• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.1-5
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• 2011

A new powdery mildew resistant squash (Cucurbita moschata Duch.) 'Miso' was bred from a cross between powdery mildew resistant true variety 'Sangol' and powdery mildew susceptible inbred line 'Seoulmadi' at National Institute of Horticultural & Herbal Science (NIHHS). The 'Miso' variety was vigorous and highly resistant to powdery mildew. It showed white green fruit color. The variety yielded 21.3MT/ha which is 52% more than control variety.

• Korean journal of applied entomology
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• v.9 no.1
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• pp.15-20
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• 1970

An investigation was carried out to know the relationship between resistance of rice varieties to blast disease and the chemical components, especially total nitrogen and total sugars, in the rice plants. The results sic summarized as follow: 1) The nitrogen contents in the resistant variety were less than those of susceptible one, and sugar contents were reversed. Accordingly, the C/N ratio in the resistant variety was higher than that obtained by susceptible one. 2) The free amino acids contents, especially, Glutamine, Valine, Leusine and Iso-leusine, in the resistant varieties were more than those of the susceptible varieties. 3) The starch synthetic activity of rice leaves in the resistant varieties was higher than that of susceptible one in fructose and glucose solutions, but it was reversed in sucrose solution. 4) When more nitrogen was dressed, the total nitrogen content of rice leaves was increased than the ordinary dressing. The rate of increase in nitrogen content in resistant variety was lower than those of the susceptible. The total sugar content of rice plants dressed more nitrogen was decreased at early tillering stage, but increased at maximum tillering stage. It seemed that the rate of increase of total sugar in the resistant variety was higher than those of the susceptible.

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.2
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• pp.85-95
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• 2006

Seveval Chinese and Japanese varieties with good characters were used in the breeding. After 5 years (15 generations), a pair of robust and high quality silkworm variety with NPV resistance was bred by means of a combination of crossing and pedigree selection complemented by the selection of NPV resistance. The variety was identified jointly nationwide in 2003 and 2004, and appraised by National Mulberry and Silkworm Appraising Committee. Results are as follows: its cocooning rate is over 93%, shell rate 23-25%, filament length 1200-1300 meters, reelability 75-88%, Length of non-broken cocoon filament 900-1100 meters, raw silk rate 17-19%, neatness 95-97 points, and cocoon crop, cocoon shell weight and raw silk weight per 10000 larvae is higher than those of the control variety by 7-10%, 14-19% and 14-18%, respectively. The variety is not only robust, resistant to high temperature and NPV, easy to rear, uniform in hatching, molting and maturing, but also lays more eggs, and its fecundity is high. It is suitable to rear in the Yangtze River Basin, the Yellow River basin and the Pearl River basin of China.

• Journal of the Korean Society of Tobacco Science
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• v.6 no.2
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• pp.185-189
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• 1984

To classify the inheritance of resistance to potato virus Y, crosses between susceptible flue-cured tobacco variety NC 95 and resistant variety McNair 30 were conducted. The parents, $F_1$ plants, $F_2$ populations, and haploid plants derived from anthers of $F_1$ plants were screened for a resistance of two potato virus Y strains (PVY-VB and PVY-VN) isolated in Korea. The Chi-square values for the $F_3$ populations and haploids of $F_1$ fitted 1 :3 and 1 :1 ratios of resistant to susceptible for two strains, respectively. Therefore, it was found that the resistance of McNair 30 for the potato virus Y was controlled by a single recessive gene. Moreover the resistance to two strains screened was inherited dependently.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.4
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• pp.324-331
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• 1981

Sixty five soybean varieties were tested to observe varietal response and to get the basic data for resistant variety breeding to soybean cyst nematode (Heterodera glycines I.). They were classified into five groups, from the most resistant to the most susceptible by decreasing rate of seed weight. A few Korean varieties were included in the most resistant group. In general, early maturing varieties were more susceptible. Total plant weight could be used as an important criterion to select a resistant variety to soybean cyst nematode.

• Korean journal of applied entomology
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• v.11 no.1
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• pp.41-43
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• 1972

1. In order to investigate the epidemic outbreak of rice blast disease on the resistant variety Kwankon in 1969, this investigation was undertaken as a basis for breeding resistant varieties. 2. The 16 isolates collected from Kyunggi area were inoculated at the 3-4 leaf stage on 12 Japanese differential varieties used for identifying races under greenhouse conditions. Out of 16 isolates 15 were identified as C race group and one as N race group. Of the 15 rates, nine were C-8, two were C-7 and two were C-1. Of the remaining two isolates, one was similar to C-1, and the other was similar to C-5. 3. It is concluded that the epidemic in the resistant variety 'Kwanok' was due to the occurrence of the C race group, which can infect the Chinese type varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.365-372
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• 2012

Native of soybean aphid (Aphis glycines Matsumura) is an Asia and aphid is one of the dangerous pests in soybean [Glycine max (L.) Merr.]. High density aphid populations can reduce crop production by causing severe damage. The objective of this study was evaluation of resistance to the soybean aphid in soybean cultivars and germplasms. A total of fifty five soybean cultivars or germplasms, including two susceptible and two resistant check varieties, were infested to evaluate their resistance in the field cage and greenhouse test by aphid colonies which derived from wild collected one soybean aphid biotype in Korea. The average number of reproduced soybean aphid was evaluated with 62.7 aphids in the resistant check variety PI 567598B and also estimated with 1,807 aphids for susceptible check variety Williams 82. In soybean varieties and germplasms, the average reproduced soybean aphid populations ranged from the lowest 497 aphids for Junjeori to the highest 3,862 aphids for Mansu. About seventy six percent of soybean cultivars and germplasms were shown high density soybean aphid populations when compared with another susceptible check variety PI 567543C in the field cage test. From the greenhouse test to evaluate aphid index, 87.3% of soybean cultivars or germplasms presented aphid index with 9.0. No soybean cultivars and germplasms were observed with soybean resistant phenotype when regarded a aphid resistant level as less than 10% aphid reproductions compared with susceptible check Williams 82. Although no Korean soybean cultivars were identified with resistant trait to the soybean aphid, we found one great resistant genetic resource PI 567598B in this study. This result will be helpful to further study for providing useful genetic information for soybean researchers.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.2
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• pp.55-62
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• 2018

We bred a mulberry cultivar named 'Saealchan' through local adaptability test, which is under registration as a new cultivar for fruit production. Local adaptability test had been carried out at four local places (Jeonju, Gongju, Jangseong, and Sangju) for five years from 2013. This variety 'Saealchan' belongs to Morus alba L. selected from seedlings collected from mother mulberry 'Shimheung'. Saealchan was resistant to popcorn disease and high yielding variety in fruit productivity by 194% compared to control cultivar 'Shimheung (Morus alba L.)' for three years. Although fruits of 'Saealchan' was smaller in size and lower in sugar content of mulberry fruits compared to control variety 'Shimheung', it showed strong resistance to sclerotial disease compared to 'Shimheung'.

• International Journal of Industrial Entomology and Biomaterials
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• v.13 no.1
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• pp.1-5
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• 2006

The major dominant fluoride-endurance (Dfe) gene was introduced into the commercial varieties by crossing and pedigree selection to breed silkworm races that could normally develop in the area that polluted by fluoride. After backcrossed for two generations, the Dfe gene was made homozygous, and individuals with good economic characters were selected to generate next generation. After 8 generations of selection, their characters became stable, and the silkworm variety which is resistant to fluoride, Huayuan${\times}$Dongsheng, for spring rearing were bred.

• Korean journal of applied entomology
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• v.16 no.4 s.33
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• pp.235-239
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• 1977

The experiments were contucted to investigate the variability of pathogenesity, growth amount and UV-sensitibity on the streptomycin resistant isolate of the rice bacterial leaf blight pathogen, Xanthomonas oryzae, which selected by the stepwise transfer in 100, 3,000 and 10,000 ug/ml Argepto contained media. And the results obtained were as follows. (1) The SM-resistant isolates were tested the pathogenesity on the differential variety of rice, wase-Aikoku-3, Rant Emas-2, Hwang ok, and Kimmase. And the SM resistant isolate, obtained from 75-6 isolate, showed the reaction of moderately resistant to the differential variety of Hwang ok instead of susceptible reaction with its parental isolate. (2) The growth amount of the SM-resistant isolate was slightly higher than that of parental isolate, on the normal media. And the growth was inhibited on the 100ug/ml Agrepto contained media until 60 hours after transfer, however, its growth exceeded than parental isolate in the normal media, after 70 hours of transfer. (3) It is considered that the resistance factor might be stable character, since the sensitivity to UV irradiation (with 254 mr wave length) of the resistant isolate was the same as that of its parental isolate.