• FLOWER RESEARCH JOURNAL
• /
• v.16 no.4
• /
• pp.234-238
• /
• 2008

This experiment was conducted to investigate the effect of growth retardants such as CCC and diniconazole in grafted cactus for control shipping product of grafted cactus, which had high degree of dependence upon export. The PGRs were 50, 100, 150 $mg{\cdot}L^{-1}$ CCC and diniconazole, respectively. Treatment of diniconazole and CCC not reduced diameter on Gymnocalycium mihanovichii var. friedrichii but number of tubercle reduced significantly according to the increase of diniconazole treatment, control was 7.2 tubercles, but with 100 $mg{\cdot}L^{-1}$ diniconazole was 6.4 tubercles. Treatment of diniconazole and CCC reduced significantly diameter and tubercle number on Chamaecereus silvestrii f. variegata at higher concentration. Diameter and height reduced significantly the treatment of CCC with 3.3 and 13.4 mm of 150 $mg{\cdot}L^{-1}$, respectively. Dry weight of root, rootstock and scion decreased at higher concentrations of CCC and diniconazole in Chamaecereus silvestrii f. variegata. The most effective method of plant growth retardants for controlling of shipping time was the 150 $mg{\cdot}L^{-1}$ CCC treatment.

• Korean Journal of Agricultural Science
• /
• v.46 no.1
• /
• pp.93-102
• /
• 2019

The materials of artificial soils in the production process of container seedlings have a great influence on plant growth. Peat moss, vermiculite, and perlite have been used as major components of artificial soils for many years; however, they could decrease carbon fixation carried out by the soil and cause environmental problems such as a change in the water quality. Thus, environmental friendly materials to replace them must be developed. The purpose of this study was to verify the optimum additive materials of artificial soils and their mixed ratios for the growth and seedling quality index (SQI) of Quercus serrata. Rice husk, mushroom sawdust, and pine bark were each used as an additive material and mixed into the growth medium at 10% and 20% of the total volume. There was no significant difference in the height growth of Q. serrata. The 20% mushroom sawdust decreased the root collar diameter by 23.4% compared to the control. The total dry weight was highest with the 10% rice husk and was significantly lower by 10.3% for the 20% mushroom sawdust compared to the control. Additionally, the SQI for all the treatments showed no tendency to increase compared with the control. Thus, this study showed the possibility of recycling biomaterials from agriculture and forest for seedling production. This method could reduce environmental problems and help eco-friendly nurseries to achieve a carbon negative impact by the recycling of by-products.

• The Plant Pathology Journal
• /
• v.37 no.2
• /
• pp.173-181
• /
• 2021

The genus Streptomyces demonstrates enormous promise in promoting plant growth and protecting plants against various pathogens. Single and consortium treatments of two selected Streptomyces strains (Streptomyces shenzhenensis TKSC3 and Streptomyces sp. SS8) were evaluated for their growth-promoting potential on rice, and biocontrol efficiency through induced systemic resistance (ISR) mediation against Xanthomonas oryzae pv. oryzicola (Xoc), the causal agent of rice bacterial leaf streak (BLS) disease. Seed bacterization by Streptomyces strains improved seed germination and vigor, relative to the untreated seed. Under greenhouse conditions, seed bacterization with consortium treatment TKSC3 + SS8 increased seed germination, root length, and dry weight by 20%, 23%, and 33%, respectively. Single and consortium Streptomyces treatments also successfully suppressed Xoc infection. The result was consistent with defense-related enzyme quantification wherein single and consortium Streptomyces treatments increased peroxidase (POX), polyphenol oxidase, phenylalanine ammonia-lyase, and β,1-3 glucanase (GLU) accumulation compared to untreated plant. Within all Streptomyces treatments, consortium treatment TKSC3 + SS8 showed the highest disease suppression efficiency (81.02%) and the lowest area under the disease progress curve value (95.79), making it the best to control BLS disease. Consortium treatment TKSC3 + SS8 induced the highest POX and GLU enzyme activities at 114.32 µmol/min/mg protein and 260.32 abs/min/mg protein, respectively, with both enzymes responsible for plant cell wall reinforcement and resistant interaction. Our results revealed that in addition to promoting plant growth, these Streptomyces strains also mediated ISR in rice plants, thereby, ensuring protection from BLS disease.

• Journal of Plant Biotechnology
• /
• v.47 no.4
• /
• pp.324-329
• /
• 2020

Reed (Phragmites spp.) is a rhizomatous plant of the Poaceae family and is known as high tolerant plant to heavy metal contaminants. This plant is widely recognized as a Cd root-accumulator, but improved heavy metal tolerance and uptake capacity are still required for phytoremediation efficiency. To enhance capacity of hyperaccumulator plants, ethyl methane sulfonate (EMS) as chemical mutagen has been introduced and applied to remediation approaches. This study aimed to select EMS-mutagenized reeds representing high Cd resistance and large biomass and to investigate their ability of Cd accumulation. After 6 months cultivation of M₂ mutant reeds under Cd stress conditions (up to 1,500 µM), we discovered seven mutant individuals that showed good performances like survivorship, vitality, and high accumulation of Cd, particularly in their roots. Compared to wild type (WT) reeds as control, on average, dry weight of mutant type (MT) reeds was larger by 2 and 1.5 times in roots and shoots, respectively. In addition, these mutant plants accumulated 6 times more Cd, mostly in the roots. In particular, MT8 reeds showed the greatest ability to accumulate Cd. These results suggest that EMS mutagenesis could generate hyperaccumulator plants with enhanced Cd tolerance and biomass, thereby contributing to improvement of phytoremediation efficiency in Cd-contaminated soil or wastewater. Further studies should focus on identifying Cd tolerance mechanisms of such EMS-mutagenized plants, developing techniques for its biomass production, and investigating the practical potential of the EMS mutants for phytoremediation.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.11
• /
• pp.1435-1446
• /
• 2022

Zinc-solubilizing bacteria can convert the insoluble form of zinc into soluble forms available to plants. This study was conducted to isolate and screen zinc-solubilizing actinobacteria from rhizosphere soils and to assess their effect on vegetable soybean growth. In total, 200 actinobacteria strains belonging to 10 genera were isolated from rhizosphere soil samples. Among these isolates, four showed zinc solubilization with solubilizing index values ranging from 3.11 to 3.78 on Bunt and Rovira agar supplemented with 0.1% zinc oxide. For the quantitative assay, in broth culture, strains CME34 and EX51 solubilized maximum available zinc contents of 529.71 and 243.58 ㎍/ml. Furthermore, indole-3-acetic acid (IAA) and ammonia were produced by these two strains, the strain CME34 produced the highest amount of IAA 4.62 ㎍/ml and the strain EX51 produced the highest amount of ammonia 361.04 ㎍/ml. In addition, the phosphate-solubilizing abilities in Pikovskaya's medium of CME34 and EX51 were 64.67 and 115.67 ㎍/ml. Based on morphological and biochemical characterization and 16S rDNA sequencing, the strains CME34 and EX51 were closely related to the genus Streptomyces. In a greenhouse experiment, single-strain inoculation of Streptomyces sp. CME34 or EX51 significantly increased the shoot length, root length, plant dry weight, number of pods per plant and number of seeds per plant of vegetable soybean plants compared to the uninoculated control. These findings facilitated the conclusion that the two Streptomyces strains have potential as zinc solubilizers and can be suggested as bioinoculants to promote the growth and yield of soybean.

• Geomechanics and Engineering
• /
• v.34 no.6
• /
• pp.697-726
• /
• 2023

Brittleness as an important property of rock plays a crucial role both in the failure process of intact rock and rock mass response to excavation in engineering geological and geotechnical projects. Generally, rock brittleness indices are calculated from the mechanical properties of rocks such as uniaxial compressive strength, tensile strength and modulus of elasticity. These properties are generally determined from complicated, expensive and time-consuming tests in laboratory. For this reason, in the present research, an attempt has been made to predict the rock brittleness indices from simple, inexpensive, and quick laboratory test results namely dry unit weight, porosity, slake-durability index, P-wave velocity, Schmidt rebound hardness, and point load strength index using multiple linear regression, exponential regression, support vector machine (SVM) with various kernels, generating fuzzy inference system, and regression tree ensemble (RTE) with boosting framework. So, this could be considered as an innovation for the present research. For this purpose, the number of 39 rock samples including five igneous, twenty-six sedimentary, and eight metamorphic were collected from different regions of Iran. Mineralogical, physical and mechanical properties as well as five well known rock brittleness indices (i.e., B₁, B₂, B₃, B₄, and B₅) were measured for the selected rock samples before application of the above-mentioned machine learning techniques. The performance of the developed models was evaluated based on several statistical metrics such as mean square error, relative absolute error, root relative absolute error, determination coefficients, variance account for, mean absolute percentage error and standard deviation of the error. The comparison of the obtained results revealed that among the studied methods, SVM is the most suitable one for predicting B₁, B₂ and B₅, while RTE predicts B₃ and B₄ better than other methods.

• Korean Journal of Environmental Agriculture
• /
• v.42 no.2
• /
• pp.121-130
• /
• 2023

The RGB (red, green, and blue) imagery analysis is an important remote sensing tool, which estimates the effect of environmental stress on turfgrass growth and physiology. Therefore, this study investigated the effect of continuous wear stress treatment on Zoysia japonica through RGB imagery analysis. The results of the growth measurement showed that the plant height substantially decreased, after nine hours of treatment with no considerable difference thereafter. Dry weight measurement showed a substantial difference in the morphological growth characteristics of the aerial part of the turfgrass, but none in the stolon and root zone. This could be attributed to the short period of compaction treatment. The ROS (reactive oxygen species) analysis showed that ROS rapidly increased due to wear stress treatment. The MDA content increased during the traffic process, whereas the green pixels increased and decreased repeatedly; however, overall, the trend declined but the overall trend decreased. Thus, this study confirmed that MDA was effective in reflecting the wear stress of turfgrass; however, it could through RGB image analysis.

• Journal of Plant Biotechnology
• /
• v.50
• /
• pp.115-126
• /
• 2023

A hydroponics experiment was performed to study the physiological and biochemical changes in Moroccan barley (Hordeum vulgare L.) varieties cultivated under salt stress conditions. Four barley varieties were grown under exposure to three salt concentrations, including 0, 200, and 300 mM NaCl. The ANOVA for both salt stress-sensitive and resistant varieties indicated that salt treatment represented the main source of variability in all studied traits. Salt treatment significantly reduced root and shoot dry weight (RDW and SDW), relative water content (RWC), and chlorophyll content (Chl a, Chl b, and Chl T). However, increases in electrolyte leakage (EL) along with proline and total soluble sugar (TSS) contents were recorded. In addition, large variations in all measured traits were found between varieties. The 'Massine' and 'Laanaceur' varieties displayed relatively higher RDW and SDW values. The 'Amira' and 'Adrar' varieties showed lower RWC values and Chl contents than those of the controls indicating their relative sensitivity to salt stress. Principal component analysis revealed that most of the variation was captured by PC1 (72% of the total variance) which grouped samples into three categories according to salt treatment. Correlation analyses highlighted significant associations between most parameters. Positive relationships were found between RDW, SDW, RWC, Chl content, and soluble proteins contents, while all of these parameters were negatively associated with EL intensity, proline content, and TSS content. The results from this study showed that the 'Massine' and 'Laanaceur' varieties were relatively salt-tolerant. These two salt-tolerant varieties present a good genetic background for breeding of barley varieties showing high salt tolerance.

• Proceedings of the Turfgrass Society of Korea Conference
• /
• 2011.02a
• /
• pp.5-8
• /
• 2011

This research was conducted to determine the effect of capillary rise interruption layer on the sand based growing media when growing Kentucky bluegrass under soil reclamation and saline water irrigation. Rootzone profile consists of three layers as top soil of 30 cm, 20 cm of capillary interruption layer and 10 cm of reclaimed paddy soil. Rootzone profile was packed in column pots. The top soil was a mixture of sand dredged up from Lake Bhunam Tae Ahn, Korea and peat at the ratio of 95:5 by volume. Bottom part of column was covered with plastic net and the pots were soaked into 5 cm depth saline water reservoir with salinity $3-5dsm^{-1}$. Kentucky bluegrass was installed by sod and irrigated using $2dSm^{-1}$ saline water(5.7mm $day^{-1}$)in 3days interval. The results showed that the largest accumulation of salt in the spring with ECe of $5.4dSm^{-1}$ and SAR34.0 in rootzone with out capillary rise interruption layer and ECe of $4.6dSm^{-1}$ and SAR8.24 at rootzone using gravel as capillary rise interruption layer material. Kentucky bluegrass grown in growing media with gravel as capillary rise interruption layer resulted in the average visual quality rate of 8.1and clipping dry weight of $24.8gm^{-2}$, while Kentucky bluegrass grown in the growing media with out capillary rise interruption layer showed the visual quality rate of 7.9 and clipping dry weight of $34g.m^{-2}$. Capillary rise interruption layer of gravel and coarses and enhanced the visual quality by 4.1and 4.0%, root length by 50 and 38%, and root dryweight by 35and 17% of Kentucky bluegrass, and reduced the accumulation of Na by 16% and 25%, ECe by 7% and 13% in the rootzone.