• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.2
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• pp.120-130
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• 2018

Improvement in rice grain yield has been approached by means of genetic amendment, cultural management, and environmental adaptation. Subjecting the plant during the grain filling period to an appropriate environment plays a key role in achieving a high grain yield in temperate rice. Field experiments were conducted for two consecutive years with two planting times to assess the relations among grain filling traits, loss of leaf activity during the ripening period, and the grain yield of temperate japonica rice with wide environmental variation. Higher grain yields were attained in 2017 than in 2016 and with late planting than with early planting. The high grain yield accompanied a comparatively lesser increase in grain weight at the early filling stage but more gain in grain weight occurred during the late filling stage. Final grain weight correlated positively with grain filling duration but negatively with grain filling rate. Extended grain filling duration was associated with higher cumulative temperature and cumulative solar radiation for an effective grain filling period. The reduction in SPAD value ${\times}$ leaf dry weight from heading to harvest significantly correlated with final grain dry weight in a positive manner. No significant relation was found between grain filling duration and the decrease in SPAD value ${\times}$ leaf dry weight during the grain filling period. The results suggest that grain filling duration and loss of leaf activity during ripening independently contribute to environmentally induced yield improvement in temperate japonica rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.214-219
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• 1991

To clarify the relationship between ambient water temperature and heading characteristics of rice (Oryza sativa L.), twelve of varieties rice were grown in a cold tolerance screening field where water temperature was controlled by continuous cold water irrigation system to test the cold tolerance of rice. When cold water was continuously irrigated with 5 cm of water depth, the water had stagnated for about three hours, and the water temperature increased gradually from inlet toward outlet in the experimental plot. The fluctuation of water temperature was well synchronized with that of ambient air temperature, and the water temperature near outlet became higher than the air temperature at the vegetative phase, while became lower at the reproductive phase of rice plant community. The leaf development rates on main culm increased by increased water temperature. The rice varities, Fukuhikari, Sangpungbyeo and YR3486-16-2 were more sensitive than the others in the response of leaf development to water temperature. However, Janack and Milyang 42 were comparatively less sensitive to water temperature in leaf development. Janack and Paro -white rices required longer days to develop one leaf on main culm at reproductive phase than at vegetative phase. Varietal difference in days required to develop one leaf on main culm of rice plant was more distinctive at the reproductive phase when water temperature was relatively lower than at the vegetative phase with relatively higher water temperature condition. No difference was found between the growth phases, vegetative and reproductive, in the response of average leaf developmental rates to water temperature under the similar air temperature condition. The estimated average days required to develop one leaf on main culm decreased by 1.3 day by 1$^{\circ}C$ increase in water temperature. Varietal differences in the total number of leaves on main culm depended upon the water temperature, in which the varieties such as Fukuhikari, Gwangmyeon-gbyeo, China 988, and YR3486-16-2 showed increased one leaf by increased water temperature, while Sobaekbyeo, Paro-white, Sangpungbyeo, Pungsanbyeo, Samgangbyeo, and Milyang 42 were kept at the same leaf number regardless of water temperature. However, the total leaf number on main culm and days to heading of Janack increased by increased water temperature. The other varieties showed the shortened days to heading by the increase in water temperature with noticeable varietal differences regardless of the variation in the total number of leaves on main culm.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.9
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• pp.1449-1457
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• 2018

Objective: The objective was to evaluate feed intake, digestibility, body weight change and carcass characteristics of sheep fed a basal diet of hay supplemented with banana leaves and silver leaf desmodium. Methods: Thirty yearling lambs with an average initial body weight of $15.85{\pm}1.6kg$ were grouped into six blocks of five rams in each block. The treatments were: hay alone (T1), hay+100% banana leaf (T2), hay+67% banana leaf+33% desmodium leaf (T3), hay+33% banana leaf+67% desmodium leaf (T4), andhay+100% desmodium leaf (T5). Three hundred grams of treatment diets were offered daily on as fed basis. The feeding and digestibility trials lasted for 84 and 7 days, respectively, followed by carcass evaluation. Results: The total dry matter (DM) intake for T3, T4, and T5 were greater (p<0.05) than those fed T1 and T2 diets. The lowest (p<0.05) organic matter (OM) intake was recorded in rams reared on T1 diet. The total crude protein (CP) intake was in the following order: T5>T4>T3>T2>T1. Ram lambs receiving supplementary diets had higher (p<0.05) DM, OM, CP, neutral detergent fiber and acid detergent fiber digestibility compared with the control diet. The empty body weight and slaughter weight was highest (p<0.05) in rams receiving T3, T4, and T5 diets. The average daily gain and feed conversion efficiency was highest (p<0.05) in rams receiving the supplementary diets. The dressing percentage on the basis of hot carcass weight linearly increased with increasing levels of desmodium. Rams reared on supplementary diet had higher (p<0.05) rib eye area compared with the control diet. Conclusion: In conclusion, when banana leaf is used as a supplement to poor quality grass, better body weight gain was obtained when fed in combination with desmodium.

• Journal of Plant Biotechnology
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• v.30 no.4
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• pp.307-313
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• 2003

Fluorescent differential display (FDD) is a method for identifying differentially expressed genes in eukaryotic cells. The mRNA FDD technology works by systematic amplification of the 3' terminal regions of mRNAs. This method involve the reverse transcription using anchored primers designed to bind 5'boundary of the poly A tails, followed by polymerase chain reaction (PCR) amplification with additional upstream primers of arbitrary sequences. The amplified cDNA subpopulations are separated by denaturing polyacrylamide electrophoresis. To identify the genes involved in the development of first trap leaf, we applied a FDD method using mRNAs from leaf base, first trap leaf and flower tissue, respectively. We screened several genes that expressed specifically in first trap leaf. Nucleotide sequence analysis of these genes revealed that these were protease inhibitor (PI), myo-inositol-1-phosphate synthase and lipocalin-type prostaglandin D synthase. Northern blot analysis showed that these genes were expressed specifically in first trap leaf (in vivo and in vitro). FDD could prove to be useful for simultaneous scanning of transcripts from multiple cDNA samples and faster selection of differentially expressed transcripts of interest.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.294-294
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• 2022

To date, there have been no reports on the cloning and characterization of a gene encoding SQS from Amaranthus, although there have been some reports on methods of extracting and purifying squalene from Amaranthus seeds. In this study, we monitored the expression pattern of the amaranth SQS gene in seeds at different developmental stages and in different tissues. The transcript expression pattern of the SQS gene was investigated using total RNA isolated from seeds at different stages of development. There were low levels of SQS transcripts at the early stage of seed development, and the levels remained low until the middle developmental stage. The expression of SQS increased rapidly to reach a peak at the mid-late developmental stage, and then declined dramatically. This pattern of expression was consistent with the results of RT-PCR analyses. All RNA samples generated a fragment of the expected size (183-bp). The amaranth SQS was expressed at low levels during the initial to middle stages of seed development, and its expression level increased at the mid-late development stage. Also The tissue-specific expression of amaranth SQS was determined by quantifying its mRNA in total RNA isolated from the leaves, petioles, stems, and roots of seedlings at the four- and six-leaf stages. Using qRT-PCR and RT-PCR analysis, we detected amaranth SQS transcripts in some of the tissues at the six-leaf stage, but in none of the tissues from plants at the four-leaf stage. SQS transcripts accumulated in almost equal amounts in stems and roots, while a lower level accumulated in leaves and petioles during seedling development at the four- to six-leaf stages. This study provides useful information about the molecular characterization of the SQS clone isolated from grain amaranth. A basic understanding of these characteristics will contribute to further studies on the amaranth SQS.

• Asian Journal of Turfgrass Science
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• v.13 no.1
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• pp.29-36
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• 1999

This study was conducted to make the utmost use of the good traits and to improve the poor traits of zoysiagrass through the production technology for mixed lines sod in addition to breeding. Mixed lines sod was produced by mixing broad or middle leaf line with narrow leaf line by volume, a ratio of 1 to 2. The mixed lines sod of zoysiagrass was superior to the single ling sod, which is used commonly, for the establishment rate, coverage rate, shoot density, texture, leaf color, dormancy period cnd color, and visual quality.

• Journal of Plant Biology
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• v.26 no.1
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• pp.41-51
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• 1983

This study was carried out to investigate ontogeny of stomata and aerenchyma tissue in Trapa natans L. var. bispinosa Makino, an aquatic plant. Ontogeny of stomata in this plant was an aperigenous type surrounding with 5 to 8 epidermal cells without subsidiary cells. Stomata were distributed abundantly on the upper surface of leaf, however, no stoma was found on the lower surface of leaf, and on the epidermis of reproductive organ, petiole and stem. Ontogency of aerenchyma tissue was progressed with five steps; 1) formation of angular cells by division of cortex cells, 2) development of small and large globular cells in accompany with schizogenous intercellular space, 3) enlargement of globular cells and more expansion of intercellular space, 4) cell induction of long elliptic and triarmed shape, 5) completion of the largest intercellular space from endodermis toepidermis. During the growth period two types of leaf were appeared at each node of stems; one type was a submerged and early-fallen leaf, the other was a floating leaf on water surface.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.6
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• pp.103-112
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• 2001

The development of infrared thermometry has led many researchers to use plant temperatures, and specifically the temperature of the crop canopy in the field, for estimating the water stress of a crop. The purpose of this study was to evaluate the role of leaf temperature in irrigation scheduling. An experiment was carried out in a greenhouse with chinese cabbage. Leaf temperature was measured with infrared thermometry and evapotranspiration of the crop was measured by lysimeters. Influence of the difference between leaf temperature and air temperature on crop evapotranspiration was evaluated under varying water stress condition. A further objective was to evaluate the effect of other climatic variables on the relationship between evapotranspiration and temperature difference between leaf and air. A statistical model for estimating evapotranspiration using the temperature difference, relative humidity. and radiation was developed and tested. Crop water stress index was calculated using vapour pressure deficit and the temperature difference. Relations between the crop water stress index and crop evapotranspiration was tested. The index was closely related with evapotranspiration.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.94-99
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• 2003

As the rotating speed of rotors is increased, the instability and power loss become serious problems. Gas bearings are introduced as a good solution to those problems. But in the development of gas bearings, high load capacity and high damping force to vibrations are required. In this study a new air bearing using leaf spring pad is introduced to improve load capacity and damping force. The experimental results of the leaf spring pad air bearings show high load capacity and high damping forces. And the results show that leaf spring pad air bearings can be simultaneously acted as radial and thrust bearings

• Journal of Plant Biology
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• v.18 no.1
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• pp.1-10
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• 1975

Development of a model system for mode of action studies of $SO_2$ was attempted with a plant tissue. Leaf disks, 1.0cm diameter, cut from the lamina of lettuce leaves, were floated on the testing medium and placed in light or dark condition to investigate the discoloration pattern with various sources of $SO_2$. Discoloration of leaf disks tended to be more serious with higher concentrations of $SO_2$ and on exposure to the light. Leaf disks were more severely discolored at lower pH with constant SO2 concentration. These discoloration patterns were highly reproducible and similar in all sources of $SO_2$. Spectrophotometric evidence suggested that light-mediated discoloration of leaf disks in the presence of $SO_2$ might occur mainly through chlorophyll ${\alpha}$ degradation.