• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.298-301
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• 2010

A new intermediate parent 'Wonye 30002' (Allium cepa L.) was developed by Bioenergy Crop Research Center, NICS in 2009. As a male sterile line, 'Wonye 30002' can be used to hybrid seed production by crossing with pollen parent. The first cross was conducted between male sterile plants of 402AC203 and M1 in 2002. The male sterile line 'Wonye 30002' has circular bulb and bulb weight is 283 g. As early maturing type, lodging date is May 6. Plant height and pseudostem diameter are 43 cm and 15.5 mm, respectively. In seed harvesting characteristics, number of flower stalks and the length are 43 cm and 110 cm, respectively. The flowering date of 'Wonye 30002' is around May 24 and is completely male sterile. 'Wonye 30002' is a promising male sterile line for hybrid bulb onion seed production.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.364-371
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• 2017

The key to development of barnase-barstar transgene based hybrid seed technology is the availability of tightly regulated tapetum specific promoter, as any leaky expression of the barnase gene leads to several unintended effects. In the present study, we used two different tapetum specific promoters i.e. promoter of the RTS gene isolated from rice cultivar IR64 and the OsG6b promoter from japonica rice cultivar Hayayuki to express the barnase gene in rice transgenic lines. While viable male sterile transgenic lines could not be obtained with RTS promoter we could develop single copy male sterile lines when the barnase gene was expressed under the OsG6b promoter.

• Korean Journal of Medicinal Crop Science
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• v.17 no.3
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• pp.198-203
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• 2009

Isatis tinctoria var. yezoensis (Ohwi) Ohwi (Cruciferae) is one of major natural dyeing crops in the world and also have used as a medicinal plant in Korea. We evaluated seed purity in $F_1$-hybrid accessions using amplified fragment length polymorphism (AFLP) markers. One hundred sixty seeds from the male and female harvests were subsequently screened for seed purity with ten primers. The 13 accession-specific bands and many variable AFLP bands scored for accessions. Especially, E-AAC/M-CAA and E-AAG/M-CAT were presented clear hybrid bands for $F_1$ hybrids. $F_1$ hybrids maintained higher average level of genetic diversity compared with their correspondent parents. Self-inbred seeds from the female and male harvests were revealed 8.0% and 5.0%, respectively. The AFLP may lead to a better insight in to the hybrid seed purity test in I. tinctoria var. yezoensis.

• Horticultural Science & Technology
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• v.17 no.4
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• pp.470-472
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• 1999

When the type and ratio of male-sterile plants in $F_1$ hybrids collected from several seed companies were investigated, there were differences in the male-sterile type depending upon region, seed company and variety group. The differences were inferred due to the easiness in breeding of maintainer line among the variety groups. American seed companies mainly used petaloid type male sterility with Imperater group varieties. European companies used brown anther type male sterility mainly with Nantes group but some companies used petaloid type also in varieties that were different from Nantes group. Asian companies (Japan, Korea) used both types with Chantaney and Kuroda group varieties, but one type was mainly used depending on individual seed company. Only one type of male-sterility in one variety was observed and the results were agreed well with other's results that male-sterility type was determined by cytoplasm factor. Some breeding lines were backcrossed to both types of cytoplasm (Sa, Sp) for maintainer line selection. We could select 15 maintainer lines from 20 lines in petaloid cytoplasm (Sp) and 3 from 4 lines in brown cytoplasm (Sa). In petaloid cytoplasm, maintainer lines can be selected at considerably high frequency. But in brown anther cytoplasm, the used materials are too restricted to tell general frequency maintainer lines.

• Journal of the Korean Society of Tobacco Science
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• v.20 no.2
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• pp.166-171
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• 1998

In order to improve the efficiency of F$_1$ hybrid seeds production(KF 114), some experiments were carried out in a greenhouse this year. Mother plant(MSNC567) and pollen plant(NC) were grown in some pots (30 x 30cm, WxH). The gathered pollens were mixed with celite, pollen deluent dusts and stored in refrigerator at l$0^{\circ}C$ before pollination. To establish the critical range of the mixed rate and the storage period of pollens, the change in a percent of capsule set, number of seed and seed weight per capsule, weight of 1000 seeds and germination percent of seed resulted of pollination with pollen deluent dusts were investigated. The results are as follows; Percent of capsule set showed the mixed rate 1:5 resulted in no difference and those of 1:10 and 1:20 decreased about 5 ～15% when compared with trials using pollen alone. There was no difference among duration of storage in a same mixed rate. Numbers of seed per capsule showed a significant difference among the mixed rates and among durations of storage. Numbers of seed per capsule were decreased about 55 ～ 90 % as the mixed rate increase, about 2 ～ 28 % as the duration of storage increase. Weight of seed per capsule decreased about 16 ～ 23 % as the duration increase and decreased about 3 ～ 89 % as the mixed rate increase when compared with trials using pollen alone. Weight of 1000 seeds showed non significant difference among duration of storage but were higher than trials used pollen alone as the mixed rate increase.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.717-724
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• 2001

This study was conducted in an attempt to quantify some traits that may be involved in the reproductive process of Pinus thunbergii. During the past 6 years (1995-2000), we surveyed flowering patterns of 60 P. thunbergii clones in a seed orchard which was established in Anmyon-do, 1979. From this survey, we estimated clonal contributions of male and female flowers and sexual asymmetry. Among 60 clones, 18 clones (30%) accounted for 0.37 (1999)~0.46 (1995) of clonal contribution in female flowers and 0.44 (1999)~0.57 (1995) of clonal contribution in male flowers. As compared with the previous reports in other pine species, more clones made contributions to reproductive process in P. thunbergii seed orchard. The relative effective population numbers for females (v♀) varied from 0.59 (1995) to 0.91 (1999) and those for males ( v♂) were between 0.56 (1995) and 0.83 (1998) at gamete level. This showed that the female gametes effectively contribute to the reproductive process more than did the male gametes. The relative effective population numbers at clonal level ($v_b$) were in the range of 0.72 (1995) and 0.93 (1999). More than 73% of the total clones showed values of 0.4~0.6 ($0.5{\pm}0.1$) in maleness index. The values averaged over all the clones were temporally variable with the range of 73% in 1996 and 100% in 2000. The degree of sexual asymmetry ($A_s$) ranged from 0.09 to 0.26. These values were relatively low when compared with those of other trees, suggesting that P. thunbergii seed orchard remains a high level of homogeneity in the number of male and female. All of the various types of effective population numbers were positively correlated with each other while they were negatively correlated with the degree of sexual asymmetry.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.205-205
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• 2022

Sorghum (Sorghum bicolor L.) is a major cereal grain crop of the world and It can be cultivated under high temperature and dry condition with high adaptability to the adverse environment. It is usually eaten with rice in korea and most of domestic sorghum cultivars have been developed by pure line selection and cross breeding. In prior studies, Hybrid cultivar (F1 seed) was known to improve 30-40% in yield and resist to disease and pest than pure line varieties due to hybrid vigor. Therefore, study on the hybrid sorghum is continuously necessary. In korea, hybrid sorghum cultivar have been developed, so we need to find methods seed production technology for supply and commercialization of hybrid seed cultivar. Female inbred line(A-line) and male inbred line(R-line) are needed for hybrid seed production. This study was carried out to investigate growth characteristics and yield of hybrid sorghum according to the seedling period and planting rate between female inbred line(YSA1) and male inbred line (Sodamchal, Miryang 19). When the flowering period of two inbred groups in the process of hybrid seed production is coincides, hybrid seed production is increase. The female inbred line and male inbred lines were cultivated at Daegu in 2021. Two inbred lines were sown at intervals of 3 days and 7days and were evaluated flowering period. As a result, the flowering period of the female inbred line and male inbred lines were matched at the 7days interval. To find out optimal planting rate, two inbred lines were cultivated under different plating rate (4:2, 5:2, 6:2). Yield of YSA1/Sodamchal(F1) was the highest 130(kg/10a) in the 4:2 ratio and yield of YSA1/Miryang 19 was the highest quantity of 139(kg/10a) in the 6:2 ratio. The results of this study could be helpful for hybrid Sorghum seeds production.

• Journal of Life Science
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• v.18 no.7
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• pp.907-911
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• 2008

Radish (Raphanus sativus L.) is one of very important crop plants in the world. It is very important to determine hybrid seed quality in the production of hybrid Brassica vegetable seeds to avoid unacceptable contamination with self-inbred (sib) seeds. The allozyme for evaluating seed purity in a commercial $F_1-hybrid$ radish cultivar is demonstrated. Three hundred sixty seeds from the male and female harvest were subsequently screened for seed purity using 27 isozyme loci. Especially, F1 hybrids of radish, Per-1 ($aa{\times}bb$), Lap-1 ($aa{\times}bb$), Est-1 ($aa{\times}bb$) were presented clear hybrid bands. Est-1 locus revealed that 15 (8.3%) seeds from the female harvest and 26 (14.4%) seeds from the male harvest were sibs. It maintains higher than average level of genetic diversity compared with their correspondent parents. Shannon's index of phenotypic diversity (I) of hybrids was the highest of all accessions (R. sativus L. cv. Daepeng, R. sativus L. cv. Backza, and their hybrids). The allozyme may lead to a better insight into the hybrid seed purity.

• Journal of Aquaculture
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• v.13 no.4
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• pp.325-330
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• 2000

For development of all male seed production at hatchery scale, a comparative study was made on the seed production traits of supermale (IT - t) and superfemale (IT - L1 ~) Nile tilapia, Oreochromis niloticus. Supermales were crossed with normal females (XX- f) and the superfemales with normal males (XY - t ) or sex reversed males (XX- L1 t); progeny survival of these crossings and sex ratio were evaluated. Hatching success of the eggs, fertilized by the supermale was significantly lower than that by the normal male. Over 95-99 % progenies sired by crossing supermales with normal females were males, while 52-55 % progenies alone were males with the cross of normal males and normal females. Hatching success and survival of alevins were significantly higher for the progenies of the crosses between superfemales and sex reversed males than those resulting from the crosses between superfemales and normal males. However, there was no significant difference in the sex ratio among the progenies of these crosses. Therefore, crossings of superfemales with sex reversed males provide the highest percentage of survival and male progenies.

• Advances in Traditional Medicine
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• v.9 no.1
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• pp.49-57
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• 2009

The antifertility activity of methanol extract of Cuscuta reflexa Roxb. stem (MECR) and Corchorus olitorius Linn. seed (MECO) were studied on male Swiss albino mice. The extracts were found to decrease sperm count, percentage of motile sperm and testosterone level in treated mice when compared with vehicle control after 17 days of treatment. The weight of gonads, epididymis were decreased whereas no significant changes of the body weight of mice were observed after methanol extract treatments. The fertility test showed 100% negative result in MECR and MECO treated mice at medium and high dose level of treatment. MECR and MECO in low (25 mg/kg and 15 mg/kg, respectively), medium (50 mg/kg and 20 mg/kg, respectively) and high (75 mg/kg and 25 mg/kg, respectively) dose level caused a simultaneous fall in testicular ${\Delta}5$-$3{\beta}$-hydroxy steroid dehydrogenase and glucose-6-phosphate dehydrogenase activities which are involved in testicular steroidogenesis. Total cholesterol and ascorbic acid content in testis were increased significantly in gonads. The activities of lactate dehydrogenase, malic dehydrogenase and ascorbic acid oxidase were reduced whereas that of carbonic anhydrase was increased significantly in the testis of MECR and MECO treated mice. All these observations indicate that the methanol extract of C. reflexa stem and C. olitorius seed produced antifertility activity in sexually matured male mice, which may be due to inhibition of gonadal steroidogenesis. This activity may be attributed due to the presence of flavonoids and steroids, respectively.