• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.1
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• pp.89-93
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• 1983

Rice plant was tested in the phytotron to know the varietal difference of ethylene production in different nitrogen levels. The high nitrogen concentrated varieties among tested varieties produced a large amount of ethylene. But high nitrogen concentrated leaf in the one variety produced less amount of ethylene. The varieties which produced a large amount of ethylene was remarkably increased ethylene in no nitrogen plot$(N_0)$ compare to standard level$(N_1)$. In contrast low ethylene producing varieties was remarkably decreased in double nitrogen level$(N_2)$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.4
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• pp.309-314
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• 1990

A pot experiment was carried out to find the effects of chemicals and its application time on the sterility and other agronomic characters of rice. Two rice cultivars, Samgangbyeo, a Tongil type, and Chuchungbyeo, a japonica type rice were treated with maleic hydrazide (6000ppm), ethephon (6000ppm) and GA3 (10ppm) at five different growth stages. The application times of chemicals were comprised of two different stages of stem elongation and booting and panicle emerging stage. Grain sterility and panicle length were measured for panicles per pot. Culm length was measured for pot basis. MH induced complete grain sterility in rice, but caused severe plant damage (phytotoxicity) ; restricted spike emergence and drying out of plant leaves, sheath and panicles. Ethephon induced 50-60% grain sterility in rice with the least in plant damage. GA3 was not effective in inducing grain sterility in rice, but it increased culm length. The earlier application of chemicals, the higher sterility was induced. Both MH and ethephon reduced culm length and grain yield. Also observed was the varietal response in the occurrence of to chemicals Samgangbyeo showed the higher response to chemicals than Chuchungbyeo.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.8 no.1
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• pp.105-110
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• 1970

Resistance to Black shank of various varieties were investigated in field and incubator. The results were summarized as follows; 1) In occurrence of this disease, yellow tobacco varieties were ranged from 4 days to 12 days after inoculated. 2) Korean native varieties were ranged from 6 days to 20 days. 3) Orient tobacco takes from 8 days to 17 days in occurrence of this one. 4) Japanese varieties ranged from 4 days to 3 days in occurrence of this disease. 5) Dark air-curing tobacco was ranged from 5 days to 14 days. 6) Chinese variety was ranged from 6 days to 11 days. Each varieties of resistant to Black shank was as follows; 1) Yellow tobacco varieties; Cash, Oxford-1, Oxford-3, N.C-75, N.C-95, Golden-cure Delcrest. 2) Native varieties; Sinzongtchio, Muktchio Sosa-3 Mokgitchio. 3) Japanese varieties; Hatano Outaruma Maruha. 4) Chinese variety; Gkzuoe, Yung-zung, Tongzuoe. 5) Orient tobacco; Samsun, Baffra, Xanthix. 6) Dark air-curing varieties; B-Hw, Connecticut-Broad leaf, Connecticut-Havana, Tennessee-Black.

• Journal of Life Science
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• v.6 no.4
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• pp.227-233
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• 1996

The capsaicinoid content of F$_{1}$ hybrids between annuum L. 'California Wonder', four native Japanese cultivars, and three Korean F$_{1}$ cultivars were evaluated and the results compared with parental cultivars. The capsaicinoid content was higher in the placenta than in fruit flesh. The placenta of 'Yatsufusa', 'Taka no Tsume', 'Cheongyang', 'Sinhong', and Geoseong' were the most pungent cultivatrs, with capsaicinoid content of more than 1000mg/100g DW, while 'California Wonder', and 'Fushimi Amanaga' contained trace amounts. Capsaicinoid content in F$_{1}$ hybrids varied with reciprocal crossing. Capsaicinoid content also varied with fruit development, rapidly increasing in the fourth or fifth week after flowering, and thereafter slowly declined.

• Journal of Life Science
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• v.8 no.4
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• pp.426-430
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• 1998

The molecular relationships have analyzed between the Bombyx mandarina(wild silkworm) and Bombyx mori strains (domesticated silkworm, geographical silkworms). A total of 166 polymorphic RAPD markers amplified from 35 different primers were used to analyze the molecular relationships among thirteen silkworm strains. The genetic similarity coefficient between Bombyx mandarina and Jam305 showed the lowest genetic similarity value with 0.451, Bombyx mandarina and Bibaekjam showed the highest genetic similarity value with 0.958. These strains were classified into Bombyx mandarina(a wild silkworm) and Bombyx mori(twelve domesticated silkworm) groups upon the genetic similary coefficient of 0.55. Further classificient of 0.60; the 1st sub-group (J111, Bibaekjam, $pnd^{ps}$), the 2nd sub-group (Galwon, C18, od yujam, JAM306, C108), the 3rd sub-group(R-hwang, p50), the 4th sub-group(zebra) and the 5th sub-group(JAM305). According to this study, RAPD markers seems to be a valuable tool for molecular relationships and classification among the silkworms.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.257-265
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• 1996

To obtain the basic informations necessary to develop the production technology of vegetable soybean seeds, this study was conducted at the National Crop Experiment Station, RDA, Suwon, Korea in 1993. Seeds of three vegetable soybean varieties, 'Mikawashima', 'Hwaeomputkong', and 'Seokryangputkong' produced at Pyeongchang, a highland in Korea and introduced from Japan were planted on April 20 in the field. The emergence rate among varieties was significanlty different. Emergence rate of seeds produced at Pyeongchang was higher by 7% than that of the seeds from Japan. Rate of pod infection by Phamapsis spp., brown spot by Septaria glycines, soybean mosaic virus(SMV), and downy mildew by Peronospora manshurica in the field was not different between locations. The growth characteristics, yield components, and green pod and grain yields were not different between locations. Therefore, it was proved that the production of vegetable soybean seeds with the better quality and higher emergence is possible in highland, Korea. possible in highland, Korea.

• Research in Plant Disease
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• v.10 no.4
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• pp.217-226
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• 2004

One hundred isolates of Magnaporthe grisea from Korea and China were characterized for pathogenicity using eight Korean differential varieties(KDV), six Chinese differential varieties(CDV) and six near isogenic lines(NILs) developed in China. The restriction length polymorphism of M. grisea isolates from each country also was analyzed using MGR586 as a probe. One hundred Korean isolates classified into 17 races on KDV were grouped into 29 pathotypes on Chinese near isogenic lines(NILs). Virulence of 46% of Korean isolates against all the six Chinese NILs indicated that the current six Chinese NILs alone was not enough to be used as differential varieties in Korea. Especially, susceptibility of the BL1 carrying resistance gene Pi-b to 70% of tested Korean isolates suggested that BL1(Pi-b) may not be a useful resistance source to Korean blast. Based on the virulence assays of M. grisea populations from each country were divided into two groups. About 50% of Chinese isolates showed similarity to the 30% of the Korean isolates. Especially, the isolates from northern part of China, where Japonica rice cultivars were grown, showed high similarity to the Korean isolates, while isolates from southern part of China, where Indica rice were mainly grown, showed low similarity to Korean isolates. The genome RFLPs of Korean isolates were quite different from those of southern part of China using MGR586 as a probe. These data indicated that the physiological and genetical characteristics of M. grisea population might be determined by strong interaction with cultivated rice.

• Journal of Sericultural and Entomological Science
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• v.50 no.1
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• pp.5-9
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• 2012

A new silkworm variety SooOkJam for spring rearing season is F1 hybrid between Jam157, a japanese race bred from introduction breeding and Jam158, a chinese race from introduction breeding. In the local adaptability test performed at 8 local areas in spring of 2011, the hatchability rate of SooOkJam was recorded 2% higher than the authorized silkworm variety, DaePoongJam. The larval period was recorded 12 hour shorter than DaePoongJam. The pupation percentage was recorded 0.8% higher than DaePoongJam. Single cocoon weight (2.40 g), Cocoon yield (22.6 kg) and best cocoon rate (95.5%) was similar to DaePoongJam. The concentration of DNJ was measured 4.12 mg in SooOkJam, lower than DaePoongJam (4.45 mg). Test of the artificial diet of SooOkJam showed excellent adaptability of the artificial diet for larval period from 1st to 3rd, similar to KumOkJam. In the Paecilomyces tenuipes production ability test, the pupal weight of SooOkJam was 1.61 g/individual, similar to DaePoongJam (1.65 g/individual).

• Korean journal of applied entomology
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• v.36 no.3
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• pp.206-214
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• 1997

The genetic relationships among the twenty parental silkworm, Bombyx mori strains authorized in Korea were evaluated using RAPDs-PCR(Random Amplified Polymorphic DNAs-Polymerase Chain Reaction). Twenty-six different 10-mer oligonucleotide primers were used to screen genetic characteristics of parental twenty silkworm strains by RAPD-PCR analysis. 24 primers showed different banding patterns among the strains. Based on these RAPD patterns, the genetic relationships among the silkworm strains were analyzed by UPGMA(Unweighed Pair-Group Method with Arithmetic average) method. The phylogenetic relationships in the twenty silkworm strains were classified into two major sub-groups at the genetic similarity coefficient of 0.60. The first sub-group included Jaml13, Jaml 19, Jaml20, Jam123, Jam1 25 and Jam 127. Jamll4, Jam1 2 I, Jam 122, Jam 124, Jam1 26, Jam 128, Jam129, Jam 130, Jam 131, Jam1 32, Jam133, Jam134, Jam301 and Jam302 were included in the 2nd group. The genetic distance values among Jam1 14, Jam120 and Jam127 were lower than those among the other strains, while Jam129 is very closely related to Jam131 as showing coefficient value of 1 .O.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.6
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• pp.521-531
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• 1991

Greenhouse experiments were conducted at the International Rice Research Institute during the 1989 dry season to investigate varietal differences in morpho-anatomical characters affecting spikelet filling in different tiller orders. There were varietal differences in tiller initiation and heading dates, and tiller duration. The main culm bad competitive advantage over the other tillers. The maximum contribution to filled spikelet weight was made by primary tillers in low tillering cultivars and by secondary tillers in high tillering cultivars. The reduction in inner vascular bundle (IVB) by tiller orders and the namber of IVB and outer vascular bundles (OVB) varied amop.g cultivars. The number of IVB in the peduncle of IR30, Rewa and Hybrid was more than OVB but in IR47705, Silewah, Unbongbyeo and SR14453, OVB was more than IVB. Early formed tillers produced more IVB than the late formed tillers. The number of IVB was positively correlated with number of spikelet and filled spikelet weight, however percent of filled spikelet did not show significant differences as well as 1000 spikelet weight in all types of cultivars.