• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.342-345
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• 2009

"Hwaweon 2" was developed from an interspecific cross between Hwaseongbyeo and a wild species, Oryza rufipogon L. (IRGC 105491) based on marker-aided selection. The recurrent parent "Hwaseongbyeo" is a high grain quality cultivar with medium-maturity. Hwaweon 2 is nearly isogenic to Hwaseongbyeo except a small O. rufipogon introgression on chromosome 9. This segment was associated with genes controlling a number of traits including grain weight, heading date, culm length, and spikelets per panicle. The preliminary and replicated yield trial was conducted at Chungnam National University in 2004, 2005 and 2006. The local adaptability test was carried out by the National Seed Management Office (NSMO) in 2007 and 2008. This cultivar was registered to NSMO with a cultivar designated as "Hwaweon 2". This cultivar averaged 98cm in culm length and has a medium to late growth duration. This variety is resistant to stripe virus as the recurrent parent. Milled rice of "Hwaweon 2" is translucent and the grain quality traits are comparable to those of the recurrent parent. The yield potential of "Hwaweon 2" in grain is about 7.68 MT/ha at the ordinary fertilizer level about 14% higher than that of Hwaseongbyeo due to increase in grain weight and spikelets per panicle.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.529-533
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• 2018

Hyowon6, a mid-late maturing, good eating quality rice variety with multi-resistance, was developed by the rice breeding team of Pusan National University in 2013. This variety was derived from a cross between Hwayeong (as a multi-resistant parent) and Koshihikari (as a good eating quality parent). Selection by the pedigree breeding method was carried out until the $F_8$ generation. A promising line, JS14-12-36-8-5-3-1-1-1, was developed and designated as HY103 in 2013. This variety headed on August 22, which was 11 days later than that of Hwayeong. The culm length and panicle length of Hyowon6 was 85.7 cm and 21.1 cm, respectively. The number of panicles per hill was 14.5 and the number of grains per panicle was 101.7. The ratio of ripened grain was approximately 92% and the 1,000-grain weight was approximately 21.36 g for brown rice, which were similar to those of Hwayeong. Hyowon6 was moderately resistant to lodging and also to neck blast, leaf blight, and stripe virus. The glossiness value of Hyowon6 was 83, which was considerably higher than that of Hwayeong.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.97-101
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• 1969

The experiment about the mixed sowing of two different growth type varieties of barley-Buheung and Suwon＃18-has been conducted to determine the competition effect between two varieties, and its results are as follows: 1. Buheung-long stem variety-showed higher survived ratio than Suwon＃18-short stem variety- and that tendency was significant under the high fertilized condition. 2. When tow varieties-Buheung and Suwon＃18-were sowed together, the culm length of Buheung was shorter than the single planted Buheung and that of Suwon＃18 was onger than the single planted Suwon＃18, however, the panicle length showed the opposite tendency to the culm length variation. 3. The number of panicles and the number of grains did not show any differences among the treatments. 4. In case of the single sowing, Suwon＃18 showed higher grain yield under the common fertilized condition but Buheung showed significantly increased grain yield under the heavy fertilized condition, however, in case of the mixed towing of two varieties, the grain yield was significantly increased in heavy fertilized plots than standard fertilization. 5. The competition power was significantly superior in Buheung to Suwon＃18 and this tendency was rather definite according to the fertilizer application.

• The Korean Journal of Ecology
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• v.27 no.1
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• pp.35-41
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• 2004

Phragmites australis is the dominant and constructive species among plant communities in the wetlands of the downstream of Yellow River, China. Its morphological characters were high variable in different habitats. Studies on Morphological and RAPD variation of 15 P. australis populations from this region showed that soil salinity was the dominant ecological factor that affected the morphological characters of P. australis. The basal diameter, height, leaf length, leaf width, internode length, internode accounts, panicle length were negatively related to salinity. 194 loci were amplified by RAPD, of which 9 loci was highly negative-related to salinity, and showed a tendency to prefer the habitats with fresh water. 4 loci were positively related to the salinity, and showed a tendency to prefer the salinized habitats. Most loci were neutral to salinity. The morphological and genetic characters of BZH were special, and the speciality should not be determined by salinity. The morphological characters were affected by genetic information and environment. The morphological characters should change gradually and continuously along environmental gradient under plasticity, but should changed continuously or not in genetic control. The relevancies among quantitive characters, ecological factors and genetic variation in natural populations still will still be a focus and difficulty of ecological genetics of P. australis in the future.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.2
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• pp.109-113
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• 1984

This study was conducted to get basic information about yield capacity and major agronomic characteristics of rice varieties with large grain. The results obtained are as follows; Between grain weight and grain components such as length, width and thickness showed highly positive correlation. The relationship between grain length and grain shape (Length/Width) was clear (r=0.5707${\ast}\;{\ast}$). 1, 000 grain weight of 14 rice varieties with large grain was negatively correlated with number of spikelets per panicle, number of panicles per hill, ripening ratio, total dry matter, grain yield and harvest index, but less clear. The relationship between grain weight of 14 rice varieties with large grain and growth duration was less clear (r=0.440). 1, 000 grain weight of 20 rice varieties differing in grain size showed a highly positive correlation with chalkiness of rice kernel (r=0.8477${\ast}\;{\ast}$).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.3
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• pp.252-260
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• 1989

This experiment was carried out to clarify the causes of sterility in terms of pollination characteristics for the sterile-type cold damage as influenced by amount of nitrogen application and shading conditions in rice plants. The results obtained are as follows: The number of young microspore per anther was not changed greatly by amount of nitrogen application. The number of ripened pollen grains per anther decreased according to increase in nitrogen application and shading degree, but the anther length and stigma length were not significantly affected by those factors. The number of pollen grains on stigma decreased by intense shading. The fertility decreased with increased nitrogen application and intensified shading. The elongation of auricle distance per day was less in less nitrogen application and intense shading. The internode length of the first and the second from the top were shortened with intense shading, but that of the fourth was elongated. The number of spikelet per panicle decreased with increase in shading intensity.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.232-247
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• 1987

Three rice varietis, Dongjinbyeo, Daecheongbyeo and Chucheongbyeo, which are leading cultivars in the Chungnam area, were planted to determine their effects of mixture on the plant characteristics and the blast occurrence. The summary obtained is as follows; 1. The heading dates of each cultivars were not affected by the mixing culture. Only a day was delayed in heading date of Chucheongbyeo under commonly standard fertilizer level. 2. The effects of cultivar mixture on the plant height was high when low level of fertilizer were applied. Of the cultivar mixture, the mixing of Dongjinbyeo and Daecheongbyeo shoed 5.1% of plant height increase. The effects of mixture on the tillering number were apparent only under the standard fertilizer level. The mixture of Dongjinbyeo and Chucheongbyeo was effective in increasing the tillering number up to 5.7% over mean tillering number of each cultivars. 3. The stem height tended to increase as the fertilizer level increased and the effects of cultivar mixture on the stem height was high. The stem height of mixture of Dongjinbyeo and Daecheongbyeo was highest compared with other mixture cropping. On the contrary, the panicle length was shortened as the fertilizer level decreased and cultivars were mixed. Among the cultivar mixtures, the mixture of Dongjinbyeo and Daecheongbyeo showed the most effectives of increasing the panicle length. 4. The total dry weight of mixed and pure cultivars were compared. The mixture of two cultivars was effective in increasing the dry weight of rice upto 3.5% over the average of dry weight of each cultivars. When three cultivars were mixed, there were 8.5% of dry weight increase over not mixed cultivars. The effects of mixture on the dry weight were more apparent under standard fertilizer level. 5. The rates of Neck and Node and Branch Blast occurrence were reduced when cultivars were mixed, and their reduction rates were 11.7% and 14.0%, respectively. The occurrence of Blasts was also decreased under the lowest fertilizer level than the standard fertilizer level. The least Blast occurrence was obtained when Dongjinbyeo and Daecheongbyeo were mixed cropped. 6. Significantly high number of spikelets of per square meter was observed when Chucheongbyeo and Dongjinbyeo were mixed. However, the spikelets of panicle were the lowest when Chucheongbyeo and Dongjinbyeo were mixed. The number of panicles per square meter was increased as the fertilizer levels increased, while the number of spikelets per panicle increased as the fertilizer level decreased. 7. The effects of mixture on the maturing were apparent regardless of the fertilizer level. The 1000 grain weight was higher when lower level of fertilizer was applied. The effects of cultivar mixture on the 1000 grain weight were more apparent in the plots of Chucheongbyeo and Dongjinbyeo mixture and three cultivar mixture. 8. The grain yield increased when cultivars mixed. The increment under mixing cropping was 4.6% over mono cropping. The effects of cultivar mixture on the yield increase were more apparent under lower levels of fertilizer application. The highest yield increase was obtained when Chucheongbyeo and Daecheongbyeo were mixed, and the rate of yield increase was 6.8% over mono-cropping. 9. The grain yield was highly correlated with number of panicles per square meter and dry weight. There was not any significant relationships found among grain yield, spikelets of panicle and ripening percentage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.172-181
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• 2020

Koshihikari has been one of the most popular rice cultivars with good eating quality since the 1960s despite its susceptibility to blast disease and lodging. To map the genes controlling blast resistance and to develop promising blast-resistant breeding lines inheriting Koshihikari's high eating quality, a recombinant inbred line (RIL) population was developed from a cross between Koshihikari and a blast resistance donor with early maturity, Baegilmi. A total of 394 Koshihikari × Baegilmi RILs (KBRIL), and the two parents, were evaluated for blast resistance and major agronomic traits including heading date, culm length, panicle length, and tiller number. A linkage map encompassing 1,272.7 cM was constructed from a subset of the KBRIL (n = 142) using 130 single nucleotide polymorphisms. Two quantitative trait loci (QTL) for blast resistance, qBL1.1 harboring Pish/Pi35 and qBL2.1 harboring Pib, were mapped onto chromosomes 1 and 2, respectively. qBL1.1 was detected in both of the experimental sites, Namwon and Jeonju, while qBL2.1 was only detected in Namwon. qBL1.1 and qBL2.1 did not affect agronomic traits, including heading date, culm length, panicle length, and tiller number. From the 394 KBRILs, lines that were phenotypically similar to Koshihikari were selected according to heading date and culm length and were further divided into the following two groups based on blast resistance: Koshishikari-type blast resistant lines (KR, n = 15) and Koshishikari-type blast susceptible lines (KS, n = 15). Although no significant differences were observed in the major agronomic traits between the two groups, the KR group produced a greater mean head rice ratio than the KS group. The present study provides useful materials for developing blast-resistant cultivars that inherit both Koshihikari's high eating quality and Baegilmi's blast resistance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.6
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• pp.514-520
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• 1992

Performance of direct seeded paddy rice in ridged dry soil was evaluated at different seeding methods (broadcasting, drilling, and seeding in group) and seeding rates (4, 6, and 8kg /10a). The number of maximum tillers at broadcasting and drilling of seeds was higher than that at seeding in group. At broadcasing and drilling the number of maximum tillers at seeding rate of 6kg /10a was greater than that at 4 or 8kg /10a, but at seeding in group the number of maximum tillers increased with seeding rates. Among the seeding methods there were no differences in the number of seedlings per unit area, culm and panicle lengths, and productive tiller ratio, but heading date at seeding in group was delayed by a day compared with broadcasting or drilling. At heading stage leaf area index(LAI) and dry matter production at broadcasting of seeds were higher compared with drilling and seeding in group, but light transmission ratio at drilling and seeding in group was higher than that at broadcasting of seeds. Although the number of seedlings increased with seeding rates, LAI and dry matter production at heading stage, culm and panicle lengths, and productive tiller ratio were not different among the seeding rates. There were no differences in the number of panicles and spikelets per unit area, 1,000 grain weight, yield, and harvest index among the seeding methods. The number of spikelets per panicle at seeding in group was higher, but percent ripened grains was lower compared with broadcasting and drilling. There were no significant differences in the number of panicles and spikelets per panicle and unit area, percent ripened grains, and harvest index among the seeding rates, but yield at seeding rate of 6kg /10a was higher than at 4 or 8kg /10a. There were no significant differences in tiller length, bending moment, and fresh weight of tiller among the seeding methods. Breaking strength was lower in the order of seeding in group, drilling, and broadcasting of seeds. However, lodging index was similar among the seeding rates and lodging was not occurred in the field. There was a significant interaction in the cellulose, hemicellulose, and lignin contents of culm base between seeding methods and seeding rates.

• Applied Biological Chemistry
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• v.22 no.3
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• pp.181-189
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• 1979

In order to establish fertilizing technique for the increase of grain yield and its stability, the total absorbed amount of nutrients and nutritional status of rice plants at different growth stages were studied with respect to the nutrient contents and its relation to grain yield and yield components. This experiment was carried at three different level of nitrogen fertilization; two different seeding and transplanting times, and eight cultivars including both Japonica-and Tongil-type. The results of a part of these experiments are summarized as fallows: 1. The culm length tended to Increase with increasing fertilizer amount, but no significant difference between ordinary and heavy fertilization was observed in Tongil-type cultivars. 2. The panicle length was some what longer in ordinary and heavy fertilization than non-fertilization. 3. As the N-fertilizer level increases, the number of panicles per plant increased with higher response in Japonica-type cultivars than in Tongil-type cultivars. 4. The number of grains per panicle increased significantly in ordinary and heavy fertilization, compared to non-fertilization, but the difference in grain number per panicle among fertilizer treatment was smaller in Japonica-type cultivars than Tongil-type. 5. The 1,000 grains weight showed no significant difference among fertilization levels in ordinary transplanting, but indicated gradual decreasing tendency as the transplanting delayed. 6. In percentage of ripeness, there was no significant difference in ordinary transplanting, but hightly significant in late transplanting among N-fertilization levels and cultivars. 7. In yield, highly significant difference was shown among N-fertilizer levels and cultivars In Tongil-type variety, higher yield was obtained in ordinary fertilization than heavy fertilization. 8. The straw weight showed the tendency to increase in higher nitrogen level, but no significant difference between ordinaly and heavy fertilization was observed in Tonsil-type cultivars.