• Korean Journal of Environmental Agriculture
• /
• v.19 no.2
• /
• pp.166-170
• /
• 2000

This study was conducted in to elucidate the changes of growth characteristics and photosynthesis in three soybean (Glycine max L. cv. Danwonkong, Hwangkeumkong and Kwangankong) 30 day old seedlings to 100mM NaCl concentration containing 1/2 Hoagland's nutrient solution in sand culture. The main stem height and number of main stem node were decreased. thus, leaf area and dry matter were decreased with 100mM NaCl. Growth reduction was less little in Hwangkeumkong than other cultivars. The stem growth rate was affected less than other parts as root or leaf, by NaCl treatment. The specific leaf area (SLA), shoot : root ratio and leaf : root ratio decreased with NaCl solution except for those of Hwangkeumkong. There is no general tendency in leaf thickness by leaf position of three cultivars. The chlorophyll content (SPAD) of the primary and 2nd leaf slightly decreased under NaCl solution but rapidly increased in non-NaCl solution at 15 days after treatments. The photosynthesis, stomatal conductance and transpiration of 2nd leaf positions reduced by NaCl and there were a sigificant correlation between photosynthesis and stomatal conductance or transpiration.

• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.6
• /
• pp.652-658
• /
• 2013

A huge number of greenhouse soils in Korea have accumulated mineral elements which induce many nutritional and pathological problems. The present study was performed to the effects of the reduced fertilization on plant growth, and uptake and partitioning of minerals (N, P, K) and soluble carbohydrates using highly minerals-accumulated farmer's greenhouse soil. On the basis of the recommended application for tomato crop, the application rates of N, P and K were 110(50%)-5.2(5%)-41.5(35%)kg $ha^{-1}$, respectively, using Hoagland's nutrient solution. Tomato growth rates during the whole experiment were not significant between treatments, but it was found that a decrease in daily growth represented after 60 days of treatment (DAT). The reduced application led to a drastic decrease in the concentration of N, P and K in fruits, and, thus, this resulted in lower uptake after 40 DAT. The lower phloem export and utilization of soluble carbohydrates caused an accumulation of extra-carbohydrates in leaves, stems and fruits in the reduced application. The reduced fertilization induced the capture of N, P and K in leaves and of soluble carbohydrates in stems compared to the conventional application. In this study, we suggest that it is possible to delay the first fertigation time in minerals-accumulated soils without an adverse impact on crop growth, but it is necessary to regularly monitor mineral status in soil to ensure a balanced uptake, synthesis and partitioning of minerals and carbohydrates.

• Korean Journal of Environmental Agriculture
• /
• v.18 no.4
• /
• pp.361-365
• /
• 1999

This atudy was conducted to determine the growth characteristics and photosynthesis of soybean (Glycine max L. cv. Keumjongkongl) 30 day old seedling to 100mM NaCl concentration containing 1/2 Hoagland`s nutrient solution in sand culture. The nodule formation of root is not found perfectly with NaCl stress. The leaf dry matter weight (g/plant) of stressed plant is more reduction in 77% to control than any other characters. The water content (%) is tend to increase but water potential (MPa) is tend to decrease at NaCl stress. The chlorophyll content (SPAD) is tend to increase at growing leaf age of control but decrease at NaCl stress. The photosynthesis, stomatal conductance and transpiration are tend to decrease sharply at NaCl stress.

• Journal of Photoscience
• /
• v.5 no.4
• /
• pp.169-174
• /
• 1998

Photosynthetic responses to dehydration were examined by the simulataneous measurement of O2 evolution and chlorophyll (Chl) fluorescence in green pepper leaves. Dehydration was induced by immersing the plant roots directly in the Hoagland solution containing varying concentration (2-30%) of polyethylene glycol(PEG-6000) . Water potential of the leaf was decreased time-and concentation -dependently by PEG-treatment. The decrease in water potential of leaf was correlated with the decrease in both the maximal photosynthesis (Pmax) and quantum yield of O2 evolution, but Pmax dropped more rapidly than quantum yield at all water deficit conditions tested. However, Chl fluorescence parameters were not affected much. Dehydration did not change the initial fluorescence (Fo) and maximum photochemical efficiency(Fv/Fm) of photosystem(PS) II. Both the photochemical quenching (qP) and non-photochemical quenching(NPQ) were not changed by dehydration under low PFR(50 $\mu$mols m-2s-1 ). In contrast, under high PFR(270$\mu$mols m-2s-1)qP was slightly decreased while NPQ was greatly increased. The fast induction kinetics of Chl fluroecence showed no change in Chl fluorescence pattern by dehydration at high PFR (640 $\mu$mols m-2s-1 ), but exhibited a significant drop in peak level(Fp)at low PRFR (70$\mu$mols m-2s-1 ). PS I oxidation and reduction kinetics revealed normal reduction but delayed oxidation to P-700+, suggesting no lesionin electron flow from PSII to PSI , but impaired electron transport to NADP+,These results suggest that water stress caused by PEG-treatment results in the reduction of photosynthesis, promarily due to the reducted electron trasport from PSI to NADP+ or hampered subsequent steps involving Calvin Cycle.

• Journal of Environmental Science International
• /
• v.13 no.6
• /
• pp.513-518
• /
• 2004

3-weeks old Commelina was transferred to and grown in Hoagland solution (Control, $100\muM$ $Cd^{2+}$, $100\muM$ $Cd^{2+}$+ $100\muM$ IAA, $100\muM$ $Cd^{2+}$+ $100\muM$ IAA + 2 mM sucrose) for 3 weeks and then the effects of indole acetic acid (IAA) on the accumulation of $Cd^{2+}$ and growth of $Cd^{2+}$-treated Commelina were investigated. In the treatment of $Cd^{2+}$, $Cd^{2+}$ was uptaked to 1.74, and 51.36 ${\mu}g/g$ frwt. at the first week, but for three weeks, 0.51 and 34,53 ${\mu}g/g$ frwt, in leaf and stem respectively. When IAA was treated along with $Cd^{2+}$, $Cd^{2+}$ was uptaked to 0.18 and 8.63 ${\mu}g/g$ fiwt, at the first week, and for the incubation of 3 weeks, 0,51 and 45.0 ${\mu}g/g$ fiwt. in leaf and stem. In case of $Cd^{2+}$+IAA+sucrose, $Cd^{2+}$ was uptaked to 1.45 and 18.33 ${\mu}g/g$ frwt. at the first week, but for 3 weeks, 0,51 and 25.45 ${\mu}g/g$ fiwt. in leaf and stem. Likewise $Cd^{2+}$ uptake, the growth was also affected by $Cd^{2+}$ and IAA. During the incubation of 3 weeks, $Cd^{2+}$ reduced the stem growth about 8% in all weeks, but the treatment of IAA recovered the inhibition of stem growth caused by $Cd^{2+}$ to the degree of the control Therefore, it could be concluded that IAA altered the pattern of $Cd^{2+}$ uptake and the growth which were supposed to change $Cd^{2+}$ toxicity.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.355-355
• /
• 2017

South Korea is largely dependent on imports of forage crops. In order to raise the self-sufficiency rate of forage crops, it is necessary to cultivate forage crops in 135,100 ha reclaimed land of South Korea. This study was conducted to investigate the growth of halophytes and forage crops in order to search for stable plants on reclaimed land. The plants were cultured in Hoagland solution and grown at 0%, 0.5%, 1.0% and 2.0% of salt concentrations. Plants with good growth at 0.5% of salt concentration were halophytes such as Suaeda asparagoides and Salsola komarovii. Salicornia herbacea and Suaeda maritima showed good growth at 2.0% salinity, and Suaeda maritima showed stable growth at all of salt concentrations. In conclusion, Suaeda asparagoides showed the best growth at 0.5% of salt concentration and was considered the most biomass at reclaimed land in Korea with less than 0.5% of salt concentration.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.37-37
• /
• 2017

Mechanistic studies of halophytes are urgent areas of agricultural research due to the increase in saline-contaminated and irrigated land worldwide. The halophyte Suaeda glauca (S. glauca) has advantages in terms of biomass and saline elimination due to its large mass and well-developed phenotype on seashores, although its mechanistic features and growing specificities still require systematic investigation. In this study, S. glauca was cultivated under various saline concentrations (0-400 mM) in Hoagland's solution in the absence or presence of indole derivatives to elucidate physiological features. The results confirmed the optimal growth and development of S. glauca in 50 mM NaCl, and morphologies such as the number of branches, shoot length, and fresh and dry weights were improved by indole-3-carboxylic acid (ICA) treatment. The cation concentrations in roots, shoots and leaves were investigated to examine the ionic imbalances in response to saline treatment, and the results demonstrated that sodium ions accumulated to high concentrations in leaves. The levels of calcium and potassium ions in roots were maintained or slightly decreased in the presence of 50 mM NaCl and proline concentration was increased significantly in roots at optimal concentrations. These results demonstrate that the concentrations of ions and metabolites are key regulators of optimal growth by regulating the physiology of halophytes.

• Journal of Environmental Science International
• /
• v.14 no.3
• /
• pp.345-350
• /
• 2005

Three-week old Commelina communis was transferred and grown in Hoagland solution containing $100{\mu}M\;Cd^{2+},\;100{\mu}M\;Cd^{2+}+100{\mu}M\;kinetin,\;100{\mu}M\;Cd^{2+}+100{\mu}M\;zeatin\;and\;100{\mu}M\;Cd^{2+},\;200{\mu}M$ zeatin for 7 days, and then a number of physiological activities were investigated. In control, the length of the stem of plants was increased to 4.7cm, but in $Cd^{2+},\;Cd^{2+}+kinetin,\; Cd^{2+}+100{\mu}M\;zeatin\;and\;Cd^{2+}+200{\mu}M$ zeatin treatments, the growth of plants were increased to 1.5cm, 2.1cm, 3.9cm and 4.3 em, respectively. In the treatments of $Cd^{2+},\;Cd^{2+}+kinetin,\;Cd^{2+}+100{\mu}M\;zeatin\;and\; Cd^{2+}+200{\mu}M$ zeatin, total chlorophyll contents were reduced to $26\%,\;24\%,\;15\%\;and\;3\%$, respectively, on the contrast to the control. In chlorophyll fluorescence experiments, Fv/Fm ratios were also reduced to $44\%,\;21\%,\;17\%\;and\;5\%$ in the light intensity of $2100{\mu}Mmole\;E\;m^{-2}s^{-1}\;by\;Cd^{2+},\;Cd^{2+}+kinetin,\;Cd^{2+}+$100{\mu}M\;zeatin\;and\;Cd^{2+}+200{\mu}M$ zeatin treatments on the contrast to the control. Water stresses were increased to 2.6, 1.7 and 1.2 times by $Cd^{2+},\; Cd^{2+}+kinetin\;and\;Cd^{2+}+{\mu}M$ zeatin. On the other hand, combination of $Cd^{2+}+200{\mu}M$ zeatin reduced water stress to $0.12\%$. In $Cd^{2+}$ accumulation experiments $Cd^{2+}$transports were inhibited to $33\%\; 48\%\;and\;70\%\;by\;Cd^{2+}+kinetin,\;Cd^{2+}+100{\mu}M\;zeatin\;and\;Cd^{2+}+200{\mu}M$ zeatin. Therefore, it could be concluded that zeatin clearly reduced the toxicities of $Cd^{2+}$ by reducing the absorption of $Cd^{2+}$.

• Korean Journal of Weed Science
• /
• v.15 no.4
• /
• pp.247-253
• /
• 1995

The herbicide butachlor [N-(butoxymethyl)-2-chloro-N-(2,6-di-methylphenyl) acetamide] is widely used by farmers as a tool for weed management of transplanted rice(Oryza sativa L.) in Taiwan. The herbicide did not stop germination of rice and weed seeds, but strongly inhibited the subsequent growth of young shoots and roots. The inhibition was also strong on established seedlings. However, they could recover to normal growth after the herbicide effect disappeared. Butachlor greatly decreased the endogenous indole-3-acetic acid (IAA) but increased the endogenous abscisic acid (ABA) contents of rice seedlings. Addition of lAA into growth medium (Hoagland's solution) partly relieved growth inhibition. Pretreatment of both gibberellic acid ($GA_3$) and IAA 24 hours before butachlor treatment almost completely alleviated the butachlor-interfere with GA and/or IAA metabolism or their action resulting in the growth inhibition of rice. Butachlor was readily absorbed by rice roots. During 24 hours of uptake experiment, 32% of the applied herbicide was absorbed. Pretreatment of the herbicide for 2 days did ncx affect the absorption. Of the absorbed herbicide, 80% remained in roots, only 20% transported into shoots, and more than 50% was metabolized to water soluble substances. Thin-layer chromatographic (TLC) analysis indicated that the Rf value of the most abundant metabolite was butachlor-glutathione conjugate. Rice, barnyardgrass (Echinochloa crus-galli (L.) Beauv.), and monochoria (Monochoria vaginalis Presl) seedlings contained relatively high level of non-protein thiols, while the glutathione S-transferase (GST) activity was found highest in rice, barnyardgrass the next, monochoria the lowest. The difference in GST activity among these species might be related to their sensitivity to butachlor.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.52 no.3
• /
• pp.264-273
• /
• 2007

In order to examine the cross-tolerance of two chilling-tolerant cultivars (Donganbyeo and Heukhyangbyeo) and two chilling-susceptible cultivars (Hyangmibyeo and Taekbaekbyeo) to salt, paraquat, and drought, changes of physiological response and antioxidant enzymes were investigated. The seedlings were grown in a growth chamber until the 4-leaf stage. The seedlings were exposed to chilling at $5^{\circ}C$ for 3 days. For drought treatment, the seedlings were subjected to drought by withholding water from plants for 5 days. For paraquat study, plants were sprayed with $300{\mu}M$ paraquat. For the salt stress, the seedlings were transferred to the Hoagland's nutrient solution containing 0.6% (w/v) NaCl for 4 days. Chilling-tolerant cultivars showed cross-tolerant to other stresses, salt, paraquat, and drought in physiological parameters, such as leaf injury, chlorophyll a fluorescence, and lipid peroxidation. The baseline levels of antioxidative enzyme activities, catalase (CAT) and peroxidase (POX) activities in chilling-tolerant cultivars were higher than in the chilling-susceptible cultivars. However, there were no differences in ascorbate peroxidase (APX) and glutathione reductase (GR) activities between chilling-tolerant and -susceptible cultivars in untreated control. CAT activity in chilling-tolerant cultivars was higher than that in chilling-susceptible cultivars during chilling, salt, and drought treatments, but not during paraquat treatment. However, other antioxidative enzymes, APX, POX, and GR activities showed no significant differences between chilling-tolerant and -susceptible cultivars during chilling, salt, paraquat, and drought treatments. Thus, it was assumed that CAT contribute to cross-tolerance mechanism of chilling, salt, and drought in rice plants.