• Journal of Life Science
• /
• v.19 no.7
• /
• pp.839-844
• /
• 2009

This experiment was conducted to evaluate pollen viability of Nakdongbyeo, transgenic rice lines, an F$_1$ hybrid from a cross between Milyang weedy rice and ABC-promoter transgenic rice line containing basta-resistant (bar) gene and subsequent selfed progenies, F$_2$ and F$_3$. The reaction of pollen with 3-{4,5 dimethylthiazolyl-2}-2,5-diphenyl monotetrazolium bromide (MTT) as a staining chemical immediately after pollen shedding showed maximum pollen viability of 86% in Nakdongbeyo, 75% in ABC-promoter transgenic rice line, 62% in ubiquitin-promoter transgenic line, 68% in F$_1$, 79% in F$_2$ and 78% in F$_3$. Viability gradually declined during subsequent observations at 20-minute intervals. However, there was a drastic decline in pollen viability after 40 minutes of pollen shedding. The mean difference of pollen viability among rice lines and time was highly significant, indicating significantly different pollen viabilities at different time intervals. Maximum viability of 36.2% was observed in F$_3$ and minimum viability of 3.5% was found in F$_2$ at 90 min after pollen shedding. Results of this experiment on pollen viability and longevity elucidate potential risks of pollen-mediated flow of herbicide-resistant gene from transgenic rice lines and possible integration of it into the weedy rice population.

• Journal of Life Science
• /
• v.28 no.4
• /
• pp.398-407
• /
• 2018

The Purple pericarp (Prp) trait is a trait often bred for in black rice. Generally, the Prp trait is displayed in the color variations of seeds following the 9:3:4 purple, brown, and white ratio, respectively. The Prp trait is a recessive epistasis of two gene interactions; however, it is caused by the two complementation genes Pb and Pp. Here we present a study of the genetic characteristics of the Prp trait using an $F_1$ hybrid with a Pbpb Pppp genotype. This hybrid generated four seed colors with the following numbers: 3 dark purple, 6 medium purple, 3 brown, and 4 white (or 9 purple, 3 brown, and 4 white). However, further biochemical analysis of the all progenies divided them into two groups. One group had the Pb_ Pp_ allelic constitutions and contained cyanidin 3-O-glucoside (C3G) in both the dark purple or medium purple seeds. The other group, however, was absent of C3G in both the brown and white seeds, resulting in a ratio of 9:7, respectively. This segregation revealed the extended Mendelian 9:7 ratios of the complementary gene interactions with a good fitness in ${\chi}^2$ analysis. Further analysis revealed that brown seeds with the Pb_ pppp genotype corresponded with a null C3G, indicating that the Brown pericarp trait in rice is caused by a dominant allele of the Pb gene. Therefore, we conclude that the production of C3G is a main phenotype of the black and purple colored rice in the Prp trait, and it is governed by the complementary gene interactions between Pb and Pp genes.

• Korean journal of applied entomology
• /
• v.32 no.3
• /
• pp.307-316
• /
• 1993

The potential of using GIS in analyzing pest surveillance data was explored. The Spatial Analysis System (SPANS) was used to construct a spatial data base to study pest distributions using pest surveillance data collected from 152 stations in South Korea. The annual spatIal distributions of the striped rice borer(SRB), Chdo suppressalis, showed that high densities started to expand in the early 1980s, reaching a peak in 1988. The pattern change appears to be related to cultivation of japonica and indica-japonica hybrid varieties in South Korea. Japo7l!ca varieties have longer duration resulting in the SRB haVlng more time to mature and hibernate in wmter. The locus of SRB spread appears to be located in the mid-west region near lri, Chun~ Buk Province. High brown planthopper (BPH) populations in South Korea are often related to the early immigration and temperature. The simulated distribution of PPH densities in September using these two factors was compared with the actual distribution obtained using 1990 data. The two density maps corresponded closely excepL for differences in the south eastern valley. By overlaying the simulated map layer with the elevation and rice area maps, more specific BPH risk zones could be identified.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.31 no.1
• /
• pp.74-77
• /
• 1986

The male sterility gene of IR36ms was transferred to four Korean rice cultivars Gayabyeo, Nampungbyeo Sinkwangbyeo and Suweon 296 by five times back crosses. From the BC$_4$F$_2$, the genetic male sterile rices having the backgrounds of the Krean cultivars, Gayabyeo ms, Nampungbyeo ms, Sinkwangbyeo ms and Suweon 296 ms were selected. No differences in number of panicles per hill, number of florets per panicle, heading date and length of panicle, were found between the male sterile lines and their parental cultivars in the four series of male sterile rices. The culm length of the male sterile lines was shorter than that of their parental cultivars in the four male sterile rice. Significant difference in out cross rate was found from the genetic male sterile rices having different back-grounds even though they have the same male sterility gene. The out cross rates of Gayabyeo ms, Nampungbyeo ms, Sinkwangbyeo ms and Suweon 296 ms were 11.5%, 13.1 %, 1.9% and 12.7% respectively. No difference in out cross rate was found on the genetic male sterile plants planted from I 5cm to 90cm from the pollinater.

• Korean Journal of Soil Science and Fertilizer
• /
• v.14 no.4
• /
• pp.195-200
• /
• 1982

Fused phosphate and slag have used as a sources of phosphate and silicate fertilizers. In order to find out effects of these fertilizers on the growth of young rice plants in nursery, relationships between dry matter production and nutrient uptake at different fertilizer application rates were investigated for two rice varieties, Milyang 23 (a Indica-Japonica hybrid) and Akibare (a Japonica). The results were summarized as followers; 1. The maximum dry matter production was obtained at 75-150 kg/10a of fused phospate and 100-200 kg/10a of slag, respectively, however, a some variations between varieties were recognized. 2. The top/root ratio of varieties around 1.0 was proper for healty see dings and this ratio was reached at application of 75 kg/10a of fused phosphate and 200 kg/10a of slag. 3. The efficiency of applied silicate of rice seedlings was higher in fused phosphate than in slag. 4. The growth of seedling was severely retarded when soil pH was increased above 7 by the application of more than 225 kg/10a of fused phospahte and 400 kg/10a of slag.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.40 no.3
• /
• pp.398-405
• /
• 1995

In termperate zone planting rice at different date subjects the crop to different climatic condition. This study aimed at comparison of the change in source-sink relationship of the Japonica(J) and that of Indica Japonica(I$\times$J) type rice cultivars caused by shift of heading date. Two J-and two I$\times$J-type cultivars were made to head on Aug. 16, Aug. 26 and Sep. 5. Percent grain fertility was not changed in response to shift of heading date. Ripening patterns of 4 rice cultivars were similar to sigmoid curve type but when the heading date was delayed to Sep. 5, the form is changed to log type of curve. In J-type, physiological maturity was delayed about 5 day when headed at Sep. 5, in compare to headed at Aug. 16 and Aug. 26. However ripening was continued about 10 days when the diurnal, nocturnal and minimum temperature was above 17, 12$^{\circ}C$ and about 3~8$^{\circ}C$. In I$\times$J hybrid, real ripening was continued when the diurnal, nocturnal and minimum temperature was over 20, 17$^{\circ}C$, but if the minimum temperature was downed bellow 1$0^{\circ}C$, it was impossible. Simulated photosynthetic amount based on photosynthetic ability, temperature, leaf area and day length was varied according to changes in heading date and it was decreased seriously if the minimum temperature was fall down bellow 4$^{\circ}C$ in field, that's why decrease in photosynthetic ability and aging. The temperature range of optimum ripening was 21~26$^{\circ}C$, if there is nothing hindering factor.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.30 no.4
• /
• pp.427-430
• /
• 1985

Extrusion degree of stigma, numbers of opened florets at different time during anthesis, angle of opening florets and outcrossed seed set percent were investigated in four male sterile rices having background of Korean cultivars; Suwon 296A, Suwon 304A, Suwon 310A and Suwon 296GMS, and the Chinese cytoplasmic genetic male sterile rice Zhenshan 97A as control in order to get basic informations for hybrid rice breeding. The results obtained were summarized as follows; Extrusion degree of stigma in the four Korean male sterile lines tested was lower than in the Chinese one Zhenshan 97A. The better extrusion of stigma showed the higher outcross rate in male sterile rices. There were almost no relationships between peak of anthesis and outcrossed seed set in the male sterile rices tested. Large anthesis angle with long anthesis duration appeared to be essential for high outcrossed seed set of the male sterile rices. The genetic male sterile line showed the larger anthesis angle than the cytoplasmic and genetic male sterile one in the lines having the same background to the Korean rice cultivar Suwon 296.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.20
• /
• pp.27-62
• /
• 1975

These studies were aimed at clarifying whether or not selecting agronomic characteristics of hybrid-rice populations under greenhouse conditions was useful. The selection of two quantitative characteristics, culm length and heading date, and two qualitative characteristics, shattering and awnedness, was very effective, but the flag leaf length and the exsertion of panicle was not consistent, varying from one cross to another.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.2 no.3
• /
• pp.18-24
• /
• 1999

This study was aimed to develope appropriate soil media for the growth of Rhododendron hybrid $J_{ASANHONG}$ on the artificial ground five types of soil media was tested such as "sandy loam-general soil (T1)", "vermiculite-artificial soil (T5)", "sandy loam 50% + vermiculite 30% + sand 20% (improved of soil 2-T2)", "sandy loam 50% + carbonized rice hust 30% + sand 20% (improved of soil 3-T3)", "sandy loam 50% + humus sawdust 30% + sand 20% (improved of soil 4-T4)". The result of the research are as follows. 1. Among the type of soil media, the sandy loam(T1) soil type gave the worst effects on growth of above ground parts(height, No. of leaf, width of leaf, No. of flowering, dry weight of upper parts) and under ground parts(dry weight of roots). 2. Vermiculite(T5) showed the highest root growth(dry weight of roots). it seemed to be caused high saturated hydraulic conductivity and porosity. As a result, there is much available space for enabling the root spreads. 3. "sandy loam 50% + vermiculite 30% + sand 20%(improved of soil 2-T2)", "sandy loam 50% + carbonized rice hust 30% + sand 20%(improved of soil 3-T3)" showed good effects on growth of above ground parts and under ground parts compared with sandy 10am(T1) 4. "sandy loam 50% + humus sawdust 30% + sand 20% + (improved of soil 4-T4)" showed the highest effects on growth of above ground parts.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.26 no.2
• /
• pp.137-145
• /
• 1981

Using the milled, blast infected leaves (BIL) as an inoculum source on the screening for the resistance to blast of rice plant was a simple and useful technique. The temperature with high (25^\circ C\sim 35^\circ C) and low (15^\circ C\sim 28^\circ C) and the water stressed or not, was conditioned of to the inoculation with the BIL to the test varieties in seedling stage. In low temperature, most of the varieties were more infected with blast, however the Indica-Japonica hybrids were more infected in high temperature conditions. The water stressed was more infected with blast than the not stressed. The interaction of variety with water stress was not so much as that of variety with temperature. Resistant reaction to blast (BIL) was not affected by the temperature and water stress, but the moderately resistant or susceptible one was much affected by them. Inoculum of BIL was virulent to the newly bred Indica-Japonica hybrid cultivars such as Tongil, Nopung, etc, but not virulent to the Japonica cultivars such as Nongbaek, Jinheung, etc. The discrete, mixed or variable lesions were observed mainly in the moderately resistant or susceptible cultivars such as Kanto 51, Yashiromochi, Ishikari-shiroke, etc.