• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.215-222
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• 2008

Fifty-two Korean japonica rice cultivars were analyzed for leaf blast resistance and genotyped with 4 STS and 26 SSR markers flanking the specific chromosome sites linked with blast resistance genes. In our analysis of resistance genes in 52 japonica cultivars using STS markers tightly linked to Pib, Pita, Pi5(t) and Pi9(t), the blast nursery reaction of the cultivars possessing the each four major genes were not identical to that of the differential lines. Eight of the 26 SSR markers were associated with resistant phenotypes against the isolates of blast nursery as well as the specific Korean blast isolates, 90-008 (KI-1113), 03-177 (KJ-105). These markers were linked to Pit, Pish, Pib, Pi5(t), Piz, Pia, Pik, Pi18, Pita and Pi25(t) resistance gene loci. Three of the eight SSR markers, MRG5836, RM224 and RM7102 only showed significantly associated with the phenotypes of blast nursery test for two consecutive years. These three SSR markers also could distinguish between resistant and susceptible japonica cultivars. These results demonstrate the usefulness of marker-assisted selection and genotypic monitoring for blast resistance of rice in blast breeding programs.

• Korean Journal of Agricultural Science
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• v.5 no.2
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• pp.49-55
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• 1978

In order to get healthy seedling of rice suitable for rice transplanter, the growing characteristics of the seedling grown under different growing days and sowing densities were invesigated and the results obtained were summarized as follows; In the 20 days old seedling, the difference of growing state of seed ling and its characteristics between the two types of nursery bed was not found, but for the 30 days old seedling, both of the crop growth rate and the relative growth rate on the band-type nursery bed appeared higher than those on the mat-type nursery bed. And also, "the dry weight, the content of cardohydrate and the ratio of dry weight to plant height of the seedling grown on the band-type nursery bed were much higher than those on the mat-type nursery bed, however the amount of difference of seedling characteristics between two types of nursery bed was decreased for 40 days old seedling and leaf number was not increased. The amount of the seedling growth was increased with less density of sowing and for the difference between the higher and the less density, the difference getting bigger with the longer nursery days. The maximum density of sowing was approximately 200cc per nursery case on the band-type nursery bed and 250cc per nursery case on the mat-type nursery bed. It was seemed that the growing uniformity of the seedling grown on the mat-type nursery bed was better than that on the band- type nursery bed, As the coefficient of variation of the plant height and the leaf numbers of the seedling grown on the band- type nursery bed was higher than that on the mat-type nursery bed.

• Korean Journal of Medicinal Crop Science
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• v.18 no.2
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• pp.74-78
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• 2010

This experiment was carried out to select suitable organic matter in To-jik nursery (self soil nursery) for complement To-jik nursery's defects that are deterioration of raw material by poor quality of seed ginseng and reduction of the quantity in seed ginseng production. Organic matter used were Yacto, rice bean, defatted rice bran, soybean cake and their mixture. As follows, bulk density in soil physical property by treating organic composts was the greatest in soybean cake and the next was followed by mix, Yacto, defatted rice bran, and rice bran treatment in order. Soil pore space ratio was totally the opposite; that was rice bran the first and followed by defatted rice bran, Yacto, mix and soybean cake treatment. The incidence rate of damping off by treating organic composts was 1.5% in both soybean cake and mix while the others was 1.0%. Emergence time was the same among treatment on April 16 and Emergence rate was the highest at 73% in Yacto. There was no significant differences among treatment in the growth of aboveground part but it was a little better in defatted rice bran treatment. In Yacto treatment, the growth of underground part, total root number per kan, rate of first grade ginseng seedling, and rate of usable ginseng seedling etc. were entirely higher but there was little differences. Using defatted rice bran was slightly lower in productivity compared to Yacto, but the possibility was high as a alternative for Yacto in a view of managing cost down.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.179-183
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• 2003

In comparison of physicochemical properties between expanded rice hulls (ERH) and a commercial nursery soil (Bunong), the pH and content of organic matters were higher in ERH than those of Bunong soil. However, the content of available phosphate, $\textrm{NH}_4\textrm{-N}$ and $\textrm{NO}_3\textrm{-N}$ were lower in ERH as compared with Bunong soil. The growth characteristics of seedlings were evaluated for 15-day old seedlings grown in five different nursery soils including ERH. The plant height was the tallest (22.8cm) in Bunong soil and shortest (12.8cm) in ERH. There was no difference in number of leaves among five types of nursery soils. The best results based on the seedling quality and root intensity was obtained from the seedlings grown in the nursery soil which ERH was used for bedding and Bunong soil for covering in the seed tray. The weight of a seed tray with Bunong soils was 27% heavier than that of 'ERH + Bunong soil'.

• Research in Plant Disease
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• v.10 no.1
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• pp.69-72
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• 2004

The control activity of isoprothiolane and tricyclazole mixed with carbosulfan, and probenazole by the nursery treatment was performed against rice leaf and neck blast caused by Magnaporthe grisea. In the paddy field, three fungicides showed good activities against leaf blast 3 months after nursery treatment. Especially the activity of tricyclazole against leaf blast gradually increased by the laps of time to 85.5％, which was assessed at 6 September,2003. Although the control value of isoprotholane and tricyclazole mixed with carbosulfan against neck blast was 47.5％ and 61.1％, respectively, probenazole showed a very high activity against not only leaf blast but also neck blast, of which that was 91.2％. No phytotoxicity was observed in all the treatments after transplanting rice seedling in the paddy field. Based on these results, three systemic fungicides tested in this study showed such a good potential that they might be used to formulate the nursery treating granule.

• Current Research on Agriculture and Life Sciences
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• v.19
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• pp.1-8
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• 2001

This experiment was conducted to determine the effect of nursery soils and seeding density on seedling growth characteristics in automatic facility for raising of rice seedlings. The seedling characteristics were evaluated for the 10-day and 15-day old seedlings grown in six different nursery soils including farm-made soils. Two levels of seeding amount, 250 g and 300 g/tray ($60{\times}30{\times}2.5$ cm), were applied to compare the seedling characteristics according to seeding density on different nursery soils. There were wide difference in soil components among the nursery soils tested. In acidity of nursery soils, 'Bunoog 2' was the highest, pH 5.1, and 'Samkyung' was the lowest, pH 8.6. The content of available phosphate was the highest value, 843 ppm, in 'Bunong 1' and the lowest (74 ppm) in farm-made soils. The total nitrogen content of 'Bunong 1, 2, 3' and 'Weonjo' soils was higher than there of 'Samkyung' and farm-made soils. There was no difference in plant height among three types of 'Bunong' soils (Bunong 1, 2, 3), but the seedling height grown in farm-made soils was shorter than there in other nursery soils. The plant heigh was slightly taller as the increase of seeding amount from 250 g to 300 g/tray, and the difference in plant height was larger in 15-day old seedlings as compared with 10-day old seedlings. Dry weight of seedlings grown for 15 days in three 'Bunong' soils was heavier than those in other nursery soils. Based on the growing characteristics of seedlings grown in different nursery soils, the heat result was obtained from a nursery soil, 'Bunoog 2', among six marketing nursery soils tested.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.5
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• pp.316-321
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• 2000

Blast severity data of 39 rice varieties at 11 sites in Korea from 1997 to 1999 were analyzed using AMMI model and pattern analysis. Genotype x Environment (G$\times$E) interaction sum of squares (SS) accounted for 12 % of the total SS. Eight genotype groups and seven location groups were identified based on blast reaction pattern. The data obtained from over 21 sites with 44 test varieties from 1981 to 1996 were also considered. These were compared with the 1997-1999 data using the G$\times$E analysis results. Majority of the variability in the Korean Rice Blast Nursery (KRBN) were attributable to variations due to genotypes. Variations of G$\times$E interaction were maintained though test sites were reduced from 21 to 11 sites. Broadly compatible biological discriminative varieties identified were Nagdongbyeo and Akibare while broadly incompatible biological discriminative varieties identified were Hangangchalbyeo and Seogwangbyeo. Key sites for future evaluation work could be selected from location groups. Each location group should be represented by the site with the strongest interaction pattern. Blast responses in Cheolwon, Gyehwa, Suwon, Iksan, and Icheon showed different patterns from other locations.

• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.11-16
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• 1976

This experiment was carried out to determine the most adequate type and period of nursery for the late seasonal cultivation of the new varieties of rice, Yusin and Josaengtongil. The results obtained are summarized as follows: 1. Semi-hot up-land nursery was much effective for the increase of the number of tillerings and the roots of rise seedlings compared with the semi-hot low-land nursery. The number of tillerings and roots was increased in 60 days seedlings compared with 50 or 60 days seedlings. 2. The abnormal heading has not appeared at the variety Yusin at all. The seedlings of Josaengtongil grown over 50 days at the semi-hot low-and nursery showed the abnormal heading, but the abnormal heading was not checked out at the seedlings of same variety grown for 60 days on the semi-hot upland nursery. 3. On the nursery not to cause the abnormal heading, earlier seeding was much effective for the hastening of the heading time and the hastening effect of heading time by earlier seeding was significantly greater at the variety Josaengtongil than Yusin 4. The number of ears per hill was significantly increased in the seedlings from the semi-hot up-land nursery compared with the semi-hot low-land nursery. 5. When the growing period of rice seedlings was not considered, the semi-hot up-land nursery resulted in higher yield of rice than the semi-hot low-land nursery. Considering the growing periods of rice seedlings, 40 days seedlings showed high yield at the semi-hot low-land nursery, however, at the semi-hot up-land nursery, 60 days seedlings showed higher yield of rice.

• Current Research on Agriculture and Life Sciences
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• v.19
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• pp.23-29
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• 2001

This study was carried out to develop a seedling raising method without nursery soils in automatic raising facility of rice seedlings for machine transplanting. Pre-germinated seeds were sowed on the seed trays with three different seats such as paper seat, corrugated board, and polyethylene film instead of nursery soils. The growth characteristics of the seedlings for 20 days after sowing were compared with that of a conventional standard raising method with nursery soils. There was no difference in plant height of 10-day old seedlings among the different nursery methods, but the plant height of seedlings grown for 15 days after sowing in the trays with fivefold newspaper and nursery soils was significantly taller than those on other nursery conditions. Dry weight of seedlings grown in the tray with fivefold newspaper bottom was heavier than those in nursery trays with a corrugated board and a piece of polyethylene film. The seedlings grown in a nursery tray with fivefold newspaper showed better seedling quality and root-mat formation compared with the other nursery trays. This result suggests that the healthy seedlings for machine transplanting can be raised in the paper-sheet tray without nursery soils. The labour hours and cost required for the soil-free method using paper was reduced by about 49.3% and 26.6%, respectively, compared with the semi-adult seedling on nursery soils.

• Korean Journal of Agricultural Science
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• v.4 no.1
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• pp.94-104
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• 1977

In order to investigate the effects of mechanical transplanting on the rice, four rice varieties including Jo-saing Tongil were planted in case nursering bed for three times with 10 days interval beginning from April 16. Fourty days old seedlings were transplanted with rice-transplanter, and growth habits of seedlings in bed and rice plants in main field and yield were examined and summerized as follows: 1. The plant height and number of leaves of the 40 days old seedling in case nursery bed were appeared to be less than those of seedlings grown in ordinary nursery bed. In case nursery, the plant height and number of leaves of seedlings grown in case nursery were apparently higher than those of seedlings grown in upland case nursery. 2. The root of 40 days old seedlings were cut to investigate the rooting ability of seedlings, and the rooting ability of the seedlings grown in the case nursery bed were apparently lower in the rooting ability compared with the seedlings grown in ordinary nursery bed. The rooting ability of the seedlings grown in the lowland case nursery was higher than that of the seedlings grown in the upland case nursery. 3. The tip of leaves of the varieties derived from Indica type were becoming yellow and yellow-red in color 25 to 30 days after planted in the case nursery bed. Those varieties was almost stopped growth. 4. The seedlings transplanted by transplanter had shown more than five to seven days of delay in rooting, compared with the seedlings transplanted by ordinary method. The heading dates was delayed five to seven days when transplanter was used, even though the delay of heading dates was a little different depending on the varieties. 5. The yields of unhulled rice were a little lower than that of Yusin variety which was hand planted. When mechanically transplanted, the yield of Tongil variety was highest in the plot where seedlings were transplanted on May 26. When transplanted on June 15, Milyang#15 was highest in yield, indicating the importance of varietal selection in mechanical transplantation. 6. The rice transplanter could transplant from 73 to 108 seedlings per $3.3m^2$. If the seeds of rice were evenly planted in the bed, the two-row rice transplanter could be used five to six times more effectively with less than one percent of missing plant compared with the hand transplanting. This suggests that rice transplanter could be utilized in the mono cropping area. 7. Since the time of transplantings in the double-cropping area is rather limitted, mechanical transplantation might be possible without reducings yield providing better adapted varieties and improved case-nursery techniques.