• Korean Journal of Agricultural Science
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• v.18 no.2
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• pp.93-98
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• 1991

This research was undertaken to clarify derivation of resistance of Japonica type of rice varieties to rice strip virus. 1. The source of resistance to the rice strip virus in rice cultivars of Nagdongbyeo, Hwaseongbyeo, Gwangmyeongbyeo, Yeongdeogbyeo, Dongjinbyeo, Gyehwabyeo, Hwacheongbyeo, Suweon 362, Iri 390, Milyang 64, Milyang 96 and Milyang 101 was derived from rice cultivar of Modan. 2. The resistance of rice cultivars Donghaebyeo, Sinseonchalbyeo, Palgongbyeo, Hwajinbyeo and Somjinbyeo to the rice strip virus was derived from cultivar Milyang 23 and/or Nangdongbyeo. 3. The resistance of cultivars Jinjubyeo, Tamjinbyeo and Yongsanbyeo to the rice strip virus was derived from cultivar HR 769 and/or Milyang 20. 4. The resistance of cultivar Daecheongbyeo to the rice strip virus was deriverl from cultivar Nagdongbyeo and/or HR 769.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.5
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• pp.363-367
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• 2004

The deep irrigation of rice plants brings about some beneficial effects such as reduced tiller production which results in the formation of bigger panicles, prevention of chilling injury, reduced weed growth, etc. The present study was carried out to examine the involvement of ethylene in the suppression of tiller production due to deep water irrigation in rice (cv. Dongjinbyeo). The ethylene production was induced in leaf sheath within 24 hours after the deep water irrigation and has increased even until 30 days after the treatment, recording 4.5-fold increase as compared to the shallow-irrigated rice plants. In the deep water irrigated rice plants, ethylene was accumulated to a high concentration in the air space of submerged leaf sheath as the irrigated water deterred the diffusion of ethylene out of the leaf sheath and ethylene biosynthesis was accelerated by the deep irrigation as well. The ethylene concentration recorded 35-fold increase in the deep-irrigated rice plants for 35 days. The tiller production was reduced significantly by the deep irrigation with water, the tiller bud, especially tertiary tiller bud differentiation being suppressed by the deepwater irrigation treatment, whereas the rice plants deep-irrigated with solutions containing $10^{-5}$ M or $10^{-6}$ M silver thiosulfate (STS), an action inhibitor of ethylene, showed the same or even higher production of tillers than those irrigated shallowly with water. This implies that the ethylene is closely linked with the suppression of tiller production due to deep water irrigation. In conclusion, ethylene, which was induced by hypoxic stress and accumulated in the leaf sheath due to submergence, played a key role in suppressing the tiller production of the deepwater irrigated rice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.1
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• pp.52-60
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• 2004

The optimized in vitro culture system was investigated for improvement of regeneration efficiencies by observing the responses of scutella-derived callus of Korean rice (Oryza sativa L.). Large variations of callus induction (43.9-93.9%) and shoot regeneration (0-88.7%) were observed among the rice cultivars depending on medium. However, shoot regeneration was significantly improved by selected utilization of basal medium, growth regulators, and carbon sources. N6 basal medium was more efficient for embryogenic callus induction than MS or LS basal medium, while MS was superior to N6 for shoot regeneration. The calli of highly regenerative cultivars grew faster and showed higher rates of green tissue formation (GT) and shoot regeneration (SR) and lower rate of callus browning (CB) than those of recalcitrant cultivars. Although a higher level of kinetin stimulated the GT and SR in highly regenerative cultivars, $10\textrm{mgL}^{-1}$ kinetin generally suppressed the GT and SR, while CB was accelerated compared to $2\textrm{mgL}^{-1}$ kinetin. Additional benefits of sorbitol combined with maltose (or sucrose) under $5\textrm{mgL}^{-1}$ kinetin were certainly confirmed on regeneration efficiencies compared to sucrose alone as carbon source and osmotic regulator. This combination showed high rate of GT and SR with multiple shoots while low rate of CB. With MSRK5SM-Pr medium ($5\textrm{mgL}^{-1}$ kinetin, 3% sorbitol, 2% maltose, $500\textrm{mgL}^{-1}$ proline), the regeneration efficiencies of total 17 out of 24 cultivars were practically improved 160% on average compared to MSRK2S ($2\textrm{mgL}^{-1}$ kinetin, 3% sucrose) control medium. Especially, the medium was most effective to the cultivars showing a medium level of regenerability such as Daesanbyeo and Dongjinbyeo and Suwon477, enhancing efficiencies more than 300-600% compared to MSRK2S medium.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.221-225
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• 2002

This study was conducted to identify the effects of slow release fertilizer (LCU) on ridge direct seeding on dry paddy of rice as an irrigation water-saying cultural system. During 1999-2000, a series of experiments was carried out at field (Chonbuk series) of the National Honam Agricultural Experiment Station, RDA using Dongjinbyeo. Plant height and culm length during the total growth duration were the longest and panicle umber per $m^2$ was the highest in 100% LCU application rate. Leaf area index and top dry weight were the highest in the 100% LCU application rate. They increased as more LCU was applied. Nitrogen uptake was the highest in 100% LCU application, and N use efficiency was the highest in LCU 60% + FP (fertilization at panicle formation stage) 20% application. Milled rice yield was 7% higher in 100% LCU application rate than that of conventional N application. Ripened grain rate and 1,000-grain weight of brown rice did not differ, but panicle number per $m^2$ and grain number per m2 were the highest at 100% LCU application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.48-54
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• 1987

To search for the optimal nitrogen application method for the machine transplanting to Dongjinbyeo, compared to conventional method, in the various methods of nitrogen split application at different growth stages of rice plant. This experiment was performed at Honam Crop Experiment Station, in 1985 year. The results were as followed; the nitrogen contents of leaf blade was the highest at maximum tillering stage under the conventional method and reduction division stage under the nitrogen top-dressing at panicle initiation and 5 times split application of nitrogen for the whole rice growth stages. CGR, RGR and NAR after heading was highest under 5 times split application of nitrogen for the whole rice growth stages. Relationships between CGR and NAR, NAR and RGR, CGR and RGR showed the positive correlation significantly at each rice growth stage, respectively, and showed more high correlation according to further rice growth stages. The degree of contribution of CGR to rice grain yield was the highest at 20 days after heading. Rice grail: yield was higher under top-dressing of nitrogen at panicle initiation and basal application (30%) + 4 times equal dispensing top-dressing after basal application of nitrogen than conventional method.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.441-445
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• 2000

In order to improve phosphate use efficiency of rice using phosphate transporter (PT), transgenic rice plants containing a tobacco PT gene were developed. Calli from Dongjinbyeo (Oryza sativa L.) were cocultured with A. tumefaciens LBA 4404 harboring PT gene. Multiplied calli were transferred to MS medium supplemented with 50 mg/L hygromycin, 500 mg/L carbenicillin, 2 mg/L kinetin, 0.1 mg/L NAA. After 2 weeks, hygromycin resistant shoots were obtained from the calli on the selection medium. The putative transgenic shoots were transferred to rooting MS medium supplemented with 250 mg/L cabenicillin. Plant regeneration rate from the calli was about 52%. Stable incorporation of the tobacco PT gene into rice genomic DNA was confirmed by PCR and Southern blot analysis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.106-111
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• 1999

To investigate the effects of planting density and nitrogen level on growth and yield potential of newly bred heavy panicle japonica rice with large grain (Iksan 435 and Iksan 438) or many spikelets per panicle(HR14022-21-8-4 and HR14022-21-8-6), four heavy panicle type rices and two many panicle type rices(Dongjinbyeo and Donganbyeo) as the checks were planted under standard planting density (30$\times$15 cm) and dense planting density (15$\times$15 cm) with two nitrogen levels of standard nitrogen level(110 kg h $a^{-1}$) and heavy nitrogen level(165 kg h $a^{-1}$). Effective tiller rate decreased in dense planting or heavy nitrogen, when compared to standard nitrogen and planting, while leaf area index and to dry weight increased in dense planting or heavy nitrogen. Tiller numbers and panicle numbers were more increased by dense planting than heavy nitrogen, whereas spikelet numbers were more increased by heavy nitrogen than dense planting. Ripened grain ratio was slightly lower only in dense planting. 1,000 grain weight in brown rice was not significantly different in dense planting or heavy nitrogen. Milled rice yield was highest in heavy nitrogen with standard planting for heavy panicle type rice, while yield for many panicle type rice was highest in heavy nitrogen with dense planting, suggesting that many panicle type rice possesses higher adapt-ability for dense planting than heavy panicle type rice. Path coefficient analysis revealed that top dry weight, spikelet number and grain weight were the greatest positive contributors to yield, whereas tiller number was negative to yield.d.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.122-128
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• 1999

Three rice cultivars, Namweonbyeo (early maturing), Hwaseongbyeo (medium maturing) and Dongjinbyeo (medium-late maturing) were trans-planted with 3 different seedling ages to investigate their growth habits and to improve the cultural method in paddy fields in the southern plain area of the Honam region in 1993. The 10-day old seedlings had more vigorous elongation of plant height and higher tillering ability but lower effective tiller rate, when compared with 35-day or 40-day old seedlings. Leaf area index and top dry weight were lower in 10-day old seedlings up to 40 days after transplanting but thereafter, were not different among seedlings ages. CGR was later in 10-day old seedlings, up to 30 days after transplanting, but in 30 to 40 days after transplanting, it was reversed. RGR was the highest in infant seedlings to 40 days after trans-planting, while in 50 days after transplanting, it was reversed. Panicle number and spikelet number per square meter were the highest in 40-day old seedlings, next highest in 35-day old seedlings and the lowest and in adult seedlings up to 40 days after transplanting, while spikelet number per panicle was vice versa. Milled rice yield did not vary significantly by seedling ages, but among the varieties, it was less in Hwaseongbyeo compared with Naweonbyeo and Dongjnbyeo.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.143-148
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• 1999

Soil moisture condition is an important limiting factor in growth and yield in rice culture. The purpose of this study was to compare the influence on the growth, yield and Quality of rice subjected to soil moisture stress (SMS) at different growth stages. Ajaponica rice cultivar, Dongjinbyeo, was cultured under flooded conditions in a plastic container filled with silty loam soil. The container was subjected to SMS until the initial wilting point (IWP) coincided with about 10% in soil moisture content and about-200 kPa in soil matric potential, and was then irrigated again, at 6 and 5 of main growth stage in 1996 and 1997, respectively. At maturity, the plant height, tiller number, leaf area and top dry weight were decreased more in SMS treatments at the early stage than the late stage. The averaged yield index of SMS to control in both years was lowest at meiosis (62.5%), which primarily resulted from lower percent ripened grain and 1,000 grain weight, and second＇ reduced the spikelet number per panicle and panicle number per hill, and followed at tillering stage (68.5%) which resulted from the lower production in tiller number and top dry matter during and after SMS treatment. The percent-age of read rice in SMS plants varied with the treatment stage as order of lower at meiosis (44.0%), heading (53.9%), panicle initiation (70.1%), tillering (72.1%), ripening (75.8%) and 5 days after transplanting (DAT) (79.0%). Protein content in brown rice was slightly larger in SMS at late growth stage than the control, while the contents of fat and ash differed very little between SMS and control. Contents of Mg and K and Mg/K in brown rice with SMS were lower at some treatment stages such as at ripening or panicle initiation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.149-153
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• 1999

Prediction of rice developmental stage is necessary for proper crop management and a prerequisite for growth simulation as well. The objectives of the present study were to find out the relationship between the plastochrone index(PI) and the developmental index(DVI) estimated by non-parametric phenology model which simulates the duration from seedling emergence(DVI=0) to heading(DVI=l) by employing daily mean air temperature and daylength as predictor variables, and to confirm the correspondency of developmental indice to panicle developmental stages based on this relationship. Four japonica rice cultivars, Kwanakbyeo, Sangpungbyeo, Dongjinbyeo, and Palgumbyeo which range from very early to very late in maturity, were grown by sowing directly in dry paddy field five times at an interval of two weeks. Data for seedling emergence, leaf appearance, differentiation stage of primary rachis branch and heading were collected. The non-parametric phenology model predicted well the duration from seedling emergence to heading with errors of less than three days in all sowings and cultivars. PI was calculated for every leaf appearance and related to the developmental index estimated for corresponding PI. The stepwise polynomial analysis produced highly significant square-rooted cubic or biquadratic equations depending on cultivars, and highly significant square-rooted biquadratic equation for pooled data across cultivars without any considerable reduction in accuracy compared to that for each cultivar. To confirm the applicability of this equation in predicting the panicle developmental stage, DVI at differentiation stage of primary rachis branch primordium was calculated by substituting PI with 82 corresponding to this stage, and the duration reaching this DVI from seedling emergence was estimated. The estimated duration revealed a good agreement with that observed in all sowings and cultivars. The deviations between the estimated and the observed were not greater than three days, and significant difference in accuracy was not found for predicting this developmental stage between those equations derived for each cultivar and for pooled data across all cultivars tested.