• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.2
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• pp.145-152
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• 2002

To compare the Carbon metabolic response to high temperature stress in Zoysiagrass [Zoysia matrella (L.) Merr.] and Creeping bentgrass (Agrostis palustris Huds) with respect to heat tolerance, C metabolites were determined from April to September. Sampling was carried out on an established golf course (Muan Country Club, Chonnam, Korea). Shoot mass(g Dry weight per hole cup) of creeping bentgrass started to decrease from June and recovered from August whereas that of zoysiagrass was less varied. Chlorophyll content in creeping bentgrass was significantly higher than zoysiagrass until July, and then decreased by 43% from July to August. Zoysiagrass contained higher soluble sugar than creeping bentgrass throughout experimental period. Soluble sugar in zoysiagrass increased about 58% from April to May, and less varied until August. Soluble sugar in creeping bentgrass slightly increased until July and sharply decreased at August. Starch concentration in zoysiagrass continuously decreased to September after a significant increase from April to May. A remarkable fluctuation in both starch and fluctuation concentration was observed between June and August showing high accumulation for June to July and high degradation for July to August. These results suggest that through creeping bentgrass suffers much severely from high temperature stress than zoysiagrass especially June to August. An active accumulation and degradation in nonstructural carbohydrate in creeping bentgrass during this period might be associated with heat stress.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.1
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• pp.117-123
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• 2011

This study aims to suggest a suitable soil thickness and soil mixture ratio of a green roof system by verifying the growth of Chrysanthemum zawadskii var. coreanum as affected by different green roof systems using rainwater. The experimental planting grounds were made with different soil thicknesses(15cm, 25cm) and soil mixing ratios (SL, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$, $P_4P_4L_2$) and with excellent drought tolerance. Ornamental value Chrysanthemum zawadskii var. coreanum was planted. The change in plant height, green coverage ratio, chlorophyll content, fresh weight, dry weight, and dry T/R ratio of Chrysanthemum zawadskii var. coreanum were investigated from April to October 2009. For 15cm soil thickness, the plant height of Chrysanthemum zawadskii var. coreanum was not significantly different as affected by the soil mixing ratio. However, it was found to be higher in the amended soil mixture, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$ than in the sandy loam soil, as it was SL overall. For 25cm soil the plant height differences were in order to SL < $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ < $P_4P_4L_2$. The green coverage ratio was observed not to be different by soil mixing ratio with soil thickness of 15cm, but, the lowest green coverage ratio in the SL. In the 25cm soil thickness, the green coverage ratio was 86-89% with a good coverage rate overall. The change in chlorophyll contents with 15cm soil thickness was found to be the highest in the SL treatment and the lowest in the $P_5P_3L_2$ treatment. For 25cm thickness, the highest value was in the $P_4P_4L_2$ and SL, and the lowest in the$P_7P_1L_2$. Fresh weight and dry weight were larger in soil with 25cm thickness. Therefore, the growth of Chrysanthemum zawadskii var. coreanum as affected by a different green roof system for using rainwater was higher in soil with 25cm thickness than 15cm, and in PPL amended soil than in sandy loam.

• Journal of Bio-Environment Control
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• v.9 no.4
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• pp.193-200
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• 2000

The object of this study is to investigate the quality change of sweet basil grown with selenium(Se) in hydroponic culture. Sweet basil was cultured with 1 fold herb nutrient solution as suggested by European vegetable R & D Center in Belgium. Before three weeks harvest, sodium selenate(N $a_2$Se $O_4$) was supplied to 2 and 4 mg. $L^{-1}$ in the nutrient solution. Sweet basil was stored at 1$0^{\circ}C$ using 40um ceramic film and PET (polyethylene terephalate) for 15 days in modified atmosphere(MA) storage condition. The weight loss of sweet basil was higher in non-treatment compared to Se treatments in both of two films but it was decreased over 5% in PET treatment. Se concentrations in leaf tissues increased in the response to the treated levels of N $a_2$Se $O_4$concentrations, and this tendency was appeared similar results after storage. There was no significant effect of packing materials on volatilization of Se in sweet basil. The total chlorophyll and essential oil content was increased with increasing N $a_2$Se $O_4$concentration in nutrient solution. The amount of volatilization flavor was not higher at N $a_2$Se $O_4$4mg. $L^{-1}$ treatment compare to others during storage. Se content was 112.73 ug. $g^{-1}$ dry mass at 2 mg. $L^{-1}$ treatment before storage and the decrease of Se content was observed by 50% at 15 days after storage. The condition, which N $a_2$Se $O_4$2mg. $L^{-1}$$^{plement}$ in nutrient solution during growth stage and stored with 40um ceramic film on 1$0^{\circ}C$are acceptable for maintaining of sweet basil quality. Moreover it can be a proper Se concentration for human health. Overall, Se treatment in nutrient solution has effect on promoting and maintaining quality of herb during storage life. Also, there was not significant change of essential oil compounds by volatilization of Se.mpounds by volatilization of Se.

• Korean Journal of Weed Science
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• v.32 no.1
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• pp.35-43
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• 2012

The objective of this research was to confirm the difference in physiological responses to environmental stresses such as chilling, high temperature, NaCl, and chemical stress (paraquat) in Protox inhibitor resistant-transgenic rice (MX, PX, and AP37) and its non-transgenic counterpart (WT). Transgenic and non-transgenic rice plants were exposed to a chilling temperature of $5^{\circ}C$ for 1 day or a high temperature of $45^{\circ}C$ for 4 days and allowed to recover at $25^{\circ}C$ for 6 days after the chilling treatment or 8 days after the high temperature treatment. Leaf injury, shoot fresh weight, porphyrin biosynthesis substances, and chlorophyll content were investigated in transgenic and non-transgenic rice at 6 days after 0.5% and 1% NaCl treatments or at 5 days after 0~300 ${\mu}M$ paraquat treatments. No significant difference in leaf injury and shoot fresh weight were observed between transgenic and non-transgenic rice during chilling and recovery. Plant height and shoot fresh weight were also similar between transgenic and non-transgenic rice during the high temperature and recovery period (0~5 days). However, plant height and shoot fresh weight in transgenic rice line MX and PX were lower than in non-transgenic rice at 6 days for recovery. Leaf injury, chlorophyll, and Mg-Proto IX ME contents had no significant difference between transgenic rice and non-transgenic rice after NaCl treatment, but Proto IX content for AP37 and shoot fresh weight for PX and AP37 in 0.5% NaCl treatment were significantly reduced compared with non-transgenic rice. There was no difference in leaf injury and shoot fresh weight when comparing transgenic rice and non-transgenic rice after paraquat treatment. Although transgenic rice and non-transgenic rice showed a little difference at a particular measurement period in certain environmental stresses, there was generally no difference in physiological responses between transgenic rice and non-transgenic rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.2
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• pp.171-181
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• 2021

The purposes of this study were to determine how changes in temperature affect germination rates and growth of hulled and dehulled barley, malting barley, and naked oat plants, and to measure chlorophyll content, photosynthetic efficiency, and secondary compounds (total phenol, total flavonoid, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity) in plants grown at 13℃ or 25℃). Various types of barley seeds were collected from areas with ideal conditions for barley cultivation, hereinafter referred to as IA, and also from areas where barley cultivation is more difficult due to lower temperatures, hereinafter referred to as LTA. Seeds were tested for seed vigor. While there were significant differences in the electrical conductivity values between seeds collected from certain specific areas, no significant differences were evident between IA and LTA seeds, regardless of the type of barley seed. When plants were grown at 25℃, there were no significant differences in germination rates, plant height, root length and shoot fresh weight between plants originating from IA and LTA. However, there were differences in the measured parameters of some specific seeds. Similarly, under the low temperature condition of 13℃, no differences in the emergence rate, plant height, and shoot fresh weight were evident between plants originating from IA or LTA, regardless of the type of barley. However, there were differences between some specific seeds. One parameter that did vary significantly was the emergence date. Hulled barley and malting barley emerged 5 days after sowing, whereas naked oats emerged 7 days after sowing. There were no differences in the chlorophyll content and photosynthetic efficacy, regardless of the type of barley. There were no significant differences in total phenol, total flavonoid content, and DPPH radical scavenging activity between plants originating from IA and LTA, regardless of the type of barley. However, there were differences between some specific seeds. In particular, for malting barley the total flavonoid content differed in the order of Gangjin > Changwon > Haenam = Jeonju > Naju. The results indicate that crop growth, yield and content of secondary compounds in various types of barley may be affected by climate change.

• Horticultural Science & Technology
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• v.17 no.3
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• pp.325-328
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• 1999

This experiment was conducted to investigate the effect of the automatic control of night temperature and day length on the flower bud initiation growth responses and yield of strawberries. Flower bud initiation was observed only 14 days after treatment in plants forced with automatic system but not in plants forced with traditional methods, and flower bud development was further progressed by an automatic system. In genernal, the crown diameter of runner plants derived from strawberries grown with the automatic system was smaller than those from the plants grown under hand-operated system and this tendency was clear in plants placed at middle and low position during forcing. The rate of transpiration was higher in plants treated with hand operated method but the content of chlorophyll was lower than those treated with the automatic system. Results indicated that automatic system has an advantage in stimulation of flower bud initiation and improving the quility of runner plants.

• Journal of Bio-Environment Control
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• v.5 no.1
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• pp.1-6
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• 1996

For reducing planting distance in greenhouse grown watermelon(Citrullus vulgaris S.) this experiment was carried out to study the effect of DIF on stem elongation and growth. Day temperatures ranged from $25^{\circ}C$ to 35$^{\circ}C$ : night temperatures ranged from $25^{\circ}C$ to 35$^{\circ}C$ at 5$^{\circ}C$ interval. Stem elongation, leaf size, dry weight and flowering were influence by day and night temperatures. Stem elongation and length of internode decrease with increasing night temperature at same day temperature. The optimums for number of leaves categories was with day at 35$^{\circ}C$, and flower production was the lowest at $25^{\circ}C$. Total leaf area meter was maximized at 35/30(DT/NT), but for size pet one leave was the largest 25/25(DT/NT). Responses of leaf size per leaves were similar to that of internode length, with maximum day and night at $25^{\circ}C$. Total plant dry weight was the highest 35/30 (DT/NT) and minimum occurring at 25/30(DT/NT). The shoot/root ratios of dry weight Increased with day temperature up to 3$0^{\circ}C$ and were the highest with night at $25^{\circ}C$. Chlorophyll contents decreased with decreasing day and night temperature.

• Korean Journal of Weed Science
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• v.32 no.2
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• pp.107-114
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• 2012

This study was conducted to evaluate the weed suppressing effects of different cropping system including hairy vetch (Vicia villosa) and rye (Secale cereale) cover crops, polyethylene plastic film, and transplanting film mulching in direct sowing and transplanted sorghum field in 2011. Crop growth and development and weed occurrences in the fields were examined to know the efficiency of proposed cropping system. In polyethylene film mulching treatment, heading date of sorghum was earlier by 3 days than control, on the other hands, rye cover crop mulching delayed heading date by 11 days. Besides the effect of cover crop on the heading of sorghum, the residues changed growth characteristics. Plant height of sorghum was increased by 27.3% at hairy vetch treatment although it was reduced by 47.5% in the rye cover crop treatment. Hairy vetch treatment showed beneficial effects on sorghum growth reduced the occurrences of grasses and broadleaf weeds to 84% and 96%, respectively, as compared to control in sorghum fields. While rye cover crop treatment showed poor sorghum growth reduced less strongly grasses and broadleaf weeds by 35% and 71%, respectively. At harvest, yield of sorghum was greater in order of hairy vetch cover crop > polyethylene film mulching > rye cover crop ${\fallingdotseq}$ control in both transplanted and direct sown fields.

• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.65-76
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• 2000

Lichen flora of 'Backwoon' mountain, Korea, was investigated during the summer of 1998 and 1999 to screen out lichen species which can be used as a biomonitor for atmospheric ozone. The identified foliose or fructicose lichens in the area were classified into 9 families, 20 genera and 34 species. The dominant lichen species in the area were found to be Leptogium sp., Parmelia sp., Parmotrema sp., Phaeophyscia sp. and Cladonia sp. It was also found that lichen species showing a wide range of sensitiveness to air pollution were distributed in 'Backwoon' mountain. The Parmotrema austrosinense, P. tinctorum, Certrelia braunsiana and Ramalina yasudae collected in the area were exposed to ozone at the level of 200ppb, 8hr/day in controlled growth chamber for 2 weeks. Malondialdehyde(MDA), hydroperoxy conjugated dienes(HPCD), soluble protein content and OD435nm/OD415nm ratio for phaeophytinization of chlorophyll were measured and a pollution index(PI) was calculated for each lichen. Ozone exposure severely damaged to the lichens in the order of P. austrosinense>P. tinctorum>C. braunsiana>R. yasudae. P. austrosinens easily identified and widely distributed in Korea is likely to be a very useful biomonitor of air pollution, especially for ozone. These results indicate that Korean lichen species can be used as a biomonitor for air pollution to evaluate air quality contaminated with ozone.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.1
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• pp.22-28
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• 2014

This study was conducted to investigate the photosynthetic characters of Populus alba${\times}$glandulosa cuttings in response to elevated $CO_2$ concentration and air temperature for selecting tree species adaptive to climate change. The cuttings were grown in environment controlled growth chambers with two combinations of $CO_2$ concentration and air temperature conditions: (i) $22^{\circ}C$ + $CO_2$ 380 ${\mu}mol$ $mol^{-1}$ (control) and (ii) $27^{\circ}C$ + $CO_2$ 770 ${\mu}mol$ $mol^{-1}$ (elevated) for almost three months. The cuttings under the elevated treatment showed reduced tree height and photosynthetic pigment contents such as chlorophyll and carotenoid. In particular, the elevated treatment resulted in a marked reduction in the chlorophyll a closely associated with $CO_2$ fixative reaction system. Different levels of reduction in photosynthetic characters were found under the elevated treatment. A decrease was noted in photochemical reaction system parameters: net apparent quantum yield (7%) and photosynthetic electron transport rate (14%). Moreover, a significant reduction was obvious in $CO_2$ fixative reaction system parameters: carboxylation efficiency (52%) and ribulose-1,5-bisphosphate(RuBP) regeneration rate (24%). These results suggest that the low level of photosynthetic capacity may be attributed to the decreased $CO_2$ fixative reaction system rather than photochemical reaction system.