• Journal of Applied Biological Chemistry
• /
• v.55 no.2
• /
• pp.129-133
• /
• 2012

To exploit plant growth promoting bacteria in the roots of Miscanthus sacchariflorus, a biomass energy crop, total 64 bacteria were isolated. For the investigation of plant growth promoting effects from the isolated bacteria, production of indole acetic acid (IAA) and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activities were tested and other cultural conditions were examined. As results, 8 isolates showed plant growth promoting effects on the M. sacchariflorus and an isolate designated Agrobacterium sp. BE516 has the highest activity by enhancing the shoot elongation over 2-fold than the control. Agrobacterium sp. BE516 produced 64 ${\mu}g$ IAA per mL and showed ACC deaminase activity which is involved in the resistance to environmental stress such as high salt and drought. It could grow at low temperature in the range from 4 to $15^{\circ}C$, at pH 4.0 and at 4% NaCl. These results indicate that the Agrobacterium sp. BE516 can be useful as a bio-fertilizer for M. sacchariflorus under the stressed conditions.

• Weed & Turfgrass Science
• /
• v.5 no.3
• /
• pp.170-176
• /
• 2016

Superintendents have used a silicate fertilizer to improve a resistance of turfgrass against several diseases, drought damage and wear stress. This study was conducted to evaluate the effect of liquid fertilizer containing silicate (LFSi) on changes of turfgrass quality and growth by investigating visual quality, chlorophyll content-chlorophyll a, chlorophyll b, and total chlorophyll, root length, shoot length, dry weight of clipping, and nutrient content in leaves tissue. Treatments were designed as follows; control fertilizer (CF), SiF-1 (CF + $1ml\;m^{-2}$ LFSi), SiF-2 (CF + $2ml\;m^{-2}$ LFSi), and SiF-3 (CF + $4ml\;m^{-2}$ LFSi). As compared with CF, soil chemical properties, visual turfgrass quality, chlorophyll content, and dry weight of clipping of LFSi treatments were not significantly. Contrastingly, shoot density, root length, and the content of nitrogen or potassium were increased by application of LFSi. The content of Si in the tissue was positively correlated with potassium content or shoot length, and similarly shoot density positively with chlorophyll content or visual quality, respectively. These results suggested that the application of LFSi improved the turfgrass quality by increasing shoot density or K content in leaf tissue of creeping bentgrass.

• Journal of Bio-Environment Control
• /
• v.24 no.2
• /
• pp.51-56
• /
• 2015

The objective of this study was to evaluate the effect of silicate fertilizer on growth, physiology and abiotic stress tolerance of Chinese cabbage seedlings. Five silicate concentrations (8, 16, 32, 64, and 128mM) and control (non-treatment) were applied to Chinese cabbage seedlings twice a week. Three weeks after application of silicate treatment, seedlings were used for treating abiotic stresses and were assessed for growth and physiological characteristics. Growth parameters significantly increased in 8, 16, and 32mM treatments except 64 and 128mM. Total root surface area, total root length, and number of root tips increased in 8, 16 and 32mM treatments, but they decreased in treated seedlings with 64 and 128mM of silicate. The highest growth parameters and root morphology were observed in 8mM treatment. As for the effect on the seedling physiology, transpiration rates decreased while stomatal diffusive resistance increased to increasing silicate concentration. The application of silicate reduced the electrical conductivity, heating and chilling injury index at high and low temperatures. Silicate enhanced drought tolerance of Chinese seedlings by delaying the starting time of wilting point. The starting time of wilting point in the control was 3 days after discontinuation of irrigation, while in the 8, 64 and 128mM of silicate treatments were 4 days, and the 16 and 32mM treatments were 5 days. All plants were wilted after 5 days in control without irrigation whereas it showed in 8mM treatment after 6 days, in 16, 32, 64, 128mM treatments after 7 days.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.240-240
• /
• 2017

Quinoa (Chenopodium quinoa Willd.) is one of the ancient crops cultivated in the Andes region at an altitude of 3,500-4000m in Chile and Bolivia from 5000 BC. It contains a large amount of protein, minerals and vitamins in comparison with other crops. The cultivation area has been increasing worldwide because of its excellent resistance to various abiotic stress such as salinity, drought and low temperature. ${\gamma}$-Ray radiation of high dose is often used as a tool to induce mutations in plant breeding, but it has a deleterious effect on organisms. However, the radiation may have a positive stimulatory effect of 'hormesis' in the low dose range. This experiment was carried out to investigate the optimum dose range for creating the quinoa genetic resources and to investigate the hormesis effect at low dose on the quinoa. This experiment was performed for 120 days from November, 2016 to February, 2017 in the greenhouse of Gyeongsang National University. ${\gamma}$-Ray radiation was irradiated to seeds at 0 Gy, 50 Gy, 100 Gy, 200 Gy, 300 Gy, 400 Gy, 600 Gy, 800 Gy and 1000 Gy for 8 hours. (50 Gy) using the low level radiation facility ($Co^{60}$) of Cooperative Research Institute of Radiation Research Institute, KAERI. Fifty seeds were placed on each petri dish lined with wet filter paper and germination rate was measured at a time interval of 2 hours for 40 hrs. The length of the root length was measured one week after germination. Each treatment was carried out in 3 replicates. The growth of seedlings were investigated for 10 days after transplanting of 30 day-old seedlings. The plant height, NDVI, SPAD, Fv/Fm, and panicle weight were measured. The germination rate was highest at 50Gy and 0Gy and the rate of seeds treated with 400Gy or higher rate decreased to 25% of the seeds treated with 50Gy. The emergence rate of seedling in pot experiment was higher at the dose of 200 Gy, 300 Gy and 400 Gy than at 0 and 50Gy. However, the rate was lower at strong radiation higher than 600Gy at which $1^{st}$ leaf was not expanded fully and dead due to extreme overgrowth at 44 days after treatment (DAT). The highest value of panicle weight was observed at 50Gy (6.15g) and 100Gy (5.57g). On the other hand, the weight at high irradiated dose of 300Gy and 400Gy was decreased by about 55% compared to low dose (50 Gy). NDVI measurement also showed the highest value at 50 Gy as the growth progressed. SPAD was the highest at 400 Gy and showed positive correlation with irradiation dose except 0 Gy. Fv/Fm was high at 50 Gy up to 30 DAT and no difference between treatments was observed except for 400 Gy from 44 DAT. The plant height was the highest in 50Gy during the growing period and was higher in the order of 50Dy, 100Gy, 0Gy, 200Gy, 300Gy and 400Gy in 88 DAT. In this experiment, the optimal radiation dose for hormesis was 50Gy and 100Gy, and the optimal radiation dose for mutagenesis seems to be 400 Gy.