by Korea Forest Service on endemism of Korean vascular plants have required much attention because of discrepancies of nomenclature, taxonomic bias and inflation. Examining data for both lists proposed by Ministry of Environment and Korea Forest Service, of the total of 360 legislated taxa, around 286 taxa are shared with the list of Ministry of Environment, of which about 80% have been found as common taxa. Around 67(18.7%) are typographic errors, and 14 taxa (3.9%) are recorded as illegitimate and invalidly published names. Through this analysis 12 taxa (3.4%) were found in China as well as in Korea and these are thought to be non Korean endemic taxa. Taken together, the legislated list displayed 1/4 (24.9%) errors out of the total list. Only 59 taxa (16.5%) are identified as national endemic species. The remainder are either unresolved candidates (73 taxa, 20.4%) or synonyms (196 taxa, 54.7%) status. It must be noted, that the concept of endemism very much depends on the knowledge of the species concept, taxonomic bias and geographical range of a species. Also, the most major nomenclatural problem tend to be more stable if the information on database about Korea Plant Name, which is managed by Korea National Arboretum are well updated year to year. These exaggerated numbers underscore the urgency for regional conservation planning and implementing effective strategies to preserve these real endemic taxa into the future.

• Korean Journal of Medicinal Crop Science
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• v.4 no.4
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• pp.301-307
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• 1996

The experiment was conducted to clarify the effect of water stress treatment on growth character of Ligusticum chuanxiong Hort. The water stress treatment was imposed artificially on seedling, flowering and rhizome enlargement stage of the plant. The decrease ratio of leaf area compare with control decreased to 24.4% by water stress treatment at seedling stage and to 41.6% at rhizome enlargement stage. The reduction rate of chlorophyll content at the end of water stress treatment was 41.2% at the see­dling stage and no difference at the flowering stage. The chlorophyll content of water stress treatment on seedling and flowering stage was recovered to 95% at harvest time. The ratio of rootlet distribution from top soil to l0cm depth showed maximum to 90% at the seedling stage and to 20cm depth showed max­imum to 6.4% at the rhizome enlargement stage. The dry weight of rootlet was decreased to $19.3{\sim}40.3%$ by water stress treatment. Dry weight of aerial part and underground part of the plant decreased in the order of seedling, flowering, rhizome enlargement and control and the dry weight of aerial part decrease more severely than underground part.

• Korean Journal of Plant Taxonomy
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• v.35 no.4
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• pp.247-272
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• 2005

The Philadelphus schrenkii complex including P. schrenkii var. schrenkii, P. schrenkii var. jackii, P. schrenkii var. mandshuricus, P. tenuifolius, P. pekinensis, P. seoulensis, P. lasiogynus, and P. scaber, is distributed in China, Korea, japan, and far eastern Russia. Their taxonomic delimitations are obscure because quantitative characters, such as presence/absence and density of hair on leaf, petiole, style, disc, calyx-tube, and pedicel, are highly variable with no apparent characteristics that consistently distinguish from each other within the group. Thus, these morphological characters are reexamined using univariate analyses. P. pekinenesis is distinct from other taxa in having glabrous disk, calyx, pedicel, and leaf blade. In addition, the number of flowers in an inflorescence [(5)7-9(11) vs 5-7 in other taxa], smaller calyx tube [2.5-3 mm vs. (2.5)3-4(5.9) in other taxa], and slightly divided styles help distinguish P. pekinenesis from other related taxa in Korea. However, P. schrenkii var. schrenkii, P. schrenkii var. jackii, P. schrenkii var. mandshuricus, and P. lasiogynus show continuous variation in the pubescence of disk, calyx, pedicel, and leaf blade, and this may reflect a lack of divergence among them. Particular emphases are placed on P. tenuifolius and P. seoulensis, because of the high degree of morphological intergradation with respect to the degree of pubescence in disk, calyx, pedicel, and leaf blade and their inconsistent circumscription across various systematic treatments. P. scaber, distributed in the southern Korea, has often been treated as an independent species having exfoliated branchlets, distinct serrated leaf margin, and recurved styles. However, this current study suggests that P. scaber should be recognized as a form of P. tenuifolius because these distinguishing characters are continuous between P. tenuifolius and P. scaber. In geographical distribution, P. pekinensis is mainly distributed in the southern part of Korea, while P. tenuifoilus and P. schrenkii are commonly found all over the country.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.39-45
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• 2012

To explore on the defense strategies against hervivory of 67 broadleaved tree species, morphological characteristics of the leaf, leaf domatia structure and the number, herbivores insects and mites on the leaves, collected from the trees growing in Taean-gun, Chuncheongnam-do were investigated. 46 broadleaved tree species(68.7%) had the domatia structures, and 21 species including Quercus salicina and Magnolia grandiflora did not. 31 species including Juglans mandshurica and Carpinus laxiflora reveals tuft type, 12 species including Quercus dentata and Corylus heterophylla reveals pocket+tuft type, and 2 species, Sorbus alnifolia and Prunus yedoensis does pocket type, and Viburnum odoratissimum var. awabuki does pouch type. Domatia number per leaf proves the highest figures, 23.4/leaf for Quercus dentata. Plant defense strategies using leaf lower-surface trichomes of Magnolia grandiflora reveals dense villous, those of Populus alba and Vitis vinifera reveals dense pilose, that of Elaeagnus umbellata does dense scaly hairs, that of Pueraria lobata does dense strigose. Plant defense strategies using extrafloral nectaries were adapted 23 tree species(34.3%). Observed examples are Prunus tomentosa, Ficus carica, Viburnum dilatatum and Carpinus laxiflora. Predatory mites were observed on the leaves of 40 tree species(59.7%), and mean values of predatory mites was highest values 23.4/leaf in Quercus dentata. Minute arthropods destroying the leaf of broadleaved trees. are such as Periphyllus californiensis, P. viridis, Diaspididae sp., gall mites, thrips, and total numbers observed were odered gall mites, Diaspididae sp., aphids and thrips. Natural enemies of these hervivores arthropods are such as predatory mites, Chilocorus rubidus, Coccinella septempunctata and the nymph, Aphidius ervi. These results indicate that defense strategies including protective mutualisms may be frequent in the temperate broadleave trees.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.293-303
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• 2017

To elucidate the physiological responses of rice plants to the essential mineral silicon (Si), we assessed the effects of treatments with Si, nitrogen ($NH_4NO_3$; ammonium nitrate), and calcium ($CaCl_2$; calcium chloride), independently or in combination on mineral uptake rates and levels of the hormones abscisic acid (ABA), gibberellin ($GA_1$) and jasmonic acid (JA). We found that nitrogen and calcium uptake was inhibited by Si application. However, solo application of nitrogen or calcium did not affect Si uptake. Compared to the untreated plants, the application of Si, $NH_4NO_3$ or $CaCl_2$ increased the endogenous hormone levels in treated plants. In particular, the concentrations of $GA_1$ and JA increased significantly after the application of Si or $NH_4NO_3$. The level of $GA_1$ observed after a treatment (solo or combine) with Si, and $NH_4NO_3$ was higher than that of the control. By contrast, independent application of $CaCl_2$ or a combined treatment with Si and $CaCl_2$ did not alter $GA_1$ levels. The highest level of $GA_1$ was present in plants given a combination treatment of Si and $NH_4NO_3$. This effect was observed at all time points (6 h, 12 h and 24 h). Endogenous JA contents were higher in all treatments than the control. In particular, a combination treatment with Si and $NH_4NO_3$ significantly increased the JA levels in plants compared to other treatments at all time points. A small increase in JA levels was observed after 6 h in plants given the $CaCl_2$ treatment. However, JA levels did not differ between plants given a $CaCl_2$ treatment and controls after 12 h or 24 h of exposure. We conclude that treatment with $CaCl_2$ alone does not affect endogenous JA levels in the short term. Endogenous ABA contents did not show any differences among the various treatments.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.1
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• pp.8-14
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• 2006

High phosphate accumulations in greenhouse soils have been considered as a new agricultural problem in Korea. The effects of silicate on changes in phosphate fractions and on the yield of Chinese cabbage without P fertilization were investigated by pot experiment. For this experiment, P-accumulated soil was selected (Total-P; $2140mg\;kg^{-1}$). Three levels of silicate (0, 2, and $4Mg\;ha^{-1}$) without P fertilization and P fertilizer without silicate application (Si0+NPK) were applied in 1/2000a pots. The same amount of nitrogen and potassium fertilizers were applied to the all pots. The application of $4Mg\;ha^{-1}$ of silicate greatly increased the yield of Chinese cabbage by 25% compared to Si0+NPK treatment. Although there is no significant difference in plant P absorption among all the treatments, the uptake of P in the $4Mg\;ha^{-1}$ silicate application was significantly higher than Si0+NPK treatment due to increase in yield. The content of available $SiO_2$ in soil increased with increasing silicate application rates. The Si concentration of plant showed a positive correlation with available $SiO_2$ contents in soil and the yield of Chinese cabbage. Total P greatly decreased with increasing rates of silicate application, yet the change in available P content was not significant. The Si0+NPK treatment increased the content of Ca-P by 11%, however, which was decreased by 27% in the $4Mg\;ha^{-1}$ silicate application. Therefore, the effect of silicate on reducing total-P was mainly attributed to the change in concentration of Ca-P. Our results suggest that the application of silicate in P-accumulated soils not only increase the crops yield but also reduces phosphate accumulation.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.412-419
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• 2009

In order to study the inheritance of watermelon seed size, we used six watermelon lines of different seed sizes as parental lines. Six lines include three accessions, 'PI525088' with giant seed (GS), 'Charleston Gray' with big seed (BS), and 'NT' with normal medium size seed (NS), and three near isogenic lines, 'NTss' with small seed (SS), 'NTms' with micro seed (MS) and 'NTts' with tomato seed size (TS) bred by crosses between accession 'NT' of normal seed size and accession 'TDR' of the smallest seed size,. We inspected $F_1$, $F_2$, $BC_1F_1$ (P1), $BC_1F_1$ (P2) populations from the crosses between the adjacent seed size materials like $GS{\times}BS$, $BS{\times}NS$, $NS{\times}SS$, and $MS{\times}TS$, and two crosses between parental lines showing relatively big difference in seed size such as $GS{\times}TS$ and $NS{\times}TS$. Partial single dominant inheritance patterns were observed between $GS{\times}BS$, $NS{\times}SS$, and $MS{\times}TS$ and inheritance patterns based on two genes or more than two genes were speculated between $BS{\times}NS$. A very wide segregation range was observed from the population of $GS{\times}TS$ indicating many quantitative genes involved in the seed sizes. Overall, we speculated that more than six genes are involved in between the biggest and smallest seed size watermelon and three major genes between the normal seed size and the smallest seed size watermelon.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.403-411
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• 2009

We inspected seed sizes of 353 genetic accessions of watermelon to diversify functional utility related to seed size and classified them into six representative groups based on their seed sizes. Each group was named as giant seed (GS), big seed (BS), medium size (NS), small size (SS), micro seed (MS) and tomato seed (TS) from the biggest. As the seed size was getting smaller, decreased seed length and seed width, increased seed number per fruit, and decreased seed weight per fruit were observed, but seed shape did not change significantly. In order to study the effect of seed size on fruit weight and seed germination, we developed three near isogenic lines (NILs) with three different seed sizes, SS, MS and TS, from crossing between two accessions 'NT' and 'TDR', and one NIL with seed size of TS from crossing between two accessions 'S55' and 'TDR'. In the study on the fruit weight of NILs with various seed sizes, NS, SS, MS, and TS NILs produced an average of 6.4, 6.3, 5.9, and 4.2 kg fruits, respectively. The bigger seed types showed the better germination rate. NS type showed the highest germination percentage, while TS showed very low germination percentage. Fermentation treatment for 48 hrs increased the germination percentage on TS type seed, but still remained at a low level. In NS, SS, and MS material, the ratio of embryo/whole seed weight was over 50%, meanwhile that of TS was only 44.4% of which low embryo percentage would be one of the reason of low germination percentage. From this study, we concluded that watermelon has very wide genetic diversity on seed size which is somehow related to fruit sizes and germination rate.

• Journal of Plant Biotechnology
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• v.45 no.4
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• pp.400-408
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• 2018

Biodiversity has continued to degrade in the $21^{st}$ century due to global warming occasioned by destruction of the environment around the world.. The Nagoya protocol places Korea in a unique position to effectively develop and protect its domestic genetic resources. Microalgae under study in this research contains large amount of antioxidant substances such as beta carotene and astaxanthin, that can be used as biological resource owing to the large amounts of biomass that can be secured through photosynthesis. However, it is difficult to preserve it since cryopreservation method used for long-term preservation is yet to be developed. A basic study for long term cryopreservation was carried out on Nizschia frustulum and Nitzschia amabilis which belong to marine diatoms. As cryoprotectants (CPAs), glycerol, DMSO, and methanol which penetrate into cells were prepared at 5%, 10%, and 15% concentrations each, in case of methanol, it was tested at concentrations of 5%, 10% and 12% by its nature. Two kinds of microalgae, N. frustulum and N. amabilis, were diluted with $10^2$, $10^3$ and $10^4cells\;ml^{-1}$, respectively. The highest survival rate was shown at12% concentration of methanol, and the figures were $6.94{\pm}0.31%$ in N. frustulum and $8.85{\pm}0.16%$ in N. amabilis. As a result of 3 weeks cultivation of thawed microalgae after freezing, the result is shows that N. frustulum increased about 10 times faster and N. amabilis increased about 12 times the original concentration.