• Mycobiology
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• v.46 no.4
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• pp.361-369
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• 2018

The rice blast fungus, Magnaporthe oryzae, is an important pathogen of rice plants. It is well known that genes encoded in the genome have different evolutionary histories that are related to their functions. Phylostratigraphy is a method that correlates the evolutionary origin of genes with evolutionary transitions. Here we applied phylostratigraphy to partition total gene content of M. oryzae into distinct classes (phylostrata), which we designated PS1 to PS7, based on estimation of their emergence time. Genes in individual phylostrata did not show significant biases in their global distribution among seven chromosomes, but at the local level, clustering of genes belonging to the same phylostratum was observed. Our phylostrata-wide analysis of genes revealed that genes in the same phylostratum tend to be similar in many physical and functional characteristics such as gene length and structure, GC contents, codon adaptation index, and level of transcription, which correlates with biological functions in evolutionary context. We also found that a significant proportion of genes in the genome are orphans, for which no orthologs can be detected in the database. Among them, we narrowed down to seven orphan genes having transcriptional and translational evidences, and showed that one of them is implicated in asexual reproduction and virulence, suggesting ongoing evolution in this fungus through lineage-specific genes. Our results provide genomic basis for linking functions of pathogenicity factors and gene emergence time.

• Korean Journal of Community Nutrition
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• v.26 no.4
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• pp.296-306
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• 2021

Objectives: The objective of this study was to estimate the distribution of the usual dietary intake of foods with respect to the probability of consumption derived from the Food Frequency Questionnaire (FFQ) of the 2009 Korea National Health and Nutrition Examination Survey (KNHANES). Methods: The intake quantity and frequency of 63 food items were assessed from the 2009 KNHANES which was completed by 7,708 participants. The participants completed one or two 24-h dietary recalls and one FFQ. The usual intake distribution was estimated using the multiple source method (MSM), and the proportion of non-consumers was calculated through the usual intake distribution. This was then compared with the proportion of non-consumers from the 24-hour recall method. Results: The difference in the proportion of non-consumers ranged from 2% to 82.9%, indicating that there is a very large difference based on food groups. The food groups in which the proportion of non-consumers did not differ was composed of foods consumed daily, such as 'rice', 'cereal and barley', and 'Chinese cabbage and kimchi', or foods with distinct palatability such as 'coffee' and 'alcohol'. On the other hand, in the case of the food groups with a high difference in the proportion of non-consumers, most comprised fruits that emphasized seasonality. Conclusions: In the case of foods or food groups that are occasionally consumed, it is desirable to use 2 recalls with additional FFQ data by combining the consumption frequency and the quantity consumed.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.455-460
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• 2020

Rice grain damage caused by Paromius exiguus under various conditions in paddy fields was analyzed. One nymph of P. exiguus caused 2.7 pecky grains in brown rice in one day, and sixteen nymphs caused 132.3 pecky grains over sixteen days. The relationship between the inoculated nymphal density and the number of pecky grains was well described by a linear regression (Y = 8.8446X, r2 = 0.9622). When a pair of P. exiguus adults was inoculated in the heading stage of rice, the damage at the time of harvesting consisted of 40.2% of cracked rice and 30.5% of pecky rice among whole rice grains. Inoculation of 16 pairs resulted in 81.7% of cracked rice and 74.5% of pecky rice. The damage analysis indicated that the quantity of ripened rice decreased as the damage started earlier in the heading stage of rice. On the contrary, the proportion of cracked and pecky rice rapidly increased from the heading time until 28 days after heading of the rice grains.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.212-212
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• 2022

Soluble starch synthase (SS) IV-2 is one of the starch synthase gene family members and responsible for starch chain elongation interacting with other rice eating and cooking quality controlling genes (e.g., AGPlar and PUL). SSIV-2 is mainly expressed in leaves, especially at grain-filling stage and its alleles can significantly affect rice quality. Here, we investigated the genetic diversity and population structure analyses of SSIV-2 gene by using 374 rice accessions. This rice set was grouped into 320 cultivated bred (subsequently classified into temperate japonica, indica, tropical japonica, aus, aromatic and admixture) and 54 wild rice. Haplotyping of cultivated rice accessions provided a total of 7 haplotypes, and only three haplotypes are functional indicating four substituted SNPs in two exons of chromosome 5: T/A and G/T in exon 4, and C/G and G/A in exon 13. Including the wild, a highest diverse group (0.0041), nucleotide diversity analysis showed temperate japonica (0.0001) had a lowest diversity value indicating the origin information of this gene evolution. Higher and positive Tajima5s D value of indica (1.9755) indicate a selective signature under balancing selection while temperate japonica (-0.9018) was in lowest Tajima's D value due to a recent selective sweep by positive selection. We found the most diverse genetic components of the wild in PCA but shared in some portion with other cultivated groups. Fixation index (F_ST-values) and phylogenetic analysis indicate a closer relationship of the wild with indica (F_ST=0.256) than to its association to both of temperate japonica (F_ST=0.589). Structure analysis shows a clear separation of cultivated subpopulations at every K value, but genetic components were admixed within the wild illustrating the same genetic background with japonica and indica in some proportion.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.3
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• pp.130-136
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• 1981

Rice hull was reduced to ash by carbonization grades to illcuidate alkalinity increase and extract of inorganic nutrients in the rice hull charcoal. Alkaline reaction of water extraction was neutral at less carbonized charcoal, but much carbonized ash from 65% weight loss reached over 10 of pH value, also origin shape of rice hull was maintained until near 65% carbonized grade. Therefore, physical properties sustained good condition for seedling bed. The more charcoal carbonized to ash, the pH value and concentration of inorganic nutrient in their extracts were increased gradually. Nitric acid concentrations for neutralizing extract from charcoal were stronger in proportion to the carbonized grade but 0.1 N nitric acid solution was very reasonable to neutralize the 65% carbonized charcoal for mixing with heavy texture acidy soil(pH 5.3) of uncultivated deep horizon to transplant the tobacco seedlings. Volume ratio mixing for seedling bed is adequate at five of ash to one of acid solution. Neutralization with nitric acid solution also accelerated extraction of the inorganic nutrient in rice hull ash. Tobacco seedlings grown on bed mixed with neutralized rice hull charcoal and soil had shown better results on the agronomic measurement than alkaline ash bed, and phosphorus and cations were uptaken more amounts.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1435-1440
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• 2008

An experiment was carried out to investigate whether a local breed of cattle is better adapted than European breed crosses to low quality feeds and to variations in their supply. Four Red Chittagong (RC) and four Holstein cross Sahiwal (Hx) cattle were used to compare the intake and digestibility of German grass (Echinocloa crusgalli) and rice straw with four regimes of feed supply. These were; a choice of German grass and rice straw each offered ad libitum on the same day (A); German grass and rice straw offered ad libitum on alternate days (B); rice straw offered ad libitum for 5 days followed by German grass ad libitum for 5 days (C); and German grass offered ad libitum for 5 days followed by rice straw ad libitum for 5 days (D). Each breed was offered the treatments in a $4{\times}4$ Latin Square design. The German grass intake and total dry matter intake per kg metabolic live weight were significantly higher for the Hx than for RC, but there were no significant effects of genotype on digestibility of nutrients or live weight. Treatment A had the highest proportion of German grass relative to rice straw in the total DM intake, and had the highest total DM intake and apparent digestibility of nutrients compared with treatments B, C and D. It was concluded that there was no significant evidence that the RG cattle were better adapted to a variable supply of low quality feed than Hx cattle, and that the variable feed supply reduced the ability of cattle to select a preferred diet and consequently nutrient intake was depressed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.1 no.1
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• pp.1-4
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• 1972

The following is the result of feeding ad libitum the Wistar strain rats (male) divided into 4 groups-(a) casein group, (b) rice diet group, (c) diet group with a mixture of 80% rice and 20% buckwheat and (d) diet group of equal nitrogen levels of rice and buckwheat. Compared with the control group, the diet group given a mixture of 80% rice and 20% buckwheat put on weight slower, but quiker than the rest two. Particulariy after 10 days it was found to gain greater weight. Therefore, the discovery is that as proved by theory such a mixed food with a proportion of 20% buckwheat and 80% rice can improve the protein score even in the experiment of feeding animals.

• The Korean Journal of Food And Nutrition
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• v.23 no.1
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• pp.70-75
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• 2010

This study was conducted to determine the influence of culture conditions such as temperature, time, water content, koji-thickness and agitation on the production of organic acid by Rhizopus sp. ZB9 isolated from Korean Nuruk during the preparation of rice koji, which is used in brewing the Korean rice wines, Takju and Yakju. Rice koji was made under different culture conditions, and the acidity of each koji was tested. The temperature range suitable for the production of organic acid was $28{\sim}32^{\circ}C$, and 36~48 hours of cultivation at that temperature range seemed to produce the optimum results. The production of organic acid increased in proportion to the increase in water content of steamed rice from 25% to 60%. An increase in koji-thickness induced no adverse effects on the production of organic acid, and agitation-work during cultivation showed very beneficial effects.

• The Korean Journal of Food And Nutrition
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• v.23 no.3
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• pp.399-404
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• 2010

This study was conducted to determine the influence of culture conditions such as temperature, time, water content, koji-thickness, and agitation on the production of protease by Rhizopus sp. ZB9, isolated from Korean Nuruk, during the preparation of rice koji, which is used in brewing the Korean rice wines, Takju and Yakju. Rice koji was made under different culture conditions, and the proteolytic activity of each koji was tested. The temperature range suitable for the production of protease was $28~32^{\circ}C$. Based on the protease and color, 60 hours of cultivation at $28^{\circ}C$ was shown to produce optimum results. The production of protease increased in proportion to the increase in water content of steamed rice from 25% to 35%. An increase in koji-thickness induced no adverse effects on the production of protease, and agitation during cultivation showed beneficial effects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1742-1748
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• 2014

This study investigated the quality characteristics of commercial rice flour (CRF) and rice flours prepared by different milling methods for sulgidduk. For particle distribution, dried rice flour after the 1st roll mill using a pin mill showed a particle size of greater than $710{\mu}m$, whereas a particle size less than $250{\mu}m$ accounted for 48% of whole rice flour. This proportion was higher than CRF after the 2nd step roll mill. Crude protein, lipid, and ash contents were significantly highest in 1st roll mill samples. For color, roll & pin made up of many small particles showed a high L value. CRF and roll & pin showed significantly higher starch damage and water-holding capacity, whereas pasting temperature, peak viscosity, and setback of RVA pasting characteristics were lower than 1st roll mill. When rice cakes were made from three kinds of rice flour, roll & pin was not significantly different compared to the CRF. However, rice cakes made with 1st roll milled rice flour showed rough crumb and crust. Rice cake made with roll & pin or CRF showed similar characteristics for texture. In the quantitative descriptive analysis, rice cake made with roll & pin showed better appearance, flavor, taste, texture, and overall acceptability than CRF and 1st roll mill. Therefore, rice flour prepared by roll & pin could be applied to sulgidduk with high quality.