• Journal of Ecology and Environment
• /
• 제43권3호
• /
• pp.305-313
• /
• 2019

Background: This research aims to study the effect of climate change on the phenology, growth, and physiological traits of Silene capitata Kom., a Korean endangered species II. This study increased $CO_2$ concentration in a closed glass greenhouse, with the daily mean temperature and $CO_2$ concentration respectively being $4.61^{\circ}C$ and 93.63 ppm higher than the outside temperature (ambient conditions, control). The seeds of S. capitata were sown in control and treatment environments in March 2013 while seedlings were transplanted into individual pots in May 2013. To research phenological changes, the first day of the flowering and ripening of the plants transplanted in 2013 and first day of leafing in 2014 were observed. The growth and physiological responses of mature leaves were also studied in 2013. Results: There was no difference in the first day of flowering, but the first day of ripening was earlier in the treatment group than the control group. There was no difference in the number of rosette leaves between the two groups, but leaf area was wider in the treatment group than the control group. Transpiration rate and stomatal conductance were higher in the treatment group than the control group, chlorophyll content decreased, and photosynthetic rate and water use efficiency were the same for both groups. As a result of simple regression analysis among the transpiration rate, stomatal conductance, photosynthetic rate, and water use efficiency, stomatal conductance increased when transpiration rate increased. Stomatal conductance increased with photosynthetic rate in the control unlike in the treatment group. The photosynthetic rate and water use efficiency increased with transpiration rate in the control group unlike in the treatment group. Furthermore, water use efficiency increased as photosynthetic rate increased in both groups. Conclusion: Due to high $CO_2$ concentration, the photosynthetic rate was no longer controlled by the stomata, which appeared to suppress the excessive production of photosynthetic products by reducing chlorophyll content. It is believed that the phenological responses of S. capitata under climate change conditions will advance and that stable growth will be difficult in regions lacking moisture due to the high transpiration rate.

• 원예과학기술지
• /
• 제31권2호
• /
• pp.146-152
• /
• 2013

토마토 잎들의 엽위별 광합성 특성을 조사하고, 잎의 연령과 개화속도를 엽위별 광합성 특성과 비교분석하였다. 일중 광합성 속도 특성실험에서는 일출 전 2시간부터 일몰 후 3시간까지 1시간마다 4번째 화방의 하부엽 3매의 광합성 속도를 측정하였다. 3개체를 반복으로 총 2회 조사하였다. 토마토의 일중 광합성 속도는 일출 후 1시간 동안 급격히 증가한 후, 일몰 2시간 전까지 일정하게 유지되는 양상을 보여 급액의 시작과 마감시각을 결정하는데 적용할 수 있을 것으로 사료된다. 엽위별 광합성 속도 특성실험에서는 1화방부터 4화방까지 각 화방의 하부에 있는 본엽 3개씩을 대상으로 광합성 속도를 조사하였다. 또한 광합성 특성을 분석하는데 적용하기 위해 개화속도를 조사하였다. 광합성속도는 엽위에 관계없이 꽃이 만개하는 시기를 정점으로 지속적으로 감소하는 경향을 보였다. 이는 만개 이후에는 해당 화방 이하의 잎의 활력이 감소하고 생육단계가 노화단계로 이동하기 때문으로 사료된다. 따라서 토마토의 개화속도와 광합성 속도는 서로 밀접한 관련이 있는 것으로 나타났다. 연구결과, 생육단계(엽령)의 차이에 의해 각 화방별 광합성 속도는 차이가 있으나, 광합성 속도로 작물의 활력을 판단하려 할 때는 개화하고 있는 화방의 하부엽을 조사하는 것이 매우 효과적일 것으로 판단된다.

• 한국환경과학회지
• /
• 제21권1호
• /
• pp.89-96
• /
• 2012

The rate of photosynthesis (A) of leaves from 10 plant species (6 evergreen and 4 deciduous) of the family Fagaceae was measured using a portable photosynthesis analyzer, to examine which species take up $CO_2$ most efficiently. Of the evergreen species, the photosynthetic rate of Castanopsis cuspidata var. sieboldii was highest, and remained above 82.1~106.4 ${\mu}mol\;kg^{-1}s^{-1}$ from July to November. Of the deciduous species, the photosynthetic rate of Quercus acutissima was higher than that of the other three species, and remained high at 83.5~116.6 ${\mu}mol\;kg^{-1}s^{-1}$ from September to November. The photosynthetic rate of the 10 species was positively correlated with stomatal conductance (gs) and transpiration rate (E). However, there was no correlation between photosynthetic rate and intercellular $CO_2$ concentration ($C_i$), although there was a positive correlation just in three species (Q. gilva, Q. acutissima and Q. glauca). These results suggest that the $CO_2$ fixation capacity of C. cuspidata var. sieboldii, an evergreen species, and Q. acutissima, a deciduous species, is significantly higher than that of the other species examined, and that photosynthesis is regulated by both stomatal conductance and transpiration. Therefore, C. cuspidata var. sieboldii and Q. acutissima may be valuable for the evaluation of carbon uptake in urban green spaces as well as in afforested areas.

• ALGAE
• /
• 제17권2호
• /
• pp.83-87
• /
• 2002

Photosynthetic parameters of Scendesmus quadricauda, such as the maximum photosynthetic rate ($P_{max}$), photosynthetic efficiency (α) and the initial saturation intensity of irradiance for photosynthesis ($I_K$) were obtained using photosynthesis-irradiance (P-I) curve in a phosphorus-limited chemostat. S. quadricauda exhibitied no photoinhibition until at 200 μmol·$m^{-2}$ . $P_{max}$ (r=0.963, P=0.002) and $I_K$(r=0.904, P=0.013) showed linear relationships with growth rate. Chlorophyll-α concentration and cell dry weight decreased at higher growth rates, ut chlorophyll-α content per cell dry weight increased. The increase in photosynthetic rates at higher growth rates was due to the increase of $P_{max}$ and $I_K$ which was caused mainly by the increase in the absolute amount of chlorophyll-α rather than the increased photosynthetic efficiency of individual chlorphyll-α. The α did not show a significant relationship with growth rate (r=0.714, P=0.111). The cell quota of carbon (r=0.554, P=0.254) was not correlated with growth rate, but cell quota of nitrogen (r=0.818, P=0.047) and phosphorus (r=0.855, P=0.030) exhibited linear correlations with growth rate.

• Journal of Ecology and Environment
• /
• 제29권1호
• /
• pp.41-47
• /
• 2006

We investigated the enect of $O_3$ on the photosynthetic characteristics of tree of heaven (Ailanthus altissima) that is naturalized plant and used as restoration plant for contaminated area. Two-year-old seedlings were planted to pots and transferred into closed $O_3$ chamber. Photosynthetic pigments contents and photosynthetic characteristics were measured every three weeks under 100 pub $O_3$ fumigation. There was no visible foliar injury by $O_3$ exposure and contents of photosynthetic pigments did not show significant differences between control and $O_3$-treated seedlings. Also there were no significant differences in stomatal conductance, and water use efficiency. But photosynthetic rate and apparent quantum yield (AQY) of $O_3$ treated seedlings were reduced after nine weeks of ozone fumigation. In addition, the reduction of carboxylation efficiency and photorespiration were observed in the leave of $O_3$ treated seedlings after six weeks. In accordance with our result, carbon fixation system of A. altissima was most sensitive to $O_3$ stress to evaluate physiological damage induced by $O_3$.

• 생태와환경
• /
• 제53권3호
• /
• pp.304-310
• /
• 2020

Smart farm is a high-tech type of plant factory that artificially makes environmental conditions suitable for the growth of plants and manages them to automatically produce the desired plants regardless of seasons or space. This study was conducted by identifying the effects of Hertz and Duty ratio on the photosynthetic rate of ginseng, a medicinal crop, to find the optimal conditions for photosynthetic responses in smart farms. The light sources consisted of a total of 10 chambers using LED system, with 4 R+B(red+blue) mixed lights and 6 R+B+W (red+blue+white) mixed lights. In addition, the Hertz of the R+B mixed light was treated at 20, 60, 180, 540, 1620 and 4860 hz respectively. The R+B+W mixed light was treated with 60, 180, 540, and 1620 hz. Afterwards, experiments were conducted with the duty ratio of 30, 50, and 70%. As a result, the photosynthetic rate of ginseng according to duty ratio and Hertz was the highest at 60 hz when duty ratio was set to 50%. On the other hand, that was the lowest when the duty ratio was 30% at the same 60 hz. In addition, the photosynthetic rates were highest in the R+B mixed light and R+B+W mixed light at 60 hz. Therefore, the condition with the highest photosynthetic rate of ginseng in smart farms is 60 hz when the duty ratio in R+B mixed light is 50%.

• 한국자원식물학회지
• /
• 제21권5호
• /
• pp.357-361
• /
• 2008

고품질의 곰취, 곤달비 및 한대리곰취를 지속적으로 생산할 수 있는 임간재배기술을 개발하고자 횡성군 둔내면의 산채마을 임간재배지에 생육중인 세 식물종의 광합성을 특성을 조사 비교하였다. 광도에 따른 곰취류의 광합성율의 평균은 광도가 높아질수록 높아지는 경향을 보였다. 광도에 따른 곰취의 광합성율의 평균은 광도가 높아질수록 높아지다가 1,600 PPFD에서 최대치인 $21.1{\mu}mol\;CO_{2}m^{-2}s^{-1}$를 보이고 2,000 PPFD에서는 낮아졌다. 한대리곰취가 $27.39({\mu}mol\;CO_{2}m^{-2}s^{-1})$로 가장 높은 광합성율을 보였고, 곰취, 곤달비 순으로 낮아졌다. 5월 27일 측정에서 모두 식물종간 통계적 유의차가 인정되었으며 광합성율은 한대리곰취, 곰취, 곤달비 순이었고, 6월 21일 측정 광합성율은 한대리금취, 곤달비, 곰취순이었다. 횡성군 둔내면 산채마을과 같은 해발고가 낮은 지역에서는 곰취나 곤달비 보다는 한대리곰취의 임판재배가 적합할 것이라 사료된다.

• 한국조경학회지
• /
• 제41권6호
• /
• pp.140-146
• /
• 2013

본 연구는 휴대용 광합성측정장치(CIRAS-2, PPS, UK)를 이용하고, 토양 수분조건에 따른 섬기린초의 생리특성을 파악하였다. 섬기린초의 광합성 속도, 식물수분이용효율, 호흡속도 등 측정을 통하여 섬기린초의 생장에 가장 적합한 광도와 토양 수분범위를 명확하게 파악하였다. 광도에 따른 광합성 속도가 증가하였고, $600{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ 경우에서 최고점에 도달한 후 그 이후 감소하는 경향을 나타났다. 토양 수분 조건에 따른 섬기린초의 광합성 속도과 식물수분이용효율은 수분함량 11.31%에서 가장 높은 값을 보였으며, 호흡속도는 수분함량 7.91%에서 가장 높은 값을 나타냈다. 그 결과에 의하면, 섬기린초는 가장 적합한 광도 범위가 $600{\sim}1,200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$이고, 수분 범위가 7.09~11.31%이다.

• 생물환경조절학회지
• /
• 제17권2호
• /
• pp.101-109
• /
• 2008

인위적인 토양내 수분처리 결과 물푸레나무와 들메나무 모두 6월<8월<9월로 갈수록 엽록소 함량이 증가하였다. 생육기간이 지나는 동안 엽록소 a는 0.89mg/g에서 1.67mg/g로, 엽록소 b는 0.18mg/g에서 0.44mg/g을 나타냈으며, 두 수종 모두 6월보다 8월과 9월에 높은 함량 증가를 보였다. 두 수종의 광합성율을 보면, 물푸레나무는 각 토양수분 처리구마다 광합성율의 차이를 보였으며, 충분한 토양수분처리구($90{\sim}78%$)의 묘목이 상대적으로 낮은 토양수분조건에서 자란 묘목보다 높은 경향을 나타냈다. 들메나무 역시 물푸레나무와 비슷한 경향을 보였으며, 토양수분이 높을수록 광합성률이 높게 나타났고, 감소할수록 광합성률이 감소하였다. 광합성율의 생육시기별 변화는 두 수종 모두 9월>8월>6월 순으로. 9월에 상대적으로 높은 광합성률을 나타냈다. 이로 미루어보면 두 수종은 생장시기에 상관없이 수분함량이 높은 처리구에서 광합성이 활발히 이루어지는 것으로 생각된다.

• 한국연초학회지
• /
• 제17권1호
• /
• pp.20-26
• /
• 1995

This study was carried out to obtain the basic data which include the change of the photosynthetic rate and protein content according to growth stage in the process of senescence of tobacco plant The photosynthetic rate was the maximum with 26.31$\mu$mol.CO2/m2.sec and stomatal resistance was the minimum with 0.2552cm/sec at 15th days after leaf emergence. However, after 50 days the photosynthesis was very little occurred. During leaf developments the number of chloroplast was increased and reached at the maximum at 25th days after emergence of leaf, thereafter, it was decreased gradually. The content of protein increased continuously and showed the highest value at 15th days after leaf emergence. The degradation rate of soluble protein was more rapid than that of insoluble protein at early stage of senescence. The range of decrement in the insoluble protein was low at late stage of senescence. The content of Rubisco, the key enzyme of photoamthesis, corresponded to about 50% of soluble protein and reached to the maximum at 150 days after leaf emergence. As the senescence progressed, the content of large subunit(UV) of Rubisco showed a tendency to decrease more rapidly than that of small subunit(SSU). The total amount of amino acids was the highest at 15th days after leaf emergence.