• 한국식물학회:학술대회논문집
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• 한국식물학회 1996년도 제10회 식물생명공학심포지움 고등식물 발생생물학의 최근 진보
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• pp.4-9
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• 1996

The majority of plants sense environmental signals, such as day length or temperature, to select their transition timing from vegetative growth t flowering. Here, we report the identification of a regulatory gene, OsMADS1, that controls the photoperiod sensitivity of flowering time. Constitutive expression of OsMADS1 in a long-day flowering plant, Nicotiana sylvestris, resulted in flowering in both short-day long-day conditions. Similarly, ectopic expression of the gene in a short-day flowering plant, N. tabacum cv. Maryland Mammoth, also induced flowering regardless of the day length. The transition time was dependent on the level of the OsMADS1 transcript in transgenic plants. These suggest that OsMADS1 is a key regulatory factor that determines the transition from shoot apex to floral meristem and that it can be used for controlling flowering time in a variety of plant species.

• 한국연초학회지
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• 제16권2호
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• pp.108-112
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• 1994

Response of two ploidy levels to cool temperature and short day treatment were investigated under controlled conditione of Phytotron. The haploid and diploid of seven genotypes were started and grown to the 8- leaf stage in the greenhouse. They were treated during 15 and 20 days to 8- hour photoperiods at 18$^{\circ}C$ in controlled - environmental room to induce premature flowering, respectively. Diploid plants of seven genotypes flower later than their haploid plants at 20 days treatment. But under 15 days treatment, diploid plants of NC82, Hicks, BY4, NC2326 and Coker86 were not different from their haploid plants for days to flower. Diploid plants of seven genotypes developed the same number of leaves as their haploid plants at 20 days treatment. Under 15 days treatment, diploid plants of Coker347 and NC95 developed more leaves per plant than their haploid plants. Correlation coefficient between the ranks of leaves per plant of seven genotypes at two ploidy levels was 0.964 and 0.929 at 15 and 20 days treatment, respectively.

• Plant Biotechnology Reports
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• 제4권2호
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• pp.117-123
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• 2010

We used a flow cytometer to investigate the variations in endopolyploidy (the frequencies of nuclei with DNA contents equivalent to 4C through 16C) during the short period of the early growing stage in vigorously growing young tissues of maize seedlings. We examined different portions of the root and leaves that had been growing for 7 (day 7) and 13 (day 13) days after germination. Endoreplication showed two opposing phenomena without aging. In one case, the endopolyploidy of the first leaf was higher on day 13 than on day 7. In the latter case, endopolyploidy decreased, as clearly revealed by a comparison of the endopolyploidy of the second leaves and the 160-170 mm portion of the seminal root on days 7 and 13. Endopolyploidy was also lower in the top of the leaf. In roots, endopolyploidy was increased by the exogenous application of abscisic acid for only 1 day. The levels of endopolyploidy increased without an increase in cell size in the roots. These results showed that endoreplication occurs in actively growing and young tissue and that the variation can be induced in the short period examined.

• 한국연초학회지
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• 제18권2호
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• pp.132-137
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• 1996

This experiment was conducted to investigate varietal responses to cool temperature (18℃) and short photoperiod (8 hours a day) in a controlled room of phytotron. Five burley tobacco varieties (Nicotiana tabacum L.), Awelius (very early flowering type), Burley 21 and KB 103 (medium), Banket Al and MB 1 (slightly late) and TC 681 (late) were compared in number of leaves per plant and day to flower in different treatment periods (10, 15, 20, 25 and 30 days). The days to flower decreased significantly than the control (in the phytoron with 14hr photoperiods and a minimum temperature 20'c) when the treatment periods were over 15 days for the varieties Aurelius, Burley 21 and KB 103, and 20 days for TC 681, and 30 days for Banket Al, respectively. And also the number of leaves decreased significantly than that of the control when the periods of treatment were over 10 days for Burley 21 and Aurelius, 15 days form 103, and 20 days for TC 681 and Banket Al, and 30 days for MB 1, respectively. The decreasing ratio in the number of leaves per plant under cool temperature and short photoperiod treatments was the lowest in Banket Al and MB 1. Key words : Nicotiana tabacum, cool temperature, short photoperiod.

• 한국작물학회지
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• 제46권5호
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• pp.395-400
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• 2001

We investigated the variations of the flowering response to daylength in Perilla crop (var. frutescens). Seventeen accessions of Perilla crop and one accession of weedy type of var. crispa from China, Korea and Japan were cultivated under three daylength conditions, i.e., short-days, natural daylength and long-days. Most accessions of Perilla crop from China, Korea and Japan were divided into three types, early maturing type, intermediate maturing type and late maturing type by their natural flowering habit. In most of the accessions used, the flowering habit was significantly accelerated by short-day conditions and was delayed by long-day conditions. All the accessions of Perilla crops flowered within 57 days under the 10 hrs light treatment, whereas they did not flower at all even at 170 days after sowing under the 16 hrs light treatment. Thus, this finding suggested that there is a relationship between the types of flowering response to daylength and the geographical distribution which determines the planting season in traditional cultivation practices of Perilla crops. Positive correlation was observed between days to flowering and plant height or internode number in both the short-day and natural daylength conditions. Whereas, correlation was negative between days to flowering and inflorescence length or floret number in natural daylength condition, but it was positive in the short-day condition. Therefore, the daylength condition is considered as the most important environmental factor for flowering habit and morphological characters of Perilla crops. Flowering habit is considered as an important key character for the study of geographical differentiation of Perilla crop in East Asia.

• Journal of Plant Biology
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• 제19권1호
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• pp.14-18
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• 1976

Inhibition of flowering in Lemna perpusilla 6746 by 30 mM sucrose was reversed by the addition of acetylcholine (>$10^{-4}M) supplemented with 10^{-4}M$ ascorbic acid to 1/10-strength Hunter's growth medium. The reversible effect of acetylcholine was found to be greater at early stages of flowering than in the later period. Promotive effects of both acetylcholine ($10^{-3}M) and eserine(10^{-5}M$) on flowering in the short-day plant under various photoperiodic conditions were studied. It was indicated that the application decreased length of the critical dark period for the floral induction, and it was also shown that the endogenous status of acetylcholine was involved in the floral response which had a correlation with phytochrome. Interruption of inductive dark periods by red irradiation (1min) immediately followed by far-red light (1 min) completely inhibited flowering, while the addition of acetylcholine and eserine to the medium under the same condition slightly promoted flowering, indicating possible involvement of phytochrome system in acetylcholine activity for photoperiodic sensitivity of floral response in Lemna perpusilla 6746.

• 한국작물학회지
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• 제65권4호
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• pp.399-405
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• 2020

이 연구는 보리의 뿌리와 엽의 출현과 신장 및 체세포 분열에서 중기 염색체를 관찰함으로써 시티딘 유사체인 제부라린이 보리의 초기 생장에 미치는 영향에 대하여 조사하였다. 제부라린은 염색체 절단을 유발하기 때문에 식물의 뿌리 신장을 억제하는 것으로 알려져 있다. 이 연구에서는 이러한 식물체에 미치는 손상을 줄이기 위하여 기존의 뿌리 흡수 처리 방식이 아닌 침종 처리 방식을 수행한 결과, 제부라린 농도 2.5 μM에서 대조구와 뿌리의 신장에 차이가 없었으며, 동일 농도에서 엽의 신장력은 대조구보다 높았다. 체세포 분열에서 중기 염색체를 관찰한 결과, 대부분의 세포는 정상 형태의 염색체를 가지고 있는 것으로 확인되었다. 특이한 점은 약 2.0%에 상응하는 세포에서 정상형태의 염색체보다 크기가 매우 작은 비정상 염색체가 확인되었으며, 이 비정상 염색체의 형태는 동원체를 가지고 있으나 불규칙한 형태를 가지고 있는 것으로 확인되었다. 이 비정상 염색체의 염색체 능력과 유전력에 대해서는 좀 더 심도 있는 연구가 필요할 것으로 생각한다.

• 한국연초학회지
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• 제11권2호
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• pp.127-134
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• 1989

Several growth characteristics of two ornamental tobacco species, Nicotiana sanderae and N. affinis, were investigated in this study. Also effect of temperature and daylength on the flowering of the tobacco plants were evaluated to obtain basic information on breeding and cultivation. 1. The plants were great in high temperature-long day at the early stage and in low temperature-short day at the late stage of plant growth, for both Nicotana species. At the early growth stage the leaf length N. sanderae was great in high temperature-long day, and that of N. affinis was great in high temperature-short day period, while at the late stage of the plant growth the leaf lengths were more significantly effected by the temperature rather than daylength. Leaf width and leaf shape index were less sensitive to the conditions. 2. For both of the species, the total number of tobacco leaves not much influenced by the temperature and daylength. 3. There were no significant differences for budding and flowering period between the two species, both of which were sensitive to temperature and daylength with more influence by daylength than temperature. 4. Number of floral stalks, number of flower and flowering period were not much influenced by temperature and daylength; however, N. affinis had 2 more floral stalks, 31 more flowers, and 6 day longer flowering period than N. sanderae.

• 한국식물학회:학술대회논문집
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• 한국식물학회 2000년도 춘계학술발표대회:발표눈문요지록
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• pp.23-23
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• 2000

• 한국작물학회지
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• 제14권
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• pp.173-189
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• 1973

중부 지방에 적응할 수 있는 답전작 풋콩 재배법을 구명하기 위하여 1972년 3월부터 6월까지에 걸쳐서 건국대하교 농과대학 부속 실습 농장에서 실시한 품종, 단일 처리, 시비 및 재식 거리 등에 관한 일련의 시험 결과를 요약하면 다음과 같다. 1. 3월 15일 온상에 파종하여 육묘 정식하더라도 육묘 중 단일 처리를 하지 않으면 어떤 품종도 답전작 풋콩 재배의 개화 한계기인 5월 15일 이전에 개화하지 못하였다. 2. 육묘 중 단일 처리를 하면 극조생 계통의 품종군은 5월 15일 이전에 개화하였는데, 북해일호, 조생록, 팔중방성, 삼보백조, Verde 등이 이에 속하였다. 3. 제일정상복엽이 전개할 무렵부터 10일간의 단일 처리를 할때의 최적 일장은 중.만생 품종군이 7-9시간, 조생 및 극조생 품종군이 7-11시간이었다. 4. 11시간의 단일 처리를 할 때의 최적 처리 일수는 품종의 조만생에 관계 없이 10일 정도로 인정되었다. 5. 단일 처리에 의한 개화 소요 일수의 단축도 즉 품종의 감광성 정도는 극조생 및 조생 품종군보다 중생 및 만생 품종군이 현저하게 높았다. 6. 무질소의 경우보다 질소 표준량(4.0kg/10a) 시용에서 약 17%의 증수를 보였으나 질소 배량의 시용은 도리어 감수 경향을 보였다. 7. 인산 표준량(4.0 kg/10a) 시용에 비한 인산 배량 시용의 증수 효과는 미미하였다. 8. 재식 본수를 3.3$m^2$당 54본으로부터 130본까지 변동시킬 경우 130본구의 약 2배의 수량을 내어 밀식 효과가 극히 현저함이 인정되었다. 9. 결론적으로 중부 지방에서도 극조생 계통의 품종을 3월 15일 온상에 파종하고 제일정상복엽 전개기인 4월 6일경부터 11시간의 단일 처리를 10일간실시하여 정식하면 답전작 풋콩 재배가 가능하며, 10a당 전량 기비로 질소 및 인산 4.0 kg, 가중 6.0 kg을 주고 3.3$m^2$당 130본으로 밀식하는 것이 가장 증수됨이 인정되었다.