• Applied Biological Chemistry
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• v.36 no.6
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• pp.533-538
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• 1993

The Wx protein, known as starch synthase or starch glucosyl transferase (E.C. 2.4.1.11), is responsible for the amylose synthesis. In an effort to explain the mechanism of amylose biosynthesis, the starch synthase known as Wx protein was identified by analyzing the various wx rice mutants with SDS-PAGE of proteins extracted from rice starch. Finally, the 66 kDa protein was purified by extracting the starch-bound protein fractions followed by Suprose 12 gel filtration chromatography.

• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.121-125
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• 1997

A total of 437 landraces of rice from Vietnam were analyzed for total seed protein by SDS-PAGE and phenol reaction. The different types of glutelin $\alpha$ subunits were detected. The level of wx protein with 60kDa molecular weight was divided into 3 groups, corresponding to non-glutinous, intermediate and glutinous starch types. Based on the variation in seed storage protein and wx protein, landraces were classified into 7 groups. Frequency distribution of types A and B of glutelin $\alpha$ subunits changed with the latitude at which rice landraces were collected. Geographical cline for phenol reaction was detected.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.1
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• pp.83-109
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• 1977

Isogenic lines for glabrous leaf (gl), hull color(gh) and glutinous endosperm (wx) were used to clarify the effects of the gl, gh and wx gene on the grain yield and yield components in rice plant. Eight genotypes: glgl ghgh wxwx, glgl ghgh WxWx, glgl GH-wxwx, glgl GH-WxWx, GL-ghgh wxwx, GL-ghgh WxWx, GL-GH-wxwx and GL-GH-WxWx were evalutated in the backcrossed $F_2$ generation. Significant effects were measured for gl genotypes on heading date, gh genotypes on grain fertility, and wxwx genotypes on number of panicles per hill and 1, 000 grain weight. The grain yield of straw hull and non glutinous lines were higher than gold hull and glutinous lines. The interaction of three genes, gl, gh and wx was significant for heading date, but not significant in other characters. The average value of isogenic lines which were combined with two recessive genes and one dominant gene were lower and the C.V. value was higher than the isogenic lines which were combined with two dominant genes and one recessive gene in all characters except plant height and number of grains per plant. The average value of isogenic line combined with three recessive genes was lower and the C.V. was higher than the isogenic line combined three dominant genes in all characters measured.

• Korean Journal of Breeding Science
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• v.42 no.2
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• pp.151-156
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• 2010

The mutants of sugary-2 (su-2), floury (flo), shrunken-1 (shr-1), and dull-1 (du-1) were crossed to waxy (wx) to produce $F_2$ seeds. Chi-square analysis on the segregating ratio of the $F_2$ seeds revealed that flo, su-2, and shr-1 were independently transmitted with wx, while wx was epistatic over du-1. The floury and sugary-2 were crossed to Hwasunchalbyeo, a waxy variety, and then the $F_4$ of floury-waxy and sugary-2-waxy seeds were developed, respectively. As the parents phenotypes of sugary-2 and floury, the grains of these two lines showed lower hardness and grain weight than normal grain of Hwacheongbyeo. For alkali digestive value (AVD), the sugary-2-waxy showed lower ADV than Hwacheongbyeo. For the gel consistency of grain flours, the floury was medium like Hwacheongbyeo, while those of the sugary-2, floury-waxy, and sugary-2-waxy were soft like Hwasunchalbyeo. The amylose contents in the grains of the sugary-2 and floury were decreased to ~15% whereas that of Hwacheongbyeo was 19.1%. All the lines showing waxy endosperm (Hwasunchalbyeo, floury-waxy, and sugary-2-waxy) showed less than 4% amylose contents. Interestingly, the free sugar content in the brown rice was increased to 9.27% in the sugary-2-waxy, showing transgressive segregation phenomenon where the free sugar contents in its parents, sugary-2 and Hwasunchalbyeo, were 5.98% and 3.98% respectively. Also, the floury-waxy showed transgressive segregation phenomenon, containing 6.15% of free sugar content in the grains.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.19
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• pp.1-6
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• 1975

From the cross Tongil$^2//IR833/IR1317$ glutinouse rice lines wx 126 were bred. Some of these lines were earlier than standard variety and later than glutinous check variety. Some of them yielded as much as standard variety and showed better resostances to blast, stripe deseases and smaller brown plant hopper than standard variety. It was sosscussed that, theough the vreedong procedure, following points were proved, 1)back-cross program in roce breeding was effocoent, 2)semi-dwarf plant type of "Tongil" has high yielding poteneoality and 3) the variety "Tongil" was a good for recurrent parent for back-cross program. back-cross program.

• Applied Biological Chemistry
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• v.45 no.4
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• pp.195-202
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• 2002

The cytotoxic, mutagenic and antimutagenic activities against chemical direct mutagens such as mitomycin C, 4-nitroquinoline-N-oxide, 2,4,7-trinitro-9-fluorenone of the 70% ethanol extracts of 29 colored rice varieties and chuchung as a control were examined. The results obtained using authentic alkaline phosphatase activity as a growth representative of the indicator cell E. coli PQ 37 demonstrated that the extracts of 13 kinds of colored rice varieties including Jumlalocal and Jumlalocal-1 showed strong toxic effect on the cell growth. However the extracts of DK 1, SC-5, LK 1A-2-12-1-1 and wx 139-3-64-20-3-1 seemed to have stimulatory effects on the cell growth. The mutagenicity and antimutagenicity of the colored rice varieties were screened using SOS chromotest. The mutagenic activity was detected from Jumalocal-1, IR 17491-5-4-3-3 and Jumlalocal. On the contrary, 7 samples including LK 1-3-6-12-1-1, Parnkhari 203, Jumlalocal, wx 139-3-64-20-3-1, Muthumanikam, HP 883-1-1-1-B-1-1 and Jumlalocal-1 were shown to have antimutagenic acitivities against the chemical direct mutagens used in this study.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.267-267
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• 2022

Glutinous rice is a key grain quality trait occupying an important part during rice processing in most rice growing areas. Amylose content (AC) of rice determine eating quality which is one of the major traits in rice breeding program. In this study, a gene pyramiding approach was used to introduce two dull genes, responsible for low amylose contents, for glutinous rice breeding using marker assisted selection (MAS). Two dull genes were located on chromosome 6 (wx-mq, AC: 12.7 %) and chromosome 10 (du1, AC: 10.3%), respectively. To test whether these two dull genes have an epistatic interaction, we developed an F₂ population by crossing two nearly isogenic lines(NILs) harboring wx-mq and du1. Gene based marker and KASP marker were used to select NILs(NIL-nor, NIL-wxmq, NIL-du1, and NIL-wxmq/du1) from the F2 population. A two-way ANOVA revealed an epistatic interaction between the two genes in the F2 population. The mean of Amylose contents for NIL-nor, NIL-wxwq, NIL-(du1, and NIL-wxmq/du1 were 17.3%, 12.5%, 9.7%, and 7.2%, respectively. This interaction was confirmed by an analysis of NILs indicating that both genes are involved in the same genetic mechanism controlling amylose contents. This result will be useful for rice breeding related to amylose content.

• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.227-232
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• 2008

Drought stress is one of the major abiotic stresses in agriculture worldwide. We report here a proteomic approach to investigate the impact of post-fertilization drought on grain quality in rice seed endosperm (Oryza sativa cv. IR-64). Plants were stressed for 4 days at 3 days before heading. Total proteins of endosperm were extracted and separated by two-dimensional gel electrophoresis. Not many protein spots showed differential accumulation in drought-stressed samples. More than 400 protein spots were reproducibly detected, including three that were up-regulated and five down-regulated. Mass spectrometry analysis and database searching helped us to identify six spots representing different proteins. Functionally, the identified proteins were related to protein synthesis and carbohydrate metabolism, such as Granule-Bound Starch Synthase (GBSS, Wx protein), which is thought to play a very important role in starch biosynthesis and quality, a very crucial factor in determining rice grain quality.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.449-454
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• 1985

In order to search for the semi-dwarf japonica varieties allelic to the semi-dwarf rice cultivar which is controlled by d-t gene, seven dwarf japonica varieties. Reimei, Hoyoku. Shiranui, Kokumasari, M 7. S.224 and S.295 were crossed to the semi-dwarf cultivar, wx 817. wx 817 is known to have semi-dwarf gene d-t. Their F$_1$, F$_2$ and F$_3$ were grown in 1984 and 1985 and culm lengths were measured at harvest. The results are summarized as follows. 1. The F$_2$s of all 7 cross combinations showed normal distribution and no segregation. 2. The range of culm length variation in the F$_3$ was variable depending on the cross combination, but the general pattern was similar in the all 7 crosses. 3. The mean of F$_3$ and parental F$_2$ mean which were selected into short, medium and tall groups were similar and showed no segregation, implying the selection efficiency in F$_2$. 4. From the results of F$_2$ and F$_3$ segregations, it is concluded that the culm length of the 7 semi-dwarf japonicas tested here are controlled by the same major gene d-t although they are modified by different minor genes.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.3
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• pp.233-238
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• 1990

Weedy rice(red rice) collected in Korea were crossed with the Japonica, Javanica and Indica tester cultivars, and also crossed among those collected lines. Their seed fertility was counted and refered to their cross affinities. Some tester cultivars such as, Suweongjo, Malagkit Sinaguing and wx 817 which were regarded as belong to the Japonica, Javanica and Indica respectively, showed the typical tendencies of hybrid sterility when they were crossed each other. But, other testers such as Kwanak, Tapaiko, Belle Patna and Tarichaosun showed some differencies from those typical patterns, implying some varigations within a ecotype. The hybrids of weedy rice crossed to the Japonica testers showed higher fertility with a few semisterilities. While the crosses of weedy rice to the Javanicas or Indicas showed high sterility implying closer affinity relationships of weedy rice to the Japonicas. Even those weedy rice lines such as Samsanmyeon 8 and Sanchungaengmi B which showed semi-sterility when they were crossed to the Japonica testers showed high sterility when they were crossed to both Javanicas and Indicas. The hybrids among weedy rice lines showed high fertility raning 69% to 96%. Even those weedy rice lines which showed semi-sterility in the crosses with Japonica testers, showed high-fertility when they were crossed with those weedy rice lines. Though the amylose content, Alkali Digestive Value, Phenol reaction and grain shapes of theose weedy rice lines showed divers variations, the cross affinities of them showed closer phylogenie relationship to the Japonicas than to Japvanicas or Indicas. But the genetic influinces of Indicas to those weedy rices were not ignorable.