• Title/Summary/Keyword: Pressure Variation

Search Result 2,572, Processing Time 0.03 seconds

Xylem Sap Flow Affected by Short-term Variation of Soil Moisture Regimes at Higher Growth Period in 'Fuji'/M.9 Apple Trees with Different Fruit Loads (착과량 수준 및 생육성기 토양수분 함량 변화에 따른 '후지'/M.9 품종의 수액이동 특성)

  • Park, Jeong-Gwan;Kim, Seung-Heui;Lee, In-Bok;Park, Jin-Myeon
    • Korean Journal of Environmental Agriculture
    • /
    • v.25 no.2
    • /
    • pp.164-169
    • /
    • 2006
  • This study was conducted for 10 days from 17 July to 26 July in 2005 to measure the amount of xylem sap flow under short-term variation of soil moisture regimes at -20 kPa, -50 kPa and -80 kPa in eight-year-old 'Fuji'/M.9 apple trees with different fruit loads. Fruit load was adjusted as three different treatments with standard (100%), 1/2 times (50%) and 2 times (200%) on the basis of optimum fruiting number per tree as the standard fruit load of Fuji cultivar. Trees with standard fruit load during the experimental period showed higher xylem sap flow at -50 kPa of soil moisture regimes than those of trees with 1/2 times and 2 times fruit load. Trees with 1/2 times and 2 times fruit load had similar patterns of the diurnal changes of xylem sap flow, vapor pressure deficit (VPD), and maximum evapotranspiration (ETm). However, trees with 2 times fruit load at -50 kPa and -80 kPa of soil moisture regimes produced lower amount of xylem sap flow than ETm. Trees with standard fruit load produced $1.06{\sim}3.93$ L/tree more amount of xylem sap flow than ETm at all soil moisture regimes. But xylem sap flow of tees with 2 times fruit load had 21% lower at -50 kPa and $31{\sim}36%$ lower at -20 kPa and -80 kPa of soil moisture regimes, respectively than that of trees with standard fruit load. Shoot growth and leaf area were significantly the highest in trees with standard fruit load while those of trees with 2 times fruit load recorded significantly lowest. Leaf water potential of trees with standard fruit load was lower than that of trees with 1/2 times and 2 times fruit load. It indicated that tees with standard fruit load had higher water use for transpiration than other treatments and tees with 2 times fruit load received more stress for the transpiration process under low soil moisture regimes. Consequently, 'Fuji'/M.9 apple trees, the fruit load and soil moisture should be maintained optimum to increase xylem sap flow and transpiration during higher growth period.

Petrochemical Study on the Cretaceous Volcanic Rocks in Kageo island, Korea (가거도(소흑산도)의 백악기 화산암류에 대한 암석화학적 연구)

  • 김진섭;백맹언;성종규
    • The Journal of the Petrological Society of Korea
    • /
    • v.6 no.1
    • /
    • pp.19-33
    • /
    • 1997
  • This study reports the results about the petrography and geochemical characteristics of 10 representative volacanic rocks. The Cretaceous volcanic rocks distributed in the vicinity of the Kageo island composed of andesitic rocks, dacitic welded tuff, and rhyolitic rocks in ascending order. Sedimentary rock is the basement in the study area covered with volcanic rocks. Andesitic rocks composed of pyroclastic volcanic breccia, lithic lapilli tuff and cryptocrystallin lava-flow. Most dacitic rocks are lapilli ash-flow welded tuff. Rhyolitic rocks consists of rhyolite tuff and rhyolite lava flow. Rhyolite tuff are lithic crystal ash-flow tuff and crystal vitric ash-flow tuff with somewhat accidental fragments of andesitic rocks, but dacitic rocks. The variation of major and trace element of the volcanic rocks show that contents of $Al_2O_3$, FeO, CaO, MgO, $TiO_2$ decrease with increasing of $SiO_2$. On the basis of Variation diagrams such as $Al_2O_3$ vs. CaO, Th/Yb vs. Ta/Yb, and $Ce_N/YB_N$ vs. $Ce_N$, these rocks represent mainly differentiation trend of calc-alkaline rock series. On the discriminant diagrams such as Ba/La and La/Th ratio, Rb vs. Y + Nb, the volcanic rocks in study area belongs to high-K Orogenic suites, with abundances of trace element and ternary diagram of K, Na, Ca. According to the tectonic discriminant diagram by Wood, these rocks falls into the diestructructive continental margin. K-Ar ages of whole rocks are from andesite to rhyolite $97.0{\pm}6.8~94.5{\pm}6.6,\68.9{\pm}4.8,\61.5{\pm}4.9~60.7{\pm}4.2$ Ma, repectively. Volcanic rocks in study area show well correlation to the Yucheon Group in terms of rock age dating and geochemcial data, and derived from andesitic calc-alkaline magma that undergone low pressure fractional crystallization dominated plagioclase at <30km.

  • PDF

Deodorization of H2S, CH3SH in Soil Filter Reactors Packed with Montmorillonites, Rice Hulls and Thickening-activated Sludge (Montmorillonites, 왕겨 및 농축활성슬러지를 충진한 토양상에서의 H2S, CH3SH의 제거)

  • Kim, Hwan-Gi;Park, Chan-Soo
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.22 no.1
    • /
    • pp.43-52
    • /
    • 2000
  • Deodorization characteristics and removal rate of sulfur-containing odor have been investigated in the soil filter reactors packed with montmorillonites (Mont.), rice hulls(Rh.), and thickening-activated sludge(Ts.). And variation of pH and $SO_4{^{2-}}$ with the removal of malodorous sulfur compounds have been investigated together. As compared removal rate of montmorillonites between wet and dry condition for sulfur compounds through batch test, it showed that wet condition was better than dry one; removal ratio, as wet/dry, was $H_2S$ of 1.2 and $CH_3SH$ of 1.9, and decrease of pH and increase of $SO_4{^{2-}}$ concentration in the wet condition also showed to be larger than in dry condition. In continuous test for biological deodorization experiment, removal rate of sulfur compounds in reactor packed with Mont., Rh. and Ts, was more than 98 %, and the variation of static pressure was maintained stably under condition of SV $150h^{-1}$, LV 4.2 mm/sec and SV $200h^{-1}$, LV 5.6 mm/sec, and in reactor packed with Mont. and Rh., $H_2S$ was 76.4 % to 87.2 % and $CH_3SH$ was 87.8 % to 93.3 % under the same condition. From above results, it ascertained that it can obtain the high deodorization efficiency by inoculating thickening-activated sludge in soil filter using montmorillonites.

  • PDF

Variation of Vital Sign according to Time in Full Immersion of Hot and Cool Bath (온.냉욕 전신침수욕시 기간에 따른 vital sign의 변화)

  • Yi, Seung-Ju
    • Journal of Korean Physical Therapy Science
    • /
    • v.3 no.3
    • /
    • pp.35-49
    • /
    • 1996
  • This study was conducted to see variation of vital sign of hot and cool bath according to time, a questionnair survey and measurement was carried out for 32 students(sophomore) of department of physical therapy Andong Junior College on the 27th of June, 1995. The result were as follows: The average systolic blood pressure(SBP) of stability for 32 college students who were measured was 105.3mmHg, the average diastolic blood pressure(DBP) was 67.3mmHg, the average pulse frequency(PF) was 70.7(frequency/min), the average respiratory frequency (RF) was 15.6 (frequency/min), and the body temperature(BT) was $36.6^{\circ}C$. As time went on, SBP for 32 students who were measured in hot bath according to stability, 3 min, 6 min, 9 min, and 12 min was decreased(105.15 mmHg, 104.69mmHg, 104.24 mmHg, 103.03 mmHg, and 96.69 mmHg)(P=0.3006). SBP was decreased in cool bath, too(105.15 mmHg, 103.33 mmHg, 103.33 mmHg, and 100.91 mmHg), but it at 12 min was a little higher(l03.09 mmHg)(P=0.7566). As time went on, DBP according to stability, 3 min, 6 min, 9 min, and 12 minutes was decreased in hot bath(66.82 mmHg, 65.45 mmHg, 64.54 mmHg, 63.03 mmHg, and 59.39 mmHg)(P=0.0906). It was similar in cool bath(66.82 mmHg, 67.87 mmHg, 68.48 mmHg, 67.87 mmHg, and 68.78)(P=0.9654). As time went on, PF was significantly increased in hot bath(70.42 times, 86.96 times, 93.57 times, 99.30 times, and 101.78 times)(P=0.0001). It was a little increased in cool bath, too (70.42 times, 70.85 times, 71.63 times, 71.06 times, and 71.45 times)(P=0.9803). As time went on, RF was significantly increased in hot bath(15.75 times, 19.09 times, 22.09 times, 24.94 times, and 26.48 times)(P=0.0001). I t in cool bath of stability, 3 min, and 6 min was a little increased(15.75 times, 19.30 times, 19.39 times), but it in 9 min(18.67 times), and 12 min(18.09 times) was a little decreased(P=0.0176). As time went on, BT was significantly increased in hot bath($36.63^{\circ}C,\;37.45^{\circ}C,\;37.81^{\circ}C,\;38.12^{\circ}C,\;38.33^{\circ}C$)(P=0.0001). It was a little increased in cool bath of stability and 3 min($36.63^{\circ}C,\;37.40^{\circ}C$), but others are similar($37.33^{\circ}C,\;37.37^{\circ}C$, and $37.36^{\circ}C$)(P=0.0001). It was revealed by this study, SBP and DBP according to time in hot and cool bath were decreased. PF, RF, and BT in hot bath were higher, RF and BT in cool bath were higher too. but PF was similar.

  • PDF

A New Method For Measuring Acupoint Pigmentation After Cupping Using Cross Polarization (교차편광 촬영술(Cross Polarization Photographic Technique)를 이용한 부항요법의 배수혈 피부 색소 침착 변화 측정 평가)

  • Kim, Soo-Byeong;Jung, Byungjo;Shin, Tae-Min;Lee, Yong-Heum
    • Korean Journal of Acupuncture
    • /
    • v.30 no.4
    • /
    • pp.252-263
    • /
    • 2013
  • Objectives : Skin color deformation by cupping has been widely used as a diagnostic parameter in Traditional Korean Medicine(TKM). Skin color deformation such as ecchymoses and purpura is induced by local vacuum in a suction cup. Since existing studies have relied on a visual diagnostic method, there is a need to use the quantitative measurement method. Methods : We conducted an analysis of cross-polarization photographic images to assess the changes in skin color deformation. The skin color variation was analyzed using $L^*a^*b^*$ space and the skin erythema index(E.I.). The meridian theory in TKM indicates that the condition of primary internal organs is closely related to the skin color deformation at special acupoints. Before conducting these studies, it is necessary to evaluate whether or not skin color deformation is influenced by muscle condition. Hence, we applied cupping at BL13, BL15, BL18, BL20 and BL23 at Bladder Meridian(BL) and measured blood lactate at every acupoint. Results : We confirmed the high system measurement accuracy, and observed the diverse skin color deformations. Moreover, we confirmed that the $L^*$, $a^*$ and E.I. had not changed after 40 minutes(p>0.05). The distribution of blood lactate levels at each part was observed differently. Blood lactate level and skin color deformation at each part was independent of each other. Conclusions : The negative pressure produced by the suction cup induces a reduction in the volumetric fraction of melanosomes and subsequent reduction in epidermal thickness. The relationship between variations of tissue and skin properties and skin color deformation degree must be investigated prior to considering the relationship between internal organ dysfunction and skin color deformation.

Compositional Variation of Arsenopyrites in Arsenic and Polymetallic Ores from the Ulsan Mine, Republic of Korea, and their Application to a Geothermometer (울산광산산(蔚山鑛山産) 유비철석(硫砒鐵石)의 조성변화(組成變化) 및 지질온도계(地質溫度計)에 대(對)한 적용(適用))

  • Choi, Seon-Gyu;Chung, Jae-Ill;Imai, Naoya
    • Economic and Environmental Geology
    • /
    • v.19 no.3
    • /
    • pp.199-218
    • /
    • 1986
  • Arsenopyrite in arsenic and polymetallic ores from calcic Fe-W skarn deposit of the Ulsan mine, Republic of Korea, has been investigated by means of electron microprobe analysis and X-ray diffractometry. As a result, it is revealed that the Ulsan arsenopyrite may be classified into the following three species with different generation on the basis of its mode of occurrence, chronological order during polymetallic mineralization and chemical composition; arsenopyrites I, II and III. 1) Arsenopyrite I-(Ni, Co)-bearing species belonging to the oldest generation, which has crystallized together with (Ni, Co)-arsenides and -sulpharsenides in the early stage of polymetallic mineralization. In rare cases, it contains a negligible amount of antimony. It occurs usually as discrete grains with irregular outline, showing rarely subhedral form, and is diffused in skarn zone. The maximum contents of nickel and cobalt are 10.04 Ni and 2.45 Co (in weight percent). Occasionally, it shows compositional zoning with narrow rim of lower (Ni+Co) content. 2) Arsenopyrite II-arsenian species, in which (Ni+Co) content is almost negligible, may occur widely in arsenic ores, and its crystallization has followed that of arsenopyrite I. It usually shows subhedral to euhedral form and is closely associated with $l{\ddot{o}}llingite$, bismuth, bismuthinite, chalcopyrite, sphalerite, bismuthian tennantite, etc. It is worthy of note that arsenopyrite II occasionally contains particles consisting of both bismuth and bismuthinite. 3) Arsenopyrite III-(Ni, Co)-free, S-excess and As-deficient species is close to the stoichiometric composition, FeAsS. It occurs in late hydrothermal veins, which cut clearly the Fe-W ore pipe and the surrounding skarn zone. It shows euhedral to subhedral form, being extremely coarse-grained, and is closely associated with pyrite, "primary" monoclinic pyrrhotite, galena, sphalerite, etc. Among three species of the Ulsan arsenopyrite, arsenopyrite I does not serve as a geothermometer, because (Ni+Co) content always exceeds 1 weight percent. In spite of the absence of Fe-S minerals as sulphur-buffer assemblage, the presence of $Bi(l)-Bi_2S_3$ sulphur-buffer enables arsenopyrite II to apply successfully to the estimation of either temperature and sulphur fugacity, the results are, $T=460{\sim}470^{\circ}C$, and log $f(S_2)=-7.4{\sim}7.0$. With reference to arsenopyrite III, only arsenopyrite coexisting with pyrite and "primary" monoclinic pyrrhotite may serve to restrict the range of both temperature and sulphur fugacity, $T=320{\sim}440^{\circ}C$, log $f(S_2)=-9.0{\sim}7.0$. These temperature data are consistent with those obtained by fluid inclusion geothermometry on late grandite garnet somewhat earlier than arsenopyrite II. At the beginning of this paper, the geological environments of the ore formation at Ulsan are considered from regional and local geologic settings, and physicochemical conditions are suspected, in particular the formation pressure (lithostatic pressure) is assumed to be 0.5kb (50MPa). The present study on arsenopyrite geothermometry, however, does not bring about any contradictions against the above premises. Thus, the following genetical view on the Ulsan ore deposit previously advocated by two of the present authors (Choi and Imai) becomes more evident; the ore deposit was formed at shallow depth and relatively high-temperature with steep geothermal gradient-xenothermal conditions.

  • PDF

Petrology of the Syenites in Sancheong, Korea (경남 산청 지역의 섬장암에 관한 암석학적 연구)

  • Ok, Eun-Young;Kim, Jong-Sun;Lee, Sang-Won;Kang, Hee-Cheol
    • The Journal of the Petrological Society of Korea
    • /
    • v.24 no.1
    • /
    • pp.25-54
    • /
    • 2015
  • Syenite is not a common rock, unlike granitic rocks formed the major component of the continental crust. The aim of this study is to decipher the occurrences and detailed descriptive characteristics of the syenite distributed in Sancheong area, and to investigate the petrogenesis of the syenitic magma based on geochemical study. The dominant minerals in syenite are alkali feldspar (usually orthoclase and rarely microcline), plagioclase, amphibole, biotite, and quartz. Syenites are found in a wide variety of colors. The anhedral hornblende and biotite filling the boundary of feldspar and quartz indicate that the hydrous minerals were crystallized lately, and that water was insufficient at the beginning of crystallization in magma. According to the analysis of mineral composition, amphibole in syenite is mostly ferro-edenite, and the pressure is calculated as 3.3~4.9 kb with 11.9~17.3 km of emplacement depth. Biotite and pyroxene are plotted in the region of annite and hedenbergite, respectively. Based on petrochemical studies of major elements, syenite belongs to alkaline series, metaluminous, and I-type. On the other hand, the variation patterns of trace and rare earth elements of syenite differ from the patterns of diorite and granite. In the geochemical characteristics, syenite is different from gabbro-diorite spatially adjacent to syenite, as well as granite. These results suggest that each rock has been generated from the different sources of magma. Additionally, based on the experimental data, the syenitic magma can be formed (1) by the partial melting at a high pressure and dry system, (2) when the initial crystallization minerals to be residue with migration of the residual melts separated from the ascending cotectic magma (3) when fluorine compositions to be plentiful in the protolith and/or at depth of the magma. Based on the petrographic characteristics of the syenite, Sancheong syenitic magma may have been formed by partial melting in a dry system.

Ecophysiological Interpretations on the Water Relations Parameters of Trees(IX) - Measurement of the Transpiration Rate by the Heat Pulse Method in a Quercus mongolica Stand - (수목(樹木)의 수분특성(水分特性)에 관(關)한 생리(生理)·생태학적(生態學的) 해석(解析)(IX) - Heat pulse법(法)을 이용(利用)한 신갈나무임분(林分)의 증산속도(蒸散速度) 측정(測定) -)

  • Han, Sang Sup;Kim, Sun Hee
    • Journal of Korean Society of Forest Science
    • /
    • v.85 no.2
    • /
    • pp.288-299
    • /
    • 1996
  • This is the basic study to investigate the amount of transpirational water loss in thrifty mature Quercus mongolica stand by the heat pulse method. The differences of heat pulse velocity by direction and depth, differences of heat pulse velocity by dominant, codominant and suppressed trees, diurnal changes of heat pulse velocity due to the change of leaf water potential, vapor pressure deficit and radiation, and sap flow path way in sapwood by dye penetration were measured in stems. Finally the amounts of daily and annual transpiration in stand were calculated by the heat pulse velocity. The results obtained were summarized as follows : 1. Relationship between heat pulse velocity(V) and sap flow rate(SFR) was obtained as a equation of SFR=1.37V. 2. The sap flow rate was high in the order of dominant, codominant, and suppressed trees. The daily heat pulse velocity changed with radiation, temperature and vapor pressure deficit. 3. The heat pulse velocity showed the similar diurnal variation as the leaf water potential change. 4. The heat pulse velocity showed the highest value in May(4.0cm/hr in average), the lowest one in July(2.9cm/hr in average). 5. The heat pulse velocity in the same stem presented the highest value in the northern direction, medium in western, and the lowest in southern and eastern. 6. The heat pulse velocity in stem was highest in 0.5cm, medium in 1.0cm, and lowest in 1.5cm depth from the surface of stem. 7. The sap flow path way in stem showed sectorial straight ascent pattern in four sample trees. 8. The amount of sap flow(SF) was presented as a equation of $SF=1.37A{\cdot}V$(A: the cross-sectional area of sapwood, V: heat pulse velocity), and especially SF was larger in dominant tree than codominant and suppressed trees. 9. The amount of daily transpiration was 5.6ton/ha/day, and its composition ratio was 72% at day and 28% at night. 10. The amount of stand transpiration per month was largest in May(168ton/ha/month), lowest in July(125ton/ha/month). The amount of stand transpiration per year was 839ton/ha/year.

  • PDF

Major Dishes Contributing Absolute and Between-Person Sodium Intake Variations in University Students in Gyeonggi-do (경기지역 일부 대학생에서 나트륨의 주요 기여 음식과 변이 음식)

  • Chung, Eun-Jung;Ryu, Ha-Jung;Shim, Eugene
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.45 no.3
    • /
    • pp.409-419
    • /
    • 2016
  • The objective of this study was to investigate dietary sodium sources at the dish level in 228 university students (71 men, 157 women) in Gyeonggi-do. Daily sodium intake was estimated from a validated 125-dish frequency questionnaire. In men, body mass index, systolic blood pressure, and sodium intake were significantly higher than in women. Men showed higher sodium intake from soups, fish or shellfish dishes, meat dishes, and soybean dishes than women. The dishes that most largely contributed to daily sodium intake were Napa cabbage kimchi and ramen in both men and women. In addition, relatively higher amounts of sodium from ramen were consumed in men, whereas cookies were the 5th highest sodium source in women. In both men and women, the high sodium intake groups consumed more sodium from kimchi, dishes cooked with kimchi, dishes with broth, and salted mackerel than the low sodium intake group. There were significant differences in major dishes contributing to between-person sodium intake variations between men and women. Short rib soup for men and Korean sausage for women were the largest contributors to sodium variations, which are common dishes served with salt. Men consumed more drinks and also more sodium from drinks than women. In conclusion, there were significant differences in major dishes contributing to absolute and between-person sodium intake variations in university students between men and women. Further studies on effects of gender on blood pressure, sodium and drink intake, and obesity are necessary.

Studies on Inheritance and Ecological Variation of the Culm Length and Its Related Characters in Short-Statured Rice Varieties (수도단간품종의 간장 및 관련형질의 유전과 생태적 변이에 관한 연구)

  • Sung-Ho Bea
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.13
    • /
    • pp.1-40
    • /
    • 1973
  • These studies were aimed at clarification of genetic and ecological variation in culm length, panicle length and plant height of the $\textrm{F}_2$ plants in some selected crosses made between semi-dwarf rice varieties and tall Japonica ones. One Indica semi-dwarf, Taichung Native 1, one Indica $\times$ Japonica hybrid, IE51 and one Japonica semi-dwarf, Tankanbaekmang were used as short-gene donors while two of medium maturity varieties, Jinheung and Kwanok and one late veriety, Palkweng were used as the corresponding counterpart of respective dwarf varieties in a series of crosses. Five different crosses, Kwanok $\times$ Tankanbaekmang, Palkweng $\times$ Tankanbaekmang, Jinheung $\times$ T(N)1, Kwanok $\times$ T(N)1 and Kwanok $\times$ IE51, were made among the above six varieties. The $\textrm{F}_2$ plants of these crosses together with the concerned parental varieties were grown under several different conditions including three levels of each nitrogen and planting space, three planting seasons and three locations in 1968, to investigate variation in length of culm and panicle, and plant height. On the other hand, the F$_3$ progenies which were derived from the shortest 10 percent of the plants of three $\textrm{F}_2$ populations, Kwanok $\times$ T(N)1, Jinheung $\times$ T(N) 1 and Kwanok $\times$ IE51 grown in the previous year, were compared each other on the basis of selection efficiency in culm length. The experimental results could be summarized as follows; 1. Genetic behavior A. It was revealed that Tankanbaekmang, one of Japonica dwarf has a simple recessive gene responsible for short culm expression, showing a typical segregation ratio of three tall to one short culm plants in $\textrm{F}_2$ generation of the crosses either with Kwanok or Palkweng. B. In the both combinations, segregation pattern of the panicle length was exactly same as that of culm length. It seems that the same gene controls both culm length and panicle length. C. No difference between segregation of culm length and plant height in the above crosses was observed. D. T(N)1, one of Indica semi-dwarf did not show such a simple genetic behavior as detected from the crosses with Tankanbaekmang in segregation of culm length but formed a continuous and normal distribution curve. Therefore, some nonallelic genic actions might be involved in expression of culm length of the counterpart varieties of T(N)1. In particular, a transgressive segregation appeared toward the direction of longer culm length in case of Jinheung $\times$ T(N)1. The genetic behavior of panicle length and plant height generally coincided with that of culm length in all the cases. E. IE51 demonstrated exactly the same genetic behavior as that of T(N)1 when this variety was crossed with Kwanok. It was clearly clarified that the simple recessive gene controlling dwarfism from T(N)1 was well incorporated into this variety. 2. Ecological variation A. In general, there was a decreasing tendency in culm length and plant height of rice plant as seeding delayed while it was not so noticeable in panicle length. The decreasing magnitude varied from variety to variety and from cross to cross. Genetic behavior of the culm length and related characters of these materials was not disturbed by the variation of seeding season, nitrogen level, planting space and experimental location. E. The elongation mode of the upper three internodes was very similar to the segregation mode of culm length, panicle length and plant height in $\textrm{F}_2$ populations of . all the crosses investigated in this study. Accordingly, this result confirmed that the roles of the upper three internodes are very important in manifesting plant stature in rice. C. The effect of nitrogen on culm length and the related other two characters seemed to be meager. However, it was true to show an increasing tendency of those characters as nitrogen level got increased from 4 kg to 12kg per l0a, with different magnitude depending upon variety or cross. D. Also, the effect of planting space on culm length, panicle length and plant height was relatively small in all the cases. Those characters varied again depending upon variety or cross. However, a general increasing tendency was detected in manifestation of those traits under denser planting space condition. E. All the parental varieties produced shorter culm, panicle and plant height when they were grown at the lower latitude locations. It might be attributed to the fact that their reproductive growth accelerated with increased temperature prevailing at the lower latitude locations such as Iri and Mi1yang. On the countrary, $\textrm{F}_2$ population reacted differently to the different locations from the parental varieties. All the $\textrm{F}_2$ plants produced the longest culm, panicle and plant at Milyang. 3. Selection efficiency A. The heritability of culm length in Kwanok $\times$ T(N)1, Kwanok $\times$ IE51 and Jinheung$\times$T(N)1 was 92 percent, 74 percent and 55 percent, respectively. B. The actual genetic advance for culm length obtained from the progeny lines of the selected plants(10 precent) from the $\textrm{F}_2$ generation, was comparable to the expected advance calculated from the original $\textrm{F}_2$ populations. As compared with the $\textrm{F}_2$ population, the $\textrm{F}_3$ plants of Kwanok $\times$ T(N)l shortened on the average by 20.8cm, those of Kwanok $\times$ IE51 did 8.7cm and those of Jinheung$\times$T(N)1 20.0cm, respectively. C. Panicle length of the populations was differently affected from one cross to another by the selection based upon culm length in $\textrm{F}_2$ Kwanok $\times$ T(N)1 did not show any noticeable shortening of its culm length due to the selection pressure. On the other hand, both Kwanok $\times$ IE51 and Jinheung $\times$ T(N)1 showed a considerable shortening of their panicles in case of selection for culm length. Based upon the above results, it could be concluded that the ecological variation in culm length, panicle length and plant height was relatively small and fallen within the range of genetic variation. Considering from the fact that the simple recessive gene governing short height of Tankanbaekmang always accompanied with some undesirable characters such as short panicle and extremely small grain, the short gene of T(N)1 seemed to be more useful as dwarf gene source since it did not carry short gene together with such undesirable traits.

  • PDF