• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.86-94
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• 1999

A set of rice recombinant inbred lines was developed from a cross between a Tongil type variety, Nonganbyeo, and an indica variety, BG276, by the single seed descent method. The number of the lines in the population was 272. All the agronomic characters studied except ADV (alkali-digestion value) showed continuous variation among the RILs, implying that their inheritance mode should be quantitative. The patterns of the variation in the RILs were either normal or skewed distribution. ADVs of RILs were segregated into two groups with 1:1 ratio, indicating that ADVs in this KIL population might be controlled by one major gene. Transgressive variations were also observed in all characters. Heritability values of the characters varied from 0.488 in brown/rough rice ratio to 0.895 in alkali-digestion value. In the analysis of genotypic and phenotypic correlations, the character of yield was positively correlated with 8 different agronomic characters. The number of panicles per hill was negatively correlated with culm length, panicle length, and number of spikelets per panicle. Grain length was positively correlated with grain width, grain thickness, grain length/width ratio, white belly, ADV, and amylose. However, grain length/width ratio was negatively correlated with grain width. White core was also negatively correlated with white belly and ADV.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.3
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• pp.244-249
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• 1992

To investigate the varietal variations in absolute density of milled rice grain and its relations with other grain characters, the 235 rice varieties which consist of 30 Tongil type rices, 72 Japonica rices and 133 Indica rices were tested on grain size, volume, hardness, chalkiness and 1000 grains weight of brown rice, ADV, amylose content, starch composition on SEM and absolute density of milled rice grain using completely ripened grains. Average absolute density of milled rice grain was 1.496g / cm$^3$ in Tongil type rices, 1.506g / em in Japonica rices, and 1.500g / cm$^3$ in Indica rices. It was correlated positively with days to heading and grain hardness, and negatively with chalkiness, volume, grain weight and grain length of brown rice. Regression analysis indicated that grain volume and weight were the major characters affecting the density. However, since the absolute density of milled rice grain did not show great varietal variations it might not seem important as one of the characters contributing to the grain yield, while it could be a factor affecting the grain quality because there were definite varietal differences even though small. The microscopic feature of starch composition on SEM revealed differences between clear and chalky parts of the grain in shape and compactness of starch composition but did not discriminate between high and low-density grains.

• Journal of Life Science
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• v.20 no.1
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• pp.22-26
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• 2010

Seven rice germplasms with red pigmentation within the pericarp were isolated from a large mutant collection. These red pericarp phenotypes resulted from the functions of the Rc, Rd and RdRc genes. Among them, two brown pericarp of the Rc type, four red pericarp of the RdRc type, and one white pericarp of the Rd type were identified. Morphological and agronomic characteristics of those rice germplasms were studied. The Rc type germplasms have the faint red or brown color pericarp and the Rd types produce the white pericarp, whereas the RdRc type germplasms have the dark red pericarp. Most of the important agronomic characteristics including plant stature, tillering ability, spikelet fertility, and total grain yield were lower in the colored rice than those of the wild-type control. All of the studied colored rice germplasms had a tendency of easy seed-shattering in comparison to the control. These characteristics of newly identified germplasms will be useful for identifying the genes responsible for pericarp color phenotype determination.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.118-118
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• 2017

A high-resolution physical map targeting a cluster of yield-related QTLs on the long arm of rice chromosome 9 was constructed across a 35.5kb region containing the six predicted genes including the probable ascorbate peroxidase (OsApx). The $BC_3F_6$ near isogenic lines (NILs) were derived from a cross between the Oryza sativa Hwaseong and O. rufipogon. The plant height and length of internodes were compared between Hwaseong and NILs. There were significant differences in plant height between Hwaseong and NILs. The NILs internodes were longer than Hwaseong, showing dramatic elongation in the first and fourth internodes; thereby, leading to increased plant height. The antioxidant activity of Hwaseong and NILs was also analyzed by 3,3-diaminobenzidine (DAB) staining and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. In order to understand whether or not OsApx gene is important in scavenging $H_2O_2$ in rice, DAB staining was used. Intense dark-brown coloration was observed in Hwaseong than NILs. In addition, DPPH scavenging ability of Hwaseong showed lower value than NILs. These results indicated that the internode elongation and antioxidant activity might possibly be controlled by OsApx. To know the causative relationship of the gene and phenotype, we will further analyze the gene expression and use it for functional studies by complementation transgenic approach.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.165-175
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• 2019

In response to elevated temperature, a shift in the rice planting period was proposed as a promising option in temperate regions. To understand the yield response of early maturing rice to different transplanting dates and to analyze the related agronomic traits in the central plain area, we performed a two-year study using different transplanting dates and six varieties in Suwon, Korea. The maximum head rice weight was achieved in the treatments transplanted between June 14 and 29, depending upon the varieties. The optimal mean temperature during the 40 days from heading stage for attaining the maximum head rice weight was $21.8^{\circ}C$ on the average of six varieties. The index of head rice weight was positively correlated with the indices of both the milled rice weight and head rice percentage, the latter showing a higher coefficient of determination. The highest milled rice weight was commonly achieved from the treatment transplanted on June 29, where the head rice weight was also the highest. The index of milled rice weight was significantly correlated with the indices of grain filling percentage and number of spikelets per area, but not correlated with the index of 1000-brown rice weight. The transplanting date with the highest milled rice yield produced the largest number of spikelets per area, greatest biomass at the heading and harvesting stages, and highest level of harvest index. We suggest that the optimal transplanting date for early maturing rice varieties in the central plain area is from June 14 to 29. High head rice yield in this study was attributed to increased spikelets owing to the increased biomass production at the heading stage, enhanced grain filling due to the high biomass production and harvest index at maturity, and improved head rice percentage.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.3
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• pp.156-164
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• 2004

This study was conducted to evaluate the effect of the application of green manure in the form of either green barley and Chinese milkvetch in reducing the amounts of N fertilizers and conventional fertilizers needed for paddy rice. Prior to rice transplanting, the green barley and Chinese milkvetch as a green manure produced respectively $668kg\;10a^{-1}$ and 3,492kg\;$10a^{-1}$ in fresh shoot weight basis. Calculated nitrogen content from harvested green manures was 3.9 and $17.8kg\;10a^{-1}$, respectively. Plant height and tiller number of rice increased when two kinds of green manure incorporated into soil. Above mentioned parameters also increased with increasing amounts of N fertilizers at both ear formation and heading stage of rice. Rice grain number was not affected by green manures treatment but increased when N fertilizers were applied. Although rice panicle and grain number increased with green manure treatments and fertilizer applications, whereas the percentage of ripened grain decreased. Chinese milkvetch with additional N fertilizer applications increased brown rice yield from 1 to 5% compared to rice yields in plots where non-green manure with the conventional amount of fertilizer application was applied. Rice treated with Chinese milkvetch and 30% of the conventional N fertilizer rate yielded the same as rice fertilized conventionally. During the rice growing season, $NH_4-N$ content of paddy soil was higher in green manures treatment than non-green manure one. Average $NH_4-N$ content in paddy soil drastically decreased after heading stage below $5.7mg\;kg^{-1}$ in non-green manure treated plots. While on the other, $NH_4-N$ content in soil slowly decreased in plots those were treated with green manures at harvesting stage, average $NH_4-N$ content was still greater than $5.5mg\;kg^{-1}$. Nitrogen content of rice shoot and brown rice seed was higher in green manure treatment.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.4
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• pp.327-333
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• 1995

The sludge application increased the panicle number per plant and number of spikelets per panicle, resulting in an increase in yield by 10% at Cheongdo, 15% at Chinju and 7% at Yeocheon. With the sludge application (3% w/w), $SiO_2$ content of brown rice was significantly increased. The sludge aplied up to 34.8 ton per hectare increased pH, calcium, and potassium in paddy soils, the application of the sludge to reclaimed saline soil at Yeocheon needs to be reevaluated since the sludge increased soil pH to 7.2 and aggravated drainage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.1
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• pp.1-8
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• 1976

Two paddy rices and two upland rices were cultivated both in the paddy-field and in the upland in order to find out the effects of the different cultural environments on the growth and yield of the four varieties. Three plots (standard fertilizer without irrigation, standard fertilizer with irrigation and nitrogen-increased fertilizer with irrigation) were set in the upland and one plot (standard fertilizer with conventional water control) was set in the paddy-field. The weight of brown rice of paddy rices was higher in the paddy-field than in the upland, while that of upland rices was higher in the upland. The heading-date of paddy rices was later about a week in the upland than in the paddy-field. The maturity ratio and the weight of 1, 000 grains of upland were higher and heavier than those of paddy rices in both cultural conditions. The results show that it is very desirable for the culture of paddy rices to be cultivated under the upland condition, on the view point of its yield and quality compared with those of upland rices.

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.3
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• pp.150-155
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• 2001

The hull dehydration in dough stage did not serious affect the rice yield though grain appearance texture may decline by severe occurrence of the symptom. As to white head in heading stage of rice, the occurrence of hull dehydration in 1998 was directly affected by high temperature, low air humidity and sometimes of strong wind and sunshine in early September. At harvest stage, 1,000-grain weight of brown rice was not found to be significantly different between the hull dehydrated grains and normal ones. That reason can be considered that the hull dehydration occurred hill was not injured on the leaf and rachis branches therefore the function of assimilation and translation of rice plant was not affected. The ratio of imperfect rice kernel such as green, cracked and white belly increased. The increase of cracked rice by the hull dehydration may caused by concurrent dehydration of kernel, or by insufficient water supply into kernel due to breaking of vascular bundles in glume.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.513-518
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• 2011

'Hongjinju', the reddish brown coloured rice variety, was developed by the rice breeding team of National Institute of Crop Science, RDA during the period from 1990 to 2006 and released in 2007. The cultivar was derived from a cross between Suwon 383, and $SR18164F_2$, a reddish brown pigmented line. 'Hongjinju' is medium maturity with 133 days of growth duration from seeding to heading and is japonica-type with about 82 cm in culm length. 'Hongjinju' has slightly less number of tillers per hill and more spikelets of panicles than those of 'Heugjinjubyeo'. It is susceptible to leaf blast, other disease and insect pests. It shows intermediate germination ratio at low temperature and similar tolerance to leaf discolor at seeding stage and heading-delay but it is resistant to spikelets-sterility type of cold damage at maturing stage compared with 'Heugjinjubyeo'. The yield performance of this variety in brown rice is about 5.07 MT/ha and is adaptable to the central and southern plain areas of Korea.