• Mycobiology
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• v.34 no.4
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• pp.191-195
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• 2006

This study was conducted to investigate the different effects of ectomycorrhizal fungal (ECMF) species on the growth of seedlings of Pinus densiflora, and the effects of ECMF diversity on plant productivity. A total of five species of ECMF were isolated from root tips of pine seedlings collected from Mt. Songni and used as inocula. Pots containing pine seedlings were inoculated with either a single ECMF species or a mixture of five ECMF species. All of the seedlings formed ECM on their roots except for the control plants. The pine seedlings' growth responses varied by the different ECMF species. Also, pine seedlings inoculated with a mixture of five ECMF species showed the highest growth response. The results of the study suggest that the colonization of diverse species of ECMF will increase plant productivity, and the selection of suitable ECMF species could be an important factor for plant growth.

• Journal of Crop Science and Biotechnology
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• v.10 no.1
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• pp.39-44
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• 2007

The effect of inabenfide was investigated in rice seedlings subjected to salt stress in relation to changes in chlorophyll fluorescence(${\Delta}F/Fm'$), lipid peroxidation, salicylic acid(SA) content, and catalase(CAT) activity. A reduction in shoot growth of rice seedlings by 120 mM NaCl treatment was significantly alleviated by pretreatment with 30 ${\mu}M$ inabenfide. Sodium ion content was not affected by pretreatment with inabenfide, suggesting that alleviation was not due to a reduction in sodium ion uptake by the rice seedlings. At three days after NaCl treatment, the rice seedlings pretreated with inabenfide showed a higher ${\Delta}F/Fm'$(30%) and lower lipid peroxidation(28%) compared with the rice seedlings treated with NaCl alone. After NaCl treatment, CAT activity in the third leaf of rice seedlings decreased significantly but alleviated by pretreatment with inabenfide. Furthermore, pretreatment with inabenfide also reduced the level of SA which accumulated drastically in the third leaf of rice seedlings within a day after exposure to salt stress. These results suggest that inabenfide prevents SA accumulation in rice seedlings under salt stress which eventually induces the alleviation of salt stress damage.

• Journal of Plant Biology
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• v.37 no.3
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• pp.301-308
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• 1994

The individual and combined effects of acidic rain, Mg deficiency (-Mg) and Al surplus (＋Al) on the growth of shoots and roots of pitch pine seedlings and the effect of humic substances (Lit) on Al toxicity were investigated. The growth of height and dry matter were not significantly less for pitch pine seedlings sprayed with simulated acid rain (SAR) of pH 3.5 than for those sprayed with SAR of pH 5.6. But treatments of Al and ＋Al-Mg in soil solution reduced the growth of seedlings in terms of height of shoots, and dry matter of shoots or roots. Effect of Mg deficiency on the growth of seedlings was apparent only when Al was treated simutaneously. The growth of seedlings, regardless of rain pH, decreased in the following order: control=-Mg>Lit＋Al>＋Al>＋Al-Mg. Treatments of Al and ＋Al-Mg in soil solution reduced the total length of secondary and teritary roots of seedlings regardless of rain pH, and decreased in the following order: the primary root

• Journal of Plant Biology
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• v.32 no.2
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• pp.89-99
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• 1989

The effect of IAA on lysine decarboxylase(LDC)activity, diamine oxidase (DAO) activity and the polyamine level in seedlings of soybean were investigated. The seedlings of soybean were treated with IAA (10-8M, 10-6M, 10-4M) and LDC activity, DAO activity and polyamine levels of cotyledon, elongating hypocotyl, elongated hypocotyl and the root were measured after 4, 6, 8, 10 days. Increased concentration of IAA stimulated the LDC activity and increased the level of polyamine in the seedlings, which reducing the DAO activity and polyamine level was increased in the seedlings. The light also stimulated the IAA effect on polyamine level and DAO activity, and polyamine level was higher in the seedlings grown in the light than those in the dark. Cadaverine was the most abundant polyamine in the seedlings of soybean. The levels of diamines, cadaverine, putrescine were higher in the elongated hypocotyl and root than in the elongating hypocotyl, but the levels of spermidine and spermine were relatively higher in the cotyledon than in the other parts. Accumulation of diamines by high concentration of IAA is postulated to be a phenomenon of inhibition in seedlings growth.

• Mycobiology
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• v.49 no.4
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• pp.396-405
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• 2021

Cinnamomum migao plants often face different degrees of drought in karst habitats, which can lead to plants' death, especially in the seedling stage. Widespread of arbuscular mycorrhizal (AM) fungi in karst soils have the potential to address this drought, which is a threat to C. migao seedlings. We inoculated C. migao seedlings with spores from Glomus lamellosum and Glomus etunicatum, two AM fungi widely distributed in karst soils, to observe seedling growth response after simulated drought. Our results showed that 40 g of G. lamellosum and G. etunicatum significantly promoted the growth of C. migao seedlings, 120 days after inoculation. Following a 15-day drought treatment, root colonization of the seedlings with G. lamellosum or G. etunicatum had lower the accumulation of malondialdehyde (MDA) and increased the accumulation of enzymes and osmotic substances in the seedlings. The relative water content in different organs (roots, stems, and leaves) of the drought-stressed seedlings was higher in plants with G. lamellosum or G. etunicatum than in plants without AM fungi colonization. Our results showed that inoculation with AM fungi was an effective means to improve the drought resistance of C. migao seedlings.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2004.11a
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• pp.139-143
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• 2004

To evaluate the biological and physiological response of Picea koraiensis Nakai to elevated $CO_2$ and nitrogen.3-year old seedlings were planted in an ambient and 700 ppm $CO_2$ at low (2mM $NH_4NO_3$) or high nitrogen (16mM $NH_4NO_3$) supplying treatments for 3 months. Photosynthetic parameters were measured monthly. Seedlings were harvested at monthly intervals and growth parameters of root system, stem and needle fractions were evaluated. The result showed that height of the seedlings grown at both of elevated $CO_2Xhigh$ nitrogen and elevated CO2×low nitrogen supplying treatments increased significantly more than that of at ambient CO2 treatments. Seedlings grown at elevated $CO_2Xhigh$ nitrogen produced more root biomass than at elevated $CO_2Xlow$ nitrogen and ambient $CO_2Xhigh$ nitrogen treatments. This result suggested that the root growth response of Picea koraiensis seedlings was greater in elevated $CO_2{\times}high$ nitrogen regime, which is very important for carbon sequestration in soil. $A_{max}$ of the seedlings grown at elevated $CO_2Xhigh$ nitrogen increased during the three months significantly, and $A_{max}$ of the seedlings grown at the other three treatments decreased significantly, suggesting that the interaction between elevated $CO_2$ and high nitrogen supplying stimulates the $A_{max}$ of Picea koraiensis. $A_{max}$ of the seedlings grown at elevated $CO_2Xlow$ nitrogen showed higher than other three treatments in the first month of the experiment, but decreased in succedent two months, suggesting that elevated $CO_2$ promotes the photosynthesis of the seedlings. However long term growth in elevated $CO_2Xlow$ nitrogen supplying condition resulted in an acclimatory decreased in leaf photosynthesis.

• Korean Journal of Environment and Ecology
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• v.15 no.3
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• pp.207-212
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• 2001

To seek for restoration method of Abies koreana forest with planting seedlings, Abies koreana seedlings(2, 3 and 5 year old) were planted by date(spring and summer) and surface treatment (coir-mat, coir-net and control) at Janggumok area in Hallasan. Survival rate and shoot growth of the seedlings were measured and compared by planting date, seedling age and surface treatments. For summer planting, survival rates of the seedlings are increased with increasing seedling ages, and those are not differed between surface treatments. For spring planting, survival rates of the seedlings are increased with decreasing seedling ages, and those are not differed between surface treatments. For summer planting, shoot growth of the seedlings are significantly differed between surface treatments. Shoot growth of the seedlings was the highest value 2.11mm at coir-matted plot, and the lowest value 1.49mm at control B)lot. Shoot growth of the seedlings are not differed between the seedling ages, but the highest shoot growth was 2.26mm at coir-matted and 3-year old plot. For spring planting, survival rates and shoot growth of the seedlings are not differed between seedling ages and surface treatments.

• Korean Journal of Plant Tissue Culture
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• v.25 no.1
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• pp.69-74
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• 1998

The somatic embryos of Daucus carota L. cv. Hongshim developed in MS basal medium far 4 weeks had varied number of cotyledons. Palisade and spongy parenchyma of cotyledon were not clearly discriminated in all seedlings developed from the embryos. No independent existence of collateral vascular bundle was observed in all seedlings with various types of cotyledon ; instead, vascular bundles were either interconnected or partially connected with one another. Most of the cotyledonary bases on hypocotyl showed short cylinder structure which encircle plumule. The vascular tissues of cotyledonary bases and nodes of seedlings with jar-shaped or 1 cotyledon were connected in ring forms, showing the pattern of ectophloic shiphonostele, and similar ring form structure was also found in the vascular arrangement of 5 cotyledon seedlings. The vascular bundles of seedlings with 2, 3 and 4 cotyledons in many cases had independently arranged within the cotyledonary bases and nodes, showing the pattern of eustele. In hypocotyl, tetrarch or hexarch xylems prevailed in seedlings with jar-shaped cotyledon or 1 and 5 cotyledon; tetrarch xylems prevailed in 2 cotyledon seedlings; and triarch xylems prevailed in 3 cotyledon seedlings. In most of seedlings, cortex vascular bundles were dispensed in the region from cotyledonary node to hypocotyl, but double vascular bundles were also observed occasionally. In roots, diarch xylems were observed in most of seedlings with 2 cotyledons, triarch xylems in half of seedlings with 3 cotyledons, and diarch xylems in most of the remaining seedlings with the occasional occurrences of tetrarch xylems.

• Research in Plant Disease
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• v.17 no.2
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• pp.177-183
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• 2011

Four-year-old seedlings of Pinus thunbergii, Pinus densiflora and Pinus rigida were inoculated with Fusarium circinatum isolate (FT-7), the pitch canker fungus, from P. thunbergii, to evaluate the effects of the pathogen on disease development and gas exchange rate. Needle dehydration was evident on 2 of 10 seedlings of P. thunbergii and P. rigida at 18 and 21 days after inoculation, respectively, while no symptoms were observed in P. densiflora seedlings throughout the experiment. Gas exchange stopped completely in 4 of 5 measured seedlings of P. thunbergii and 2 of 5 measured seedlings of P. rigida at 25 days after inoculation, and in the remaining 3 seedlings of P. rigida at 39 days after inoculation. Disease development in P. thunbergii seedlings was faster than that in P. rigida seedlings. By the time, the experiment was ended at 78 days after inoculation, 9 of 10 seedlings of P. rigida and 8 of 10 seedlings of P. thunbergii seedlings treated with FT-7 was almost dead, but all seedlings of P. densiflora were still healthy. We suggest that P. densiflora is resistant to F. circinatum in the current study, and gas exchange rate of the species after inoculation does not differ significantly compared to that of untreated control.

• Journal of Biosystems Engineering
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• v.41 no.3
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• pp.273-280
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• 2016

Purpose: This experiment was conducted to detect water stress in terms of the moisture content of cucumber seedlings under water stress condition using a hyperspectral image acquisition system, linear regression analysis, and partial least square regression (PLSR) to achieve a non-destructive measurement procedure. Methods: Changes in the reflectance spectrum of cucumber seedlings under water stress were measured using hyperspectral imaging techniques. A model for estimating moisture content of cucumber seedlings was constructed through a linear regression analysis that used the moisture content of cucumber seedlings and a normalized difference vegetation index (NDVI). A model using PLSR that used the moisture content of cucumber seedlings and reflectance spectrum was also created. Results: In the early stages of water stress, cucumber seedlings recovered completely when sub-irrigation was applied. However, the seedlings suffering from initial wilting did not recover when more than 42 h passed without irrigation. The reflectance spectrum of seedlings under water stress decreased gradually, but increased when irrigation was provided, except for the seedlings that had permanently wilted. From the results of the linear regression analysis using the NDVI, the model excluding wilted seedlings with less than 20% (n=97) moisture content showed a precision ($R^2$ and $R^2_{\alpha}$) of 0.573 and 0.568, respectively, and accuracy (RE) of 4.138% and 4.138%, which was higher than that for models including all seedlings (n=100). For PLS regression analysis using the reflectance spectrum, both models were found to have strong precision ($R^2$) with a rating of 0.822, but accuracy (RMSE and RE) was higher in the model excluding wilted seedlings as 5.544% and 13.65% respectively. Conclusions: The estimation model of the moisture content of cucumber seedlings showed better results in the PLSR analysis using reflectance spectrum than the linear regression analysis using NDVI.