• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.4
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• pp.464-469
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• 2015

This study was carried out to find relationships of genetic distance and heterosis expression degree in the developed CNU waxy corn lines. The used material were developed in Corn Breeding Laboratory, Coll. of Agri. & Life Sci., CNU. Total 10 primers used for SSR maker analysis. In genetic distance, the used lines divided into four groups; A group has two lines, B group has one line, C group has ten lines and D group has eleven lines, respectively. Among used lines, CNU427 and CNU588 were very closed as a 74, while CNU451 and CNU429 were remote as a 40 inbred coefficient, respectively. While heterosis degree were very variable not only hybrids but also cross parents. Average heterosis of most cross-parent was high in plant height, ear height, flowering day and ear length. Especially, CNU H09-23 hybrid was high as 79.4% than other hybrids. Here, we gained the fact has closely relationship between genetic distance and heterosis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.640-646
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• 1997

To determine variations in leaflet length (LL), leaflet width (LW), leaflet size (LS), and leaflet shape index (LSI), and their association with eight agronomic traits, characterization data of 884 soybean accessions which were grown in the autumn of 1992 in Taiwan were analyzed. LL ranged from 4.3 to 14.7 cm, and LW ranged from 2.8 to 9.7 cm. Also, LS (LL $\times$ LW) ranged from 12.1 to 124.6 $\textrm{cm}^2$. The absolute variation of LL, LW, and LS was not large because of limitation in vegetative growth by short day length. None was classified as a large leaflet based on the International Board for Plant Genetic Resources (IBPGR) descriptors. LSI (LL /LW) ranged from 1.21 to 3.06, and three accessions were classified as narrow leaflet. There were differences in ranges and means of LL, LW, LS, and LSI between and within temperate and tropical accessions. LL, LW, LS, and LSI had highly significant positive correlations with seven agronomic traits and highly significant negative correlation with 100-seed weight except LW for all accessions. There was variation in the closeness of association among leaflet traits, and between and within temperate and tropical accessions. Generally, LL, LW, and LS were more closely associated with days to flowering, plant height at $R_1$ and $R_8$, number of pods per plant; LSI was more closely associated with 100-seed weight than other traits.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.70-74
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• 2008

To determine an optimum harvest time for chinese milk vetch (CMV) seed production, the seeds were harvested at 4 times, according to 25, 30, 35, and 40 day after flowering (DAF), in Miryang, southern part of Korea. CMV plants were manually harvested at each time and seed threshing was done by rice threshing machine. Seed yield, 1,000-seed weight, germinability, and hard coat ratio were investigated. Seed yield was the highest, 53.9 kg/300 kg by dry weight (DW) of CMV plant, at 35 DAF. 1,000-seed weight increased according to seed harvest time from 25 DAF to 40 DAF when it was 3.10 g. The germination ratios of seeds harvested at 4 times were not significantly different when the seeds stored until August 1. In case of long period of CMV seeds stored, the seeds harvested later showed higher germination rate. On the other hand, because the hard coat ratio causing germination inhibition was declined with an increase of storage period, it was higher in the seeds harvested later. There was no difference among the seeds harvested at 4 times at October 1. In conclusion, it was presumed that an optimum harvest time for CMV seed production should be at 35 DAF considering seed yield, weight and germinability.

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.106-112
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• 2015

The objective of this study was to examine the growth reaction of strawberry plants to the mixed red and blue LED sources and their installation method. The artificial light sources were : LED PAR(PPFD $2{\sim}4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$), LED BAR(PPFD $100{\sim}120{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and incandescent(PPFD $2{\sim}4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) lamp. The lighting treatment was started at the first cluster flowering period as a night breaking lighting and was applied during 3 hours, between 22:00 and 01:00 every day. Plant height and leafstalk length were longer in plants treated with incandescent lamp, where as fresh and dry weight of shoot were heavier in LED PAR compared to incandescent lamp treatment. LED PAR treatment also resulted in the largest leaf area, chlorophyll content was increased by $0.36mg{\cdot}g^{-1}$ after 60 days from the starting of the artificial lighting. According to the experimental results application of 16W LED PAR lamps and W-type installation method can improve light environment in strawberry lighting culture.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.544-551
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• 2013

The effect of different silicon (Si) sources and methods of application on the growth of two chrysanthemum cultivars grown in a soilless substrate was investigated. Rooted terminal cuttings of Dendranthema grandiflorum 'Lemmon Eye' and 'Pink Eye' were transplanted into pots containing a coir-based substrate. A nutrient solution containing 0 or $50mg{\cdot}L^{-1}$ Si from calcium silicate ($CaSiO_3$), potassium silicate ($K_2SiO_3$) or sodium silicate ($Na_2SiO_3$) was supplied once a day through an ebb-and-flood sub irrigation system. A foliar spray of 0 or $50mg{\cdot}L^{-1}$ Si was applied twice a week. Cultivar and application method had a significant effect on plant height. Cultivar, application method, and Si source had a significant effect on plant width. Of the three Si sources studied, $K_2SiO_3$ was found to be the best for the increasing number of flowers, followed by $CaSiO_3$ and $Na_2SiO_3$. In both the cultivars, sub irrigational supply of Si developed necrotic lesions in the older leaves at the beginning of the flowering stage as compared to the control and foliar spray of Si. Cultivar, application method, Si source, and their interactions had significant influence on leaf tissue concentrations of calcium (Ca), potassium (K), phosphorus (P), magnesium (Mg), sulfur (S), sodium (Na), boron (B), iron (Fe), and zinc (Zn). The addition of Si to the nutrient solution decreased leaf tissue concentrations of Ca, Mg, S, Na, B, Cu, Fe, and Mn in both cultivars. The greatest Si concentration in leaf tissue was found in 'Lemmon Eye' ($1420{\mu}g{\cdot}g^{-1}$) and 'Pink Eye' ($1683{\mu}g{\cdot}g^{-1}$) when $K_2SiO_3$ was applied through a sub irrigation system and by foliar spray, respectively.

• Journal of Bio-Environment Control
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• v.13 no.1
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• pp.39-43
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• 2004

This study was conducted to determine the optimum planting distance under rain-shielding condition for improving quality and productivity of squash by staking cultivation. The squashes were grown by 3 planting distances, such as 120${\times}$30, 120${\times}$40 and 120${\times}$50 cm during 3 months under non heat condition. The vine length, fresh weight and leaf area were reduced as planting distance was decreased until main branch was pinching. The first female flowering day and first fruit setting nodes were not different among treatments. The first fruit length and second fruit weight were increased in 120${\times}$50 cm planting distance, but the soluble solid contents were not different among treatments. In 120${\times}$30 cm plant distance, total yield was highest (6,510 kg/10a), but marketable yie이 was lowest. When the planting distance was between 120${\times}$40 cm and 120${\times}$50 cm, the marketable rate was similar (over 98%), but marketable yield was highest in 120${\times}$40 cm planting distance (5,012 kg/10a). The results of this study indicated that the optimum planting distance of staking cultivation in squash seemed to be 120${\times}$40cm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.185-192
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• 2019

Early-maturing rice type is cultivated to produce rice before the Korean Thanksgiving Day. We investigated the flowering and ripening characteristics of major breeding lines in early maturing rice type. In Jeonju, field growth days (FGD) from transplanting to heading changed about 3.3 days by 10 days of transplanting days and about 2.5 days by the change of mean temperature during growth period. As the temperature during ripening stage, 1000 brown rice weight was changed 0.2 g, the rice quality of brown and milled rice was changed 5% and 6.5%, respectively. Baegilmi and Kittake showed early heading habit suitable for harvesting before Korean Thanksgiving. Joun and Pecos showed good ripening characteristics under high temperature during the ripening stage. We expect that these characteristics might be useful for breeding new rice cultivars for harvesting before Korean Thanksgiving.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.246-268
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• 2019

Soybean [Glycine max (L.) Merr.] is a species of legume native to East Asia. The interactions between climatic conditions and genetic characteristics are known to affect the agricultural performance of soybean. Therefore, the present investigation was conducted to identify the main elements affecting the agricultural performances of 11 soybean varieties/lines from China [Harbin ($45^{\circ}12^{\prime}N$), Yanji ($42^{\circ}53^{\prime}N$), Dalian ($39^{\circ}30^{\prime}N$), Qingdao ($36^{\circ}26^{\prime}N$)] and the Republic of Korea [Suwon ($37^{\circ}16^{\prime}N$), and Jeonju ($35^{\circ}49^{\prime}N$)]. The days to flowering (DTF) of soybeans with the e1-nf and e1-as alleles and the E1e2e3e4 genotype, except in 'Keumgangkong', 'Tawonkong', and 'Duyoukong', were relatively short compared to those of soybeans with other alleles. Although DTF of the soybeans was highly correlated with all climatic conditions [negative: precipitation, average temperature (AVT), accumulated temperature; positive: day-length (DL)], days to maturity and 100-seed weight of the soybeans showed no significant correlation with any climatic conditions. The soybeans with a dominant Dt1 allele, except 'Tawonkong', had the longest stem length (STL). Moreover, STL of the soybeans grown in the test fields showed a positive correlation with only DL; however, the results of our chamber test that was conducted to complement the field tests showed that STL of soybean was positively affected by AVT and DL. Although soybean yield (YLD) showed positive correlations with latitude and DL (except L62-667, OT89-5, and OT89-6), the response of YLD to the climatic conditions was cultivar-specific. Our results show that DTF and STL of soybeans grown in six different latitudes are highly affected by DL, and AVT and genetic characteristic also affect DTF and STL.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.196-200
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• 2008

A new spary chrysanthemum (Dendranthema grandiflorum) cultivar 'Pinky' was bred from a cross between 'Rima' and 'Yen'. Progenies were investigated from 2004 to 2006 under shading culture in spring and retarding culture in autumn and the promising line was selected based on the performance of year-round production, white rust resistance and vase life. Pinky flowered around 20 October, and year-round production was possible by shading and lighting. Its flower was 3.1 cm in diameter, and had 38.4 petals and 26.8 flowers per stem in autumn. Its petal was narrow (0.4 cm) and pink with green in color at the flower center. Days to flower from short-day start for 'Pinky' was about 47 in spring. 'Pinky' showed a vase life of 20.9 days in autumn. This cultivar was commercially registered in 2007. 'Pinky' would be suitable for culture under the greenhouse and rain shelter condition in Korea.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.159-163
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• 2008

A New spary chrysanthemum (Dendranthema grandiflorum) cultivar 'Water Fog' was bred by open pollination of 'Angaesoguk'. Its characteristics were investigated three times from 2004 to 2006 under forcing culture in spring and retarding culture in autumn. The natural flowering time of 'Water Fog' was 24 October, but year-round production was possible by shading and lighting. It had flower diameter of 2.3 cm, 46.5 petals and 34.4 flowers per stem in autumn. The petal was narrow(0.4cm) and the color of petal was white with presence of green at flower center. Days to flower from short-day start for 'Water Fog' was about 48 in spring. 'Water Fog' showed the vase life of 22.6 days in autumn. This cultivar was registered for a commercialization in 2007. 'Water Fog' would be cultured under greenhouse and rain shelter condition in Korea.