• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.4
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• pp.371-384
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• 1982

Highly cold tolerant varieties are requested not only at high latitute cool area but also tropical high elevated areas, and the required tolerance is different from location to location. IRRI identified 6 different types of cold tolerance required in the world for breeding purpose; a) Hokkaido type, b) Suweon type, c) Taipei 1st season type, d) Taipei 2nd season type, e) Tropical alpine type and, f) Bangladesh type. The cold tolerance requested in Korea is more eargent in Tongil group cultivars and their required tolerance is the one such as the physiological activities at low temperature are as active as in Japonica group cultivars at least during young seedling stage and reproduction stage. With conventional Japonica cultivars, such cold tolerant characters are requested as short growth duration but stable basic vegetative growth, less sensitive to high temperature and less prolonged growth duration at low temperature. The methods screening for cold tolerance were developed rapidly after the Tongil cultivar was reliesed. The facilities of screening for cold tolerance, such as, low temperature incubator, cold water tank, growth cabinet, phytotron, cold water nursery in Chuncheon, breeding nursery located in Jinbu, Unbong and Youngduk, are well established. Foreign facilities such as, cold water tank with the rapid generation advancement facilities, cold nurseries located in Banaue, Kathmandu and Kashimir may be available for the screening of some limitted breeding materials. For the reference, screening methods applied at different growth stages in Japan are introduced. The component characters of cold tolerance are not well identified, but the varietal differences in a) germinability, b) young seedling growth, c) rooting, d) tillering, e) discolation, f) nutrition uptake, g) photosynthesis rate, h) delay in heading, i) pollen sterility, and j) grain fertility at low temperature are reported to be distinguishable. Relationships among those traits are not consistent. Reported studies on the inheritance of cold tolerance are summarized. Four or more genes are controlling low temperature germinability, one or several genes are controlling seedling tolerance, and four or more genes are responsible for the pollen fertility of the rice treated with cold air or grown in the cold water nursery. But most of those data indicate that the results may come out in different way if those were tested at different temperature. Many cold tolerant parents among Japonicas, Indicas and Javanicas were identified as the results of the improvement of cold tolerance screening techniques and IRTP efforts and they are ready to be utilized. Considering a) diversification of germ plasm, b) integration of resistances to diseases and insects, c) identification of adaptability of recommending cultivars and, d) systematic control of recommending cultivars, breeding strategies for short term and long term are suggested. For short term, efforts will be concentrated mainly to the conventional cultivar group. Domestic cultivars will be used as foundation stock and ecologically different foreign introductions such as from Hokkaido, China or from Taiwan, will be used as cross parents for the adjustment of growth durations and synthsize the prototype of tolerances. While at the other side, extreme early waxy Japonicas will be crossed with the Indica parents which are identified for their resistances to the diseases and insects. Through the back corsses to waxy Japonicas, those Indica resistances will be transfered to the Japonicas and these will be utilized to the crosses for the improvement of resistances of prototype. For the long term, efforts will be payed to synthsize all the available tolerances identified any from Japonicas, Indicas and Javanicas to diversify the germ plasm. The tolerant cultivars newly synthsized, should be stable and affected minimum. to the low temperature at all the growing stages. The resistances to the diseases and insects should be integrated also. The rapid generation advancement, pollen culture and international cooperations were emphasized to maximize the breeding efficiency.

• Journal of Korean Society of Forest Science
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• v.43 no.1
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• pp.20-30
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• 1979

The purpose of present study is to analyze the genetic variation of natural stand of Pinus densiflora. In 1976 following after the seletion of 1974 and 1975, twenty trees from each of three natural populations of the species were selected and seeds were collected, and the locations and conditions of populations are presented in table 1, 2 and figure 1. Some morphological traits of the populations were already detailed in our fifth report of this series. The morphological traits of cone, seed and seed-wing, and also the growth performances and needle characters of the seedling were observed in the present study according to the previous methods. The results obtained are summarized as follows; 1. The meteorological data obtained by averaging the records of 30 year period(1931~1960) measured from the nearest meteorological station to each population are shown in fig. 2, 3, 4. The distributional patterns of investigated climate factors are generally considered to be similar among the locations. However, the precipitation density during growing season and the air temperature during dormant season on Samchuk area (Pop. 9) were quite different from those of the other areas. 2. The measurements of fresh cone weight, length, diameter and cone index (i.e.: length to diameter ratio) are presented in table 7. As shown in table 7, all these traits except for cone diameter seem to be not significant in population and to be highly significant in family differences within population. 3. The morohological traits of seed and seed-wing are detailed in table 8, 9, and highly significant differences are recognized among the populations and the families within population in seed weight, seed length, seed thickness but not among the populations in the other observed traits. The values of correlation between the characteristics of cone and seed are presented in table 12. As shown, the correlation between cone length and seed wing length, between seed wing width and seed width were significantly positive in population 8 and 9 but in population 7. The positive correlations between seed length and seed width were calculated in all populations studied 4. Significant statistical differences among populations and families within population are observed in the growth performances of 1-0 seedling height of these progenies. But the differences in 1-1 seedling height and root collar diameter are shown only among familes within population. As shown in table 13, the most parts of correlations are not significant statistically between the growth performances of seedling and the seed characters. 5. As shown in table 15, statistical differences are considered to be significant among the populations in stomata row on both sides of the needle but not in serration density. The correlations between progenies and parents are not generally observed in the investigated traits of needle as shown in table 16.

• Journal of Korean Society of Forest Science
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• v.38 no.1
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• pp.33-45
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• 1978

The purpose of present study is to analyze the genetic variation of natural stand of Pinus densiflora. In 1975 following after the selection of 1974, twenty trees from each of three natural populations of the species were selected and their open-pollinated seeds were collected, and the locations and conditions of the populations ate presented in table 1, 2 and figure 1. Some morphological traits of the populations were already detailed in our second report of this series, in which Myong-Ju and Ul-Jin populations were regarded to be superior phenotypically to suweon population. The morphological traits of cone, seed and seed-wing, and also the growth performances and needle characters of the seedling were observed in the present study according to the previous methods. The results obtained are summarized as follows; 1. The meteorological data obtained by averaging the records of 30 year period (1931~1960) measured from the nearest meteorological stations to each population are shown in fig.2, 3, 4. The distributional patterns of investigated climate factors are generally considered to be similar among the locations. However, the precipitation density during growing season and the air temperature during dormant season on Suweon area, population 6, were quite different from those of the other areas. 2. The measurements of fresh cone weight, length, diameter and cone index, i.e., length to diameter ratio are presented in table 7. As shown in table 7, all these traits except for cone diameter seem to be highly significant in population differences and family differences within population. 3. The morphological traits of seed and seed-wing are detailed in table 8, 9, and highly significant differences are recognized among the populations and the families within population in seed-wing length, seed-wing index, seed weight, seed-length and seed index but not among the populations in the other observed traits. The values of correlation coefficient between the characters of cone and seed are given in table 10 and the positive significant correlations can be observed in the most parts of the compared traits. 4. Significant statistical differences among populations and families within population are observed in the growth performances of 1-0 and 1-1 seedling height of these progenies. But the differences in root collar diameter are shown only among families within population. As shown in table 13, the most parts of correlations are not significant statistically between the growth performances of seedling and the seed characters. 5. The number of stomata row on both sides of needle and the serration density were measured in the seedlings from each of the families of the three populations. As shown in table 15, statistical differences are considered to be significant among the populations and among the families within population in serration density but not among the populations in stomata row on both sides of the needle. The results differ from those of the third report of this series. Even if one of the reason seems to be the diversity of selected populations, it could not be confirmed definitely. The correlations between progenies and parents are not generally observed in the investigated traits of needle as shown in table 16.

• Korean Journal of Heritage: History & Science
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• v.45 no.4
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• pp.140-157
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• 2012

The result of a study on the useful trend of plants related to landscape and how to plant and cultivate through 'ImwonGyeongjaeji Manhakji'of Seoyugu is as follows: First, 'ImwonGyeongjaiji Manhakji', composed of total 5 volumes (General, Fruit trees, vegetables and creeper, plants, others) is a representative literature related to landscape which described the names of plants and varieties, soil condition, how to plant and cultivate, graft, how to prevent the insect attack etc systematically. Second, he recorded the tree planting as Jongjae(種栽) or Jaesik(栽植), and the period to plant the trees as Jaesusihoo(栽樹時候), transplanting as Yijae(移栽), making the fence as Jakwonri(作園籬), the names of varietieis as Myeongpoom(名品), the suitable soil as Toeui(土宜), planting and cultivation as Jongye(種藝), treatment as Euichi(醫治), protection and breeding as Hoyang(護養), garden as Jeongwon(庭園) or Wonpo(園圃), garden manager as Poja(圃者) or Wonjeong(園丁). Third, the appearance frequency of plants was analyzed in the order of flowers, fruits, trees, and creepers and it showed that the gravity of deciduous trees was 3.7 times higher than that of evergreen trees. The preference of flower and trees, fruit trees and deciduous trees and broad-leaved trees includes (1) application of the species of naturally growing trees which are harmonized with the natural environment (2) Aesthetic value which enables to enjoy the beauty of season, (3) the trend of public welfare to take the flowers and fruits, (4) the use of symbolic elements based on the value reference of Neo-Confucianism etc. Fourth, he suggested the optimal planting period as January(上時) and emphasized to transplant by adding lots of fertile soil and cover up the seeds with soil as high as they are buried in accordance with the growing direction and protect them with a support. That is, considering the fact that he described the optimal planting period as January by lunar calendar, this suggests the hints in judging the planting period today. For planting the seeds, he recommended the depth with 1 chi(寸 : approx. 3.3cm), and for planting a cutting, he recommended to plant the finger-thick branch with depth 5 chi(approx. 16.5cm) between January and February. In case of graft of fruit trees, he described that if used the branch stretched to the south, you would get a lot of fruit and if cut the branches in January, the fruits would be appetizing and bigger. Fifth, the hedge(fence tree) is made by seeding the Jujube tree(Zizyphus jujuba var. inermis) in autumn densely and transplanting the jujube tree with 1 ja(尺 : approx. 30cm) interval in a row in next autumn and then binding them with the height of 7 ja(approx. 210cm) in the spring of next year. If planted by mixing a Elm tree(Ulmus davidiana var. japonica) and a Willow(Salix koreensis), the hedge whose branch and leaves are unique and beautiful like a grating can be made. For the hedge(fence tree), he recommended Trifoliolate orange(Poncitus trifoliata), Rose of sharon(Hibiscus syriacus), Willow(Salix koreensis), Spindle tree(Euonymus japonica), Cherry tree(Prunus tomentosa), Acanthopanax tree(Acanthopanax sessiliflorus), Japanese apricot tree(Prunus mume), Chinese wolf berry(Lycium chinense), Cornelian tree(Cornus officinalis), Gardenia(Gardenia jasminoides for. Grandiflora), Mulberry(Morus alba), Wild rosebush(Rosa multiflora) etc.

• Korean Journal of Ichthyology
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• v.3 no.1
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• pp.48-57
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• 1991

Changes of the activities of the hepatic cells of female mud skipper, Boleophthalmus pectinirostris were investigated under transmission electron microscopy. Monthly changes of gonadosomatic index(GSI) and hepatosomatic index(HSI), variations of protein and nucleic acid contents(total RNA and DNA) of the liver tissues with the gonadal development phase were also studied. GSI began to increase from May(the growing stage), reaching the maximum value in late June(the mature stage), and then it began to decrease from late July(the degenerative stage), reaching the lowest value in late September. Monthly variations of HSI were negatively related to GSI. HSI decreased in the summer season when the ovary was getting mature and reached the maximum in mid October when the ovary was degenerating. In June(the mature stage), the female hepatic cells of the liver tissues became large and nuclei were hypertrophic. The amounts of glycogen particles and lipid droplets in the cells gradually decreased, while a number of granular endoplasmic reticulum increased. It was assumed that well-developed granular endoplasmic reticulum binding ribosomes are supposed to play the leading role in protein synthesis and deposition for vitellogenin in the cytoplasm. In July(the spawning period), glycogen particles and lipid droplets gradually increased, and then these substances were still observed in large quantity in August(the degenerative stage). The protein contents of the liver tissues with the gonadal phases of the ovaries were shown the maximum value($4.720{\pm}0.103\;mg/g$) in June, and afterwards gradually decreased being the minimum($3.640{\pm}0.130\;mg/g$) in July, and then gradually increased in August. The mean total RNA contents per gram of the liver tissues appeared the maximum($0.523{\pm}0.040\;mg/g$) in June, and afterwards gradually decreased to the minimum($0.158{\pm}0.006\;mg/g$) in July and slightly increased in August again. From these results, it could be assumed that protein contents were closely related to RNA contents. The mean total DNA contents per weight (gr) of the liver tissues appeared to be similar although there were some monthly fluctuations. The ratio of the mean total RNA/DNA were 0.745 in June, 0.262 in July, 0.341 in August respectively.

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.112-121
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• 2004

A study was performed to examine the effects of UV-disinfected reclaimed water on microorganism concentration during rice culture. Four treatments were used and each one was triplicated to evaluate the changes of microorganism concentrations: stream water irrigation (STR), biofilter effluent irrigation (BE), UV-disinfected water irrigation with dose of 6 mW ${\cdot}$ s $cm{-2}$ (UV-6), and UV-disinfected water irrigation with dose of 16 mW ${\cdot}$ s $cm{-2}$ (UV-16). The indicator microorganisms of interest were total coliform (TC), fecal coliform (FC), and E. coli. The biofilter effluent from 16-unit apartment sewage treatment plant was used as reclaimed water and flowthrough type UV-disinfection system was used. Concentrations of indicator microorganisms in the treatment plots ranged from $10^2$ to $10^5$ MPN/100 mL during 24 hours after irrigation in May and June, where initial irrigation water for transplanting reparation was biofilter-effluent without UV-disinfection. It implies that initial irrigation using only non-disinfected reclaimed water for puddling in paddy field can be health-concerned because of more chance of farmer's physical contact with elevated concentration of microorganisms. The concentrations of microorganisms varied widely with rainfall, and treatments using UV-disinfected water irrigation showed significantly lower concentrations than others and their levels were within the range of paddy rice field with normal surface water irrigation. The mean concentrations of STR and BE during growing season were in the range of 4 ${\times}\;10^3$ MPN/100 mL for TC, and 2${\times}\;10^3$ MPN/100 mL for FC and E, Coli, While mean concentrations of UV-S and UV-lS were less than 1${\times}\;10^3$ MPN/100 mL for all the indicator microorganisms. Overall, UV-disinfection was thought to be feasible and practical alternative for agricultural reuse of secondary level effluent in Korea.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.349-354
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• 2013

This study examined a technique for cooling root zone aimed at lowering substrate temperature for sweet pepper (Capsicum annum L. 'Orange glory') cultivation in coir substrate hydroponics during hot season, from the $16^{th}$ of July to $15^{th}$ of October in 2012. The root zone cooling technique was applied by using an air duct (${\varnothing}12$ cm, hole size 0.1 mm) to blow cool air between two slabs during night (5p.m. to 3a.m.). Between the $23^{rd}$ of July and $31^{st}$ of August (hot temperature period), average daily substrate temperature was $24.7^{\circ}C$ under the root zone cooling, whereas it was $28.2^{\circ}C$ under condition of no cooling (control). In sunny day (600~700 W $m^{-2}{\cdot}s^{-1}$), average substrate temperatures during the day (6a.m. to 8p.m.) and night (8p.m. to 6a.m.) were lower about $1.7^{\circ}C$ and $3.3^{\circ}C$, respectively, under the cooling treatment, compared to that of control. The degree of temperature reduction in the substrate was averagely $0.5^{\circ}C$ per hour under the cooling treatment during 6p.m. to 8p.m.; however, there was no decrease in the temperature under the control. The temperature difference between the cooling and control treatments was $1.3^{\circ}C$ and $0.6^{\circ}C$ in the upper and lower part of the slab, respectively. During the hot temperature period, about 32.5% reduction in the substrate temperature was observed under the cooling treatment, compared to the control. Photosynthesis, transpiration rate, and leaf water potential of plants grown under the cooling treatment were significantly higher than those under the control. The first flowering date in the cooling was faster about 4 days than in the control. Also, the number of fruits was significantly higher than that in the control. No differences in plant height, stem thickness, number of internode, and leaf width were found between the plants grown under the cooling and control, except for the leaf length with a shorter length under the cooling treatment. However, root zone cooling influenced negligibly on eliminating delay in fruiting caused by excessively higher air temperature (> $28^{\circ}C$), although the substrate temperature was reduced by $3^{\circ}C$ to $5.6^{\circ}C$. These results suggest that the technique of lowering substrate temperature by using air-duct blow needs to be incorporated into the lowering growing temperature system for growth and fruit set of health paprika.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.402-410
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• 2013

Insect pests damages are increasing on the field of Lycium chinense under environment- friendly management Thus, we was to monitor the occurrence of pests on organic L. chinense in Chungnam Cheongyang and, insecticidal effect of eco-friendly agricultural materials (EFAMs) were tested against major pests. When the buds come out, injury by L. chinense was very high causing the high population density of Myzus persicae in late May and early June, and the injury by Lema decempunctata was increased from mid-June. Otherwise, injuries by Eriophys macrodonis, Henosepilachna vigintioctomaculata and Hedma spp. were continued throughout the growing season. From the fruit held in late July, Hemipteran insects including Plautia stali and Halyomorpba balys were sucking the fruit, and their injury to L. chinense were gradually increased. For the eco-friendly environmental control of M. persicae, L. decempunctata and E. macrodonis, EFAMs containing Sophora flavescens, Melia azedarach (Chinaberry), Chenopodium ambrosioides (Mexican tea), Quassia amara (Amargo), Stemona sessilifolia, Sophora seeds and Nepeta cataria (Catmint), were selected and used to control the insect pests. Control effects of the mixed extract with S. flavescens and Sophora seeds against M. persicae and L. decempunctata were higher than any other EFAM as 84.0% and 86.6%, respectively. In case of E. macrodonis, its control effect was good with the mixed extract with S. flavescens, C. ambrosioides and M. azedarach.

• Journal of Korean Society of Forest Science
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• v.48 no.1
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• pp.29-39
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• 1980

This study was initiated to find out the possible insect vector and other means of transmission of jujube witches'-broom disease. 1. Eight species of leafhoppers were found to feed on both healthy and diseased jujube trees. Among these, rhombic marked leafhoppers (Hishimonus sellatus Uhler) were most abundant throughout the growing season of jujube trees in all localities surveyed. H. sellatus was far more abundant on diseased trees than healthy ones. 2. Jujube witches'-broom mycoplasma(JWM) was transmitted to jujube seedlings by Hishimonus sellatus. Jujube seedlings inoculated with H. sellatus which had been fed for 14-21 days on diseased jujube plants, developed smaller, chlorotic leaves 40-60 days after inoculation. Electron microscopy of midveins and petioles of the infected jujube seedlings revealed the presence of numerous mycoplasmalike organisms in phloem tissues. 3. Jujube witches'-broom mycoplasma was also transmitted to Vinca rosea plants by H. sellatus. Infected Vinca rosea plants developed vein clearing and marginal chlorosis of upper leaves 25-38 days after inoculation and followed by stunting and ultimate wilting and death of plant. Electron microscopy of petioles and midveins of infected Vinca rosea plant revealed the presence of numerous mycoplasmalike organisms in phloem tissues. 4. H. sellatus survived more than 30 days on jujube, Vinca rosea, carrot, celery, eggplant, hop, Calystegia japonica, Humulus japonicus, Astragalus sinicus, white clover, red clover, and radino clover. Many second generation nymphs of H. sellatus were also abserved on these plants but clovers. 5. Jujube seeds collected from witches'-broom diseased jujube trees yielded healthy seedlings.

• Korean Journal of Plant Taxonomy
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• v.46 no.2
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• pp.213-246
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• 2016

Algific talus slopes tend to occur on steep north-facing slopes with bedrock that retains ice and emits cold air throughout the growing season. Algific talus slopes provide a suitable microclimate for disjunct or relict populations of northern plant species at low altitude habitats in temperate zones. The purpose of this study is to suggest a strategy for the comprehensive conservation of the vegetation of algific talus slopes through studies of the floristics and plant species compositions and threat factors at present and in the future of 15 major algific talus slopes in Korea. As a result, the vascular plants surveyed on 15 major algific talus slopes were recorded, with a total of 587 taxa, 109 families, 323 genera, 531 species, 7 subspecies, 47 varieties 1 form and 1 hybrid. Of them, endemic plants numbered 26 taxa, and threatened species according to the IUCN valuation basis numbered 8 taxa. Fourth (IV) and fifth (V) degree indicator species as specified by floristic subregions numbered 31 taxa. Peculiarly, several subalpine-native plant species, in this case Cystopteris fragilis, Gymnocarpium dryopteris, Huperzia selago, Rosa koreana, Vaccinium vitis-idaea and Woodsia hancockii, were distributed on algific talus slopes at 100-600 m above sea level. Numerous and diverse biological resources native to algific talus slopes in Korea have been consistently disturbed or damaged by human activities without some form of protection. An all-taxa biodiversity inventory should be surveyed to provide more information about all biological species living on algific talus slopes. In addition, conservation strategies to ensure biodiversity and effective management of algific talus slopes are discussed in detail.