• Journal of The Korean Society of Grassland and Forage Science
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• v.12 no.3
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• pp.173-177
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• 1992

This experiment was carried out to determine the effect of harvesting dates on the dry matter yield and quality of "Kool grazer" winter rye(Seca1e cereale L.) as a soilage crop at the Forage Experimental Field of College of Agrlc. and Life Sciences, SNU, Suweon. Four-day harvasting interval was allocated to measure the growth, yield and quality of rye from April 14 to May 18, 1987. Rye was rapidly grown as 3 cm/day and the growth was linearly recorded from the elongation to flowering stage. The dry matter and in vitro digestible dry matter(1VDDM) yields per ha were linearly increased up to 0.26 and 0.19 tonlday from April 14 to May 4 and April 14 to 29, respectively, but major breaks in yield increases occurred at the 50% heading stage, than yields increased. The highest crude protein yield was observed at the first heading stage of April 29, then decreased. Acid detergent fiber (ADF) and crude protein(CP) contents of rye at the heading stage of May 5 were 35 and 17%, respectively and the nutritive value of rye in terms of ADF and CP contents was evaluated as the I st grade hay, but neutral detergent fiber(NDF) content of rye was 47 % at the boot stage ofApril 22 and evaluated as the 2nd grade hay in terms of NDF content. The results indicate that the first heading stage or the end of April would be the most suitable harvesting time for early maturing winter rye as a soilage crop in terms of yield and quality in the middle northwestern coast rcgion of Korea. of Korea.

• Journal of Life Science
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• v.13 no.6
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• pp.822-828
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• 2003

This study was carried out to investigate the changes of enzymes and micro inorganic nutrients that is associated with flower senescence during flower development in tulip cultivars, ‘Apeldoorn’ and ‘Golden Apeldoorn’. Ribonuclease, peroxidase and protease activities were gradually increased from the stage of early flowering to later Polyphenol oxidase showed the highest activity at stage 5, which the flower was in full bloom indicating that it acts at an initial stage of flower senescence. The protease activity was different in the petal extracts during flower development between the cultivars ‘Apeldoorn’ (red petal) and ‘Golden Apeldoorn’ (yellow petal). This result suggested that protease might relate to pigment biosynthesis in petal of tulip. In contrast to the decrease of inorganic nutrients K, Mn, Zn and P contents during floral development, Ca, Mg and Fe showed the gradual increasement that is similar with ribonuclease, peroxidase and protease. It suggests that they have some interaction during flower senescence.

• Journal of Crop Science and Biotechnology
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• v.11 no.3
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• pp.205-214
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• 2008

Blast disease caused by the fungal pathogen, Magnaporthe oryzae, is one of the most damaging diseases in rice. The use of resistant varieties is an effective measure to control the disease, however, many resistant varieties were broken down to their resistance effects by the differentiating of new virulent isolates. This study was done to analyze the haplotypes of 31 microsatellite markers linked to five major R genes and two QTLs and to identify the alleles for the putatively novel genes related to durable resistance to blast in 56 Korean japonica and four indica varieties. The 31 microsatellite markers produced 2 to 13 alleles(mean = 5.4) and had PICi values ranging from 0.065 to 0.860(mean=0.563) among the 60 rice accessions. Cluster analysis based on allele diversities of 31 microsatellite markers grouped into 60 haplotypes and ten major clusters in 0.810 genetic similarity. A subcluster IV-1 grouped of early flowering varieties harboring Piz and/or Pi9(t) on chromosome 6 and Pita/Pita-2 gene on chromosome 12. The other subcluster V-1 consisted of four stable resistance varieties Donghae, Seomjin, Palgong and Milyang20. The analysis of putative QTLs associated with seven blast resistance genes using ANOVA and linear regression showed high significance to blast resistance across regions and isolates in the markers of two genes Piz and/or Pi9(t) and Pita/Pita-2. These results illustrate the utility of microsatellite markers to identify rice varieties is likely carrying the same R genes and QTLs and rice lines with potentially novel resistant gene.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.38-49
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• 2013

Prohexadione-calcium (Pro-Ca), ethephon and transient water stress were evaluated in a factorial design, as potential inhibitors of early-season shoot growth of high density orchard management of apple (Malus domestica Borkh.) trees. In the experiment, water stress was imposed to one-half of the 7-year-old 'Golden Delicious'/M.9 apple trees in each of 5 blocks, by stopping irrigation for 3 weeks between 35 and 56 days after full bloom (AFB). Within each whole unit, the following Pro-Ca and ethephon treatments were randomly allocated at $2{\times}2$ factorial: a) 0 or 250 $mg{\cdot}L^{-1}$ a.i. Pro-Ca applied at 28 days AFB and b) 0 or 300 $mg{\cdot}L^{-1}$ a.i. ethephon applied twice (35 and 71 days AFB). All trees were hand thinned to king flowers prior to treatments. Vegetative shoot growth was markedly reduced by Pro-Ca, with its effect being obvious within 14 days after application, while ethephon and water stress treatments were less effective. Pro-Ca had no effect on fruit set and yield but slightly increased fruit size. Ethephon substantially reduced the fruit size and yield but had no effect on fruit set. Water stress reduced fruit set, fruit size and yield. With regard to fruit quality, Pro-Ca did not influence fruit shape, flesh firmness and soluble solids contents (SSC) but slightly reduced titratable acidity. Ethephon had no effect on fruit shape but increased firmness, SSC and acidity, while water stress did not influence these fruit quality attributes. Dry weight of dormant spur buds was reduced by both Pro-Ca and water stress, while increased by ethephon. The larger dormant buds led to the larger spur flowers at the tight cluster stage the following spring. Return flowering was promoted only by ethephon, especially on previous season's shoots. There were no significant interactions between Pro-Ca and ethephon or water stress on most variables observed in this study.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.697-704
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• 2015

This study was carried out to investigate conveyance environment during shipping export to Japan and the optimum pre-treatment of cut Dendranthema grandiflorum 'Baekma'. Shipping from Korea to Japan, which usually takes three to five days, requires keeping the flower at the ideal temperature. When inspection took place in Japan, the ideal temperature was lost and deterioration began. Once the ideal temperature is lost, deterioration takes place. The results of this work showed that vase life was extended by treatment Chrysal RVB and NaOCl compared to the control (distilled water), and Chrysal RVB was used to maintain the flower from bud to full bloom. Bacterial growth was not observed after pretreatment with NaOCl or $ClO_2$. However, $ClO_2$ pre-treatment was observed to affect the early growth period of the bacteria. The chlorophyll content was the highest after Chrysal RVB or NaOCl pretreatment compared to the other treatments. Therefore, these results support pretreatment with NaOCl and Chrysal RVB of Dendranthema grandiflorum 'Baekma' for export to Japan.

• Journal of Plant Biology
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• v.20 no.1
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• pp.7-14
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• 1977

The seeds of bean(Glycine max M.) and corn(Zea mays L.) soaked in 5000ppm lead solution for 24 hours were sowed in the flowerpots being placed sandy-clay soil under the field condition. The fixed concentrations of various anions and 2000 ppm lead were supplied alternately in the sandy-clay soi of the flowerpots at two days interval from May to July in 1976. After the plants were harvested prior to the flowering stage, the lead contents of plnat and soil were analyzed by atomic absorption spectrophotometer. The lead contents absorbed by the plant roots showed the highest in an weak acid soil of the best suitable condition of plant growth. The absorption of lead by the plant roots was inhibited by the various anions, especially divalent anions of the soil. Some phosphate anions inhibited lead absorption more than otehr various anions in the soil. The more various anions were in the soil, the more plants could be protected from the lead toxicity. In the case of lead supply in the soil, 99.5% of lead was accumulated in the upper layer of the soil(0-10cm), and 0.5% of lead accumulated in the lower layer (10-20cm). Therefore, the yellow-brown and white symptoms on the leaves and the inhibition of root growth by lead toxicity was increased in the early stage of the germination, however decreased in accordance with the progress of the growing stage becuase of the root growth toward beneath the lower layer of the soil. In spite of the contents of 3773ppm lead in the soil, the symptoms of lead toxicity was not found in the grown plants. At that time the lead contents of the plants absorbed from the soil were minimum 0.78ppm and maximum 3.64ppm through the growing stage.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.703-706
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• 2010

A new gerbera cultivar 'Sunny Lemon' was released by the National Institute of Horticultural and Herbal Science (NIHHS) in 2009. A cross was made between 'Pavlov' and 'Patrick' with pink and semi-double in 2006. After investigation of the characteristics for four years (from 2006 to 2009), it was selected for the use of cut flower. 'Sunny Lemon' is a vigorous cultivar with yellow flower color (RHS Y9C), brown center and semi-double. The average flower diameter is 11.0 cm. And inner ray floret and disc diameter are 7.63 cm and 2.59 cm, respectively. Days to first blooming are 84.5, approximately 2 weeks earlier than the standard cultivar. It produces a large yield with continuous supply of cut flowers and has adequate peduncle height. We believe that 'Sunny Lemon' has a great potential for expanding cultivated area of domestic gerbera cultivars and increasing farmers' income.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.664-667
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• 2010

A new poinsettia cultivar 'Clara' was bred by the National Institute of Horticultural and Herbal Science (NIHHS) in 2005. A cross was made between 'Red Velvet', a variety with dark green leaves and red bracts, and 'Freedom Bright Red', a variety with early short day responding and bright red bracts, in 2002. 'Clara' was finally selected in 2005 after the investigation of the growth and flowering characteristics from 2003 to 2005. 'Clara' has red ovate bracts and weak intensity of rugosity between bract veins. Leaf blade is ovate and medium green. Petiole length is relatively short, and stem color is reddish. 'Clara' has medium free-branching ability and makes short and compact canopy. Clara's bracts and transitional leaves are fully colored 9 weeks after short day commencement.

• Korean Journal of Breeding Science
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• v.42 no.6
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• pp.645-648
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• 2010

A new spray carnation cultivar 'Lyra' was released by the National Institute of Horticultural and Herbal Science in 2003. A cross was made between spray cultivar 'Ballantyne' and red spray cultivar 'Chateau' in 1999. After investigation of the characteristics during four years (from 2000 to 2003), the cultivar 'Lyra' was finally selected in 2003. 'Lyra' is a spray cultivar with bright pink color for a cut flower. The main characteristics are early flowering, multi branching, fragrance and long flower stalk. Also, it has medium resistance to Fusarium wilt and 7 days vase life. To avoid calyx splitting caused by high temperature, it is recommended that this cultivar be grown over $8^{\circ}C$ at night and under $25^{\circ}C$ at day time during a flower bud differentiation period and applied with additional nitrate fertilization ($30.0kg{\cdot}10^{-1}$).

• Journal of Apiculture
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• v.33 no.4
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• pp.239-250
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• 2018

We investigated the pollination activity of honeybees (Apis mellifera L.) in terms of different climatic conditions in the greenhouse cultivation of watermelons (Citrullus lanatus L.) during winter. The aim of the study was to search a climatic condition which effectively can be use honeybees as pollinators during the flowering season of watermelons in winter or early spring. The average climatic conditions inside the greenhouse during the bee activity time (BAT)-between 10:00 and 16:00 in mid-Februarywere a temperature of $30.4^{\circ}C$, relative humidity of 53.7%, illuminance level of 22,728.4lx, and UV level of $0.233mW/cm^2$. Bee traffic and foraging activity were at their greatest at 10:00 and tended to decrease with time. Male watermelon flowers typically dehisced between 10:00 and 12:00. Climatic conditions were significantly correlated with bee activities, including bee traffic and foraging activity. Bee activities were positively correlated with temperature, illuminance level, and UV level but negatively correlated with relative humidity. Temperature had the greatest effect on honeybee behavior. Among the foraging honeybees, the number of high-flying bees that did not pollinate flowers showed a strong positive correlation with temperature, and the number of bees landing on the flowers showed a positive correlation with the UV level. The temperature range inside greenhouses at which the pollination activities of honeybees can be maintained efficiently during winter watermelon pollination was found to be $21{\sim}25^{\circ}C$.