• Korean Journal of Environmental Agriculture
• /
• v.32 no.3
• /
• pp.179-184
• /
• 2013

BACKGROUND: Accurate estimates of total direct $CH_4$ emissions from croplands on a country scale are important for global budgets of anthropogenic sources of $CH_4$ emissions and for the development of effective mitigation strategies. Methane production resulted by the anaerobic decomposition of organic compounds where $CO_2$ acts as inorganic electron acceptor. This process could be affected by the addition of rice straw, water management and rice variety itself. METHODS AND RESULTS: Rice (Oryza sativa L. Japonica type, var Samkwangbyeo) was cultivated in four plots: (1) Nitrogen-Phosphorus-Potassium (NPK) ($N-P_2O_5-K_2O$:90-45-57 kg/ha); (2) NPK plus 3 Mg/ha rice straw (RS3); (3) NPK plus 5 Mg/ha rice straw (RS5); (4) NPK plus 7 Mg/ha rice straw (RS7) for 3 years (2010-2012) and the rice straw incorporated in fall (Nov.) in Gyeonggi-do Hwaseong-si. Gas samples were collected using the closed static chamber which were installed in each treated plot of $152.9m^2$. According to application of 3, 5, 7 Mg/ha of rice straw, methane emission increased by 46, 101, 190%, respectively, compared to that of the NPK plot. CONCLUSION(S): We obtained a quantitative relationship between $CH_4$ emission and the amount of rice straw applied from rice fields which could be described by polynomial regression of order 2. The emission scaling factor estimated by the relationship were in the range of IPCC GPG (2000).

• Korean Journal of Soil Science and Fertilizer
• /
• v.29 no.2
• /
• pp.137-144
• /
• 1996

A feasible way to utilize small-scale livestock farm wastewater was explored. In place of common support materials rice straw was employed as a support medium of trickling filter for pig farm wastewater treatment. The straw medium which was humified for 20 days after wastewater treatment and mixed with soil significantly enhanced in general the development of bunching lettuce grown under greenhouse conditions. Improvement of soil chemical properties in terms of fertility was also achieved by the addition of humified straw medium after wastewater treatment. It was found that rice straw served as a satisfactory support medium of trickling filters with the wastewater treatment concerning removals of biological oxygen demand, chemical oxygen demand, and suspended solids.

• KSBB Journal
• /
• v.10 no.1
• /
• pp.23-29
• /
• 1995

Calli were induced from leaf base region of germinated rice(Oryza sativa L. cv. Nakdong) with high frequency of up to 65% on LS medium supplemented with $2.5mg/{\ell}2$, 4-D in the dark at $27^{\circ}C$. Embryogenic calli of pale yellow, globular type were selected and used for the initiation of cell suspension cultures in AA2 liquid medium with $2mg/\ell$ 2,4-D, 0.2mg/$\ell$ kinetin arid $0.1mg/\ell$ GA3. Protoplasts were isolated from the embryogenic cell suspensions after 4 months of culture and then were electroporated with 400V/cm for 1 msec. Electroporated protoplasts divided with plating efficiency of 1.1% on PCM liquid medium supplemented with $2.5mg/\ell$ 2, 4-D, $0.1mg/\ell$ kinetin and 10mM proline. The protoplasts-derived microcalli were cultured on $0.2{\mu}m$ membrane fitter placed onto LS2.5 solid medium containing fine suspension cells as a feeder cells, for 2 weeks in the dark at $27^{\circ}C$. After an additional 2 weeks of culture under fluorescent light of $30{\pm}/3{\mu}E$.m^{-2}S^{-1}, yellow calli of 2mm diameter were transferred to regeneration medium. Shoots were produced from the green spot of protoplasts-derived calli and plants were regenerated form protoplast-derived green calli with frequencies of 11∼33%.

• Korean Journal of Soil Science and Fertilizer
• /
• v.29 no.4
• /
• pp.371-377
• /
• 1996

Utilization of crop residues was investigated in search of ecologically desirable treatment of wastewater from small-scale swine farm. Instead of common materials rice stray was used as a support medium of tricking filter with the farm, wastewater treatment. The treated rice stave medium was dried, crushed, and directly added to soil, where bunching lettuce seedlings were grown under greenhouse conditions. The development of bunching lettuce was significantly enhanced by the application of the straw medium up to 2100 kg/10a. Little changes in soil chemical properties were observed at harvesttime, except the pH which was raised by more than 1 unit, and the content of Mg which was depleted presumably by the uptake of the plant.

• Molecules and Cells
• /
• v.27 no.4
• /
• pp.459-465
• /
• 2009

MUG1 is a MULE transposon-related domesticated gene in plants. We assessed the sequence diversity, neutrality, expression, and phylogenetics of the MUG1 gene among Oryza ssp. We found MUG1 expression in all tissues analyzed, with different levels in O. sativa. There were 408 variation sites in the 3886 bp of MUG1 locus. The nucleotide diversity of the MUG1 was higher than functionally known genes in rice. The nucleotide diversity (${\pi}$) in the domains was lower than the average nucleotide diversity in whole coding region. The ${\pi}$ values in nonsynonymous sites were lower than those of synonymous sites. Tajima D and Fu and Li $D^*$ values were mostly negative values, suggesting purifying selection in MUG1 sequences of Oryza ssp. Genome-specific variation and phylogenetic analyses show a general grouping of MUG1 sequences congruent with Oryza ssp. biogeography; however, our MUG1 phylogenetic results, in combination with separate B and D genome studies, might suggest an early divergence of the Oryza ssp. by continental drift of Gondwanaland. O. long-istaminata MUG1 divergence from other AA diploids suggests that it might not be a direct ancestor of the African rice species.

• Journal of Plant Biotechnology
• /
• v.36 no.1
• /
• pp.23-29
• /
• 2009

We have previously isolated a CCCH type zinc-finger protein gene, OsZF2 (Oryza sativa Zinc Finger 2), from the cold-treated rice cDNA library. To investigate the potential role of OsZF2, transgenic rice lines over-expressing OsZF2 under the control of CaMV 35S promoter have been developed through Agrobacterium-mediated transformation. Elevated level of OsZF2 transcripts was confirmed by RNA gel blot analysis in transgenic rice. Under the 100 mM NaCl condition, the transgenic rice showed significantly enhanced growth rate in terms of shoot length and fresh weight, implicating that OsZF2 is likely to be involved in salt response of rice. In the field condition, however, the transgenic rice showed a dwarf phenotype and flowering time was delayed. Genome expression profiling analysis of transgenic plants using the 20K NSF rice oligonucleotide array revealed many up-regulated genes related to stress responses and signaling pathways such as chaperone protein dnaJ 72, salt stress-induced protein, PR protein, disease resistance proteins RPM1 and Cf2/Cf5 disease resistance protein, carbohydrate/ sugar transporter, OsWAK kinase, brassinosteroid LRR receptor kinase, and jasmonate O-methyltransferase. These data suggest that the CCCH type zinc-finger protein OsZF2 is a upstream transcriptional factor regulating growth and stress responsiveness of rice.

• Korean Journal of Environmental Agriculture
• /
• v.19 no.2
• /
• pp.160-165
• /
• 2000

This study was carried to select the tolerance in rice varieites for ozone treatment through comparing SOD, POD and stomata resistance. In SOD Acivity, Sangnambatbyeo showed the highest activity on 1 hr after ozone treatment and after 24 hr, SOD activity was decreased. SOD activity of Hangangchalbyeo was not different in observed all times after ozone treatment. In POD activity, Hangangchalbyeo, Sangnambatbyeo and Ilpumbyeo were similar to POD activity but Baeknabyeo was the lowest activity on 1 hr after ozone treatment. Also, all varieties represnted the highest activity (above 90 %) an 24 hr after ozone treatment. In stomata resistance, Sangnambatbyeo was decreased stomata resistance on 1 hr after ozone treatment. Hangangchalbyeo, Sangnambatbyeo and Baekna were decreased stomata resistiance on 24 hr after ozone treatment except Ilpumbyeo.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.1 no.1
• /
• pp.52-59
• /
• 1999

Vegetation canopy plays an important role in $CO_2$/$H_2$O exchange between the biosphere and the atmosphere by controlling leaf stomata. In this study, rice (Oryza sativa L.), a staple crop in Asia was investigated to formulate its single leaf model of photosynthesis and stomatal conductance. Photosynthesis and stomatal conductance were measured with a portable infrared gas analyzer system. Other plant and meteorological variables were also measured. To evaluate empirical constants in this biochemical leaf model, nonlinear least squares technique was used. The maximum catalytic activity of enzyme and the maximum rate of electron transport were $ 100\mu$㏖ $m^{-2}$ $s^{-1}$ and $140 \mu$㏖ m$^{-2}$ s$^{-1}$ (@ 35$^{\circ}C$), respectively. The empirical constants, m and b, associated with stomatal conductance model were 9.7 and $0.06 m^{-2}$ $s^{-1}$ , respectively. On a leaf scale, agreements between the modeled and the measured values of photosynthesis and stomatal conductance were on average within 20%, and the simulation of diurnal variation was also satisfactory On a canopy scale, the Simple Biosphere model(SiB2) was tested using the derived parameters. The modeled energy fluxes were compared against the micrometeorologically measured fluxes over a rice canopy. Agreements between the modeled and the measured values of net radiation, sensible heat and latent heat fluxes, and $CO_2$ flux (i.e., net canopy photosynthesis) were on average within 25%.

• Korean Journal of Soil Science and Fertilizer
• /
• v.50 no.6
• /
• pp.497-508
• /
• 2017

This study aimed to investigate correlations between concentrations of extractable Arsenic (As) with varying chemical solutions (0.1 M $Ca(NO_3)_2$, 0.1 M $(NH_4)2HPO_4$, 0.5 M EDTA, Mehlich 3, and 0.5 M $NaHCO_3$) and those of As in crops, and then to seek the most suitable soil extraction method for predicting the potential of As uptake in crops cultivated in soils contaminated with As. For a mesocosm experiment, pepper (Capsicum annuum L.), soybean (Glycine max L.), and rice (Oryza sativa L.) were cultivated for three months in pots containing soils taken from the arable areas near abandoned mines in Korea. Following the cultivation, soil pH and DOC significantly increased by treatments of lime and lime plus compost, respectively, while insignificant influences in changing total and all extractable As concentrations were found in all soils. Arsenic concentration in edible part of all crops considerably depended on the extractable As concentration in the soils, particularly with Mehlich 3. All extractable As concentrations in the soils of C. annuum and G. max were significantly correlated with As concentration in their edible parts. For O. sativa, the extractable concentrations of Mehlich 3 ($R^2$: 0.18 at p: 0.006) and EDTA ($R^2$: 0.11 at p: 0.036) showed only marked relationships with As concentration in the edible part. These results may indicate that the Mehlich 3 and EDTA are soil extractants to determine phytoavailable As in soil that provide better prediction for As transfer from soil to crop.

• Korean Journal of Soil Science and Fertilizer
• /
• v.7 no.2
• /
• pp.107-112
• /
• 1974

In order to establish a rational application method of potash to paddy rice(Oryza sativa L. Jinheung, a Japonica variety) field and pot experiments on split application of two rates (6kg and 12kg $K_2O$ per 10a) of potash at a certain critical growing stage have conducted in 1973 and the results were as follows: 1. At the treatment where a rate of 6kg $K_2O$ per 10a(lower dose) of potash was supplied in two split doses, a half at transplanting time and the other half at young panicle formation stage, the yield of paddy rice appeatred to be low due to less number of panicles per hill. (Field experiment) 2. The treatment where potash supply ceased at transplanting time or at effective tillering stage but supplied at the other two stages (including panicle initiation stage) have failed to increase K content in the flag leaf and have shown low maturity and low thousand grain weight, which resulted in low paddy rice yield. (pot experiment) 3. From above two facts, it is concluded that the application of potash at transplanting time is an important practice for the high yielding of paddy rice. 4. The application of lime seemed to stimulate later growth of paddy depressing the unnecessary increase of poor miserable tillers in early stages of growth.