• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.95-95
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• 2022

Maize is one of the world's three largest crops and has a long cultivation history, and is an important crop used for various purposes such as food, feed, and industrial raw materials. Recently, the agricultural environment is changing, in which the limit of cultivation of crops is shifted to the north due to the rise in temperature due to climate change. This study was conducted in experimental field of Suwon in 2022 by setting a seeding period earlier than the sowing time to establish the North Korean agricultural climatic zone and meteorological conditions. The test cultivars were silage cultivars, Kwangpyeongok and Dacheongok. As a priming test method, it was used to directly plant seeds in the field through immersion using 4mM zinc (Zn) and 2.5mM manganese (Mn), which are trace elements for seeds. The planting season was early on March 15th, April 1st, and April 15th. The number of days from sowing to silk stage of the two cultivars sown on March 15, April 1, and April 15 was 107, 93, and 85 days for Kwangpyeongok and 109, 95, and 87 days for Dacheongok, respectively. The seed priming test did not show any difference from the control group in the growth survey up to the middle stage of growth. In another test, low-temperature recovery was confirmed through nitrogen (2-5%) foliar fertilization after 3 days, 5 days, and 7 days in refrigeration (0 degrees), a selective low temperature treatment for com in the third leaf stage. As a result of this study, it was confirmed that the low-temperature damaged com treated at 0℃ showed the same growth as that of the untreated com through nitrogen foliar fertilization. These results suggest that urea foliar fertilization for low-temperature damage reduction of corn for silage in high-latitude climates will be helpful. In addition, through the results of the study, additional studies are needed on the recovery mechanism and field application through urea foliar fertilization.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.441-449
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• 1996

This study was conducted to find the changes of growth, seed yield and several characteristics of sesame by leaf spray of boron as a solution which is likely to be lack in the soil. It is carried out at low land developed 5 years ago. The amount of 200l /l0a boron as boric acid is sprayed in each treatment at the 11 node stage of sesame in main stem. The spraying concentrations of boric acid are 0.0, 0.2 and 0.4% in each treatment of the level low plot and the ridge height 15cm plot. The result shows that leaf area is increased in proportion to the concentration of boric acid in each treatment of the level low and the ridge height 15cm, and the degree of increase of each node order is remarkable in lower leaves and is more remarkable in the treatment of level low plot. The effects of leaf spray of boric acid are not only the increase of leaf area but also dry weight, no. of capsule per plant, 1,000 grains weight of capsule setting under middle position. As a result, the amount of seed is increased in 53% in the treatment of level low. The change of major characteristics according to leaf spray of boric acid is generally great in the treatment of level low. Especially the increase of leaf area in the part of upper leaves and low leaves is effective to improve other characteristics.

• Journal of Plant Biology
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• v.3 no.2
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• pp.6-18
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• 1960

The present experiments were designed in order to clarify the differences between the long and short styled plants and the transgressive gradition in the degree of dimorphism among the three heterostylous species of the Polygonus, P. japonica, F. esculentum, and P. senticosa, based on investigations regarding the floral structure, ecological and physiological traits, the results of which are summarized as follows: (1) P. japonica, although it exhibits typical dimorphism, has undergone so high a differentiation between long and short styled that its long styled individuals behave as if they were female; and short styled individuals as if male. In long-styled individuals, filament, anther, and pollen grains show signs of degeneration, most of the pollen being abortive. On the other hand, in short styled individuals, the filament, anther, and pollen grains have attained remarkable development; the pollen grians are large and fertile. In short-plant the fertilized flowers readily drop off in every stage of their embryo development. This species has completely lost the self-fertile property, which is characteristic of the non-dimorphic Polygonum genus. Although this specsei typically exhibits the physiological characteristics of the non-dimorphic Polygonum genus. Although this specisei typically exhibits the physiological characteristics of dimorphism in controlled pollination, the short-styled individuals bear no seed in nature, thus misleading taxonomists to idenfity the short-styled plant as male. 2) The morphological feature of the flower organ of P. senticosa obviously indicates definite dimorphism. Physiologically, however, no differentiation towards dimorphism was observed, the species still retaining, both in long and short-individuals, the self-fertile property common to the Polygonum genus. Elaborate examinations revealed that regardless of the modes of pollination, both fertiization and seed setting flourish, no differentiation betwen legitimate and illegitimate unions being recognizable. This sort of physiological property has not been observed in the investigations of other heterostylous plants. It is assumed that this species is differentiated structurally into dimorphism, but not yet physiologically. In nature, however, this plant would have more opportunities to be cross-pollinated, i.e., legitimately combined, than self-pollinated because of the development of two forms of flowers. 3) In terms of heterostylism, the F. esculentum just occupies the intermediate position between P. japonica and P. senticosa structurally, ecologically, and physiologically. Doescription of some of the physiological behavior of the plant will suffice to demonstrate the above facts. While P. japonica has completely lost its self-fertile property, P. senticosa still retains it wolly. In F. esculentum 2-6% of self-fertility is the result in illegitimate combination. There occur occasionally hereditary self fertile individuals among some of the F. or 20 min. irradiation plot, when they reach any stage of the same bacterial population. In addition to this increase of total population in the plots with the more dose of UV light irradiation, it seems that the more dose of UV light irradiation is the more shortened the generation time of Azotobacter. Therefore, it is clear that variation of reproductive rate must be, mere or less, due to the genetic effects induced by UV light irradiation. On the other hand, the lag phase or logarithmic growth phase in nonirradiated culture is shortened prominently, and this must be due to the difference in bacterial number of the original inoculm. The generation time of Azotobacter is shortened by exogeneous treatment of nuclei acid derivatives, and the degree is greater in case of DNA derivatives than RNA dervatives. W.H. Price reported that the rate of ribose nucleic acid to protein in Staphylococcus muscae is proportional to the generation time: that is the faster the cell can form ribose nucleic acid, the more rapid its growth. This explains the shortening of generation time by exogeneous RNA derivatives in this work reasonably. On the other hand, it is well known that the desoxyribose nuclic acid content per cell is constant and independent of the generation time. A.D. Laren and W.N. Takahashi reported that the infectious RNA from TMV is 6 times as sensitive to inactivation by UV as it is in the form of intact virus, and that inactivation of infectious TMV involves onlu a local change on RNA chain. But, the effect of exogeneous DNA in this work suggests that irradiated living cell which cotain DNA bring about some change on DNA moleculs as well as RNA molecules. And if the mutagenic effects of UV take into consideration, it is very reasonable. Therefore, it is clear that the variation of the generation time by UV irradiation is, more or less, due to the genetic effects. Therefore, it seems that the shortness of the average lifewpan of Azotobacter by UV irradiation is resulted not only from the influence of the environmental conditions, but also from the variation of genetic factor of the individual.

• Korean Journal of Medicinal Crop Science
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• v.12 no.3
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• pp.219-225
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• 2004

This study was conducted to evaluate growth and yield characteristics and the contribution to the yield according to the emergent sequence of tiller under two planting density $(60{\times}15\;cm,\;60{\times}25\;cm)$ in Coix lachryma-jobi L. var. mayuen Stapf. The average culm length and number of rachillas of $60{\times}25\;cm$ planting density were 20 cm shorter and 4.7 higher, respectively, whereas seed setting position of $60{\times}25\;cm$ planting density was 1.7 nodes lower compared with $60{\times}15\;cm$ planting density. Culm length and culm diameter of each tiller became shorter and thinner as the tiller emerged later. Length of rachillas was longer, number of grains was higher and ripening rate was also higher in $60{\times}25\;cm$ planting density than those of $60{\times}15\;cm$ planting density, whereas 100 grain weight in $60{\times}25\;cm$ planting density was lower by 0.5 g compared with $60{\times}15\;cm$ planting density. Length of rachillas and number of grains according to the emergent sequence of tiller were shown shorter and lower as the tiller emerged later. The highest number of bract was obtained from the main culm in both planting densities. 100 grain weight according to the emergent sequence of tiller became lower as the tiller emerged later in $60{\times}15\;cm$ planting density, but there was no clear tendency in $60{\times}25\;cm$ planting density. Among 8 tillers, 5th tiller and 4th tiller of main culm contributed 84.4% to the yield in $60{\times}15\;cm$ planting density, while it was 84.1% in $60{\times}25\;cm$ planting density. Analysis of path coefficient to grain yield showed that direct effect was the highest in the number of grain per tiller followed by in the 100 grain weight and in ripening rate.

• Journal of Plant Biotechnology
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• v.43 no.3
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• pp.261-271
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• 2016

Citrus is an economically important fruit crop widely growing worldwide. However, citrus production largely depends on natural hybrid selection and bud sport mutation. Unique botanical features including long juvenility, polyembryony, and QTL that controls major agronomic traits can hinder the development of superior variety by conventional breeding. Diverse factors including drastic changes of citrus production environment due to global warming and changes in market trends require systematic molecular breeding program for early selection of elite candidates with target traits, sustainable production of high quality fruits, cultivar diversification, and cost-effective breeding. Since the construction of the first genetic linkage map using isozymes, citrus scientists have constructed linkage maps using various DNA-based markers and developed molecular markers related to biotic and abiotic stresses, polyembryony, fruit coloration, seedlessness, male sterility, acidless, morphology, fruit quality, seed number, yield, early fruit setting traits, and QTL mapping on genetic maps. Genes closely related to CTV resistance and flesh color have been cloned. SSR markers for identifying zygotic and nucellar individuals will contribute to cost-effective breeding. The two high quality citrus reference genomes recently released are being efficiently used for genomics-based molecular breeding such as construction of reference linkage/physical maps and comparative genome mapping. In the near future, the development of DNA molecular markers tightly linked to various agronomic traits and the cloning of useful and/or variant genes will be accelerated through comparative genome analysis using citrus core collection and genome-wide approaches such as genotyping-by-sequencing and genome wide association study.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.3
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• pp.203-213
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• 2017

This study investigated the changes in yields, antioxidant compounds, and antioxidant activities among 11 adzuki bean cultivars cultivated in a paddy field with somewhat poorly drained soil. The adzuki bean cultivars were cultivated in the paddy field from 2015 to 2016 in Milyang, Gyeongsangnam, Korea. Average soil moisture content was 16.5% in 2015 and 31.0% in 2016 at the experimental site during adzuki bean cultivation. As the soil moisture content increased, most of the adzuki bean cultivars showed deceases in stem height, first setting pod node, number of pods, 100 seed weight, and yield. Chungju-pat produced the greatest yields among the 11 cultivars in 2015 and 2016, whereas Hongeon had the smallest yields. Adzuki bean yields after paddy field cultivation was lower for all cultivars than for adzuki bean yields from the same cultivars after upland field cultivation. Chungju-pat and Chilbo-pat showed the smallest decreases in yields after paddy field cultivation, whereas Hongeon and Kumsil showed the greatest yield reductions. There were no significant differences in proximate composition. Some mineral components ($P_2O_5$, Ca, and Mg) were statistically different across cultivars. Chungju-pat had the highest Ca and Mg contents, but antioxidant components (polyphenol and flavonoids) and antioxidant activities (ABTS and DPPH) were highest in Saegil and lowest in Jungbu-pat. PCA and clustering analyses, based on the growth, yield, and antioxidant component measurements, performed to identify which variables contributed the most to separating adzuki bean cultivars or to grouping cultivars with similar characteristics. These analyses showed that the antioxidant components and antioxidant activities had the most influence on grouping cultivars together. Among the 11 cultivars, Saegil was statistically different from the other cultivars, but the other 10 cultivars were not significantly different under paddy field cultivation. Soil moisture content affected adzuki bean yield and antioxidant component contents. An increase in soil moisture led to a decrease in yield, but an increase in antioxidant components. These results provide information that will improve the selection of an appropriate adzuki bean cultivar for use in paddy fields.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2003.04a
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• pp.61-62
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• 2003

Clonal propagation of high-value forest trees through somatic embryogenesis (SE) has the potential to rapidly capture the benefits of breeding or genetic engineering programs and to improve raw material uniformity and quality. A major barrier to the commercialization of this technology is the low quality of the resulting embryos. Several factors limit commercialization of SE for Corsican pine, including low initiation rates, low culture survival, culture decline causing low or no embryo production, and inability of somatic embryos to fully mature, resulting in low germination and reduced vigour of somatic seedlings. The objective was to develop a Corsican pine maturation medium that would produce cotyledonary embryos capable of germination. Treatments were arranged in a completely randomized design. Data were analyzed by analysis of variance, and significant differences between treatments determined by multiple range test at P=0.05. Corsican pine (Pinus nigra var. maritima) cultures were initiated on modified !P6 medium. Modifications of the same media were used for culture multiplication and maintenance. Embryogenic cultures were maintained on the same medium semi solidified with 2.5 g/l Gelrite. A maturation medium, capable of promoting the development of Corsican pine somatic embryos that can germinate, is a combination of iP6 modified salts, 2% maltose, 13% polyethylene glycol (PEG), 5 mg!l abscisic acid (ABA), and 2.5 g/l Gelrite. After initiation and once enough tissue developed they were grown in liquid medium. Embryogenic cell suspensions were established by adding 0.951.05 g of 10- to 14-day-old semisolid-grown embryogenic tissue to 9 ml of liquid maintenance media in a 250ml Erlenmeyer flask. Cultures were then incubated in the dark at 2022$^{\circ}$C and rotated at 120 rpm. After 2.53 months on maturation medium, somatic embryos were selected that exhibited normal embryo shape. Ten embryos were placed horizontally on 20 ml of either germination medium ($\frac{2}{1}$strength Murashige and Skoog (1962) salts with 2.5 g/l activated charcoal) or same medium with copper sulphate adjusted to 0.25 mg/1 to compensate for copper adsorption by activated carbon. 2% and 4% maltose was substituted by 7.5% and 13% PEG respectively to improve the yield of the embryos. Substitution of' maltose with PEG was clearly beneficial to embryo development. When 2% of the maltose was replaced with 7.5% PEG, many embryos developed to large bullet-shaped embryos. At latter stages of development most embryos callused and stopped development. A few short, barrel-shaped cotyledonary embryos formed that were covered by callus on the sides and base. When 4% of the maltose was removed and substituted with 13% PEG, the embryos developed further, emerging from the callus and increasing yield slightly. Microscopic examination of the cultures showed differing morphologies, varying from mostly single cells or clumps to well-formed somatic embryos that resembled early zygotic embryos only liquid cultures with organized early-stag. A procedure for converting and acclimating germinants to growth in soil and greenhouse conditions is also tested. Seedling conversion and growth were highly related to the quality of the germinant at the time of planting. Germinants with larger shoots, longer, straighter hypocotyls and longer roots performed best. When mature zygotic embryos germinate the root emerges, before or coincident with the shoot. In contrast, somatic embryos germinate in reverse sequence, with the cotyledons greening first, then shoot emergence and then, much later, if at all, the appearance of the root. Somatic seedlings, produced from the maturation medium, showed 100% survival when planted in a field setting. Somatic seedlings showed normal yearly growth relative to standard seedlings from natural seed.

• Applied Biological Chemistry
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• v.11
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• pp.173-184
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• 1969

To elucidate the effect of Amo-1618(4-hydroxyl-5-isopropyl-2-methlphenyl trimethyl ammonium chloride, 1-piperidine carboxylate) known as a kind of growth retardant, on the growth, grain yield, increasing the efficiency of nitrogen fertilizer, behavior of mineral nutritions and the rate of phosphorus utilization, this experiment was conducted pot culture method in a vinyl house. Two nitrogen level, namely, practical nitrogen level(1 N) and three times nitrogen level(3 N) was made and labelled double-calcium-superphosphate $Ca(H_2P^{32}O_4)_2.\;2H_2O)$ as a source of radioactive phosphorus(P-32) was employed $80\;{\mu}c/pot$, respectively. Rice seedlings, variety 'Suwon No. 82', was transplanted to a 1/50,000 a china pot on June 13 in 1968. For treatment, at early stage of tillering, 10,000 ppm solution of Amo-1618 was foliar sprayed only one time. The Duncan's new mutiple-range test was adopted for statistical analysis evaluating experimental data at 5% level significance. The results obtained may be summarized as follows; 1) No significant difference was found among the treatments in plant height, but in plot of Amo-1618 treatment and 3 N level, number of tillers was significantly increased than that of others. 2) Weight of 10,000 kernels and seed-setting rate was also remarkably increased in same treatment above. 3) Grain yield per pot was significantly increased in Amo-1618 and 3 N level application. This results seemed to be due to the increased the factors on the yield. 4) Contents of nitrogen and phosphorus per cent in the grain was likewise increased in Amo-1618 and 3 N application. There is, however, no difference among treatments in the content of nitrogen and phosphorus in the leaves and culms of rice plants. 5) On the other hand, the contents of potassium and magnesium, no distinctly tendeny showed among treatments. 6) The rate of phosphorus utilization was significantly increased in the plot of Amo-1618 and 3 N application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.1
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• pp.29-36
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• 2021

Recently, phytochemicals in whole grains have received increasing attention because the increased consumption of whole grains and whole grain products has been associated with a reduced risk of chronic diseases. Among the phytochemicals in whole wheat, arabinoxylan influences various physiological activities and can aid the treatment of numerous health conditions, either directly or indirectly. In this study, 614 wheat germplasms, collected from the world, were cultivated in 2018 and harvested in 2019 in South Korea. The qualities of these whole grains, including seed protein content, were evaluated using the NIR spectrophotometric method, and arabinoxylan content was determined using enzymatic methods. The ash content was 0.36 to 2.80% and protein content was 7.66 to 20. The SDS-sedimentation for gluten complex ability ranged from 26.85 to 80.63 mL, and protein content showed a high correlation with SDS-sedimentation in the germplasms. Verify the result of the enzymatic method of arabinoxylan, the reliability of the experimental method was determined through repeatability, reproducibility, and recovery. The average value of the 614 resources was 51.64 mg/g of whole grain, and when classified according to the country of origin, the South Korean origin resources tended to have a higher content compared to the genetic resources of other countries. These results are expected to be used as basic data for setting standards for whole grain quality in wheat breeding systems.

• Korean Journal of Plant Resources
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• v.36 no.4
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• pp.402-412
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• 2023

Peucedanum japonicum Thunberg is a biennial plant that usually flowers and dies after seed setting at 2^nd year. We inspected the flowering and fertilization characteristics to establish the breeding system. The plant forms complex umbel inflorescences consisting of multiple umbellets and numerous flowers. Each flower is bisexual but allogamous because of protandry. A flower bloomed for three days with matured pollen and no stigma appearance. Inspection of pollen tube growth indicates that the pollen viability can be maintained for up to 3~7 days after first flowering (DAF). In a umbellet, flowers bloomed during 1~5 DAF and the pollen maintained viability during 3~10 DAF, and the pistil developed and maintained fertility during 8~12 DAF. Theoretically, self-pollination can be possible during 8~10 DAF in the same umbellet. Approximately 4.4% of seeds were developed by self-pollination among flowers in an enveloping solitary umbel. There is at least a 9~10 days difference for the development of an umbel with another umbel at the next branch, which indicates pollination can be permitted between different branches in an individual plant. Finally, we have established a rapid breeding method to shorten the breeding cycle to one year from two years by integrating the flowering and pollination characteristics.