• Horticultural Science & Technology
• /
• v.16 no.4
• /
• pp.525-527
• /
• 1998

This study was conducted to determine the optimum cultural condition and method for in vitro mass production of Hibiscus syriacus L. 'Honghwarang'. When callus induced in MS solid medium supplemented with 0.01 mg/L TDZ was cultured in liquid medium containing 0.01mg/L TDZ, callus growth and shoot primordia formation was most effective. Formed shoot primordia were regenerated into shoot in MS or 1/2 MS medium of growth regulator-free condition. Effects of mesh size, shaking speed on callus and shoot primordia formation were examined after 5 weeks. Callus and shoot primordia formation was formed most effectively at 10 mesh and 80 rpm shaking speed in liquid medium.

• Asian Journal of Turfgrass Science
• /
• v.11 no.4
• /
• pp.311-320
• /
• 1997

This study was carried out to induce and maintain callus from 59 zoysiagrass lines, to know the effective disinfestation method for zoysiagrass stolon as explant and the difference in the response of callus induction among 59 lines, and to investigate the effect of medium, growth regulators, light, temperature, stolon part and internode position on callus induction and emhryogenic callus(E.C.) formation. The treatment of 0.lmg/L $HgCl_2$for 15 min resulted in no contamination and the highest callus induction(46.6%). Callus was induced from the 59 zoysiagrass lines. The callus growth of Z. japonica and Z. sinica was generally better than Z. matrella Ten cell lines whose callus and stolon grow fast in culture and in field, respectively were selected to he used for breeding. Callus induction was the most effective at 2.0mg /L of both 2, 4-D and picloram in MS medium. MS medium was the best for callus induction and growth while LS medium was the best for embryogenic callus and shoot formation. Callus induction and growth was better at 28, 31$^{\circ}C$. than 25$^{\circ}C$. and dark condition was better than light condition in MS me-dium containing 2mg/L 2,4-D. While callus induction was better with node part as explant than with internode part, callus growth and embryogenic callus formation was better with internode part. In 'Japonica 1', the first internode was the most effective in callus induction, but third internode was the best in '$M_2$ X $S_2$'.

• Journal of Apiculture
• /
• v.33 no.4
• /
• pp.251-260
• /
• 2018

Instrumental insemination of honey bee is an attractive alternative to natural mating in breeding program as it allows mating crosses between desirable queen and specific drone. However, nursery condition that the queen is kept before and after insemination is major factor affected to the performance of instrumentally inseminated queen. In this study, we evaluated the influences of three different nursery-conditions of push-in cages, mini nuclei and normal colonies on number of spermatozoa stored in the spermatheca, body weight, onset of ovipositon and performance of instrumentally inseminated Apis cerana queen. Our results demonstrated that instrumentally inseminated queens kept in mini nuclei and in normal hives showed no significant difference in queen's weight (159.8 and 166.2mg, respectively), number of spermatozoa in spermatheca ($2.02{\times}10^6$ and $2.76{\times}10^6$, respectively), proportion of queen supersedure (33.3 and 66.7% queen survival at 11 months after oviposition, respectively) and brood production, compared to naturally mated queens. In contrast, instrumentally inseminated queens kept in push-in cages showed significant difference of those above data in comparison to queens mated naturally. Our results suggested that instrumentally inseminated queens could be kept in mini nuclei containing about 1.000 attendant bees to have desirable performance of queen whereas the push-in method should be practiced for the purpose of using queen in the length of time less than 7 months.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.63 no.1
• /
• pp.37-48
• /
• 2021

The automatic-spreader of bedding materials was developed to reduce labor cost, and to achieve successful biosecurity in duck houses. Algorithm of the device was designed to realize a concept of the automatic unmanned operation including entire processes such as loading and spreading of the bedding materials. From the field measurement, the relationship between the expected water content reduction and weight of bedding materials per unit area according to the operation condition of the devices was induced. In the case of the measurement of particulate matters during the process of spreading works, the results of using both conventional manual-spreader and automatic-spreader were exceeded the allowable limit of inhalable and respirable dust, respectively. But, workers using automatic-spreader could be free from harmful aero-condition because they did not stay inside the facility during the spreading works. In addition, from the Duck hepatitis virus PCR test, influence on pulmonary tissue of the duck was not found. It could be expected that the development of the automatic-spreader of bedding materials for duck house can contribute to the advancement of duck breeding facilities.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.48 no.4
• /
• pp.339-344
• /
• 2003

To identify the new source of breeding materials for rice salt tolerance, the salinity tolerance of thirty-four varieties was evaluated under 0.5% saline condition at seedling stage. The salinity score showed highly significant correlations to dry weight and dead leaf ratio. The tested varieties were classified into three groups by visual score, reduction ratio of dry weight, and dead leaf ratio. Eighteen varieties were classified as the highly tolerant group (salinity scores of 1.3-3.7), seven varieties were fallen into the tolerant group (salinity scores of 4.2-5.8), and others were susceptible (salinity scores of 6.7-9.0). In highly tolerant group, most indica varieties including Getu, Dikwee and Kuatic Putic, didn't exsert a panicle under the Korean climate. But six varieties, Xiangcho V, Annapuruna, HP 3319-2wx-6-3-1, Giza 175, and GZ 2447-S-17, GZ 4255-6-3 were suitable to the Korean climate, and their heading date (6-16, August) and culm length (65-78㎝) were similar to the Korean varieties. Accordingly, these varieties can be utilized as crossing materials for the salt tolerance in japonica rice.

• The Korean Journal of Food And Nutrition
• /
• v.9 no.4
• /
• pp.536-541
• /
• 1996

Inspite of Korea's being major consuming country of sesame, the most of its supply depends on import. Furthermore, the researches of sesame have been conducted since 1973. So far total 121 academic papers have been published and their main subjects are the analysis of constituent and composition of sesame, breeding and cultivation of sesame and detection of alterated sesame oil. Though the flavor is very important at the time of eating, its study has been done only in the difference of the kinds of sesame, the condition of roasting, extraction, filtration. Thus the more detailed studies of them and sensorytest are required. Also it is found that the studies such as the improvement yield at sesame oil mill and the utilization of oil cake are nearly absent.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.36 no.1
• /
• pp.79-84
• /
• 1991

The rice plants (Oryza sativa L.) established from the shattered grains by combine harvesting at the previous year showed great variations of yield and yield components from site to site at the abandoned rice crop field. The cultural condition was very similar to direct seeding under no-tillage system but no cultural practices such as application of fertilizer, weed control, irrigation and drainage had been carried out. The highest yield of 188kg/10a was observed at one of the quadrats randomly located on the field, which showed the possibility of exploitation of no-tillage system. The interrelationship between crop growth and coverage of weed species was measured by calculating the correlation coefficients. The investigations of how to establish sufficient number of seedlings per unit area, plant succession on the abandoned crop field, crop mixture with legume crops, and breeding appropriate plant type of rice for the enhancement of competitive ability would be required for the success of no-tillage system.

• Fisheries and Aquatic Sciences
• /
• v.11 no.1
• /
• pp.50-60
• /
• 2008

Harmful algal blooms (HABs) of Cochlodinium polykrikoides frequently occur around the South Sea of Korea, causing. economic losses in coastal breeding grounds. HAB outbreak scale usually changes each year depending on physical, biological and environmental conditions. Relatively large-scale HABs occurred in 1995, 1997, 1999, 2001, 2002 and 2003 with respect to spatial scale, duration and maximum density. Considering HAB scale and temperature distributions around the South Sea, we found that low coastal temperatures in August correspond to enormous HAB outbreaks. Cold waters created by coastal upwellings around the southeastern coast of Korea also corresponded to these outbreaks. Serial oceanographic investigations in August in the South Sea revealed that sea surface temperature anomalies had distinctively negative values when large-scale HAB outbreaks appeared. With regard to temperature differences between the surface and the 30-m layer, there was a tendency for large-scale outbreaks when temperature gradients around the seasonal thermocline weakened.

• Journal of Korean Society of Rural Planning
• /
• v.1 no.2
• /
• pp.67-76
• /
• 1995

The actual condition of farmstead, mainly livestock facility, was surveyed in ChungChongBukDo in order to find out factors and problems of farmstead planning design. From the data collected, a type, plot, size and scope of farmstead, relationship of house and farmstead, topography, climate, proprietor's opinion on them were analyzed or obtained as the basic design criteria for planning: designs. The best type of farmsteads was individual farm having livestock facilities. They were mostly breeding a kind of livestock without their plan and Bone planning at residing area. The south aspect of the facility was extremely much and slope of the land was mostly 15。 below. Wind blows from East-South in summer and winter wind are West-North extremely much. Sun heat was mostly above 6 hours. In the case of collective and composite farmstead, proprietors wanted that a head of cow has 1,000-3,000 pyeong, the area of facility has 1,500-2,000 pyeong, total area of farmstead has 45,000-400,000 pyeong and an estimated expense is 0.2 - 1.5 billion won. Farmstead planning design was proposed through field survey results and contents of'references. Examples of farmstead planning design were composite and concentrated type and existed according to the situation of road(North, South, East, and West).

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2018.10a
• /
• pp.68-68
• /
• 2018

A total of 47 core collections of pepper (Capsicum chinense Jacq.) conserved in National Agrobiodiversity Center (NAC) were studied under field condition at Jeonju. All accessions were characterized for their 14 qualitative and 16 quantitative characters. Results revealed that both qualitative and quantitative characters exhibited wide variation among the studied germplasm. Distribution of fruit characters (fruit length, width, and fruit wall thickness) among the accessions was positively skewed. Of the 47 accessions evaluated, 38.3% accessions had conical shaped fruits and mature fruit color was predominantly red (51.1%), orange (21.3%) and yellow (14.9%). Principal component analyses revealed that (i) 56.64% of the qualitative (fruit shape, color and fruit surface) variation and (ii) 89.42% of the quantitative (plant width, height and fruit maturity days) variation were explained by the first two components. Clustering revealed two groups and dendrogram revealed morphological variation among accessions. The phenotypic diversity exists in this core collections provide valuable information to improve agronomic traits in pepper breeding program.