• Journal of Plant Biology
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• 제26권3호
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• pp.131-139
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• 1983

Temperature response of amoebae of thermotactic mutants have been investigated. Amoebae of the mutant strain HO 428 showed positive thermotaxs which is strong at lower temperaturs and drops sharply above the growth temperature of amoebae. The temperature response of HO 428 amoebae was not affected by the length of amoebae on the grdients. HO 596 amoebae seemed to have both positive and negative thermotactic responses shortly after food depletion. Longer exposure of these amoebae on the thermal gradients induced a stronger negative response at lower temperatures and an apparent positive response at higher temperatures. A similar changes could be observed in HO 1445 amoebae. Based on the steady positive thermotactic response by HO 428 amoebae and the mode of change in termperature response at higher temperatures, 24$^{\circ}C$ and $25^{\circ}C$, by HO 596 amoebae, a model for the temperature response of vegetative Dictyostelium discoideum amoebae, strain HL 50, has been proposed. The main features of the model are: a positive response at the thermal gradients with midpoint temperatures lower than the growth temperatures of amoebae and a negative response above it.

• 한국작물학회지
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• 제45권5호
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• pp.282-287
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• 2000

Soybean [Glycine max (L.) Merrill] crops, grown in a rice soybean rotation, can suffer when grown in soil with excessive moisture. The objective of this work were to determine the reduction in growth and yield, responses of vegetative and reproductive growth of soybean to excessive soil moisture achieved by prolonged irrigation. Responses of different cultivars were determined at growth stages from V6 to R8 to clarify the sensitive growth stages or characteristics to excessive soil moisture. Cultivar differences in response to excessive soil moisture condition were conspicuous in seed dry weight and harvest index (HI) but not in the response of seed number or pod number per plant. The timing of irrigation causing the condition of excessive soil moisture influenced the vegetative or reproductive traits. Soybean plants were more affected by irrigation commencing at the pre-flowering than at the post-flowering stage. Post-flowering irrigation did not reduce growth of vegetative organs significantly; in fact the growth of stems and leaves was facilitated by the prolonged irrigation commencing at flowering. Differences between cultivar response to prolonged irrigation were assumed to relate to the reduced amount of assimilates translocated to the reproductive organ.

• Mycobiology
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• 제31권2호
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• pp.86-94
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• 2003

The effect of four sub-lethal concentrations(400, 800, 1,200 and 1,600 ${\mu}g/ml$) of three amino acids such as isoluecine, aspartic acid and phenylalanine on vegetative growth and sexual and asexual reproduction of Achlya racemosa, A. proliferoides and Saprolegnia furcata was investigated. The density of vegetative growth and diameters of vegetative colonies of species of the Oomycetes fungi decreased with rising the concentration of the applied amino acid. Vegetative hyphae of treated fungi almost appeared branched in case of S. furcata, thick in case of A. racemosa and distorted in case of A. proliferoides as compared with control. The different treatments with amino acids depressed both sporangial formation and discharge, which were dependent on the tested species of zoosporic fungi, the amino acid and its dosage. Phenylalanine was the most effective amino acid in inhibiting sporulation and S. furcata was the most sensitive fungal species. Aspartic acid and isoleucine stimulated germination of discharged spores through the formation of germlings. Gemmae formation by the three fungi was reduced at the low concentrations of amino acids and nearly missed at high concentrations. Sex organs(oogonia and antheridia) were affected partly; rudiment oogonia were observed at low concentrations(400 and 800 ${\mu}g/ml$) and disappeared at higher concentrations, whereas antheridial branch formation was stimulated as the fungi were treated with isoleucine and to some extent phenylalanine.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2004년도 학술발표논문집
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• pp.93-93
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• 2004

• 한국작물학회지
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• 제5권1호
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• pp.45-49
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• 1969

수도재배시기이동시의 품종의 적응성 또는 외국품종도입시 그 적부판단의 기준이 되는 일장 및 온도효과의 본질과 한국품종들의 감응도를 분석비교하였다. 시험결과 공시품종들은 전부 일장에 대하여 비교적 둔감하고 어느 처리일장하에서나 출수하여 한계일장이 없었으나 만생품종은 조생종에 비하여 감광성이 예민하고 기본영양생장기간이 짧었고 조생품종은 기본영양생장성이 컸으며 최적일장은 전품종 10시간전후였다. 또한 온도도 일장과 같이 생육기간에 대하여 영향이 큰 것 같고 저온은 일장의 장단, 품종의 조만에 관계없이 출수를 지연시키고 고온은 기본영양생장기간을 단축시키고 일장감응기에는 별로 영향이 없었다.

• 한국작물학회지
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• 제51권1호
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• pp.41-47
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• 2006

To understand the heading habit of recently developed 20 Korean rice cultivars, rice plants in a phytotron were exposed to different temperature: $22.5^{\circ}C(day\;27^{\circ}C/night\;18^{\circ}C),\;27.5^{\circ}C(day\;32^{\circ}C/night\;23^{\circ}C)$, and day-length conditions: 10, 12, 13, 14, 15 hours. Four rice cultivars (Sobibyeo, Juanbyeo, Ilpumbyeo and Shindongjinbyeo) showed relatively short Basic Vegetative Phase (BVP) of 17 to 18 days, while Dasanbyeo showed the longest (35 days) BVP, compared to other remaining 15 tested cultivars which exhibited 24 to 31 days of BVP. In this experiment, it was tried out to separate the eliminable vegetative phase into photosensitivity and thermo-sensitivity with two different pathways. Many tested cultivars, however, exhibited quite different responses under low temperature and / or long day-length conditions. Especially, Surabyeo and Juanbyeo were the most difficult cultivars to separate into photo- or thermo-sensitivity in that the eliminable vegetative phase of these two cultivars increased greatly only under low temperature $(22.5^{\circ}C)$ and long day-length (15 hr.) conditions. Regarding the heading response to temperatures, tested cultivars could be categorized into 2 groups. In 1st group of rice cultivars, the eliminable vegetative phase decreased almost equally as the temperature changed from $20.0^{\circ}C\rightarrow22.5^{\circ}C\rightarrow25.0^{\circ}C\rightarrow27.5^{\circ}C$. In contrast, the 2nd group of rice cultivars exhibited eliminable vegetative phase slowly decreasing when the temperature changed from $22.5^{\circ}C\rightarrow25.0^{\circ}C\rightarrow27.5^{\circ}C$, but rapidly decreasing when the mean temperature changed from $20.0^{\circ}C\;to\;22.5^{\circ}C$. All the cultivars belonged to 2nd group, the heading date would be very delayed if cool summer comes.

• 한국작물학회지
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• 제48권6호
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• pp.490-494
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• 2003

1) 들깨 속의 개화일수는 파종기 및 품종에 따라 큰 변이를 보였다. 5월 1일 이후 파종기가 지연됨에 따라 품종간 차이가 적어지는 경향이었고 8월 1일 파종기에서 품종간 5일로 가장 적은 개화일수 차이를 보였다. 2) 들깨 속은 파종기 및 품종에 따라 개화반응이 다양하였다. 1월 1일 파종 및 5월 1일 이후 파종기에서는 영양생장에서 생식생장으로 정상적인 개화 반응을 보였으나, 2월에서 4월까지 파종한 경우에는 영양생장\$\longrightarrow$생식생장\$\longrightarrow$영양생장+생식생장\$\longrightarrow$근영양생장\$\longrightarrow$생식생장, 영양생장\$\longrightarrow$영양생장+생식생장\$\longrightarrow$영양생장\$\longrightarrow$생식생장, 상위분지는 영양생장만 하고 하위분지는 영양생장과 생식생장을 동시에 하는 등 영양생장과 생식생장이 가역 적으로 변화하였다. 3)들깨의 화성자극 이동방향과 분열조직에 있는 엽수에 따른 반응을 조사하기 위하여 처리한 결과 단일 처리된 부위만 개화반응을 보여 들깨에 있어 화성자극은 이동하지 않는 것으로 도꼬마리 등 다른 식물과는 상이하였다. 4)단일처리 기간에 따른 개화일수 단축은 9월 상순 이전에 개화하는 품종은 8일 처리로 효과가 있었으나 9월 하순에 개화하는 품종은 14일 처리에서 유의하게 단축되었다.

• Mycobiology
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• 제42권1호
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• pp.1-5
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• 2014

The typical life cycle of filamentous fungi commonly involves asexual sporulation after vegetative growth in response to environmental factors. The production of asexual spores is critical in the life cycle of most filamentous fungi. Normally, conidia are produced from vegetative hyphae (termed mycelia). However, fungal species subjected to stress conditions exhibit an extremely simplified asexual life cycle, in which the conidia that germinate directly generate further conidia, without forming mycelia. This phenomenon has been termed as microcycle conidiation, and to date has been reported in more than 100 fungal species. In this review, first, we present the morphological properties of fungi during microcycle conidiation, and divide microcycle conidiation into four simple categories, even though fungal species exhibit a wide variety of morphological differences during microcycle conidiogenesis. Second, we describe the factors that influence microcycle conidiation in various fungal species, and present recent genetic studies that have identified the genes responsible for this process. Finally, we discuss the biological meaning and application of microcycle conidiation.

• Journal of Plant Biology
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• 제33권2호
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• pp.141-146
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• 1990

Germination and vegetative growth of Enteromorpha multiramosa Bliding from Pyoson, Cheju Island were investigated in laboratory under various combinations of temperature (5-$25^{\circ}C$) and salinity (8-48$^{\circ}C$). Percent level of germination was relatively high at all combinations of the two factors. The highest value among the combinations was revealed at 15$^{\circ}C$ and 32$\textperthousand$. Dry weight also was fairly high at all levels of combination with maximum value at 2$0^{\circ}C$ and 32$\textperthousand$. Analysis of variance for germination and growth was completed respectively and polynomial prediction models were constructed. F ratio revealed that all factors had a significant effect (p<0.001) on percentage of germination and dry weight, and their interactions also were significant (p<0.001), although the F ratio of interactions was far less than that for either the separate effect of temperature or salinity. Response surface of polynomial equation represented that temperature influenced less than salinity on germination, while it effected remarkably on vegetative growth, so the Enteromorpha multiramosa was kept to visible macrothalli from winter to spring in Cheju Island.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2004년도 춘계 학술대회지
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• pp.256-257
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• 2004