• Journal of Crop Science and Biotechnology
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• v.10 no.4
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• pp.265-276
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• 2007

The 13 major blast resistance(R) genes against Magnaporthe grisea were screened in a number of Korean rice varieties using molecular markers. Of the 98 rice varieties tested, 28 were found to contain the Pia gene originating from Japanese japonica rice genotypes. The Pib gene from BL1 and BL7 was incorporated into 39 Korean japonica varieties, whereas this same gene from the IRRI-bred indica varieties was detected in all Tongil-type varieties. We also found that 17 of the japonica varieties contained the Pii gene. The Pii gene in Korean rice varieties originates from the Korean japonica variety Nongbaeg, and Japanese japonica varieties Hitomebore, Inabawase, and Todorokiwase. The Pi5 gene, which clusters with Pii on chromosome 9, was identified only in Taebaeg. Thirty-four varieties were found to contain alleles of the resistance gene Pita or Pita-2. The Pita gene in japonica varieties was found to be inherited from the Japanese japonica genotype Shimokita, and the Pita-2 gene was from Fuji280 and Sadominori. Seventeen japonica and one Tongil-type varieties contained the Piz gene, which in the japonica varieties originates from Fukuhikari and 54BC-68. The Piz-t gene contained in three Tongil-type varieties was derived from IRRI-bred indica rice varieties. The Pi9(t) gene locus that is present in Korean japonica and Tongil-type varieties was not inherited from the original Pi9 gene from wild rice Oryza minuta. The Pik-multiple allele genes Pik, Pik-m, and Pik-p were identified in 24 of the varieties tested. In addition, the Pit gene inherited from the indica rice K59 strain was not found in any of the Korean japonica or Tongil-type varieties tested.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.292-292
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• 2022

Since 1992, the Rural Development Administration (RDA), Republic of Korea in collaboration with International Rice Research Institute (IRRI) has developed 6 japonica rice varieties(MS11, Japonica 1, 2, 6, 7 and Cordillera 4) that are adaptable to tropical regions. However, these varieties show moderate resistance or susceptibility to certain biotic and abiotic stress. The development of varieties with more stable forms of resistance is highly desirable, and this could be possibly achieved through rapid introgression of known biotic and abiotic resistant genes. In this study, we analyzed the allele types of major biotic stress resistant genes including Xa5, Xa13, Xa21 and Xa25 for bacterial leaf blight, Pi5, Pi40, Pish and Pita2 for blast, tsv1 for rice tungro spherical virus, and Bph6, Bph9, Bph17, Bph18 and Bph32 for brown planthopper by using gene-specific molecular markers. In addition, seed quality related genes Sdr4 for preharvest sprouting and qLG-9 for seed longevity were also analyzed. The results revealed that2h5 and Xa25 resistance alleles showed in all varieties while Pi5 resistance allele showed only in MS11. The Pish resistance allele were present in five varieties except for Japonica 1. Meanwhile, for the rest of the genes, no presence of resistance alleles found in six varieties. In conclusions, most of tropical japonica varieties are lack of the major biotic stress resistant genes and seed quality genes (Sdr4 and qLG-9). Moreover, the results indicated that rapid deployment of a few major genes in the current tropical japonica rice varieties is urgent to increase durability and spectrum of biotic stress resistance and also seed dormancy/longevity which are essential traits for tropical environments.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.3
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• pp.236-244
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• 1985

To know the varietal differences of ethylene evolution, 55 rice varieties were tested at seedling stage. And, also, 6 rice varieties were tested the biosynthesis of ethylene production. The group of japonica varieties produced higher amount of ethylene than the indica and indica x japonica crossed varieties. The content of ACC in rice seedlings of japonica varieties was higher than in seedlings of indica and indica x japonica varieties. And, also, the conversion rate of mathionine and ACC to ethylene in seedling of japonica varieties was higher than in seedling of indica and indica x japonica varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.3
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• pp.99-105
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• 2023

Starch characteristics and pasting properties of Tongil-type rice varieties with different amylose content were analyzed. Three different Tongil-type rice varieties and one Japonica-type rice variety were examined for their properties. Tongil-type rice varieties have longer panicles and higher rice yield (721-765 kg per 10a) than Boramchan, a Japonica-type high-yield rice variety. The protein content of the Tongil-type rice variety was higher than that of Boramchan. Japonica-type rice varieties had lower amylose content than Japonica-type rice varieties, except for Amimyeon (Milyang355). Amimyeon had higher protein content than the other varieties, and its amylose content was particularly high at 39.2%. The distribution of starch granule sizes of the four varieties was similar, and the particle size corresponding to D50 was approximately 87.8-81.9 ㎛. The pasting properties of rice flour varied among varieties. The Dasanbyeo and Hanarum2 amylogram patterns were similar. These two varieties had a higher peak viscosity (PV) and lower setback (SB) than Boramchan. In the case of Amimyeon, the hot paste viscosity (HPV), cool paste viscosity (CPV), and SB were significantly higher than those of the other Toingil-type varieties, and the breakdown (BD) was very low, showing pasting properties significantly different from that of the other varieties. The onset (T_o), peak (T_p), and conclusion temperature (Tc) of gelatinization of rice flour from Amimyeon were lower than those of the other tested varieties. In addition, the gelatinization temperature, measured using differnetial scanning calorimetry (DSC), and BD, measured using al rapid visco analyzer (RVA) were low in Amimyeon. Amylose content showed a high positive correlation with pasting time (PTi), HPV, and SB and a negative correlation with PV and BD.

• Korean journal of food and cookery science
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• v.27 no.6
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• pp.735-743
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• 2011

This study examined physicochemical properties of rice grains and qualities of cooked white rice of the high yielding, Japonica type, specifically Druryechanbyeo and Boramchanbyeo, and of the Tongil-type, specifically Hanarumbyeo and Andabyeo. The changes of water absorption rate of rice grains, their textural properties and a sensory evaluation of the cooked rice s were analyzed. All varieties were short grain. The length and width of Tongil type rice grains larger than those of Japonica type. The water absorption of white rice grains increased rapidly until 1 hr when soaking and after that increased slightly. The water absorption of Druryechan grain was higher than that of the Boramchan. The sensory evaluation results showed that the Japonica type cooked rices had a higher value for overall quality than the Tongil type cooked rices. With regard to the textural properties of the cooked rices, the hardness of Boramchan and Hanarum varieties showed higher than that of Druyechan and Anda varieties. Adhesiveness, springiness and chewiness were not significantly different between varieties (p<0.05).

• Magazine of the Korean Society of Agricultural Engineers
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• v.23 no.2
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• pp.35-44
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• 1981

This experiment was conducted to find out the consumptive use of irrigated water for calculation of duty water in paddy rice. Tall statured Japonica rice varieties, Nongbaek (early), Jinheung (medium) and Akibare (late), and short statured Tongil typed varieties, Josaeng Tongil(early), Suweon 264 (medium) and Suweon 258(late) were planted on the experimental farm of Kon-Kuk University in 1979. The results obtained in this study were as follows: 1. During the experimental period, the daily mean temperature was almost similar, the relative humidity was higher as much as 2.8%, the amount of rain fall was 100mm less and the pan evaporation was 70mm less compared with those of 30 years average, respectively. 2. The paddy soil was silty loam, which was suitable for the rice cultivation. 3. Varietal differences were find out for plant height, culm length, number of tillers, number of panicles, heading date, matured grain ratio, 1000-grain weight and rough rice yield. This difference might he the cause of varietal difference of the consumptive use of irrigated water during the rice growing period. 4. The evapotranspiration was gradually increased after transplanting and showed the peak from booting to heading stage of rice varieties. The average evapotranspiration through the whole growing period was 5.67-5. 80mm/day for tall statured Japonica varieties, and 5.99-6. 39mm/day for short statured Tongil typed varieties. 5. The ratio of evapotranspiration to pan-evaporation through the whole growing period was 1.49-1.50 for Japonica varieties, and 1.60-1.66 for Tongil typed varies. 6. Average amount of percolation in paddy field was 3. 62mm/day through the whole growing period of rice plant. 7. K-value in Blaney & Criddle formula was 0.94-0.98 for Japonica varieties and 1.02-1.08 for Tongil typed varieties, and coefficient consumptive water use (Kc-value) was 0.95-1.02 for Japonica varieties and 1.04-1.12 for Tongil typed varieties in this study. The modified coefficient for consumptive water use, which was calculated from data collected through the country including this study, was as follows;

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.201-201
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• 2022

Rice bakanae disease is a serious global threat in major rice-cultivating regions worldwide causing high yield loss. It is caused by the fungal pathogen Fusarium fujikuroi. Varying degree of resistance or susceptibility to bakanae disease had been reported among Korean japonica rice varieties. We developed a modified in vitro bakanae disease bioassay method and tested 31 Korean japonica rice varieties. Nampyeong and Samgwang varieties showed highest resistance while 14 varieties including Junam and Hopum were highly susceptible with 100% mortality rate. We carried out mapping QTLs for bakanae disease resistance with four F2:F3 populations derived from the crosses between Korean japonica rice varieties. The Kompetitive Allele-Specific PCR (KASP) markers developed in our laboratory based on the SNPs detected in Korean japonica rice varieties were used in genotyping F2 plants in the populations. We found four major QTLs on chromosome 1, 4, 6, and 9 with LOD scores of 21.4, 6.9, 6.0, and 60.3, respectively. In addition, we are doing map-based cloning of the QTLs on chromosome 1 and 9 which were found with Junam/Nampyeong F2:F3 population and Junam/Samgwang F2:F3 population, respectively. These QTLs will be very useful in developing bakanae disease resistant high quality rice varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.112-116
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• 1999

Genetic diversity of 31 rice varieties including 25 japonica and 6 indica varieties was evaluated using a combination of 19 microsatellite or simple sequence repeats (SSRs) and 28 random decamer oligonucle-otide primers. All 19 microsatellite primer sets representing 19 loci in the rice genome showed polymorphisms among the 31 varieties and revealed 91 alleles with an average of 4.80 bands per primer. Also all 28 random decamer primers used were informative and generated 114 non-redundant bands with a mean of 4.07 bands. Microsatellite markers detected higher number of alleles than random primers .although the mean difference was not statistically significant. A cluster analysis based on Nei＇s genetic distances calculated from the 205 bands resolved the 31 varieties into two major groups that correspond to indica and japonica subspecies, which is consistent with the genealogical information. As few as six random decamer primers or a combination of one microsatellite and four random decamer primers were sufficient to uniquely differentiate all 31 varieties. These combinations would be potentially useful in rice variety protection and identification considering that 25 out of 31 varieties used in this study are japonica rices with high grain quality and have close make up.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.135-140
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• 1998

Diallel analysis was conducted with FI's derived from crossing in all combinations without reciprocals among six rice varieties; three tropical japonica and three temperate japonica varieties, with different traits associated with panicle and flag leaf. Epistasis was observed in the number of primary branches (PB) per panicle and of spikelets per panicle, while flag leaf length, flag leaf color, PB length and neck node thickness were explained with the additive-dominance model. The estimated genetic mode of flag leaf length and PB length was a positive complete dominance model with high heritability, and that of flag leaf color and neck node thickness was an incomplete dominance model. In particular, tropical japonica varieties with low-tillering and heavy-panicle appear to have higher number of dominant genes for flag leaf length and PB length than temperate japonica varieties.

• Korean journal of food and cookery science
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• v.2 no.2
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• pp.32-42
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• 1986

Two Tongil type rice varieties and two Japonica rice varieties were prepared and experimented to investigate the effect of physicochemical properties on rice palatibility. Obtained results are as follows; (1) Width and thickness of unhunlled and unpolished grains of Tongil type rices were shorter than those of Japonica type rices and the length of the former was much longer than the latter. (2) Protein contents of Tonsil type varieties were greater than Japonica ones and amylose contents of the former is less than the latter. Alkali digestibility of them showed no significant differences. These means that the qualities of Tongil rices are not less than Japonica ones. (3) Sensory evaluation test showed that Japonica type rices are more excellent than Tongil types in expansion, glutinosity, flavour and taste while the former is inferior to the letter in gloss. (4) Preconceived ideas on the shape of rice seemed to affect most on its palatability.