• Research in Plant Disease
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• v.18 no.4
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• pp.387-390
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• 2012

Rice black-streaked dwarf virus (RBSDV) was reported to occur on maize plants in Gochang-gun of Jeonllabuk-do region in 2011. The symptoms typically include stunted and deformed leaves. Virus infected plants usually produce poor or no head. RT-PCR analysis of genomic dsRNA extracted from the plant confirmed the infection. Specific primers for full length genome of segments 8 and 10 were used for RNA amplification. Full-length genomes of S8 and S10 were cloned and sequenced. Sequence analysis revealed that the S8 and S10 sequences of the maize isolate were same with rice isolate in size, 1,936 nt and 1,801 nt, respectively. In comparison with rice RBSDV, S8 and S10 showed 94.9-99.6% and 94.1-98.4% sequence identity, respectively. Phylogenetic analysis showed that RBSDV S8 and S10 of maize plants are categorized into the same group as RBSDV of rice plant.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.4
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• pp.323-334
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• 2004

Silage yield Potential and some agronomic characteristics of Korean improved and introduced corn hybrids from the United States were tested for five year in Gyeongsan, Gyeongsangbug-do and for one year in Hongcheon, Gangwon-do. 1. At 20 days after emergence, plant height and dry matter of hybrids were different, while the early growth of the hybrids was not correlated to the culm length and silage yield. 2. In Cyeongsan, silage yield potential of Suwon19 was relatively high, while most susceptible to rice black-streaked dwarf virus (RBSDV) disease and leaf senescence at harvest time. In contrast, silage yield potential and resistance to RBSDV of Cwanganok were moderate, while susceptible to leaf senescence at harvest. Generally, Suwon19 showed similar or higher yield than most introduced hybrids, while some introduced hybrids showed lower silage yield than Korean improved hybrids. Most introduced hybrids were more resistant to RBSDV and leaf senescence at harvest time compared to Korean improved hybrids. 3. In Hongcheon, silage yield of three Korean improved hybrids were lower than that of NC+5514 and DK729, while similar or higher than other introduced hybrids. af senescence of all Korean hybrids was severer compared to introduced hybrids.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.2
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• pp.111-116
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• 2013

This experiment was carried out to select a resistant corn variety for rice black-streaked dwarf virus (RBSDV) disease in a RBSDV prevalent area (Gochang of Jeollabukdo) from 2006 to 2008. Ten corn varieties for silage preparation were cultivated with first cropping and second cropping system in an RBSDV field, and were tested outbreak rates of RBSDV and dry matter (DM) yield of forage. The outbreak rates of RBSDV were significantly different between corn varieties. Therefore, the resistance degree of corn varieties for RBSDV were divided into 4 groups; very resistant ('Kwangpeyongok' and 'Kwanganok'), resistant ('P3156' and 'P3394'), mildly resistant ('Cheonganok' and 'P32P75') and susceptible ('Suwon19', 'DK697' and 'GW6959') groups respectively. DM yield of forage in RBSDV fields exhibited comparatively significant differences between varieties (p<0.05). DM yield of resistant varieties ('Kwangpeyongok', 'Kwanganok', 'P3156' and 'P3394'), were higher (14~26%) than those of susceptible varieties ('Suwon 19', 'DK697' and 'GW6959'). Therefore, resistant varieties were recommended for increasing forage productivity in field of RBSDV prevalent areas.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.223-228
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• 2013

Phytoplasmas were detected consistently in 42 mulberry cultivars showing dwarf disease using DNA analysis by amplification with phytoplasma universal primer pairs P1/P7 (about 1.8 kb and R16F2n/R2 (about 1.2 kb). The point mutation from 42 cultivars of mulberry tree was detected by single-strand conformation polymorphism (SSCP) analysis. The SSCP profiles were clearly observed from all of cultivars in 8% polyacrylamide gel, electrophoresizing for and running 8-15 hrs. at 150V, $10^{\circ}C$. The MD and JWB phytoplasma PCR products was mixed and electrophoresis was performed to detect their polymorphism. In this results, the SSCP profiles of all bands of MD and JWB were analyzed on single lane and were distinct in their each of band patterns. The SSCP analysis was possible to detect of 1.8 kb and 1.2 kb nucleotide size and near close band patterns were distinct by mix of two samples. Previously, it was only possible to detect of point mutation under 600 bp nucleotide sequence by SSCP analysis but this modification of SSCP technique was possible to detect clearly SSCP band patterns of about 1.8 kb and 1.2 kb nucleotides.

• Korean journal of applied entomology
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• v.23 no.4 s.61
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• pp.215-220
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• 1984

Mulberry dwarf, paulownia witches' broom, jujube witches' broom, and sumach witches' broom are known to be associated with mycoplamalike organisms(MLO) in Korea. Simple microscopic detection of MLO infection in these plants was attempted. Periwinkle plant was also tested. Application of $0.2\%\;and\;0.4\%$ solution of Dienes' stain gave diagnoatic value for MLO-induced diseases of periwinkle and mulberry. Among the various plant parts examined, young herbaceous stem just below the apical part gave the best result. Density of staining reaction was proportional to disease severity. Longitudial sections were superior to transverse sections in confirming MLO infection by staining. Light source without blue filter was useful for increasing the color contrast between sieve tube and xylem vessel and for eliminating misinterpretation. Paulownia, jujube, and sumach samples gave no clear difference in staining reaction between healthy and diseased sections even when various modifications of Dienes' staining procedure were tried.

• Journal of Sericultural and Entomological Science
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• v.44 no.1
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• pp.22-27
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• 2002

The Yongcheonppong was cultured in the form of a dense mulberry field coverd with polyethylene film and was tested in Suwon and Chunchon. The agronomic characteristic and some consideration on the result of the silkworm rearing were as follows. The Yongcheonppong was the medium budding variety and was longer in length of young shoots than the Kaeryangppong. The Yongcheonppong was higher in leaf yield in spring than the Kaeryangppong and was lower in leaf yield in autumn than the Kaeryangppong to the contrary. The Yongcheonppong was a little higher in the number of branches and was longer in the length of the branch than the Kaeryangppong and so was appropriate for rearing with mulberry shoots. Yongcheonppong was more resistant to twig blight and die-back and was a little susceptible to dwarf disease. As the Yongcheonppong was most resistant to the freezing injury, it was appropriate for the cold region and enabled the farmers to rear some amount of silkworms every year. In Chunchon, The Yongcheonppong increased by 11% in cocoon yield than the Kaeryangppong when the freezing injury occurred 1 year out of 2 years and produced about the same as the Kaeryangppong in cocoon yield when the freezing injury occurred 1 year out of 3 years.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.490-496
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• 2018

"Samkwang1," a japonica rice variety, was developed as a cross between "Samkwang" and F1 of Suwon152 (IT008283), which has a medium maturing and lodging resistance and Samkwang (IT284608), a high quality variety with bacterial blight resistance and mid-late maturing property by the rice breeding team at NICS in 2015. The heading date of "Samkwang1" was August 8 in the middle plain area, which was 2 days early than that of "Hwaseong." "Samkwang1" had a culm length of 77 cm, which was 7 cm shorter than that of "Hwaseong," and it had 128 spikelets per panicle. The viviparous germination rate of "Samkwang1" was 2.1%. "Samkwang1" showed resistance to blast, bacterial blight (K1, K2, and K3 race) and stripe virus, but was susceptible to the K3a race of bacterial blight, dwarf and black streak dwarf viruses, and plant hoppers. The milled rice of this variety exhibits translucent and medium short grains. The cooked rice grains of "Samkwang1" have an excellent palatability index (0.35) and lower protein content (6.2%) than that of "Hwaseong." The characteristics related to grain milling were better than those of "Hwaseong," especially the head rice milling recovery ratio and head rice ratio (94.2%). "Samkwang1" showed 5.62 MT/ha of milled rice productivity at 11 sites under ordinary cultivation conditions (Registration No. 6798).

• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.23-29
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• 2009

We have previously isolated a CCCH type zinc-finger protein gene, OsZF2 (Oryza sativa Zinc Finger 2), from the cold-treated rice cDNA library. To investigate the potential role of OsZF2, transgenic rice lines over-expressing OsZF2 under the control of CaMV 35S promoter have been developed through Agrobacterium-mediated transformation. Elevated level of OsZF2 transcripts was confirmed by RNA gel blot analysis in transgenic rice. Under the 100 mM NaCl condition, the transgenic rice showed significantly enhanced growth rate in terms of shoot length and fresh weight, implicating that OsZF2 is likely to be involved in salt response of rice. In the field condition, however, the transgenic rice showed a dwarf phenotype and flowering time was delayed. Genome expression profiling analysis of transgenic plants using the 20K NSF rice oligonucleotide array revealed many up-regulated genes related to stress responses and signaling pathways such as chaperone protein dnaJ 72, salt stress-induced protein, PR protein, disease resistance proteins RPM1 and Cf2/Cf5 disease resistance protein, carbohydrate/ sugar transporter, OsWAK kinase, brassinosteroid LRR receptor kinase, and jasmonate O-methyltransferase. These data suggest that the CCCH type zinc-finger protein OsZF2 is a upstream transcriptional factor regulating growth and stress responsiveness of rice.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.292-298
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• 2009

A new rice cultivar "Keumo 3" was developed for adopting under double cropping system with after or before cash crop cultivation. It was selected from the cross-combination between YR17202 $F_2$/Shinkeumobyeo//YR15727-B-B-B-102. The parent, YR17202 $F_2$ individual plant, was used for tolerance to lodging, it derived from a cross between Nonganbyeo/Shinkeumobyeo. Nonganbyeo is well known to lodging tolerance cultivar, as well as biotic stress, because it was developed by crossing with Tongil type. And the YR15727-B-B-B-102 line used as another parent with short growth duration, likewise highly resistance to rice blast disease. The pedigree derived from the cross-combination YR17202 $F_2$/Shinkeumobyeo//YR15727-B-B-B-102 were generated to $F_7$, and a best line among them named as Milyang 201. After a series of yield trials, including local adaptability test conducted throughout the peninsular of Korea, Milyang 201 was registered with the name of "Keumo 3" in 2005. The cultivar belongs to a early maturing group and heads 4 days earlier than Keumobyeo, a standard cultivar. It has short culm, and less spikelet number per panicle than Keumobyeo. However, its milled rice yield grown under extremely late transplanting time, 10. July, over the 3 local sites for 2003-2005 years, averaged 4,48 MT/ha, which is 6% higher than the standard, Keumobyeo. "Keumo 3" has showed a durable resistance to leaf blast disease during fourteen blast nurseries screening covered from south to north in Korea for 2003-2007 years. And it was confirmed harbours pi-zt, a durable blast resistance gene. Moreover it was incompatible with 19 blast isolates under artificial inoculation, except one isolate, K1101. Additionally, "Keumo 3" exhibits resistance to $K_1$, $K_2$ and $K_3$ of bacterial blight pathogen, as well as strip virus disease resistance, and moderate resistance to dwarf virus disease. Consequently, the new rice cultivar "Keumo 3" would be well adopted where a bio stress makes a big problem annually.

• Research in Plant Disease
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• v.18 no.4
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• pp.391-395
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• 2012

To investigate the occurrence of viruses in peach, leaf samples were collected from peach trees in commercial orchard of six areas in Korea. Reverse transcription polymerase chain reaction (RT-PCR) was used to identify the presence of the following stone fruit viruses: Apple chlorotic leaf spot virus (ACLSV), Apple mosaic virus (ApMV), Prune dwarf virus (PDV), Prunus necrotic ringspot virus (PNRSV) and Plum pox virus (PPV). About 65.0% of the 515 samples were infected with ACLSV and PNRSV. Virus-like symptoms showing mosaic on leaves was observed in ACLSV infected peach trees. However, PNRSV infected peach trees showed no symptoms. These viral DNAs by sequence analysis were confirmed 4 ACLSV isolates and 3 PNRSV isolates. The Korean peach isolates of ACLSV and PNRSV showed 70-99% and 88-99% amino acid sequence identities, respectively, with those reported previously and their amino acid sequence identities with each other were approximately 95% and 88%, respectively. Phylogenetic analysis indicated that the Korean ACLSV isolates belong to the A group of ACLSV. The Korean PNRSV isolates reported in this study were grouped into I (PV32), II (PV96) and III (PE5) groups.