• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.285-285
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• 2022

Recent unpredictable climate change is a major cause of rice yield loss. In particular, methane is a key factor in global warming. Therefore rice breeders are trying to breed the reducing-methane gas emission rice using the crossbreeding method. However, the traditional crossbreeding method takes 8 to 10 years to breed a cultivar, and the anther culture method developed to shorten the breeding cycle also takes 6 to 7 years. On the other hand, CRISPR/Cas9 accurately edits the target trait and can rapidly breed rice cultivars by editing the target trait as a homozygous in 2-3 years. In addition, exogenous genetic elements such as Cas9 can be isolated from the G₁ generation. Therefore, the flowering time was regulated by applying CRISPR/Cas9 technology, and OsCKq1 genome-editing (OsCKq1-G) rice with early flowered and high yield was bred in the field. Genome-editing of OsCKq1 applied CRISPR/Cas9 technology up-regulates the expression of the flowering promotion gene Ehd1 under long-day conditions induces early flowering and increases the yield by increasing the 1,000-grain weight. And as the generations advanced, each agricultural trait indicated a low coefficient of variation. As a result, indicated that OsCKq1 plays an important role in regulating the flowering time and is related to the trait determining yield. Therefore, OsCKq1-G can suggest a breeding strategy for the Net-Zero national policy for reducing-methane gas emission rice by shortening the breeding cycle with the early flowered, and high-yield rice. CRISPR/Cas9 technology is a rapid and accurate breeding technology for breeding rice cultivars with important characteristics.

• Journal of the Korean Society of Tobacco Science
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• v.7 no.1
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• pp.25-31
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• 1985

For shortening the tobacco breeding cycle, seedlings with 6, 8 and II leaves of 2 flue.cured tobacco varieties, day. neutral type and photoperiod-sensitive type, were grown in controlled-environment room (CER), programmed for temperature of $18^{\circ}C$ and 8.hour day period of 30 klux, for 20, 30 and 40 days. All of plants of day.neutral type variety treated in CER, regardless of seedling stage and duration, flowered earlier than the untreated plants. In the 6.leaf seedlings stage of photoperiod-sensitive type variety, plants treated for 20 and 30 days in CER did not accelerate the flowering. the tobacco plants, treated with low temperature for 20 days at 8.leaf seedling stage, flowered earlier in comparison with. the other treatment.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.495-501
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• 1995

Betula pendula and B. platyphylla var. japonica seedlings and/or grafts growing inside and outside of a plastic-greenhouse were treated with growth regulators to induce flowering at early stages of seedling and graft developments. The seedlings began to develop female catkins visibly in eight to nine months after seeding and in five months after the first treatment of growth regulators. Thirty three percents of the seedlings grown under controlled environment in the plastic-greenhouse with sufficient nutrient supply developed female catkins both in control plants and in the plants treated with IAA, $GA_3$ and kinetin, while none on the control plants grown in the field showed any sign of the development of floral organs. Sixty seven percents of the seedlings treated with ABA and SADH grown in the Plastic-greenhouse developed female catkins. All the seedlings treated with 6.24 mM of SADH developed female catkins. SADH treatment to 2-5 year old seedlings and grafts of birch had a tendency of positive effect on inducing and increasing the flowering of the two birch species.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.489-494
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• 1995

Seedlings and grafts of Betula pendula and Betula platyphylla var. japonica were grown under partially controlled environments in a greenhouse and in a plastic-greenhouse installed inside a laboratory. Plant growth conditions such as photoperiod, temperature, nutrient supply were partially controlled to enhance the vegetative and reproductive growth of the birch seedlings and grafts. By the treatments twenty and seventy one percents of the seedlings, respectively, for the Betula pendula and Betula platyphylla var. japonica developed visible floral organs between 250 to 508 days after seeding. By the same treatments eighty and fifty three percents of the grafts, respectively, for Betula pendula and Betula platyphylla var. japonica developed visible male catkins between 51 to 497 days and female catkins between 365 to 396 days after grafting. Breeding cycle of birch species can be reduced to a great extent by the induction of precocious flowering at early stages of seedling and graft development.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.2
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• pp.191-197
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• 1984

This study was conducted to investigate the flowering habit for the botanical types of peanut (Arachis hypogaea. L) in cultural limiting region. Eight peanut varieties pertaining to virginia, Spanish, Valencia, Shinpung type were used in this study. Shinpung type, a new erect type was developed at Crop Experiment Station, ORD. Appearance of the first flower of peanut plants is observed at a relatively early growing stage. Number of days to first flower were 41 days under vinyl-mulching while non-mulching culture took 55 days. Number of days to first flower were delayed in order of Valencia, Spanish, Shinpung, Virginia type. Flowering durations were distinguished among botanical types and days of those were Virginia 85-93, Spanish 101-105, Valencia 106-113, Shinpung 82-88 days, respectively. The Spanish and Valencia types produced more flowers than Virginia and Shinpung types. The maximum flowering stage of Shinpung and Virginia types reached early and ceased by one cycle, while Spanish and Valencia types came late and showed maximum stage through the early and late stage during the growth stage. By vinyl-mulching, the maximum flowering stage was shortened by 20 days than that of non-mulching. Distribution of flowers for each of branch positions to total flowers occupied 52-53% in two cotyledonary branchs, 23-27% in 3rd to 5th branchs, 20-25% in over. 6th branchs. Shinpung type was considered more favorable botanical type than the other types for the breeding of early maturing high yielding variety because of shortening of days to first flower, flowering duration and distribution of lower branch of effective flowers.