• Research in Plant Disease
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• v.19 no.3
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• pp.183-187
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• 2013

Barley kernel discoloration (KD) leads to substantial loss in value through downgrading and discounting of malting barley. The objective of this research is to investigate fungal distribution and varieties resistance to KD in Korean two-rowed barley. Several fungal organisms including Alternaria spp., Fusarium spp., Aspergillus spp., Epicoccum spp. and Rhizopus spp. were isolated from Korean two-rowed barley representing KD. The symptoms of KD were brown and black discolorations of the lemma and palea. The most frequently detected fungal species was Alternaria spp. which exhibited 69.1% and 72.2% in 2011 and 2012, respectively. Epicoccum spp., Fusarium spp., and Aspergillus spp. were also detected. Fusarium spp., primary pathogen of barley head blight, were rarely occurred in the 2011 and their occurrence increased to 4.7% in 2012. Twenty cultivars of Korean two-rowed barely were evaluated to KD. The average percentage of KD was 8.0-36.0% in 2011 and 5.2-36.6% in 2012. Two cultivars ('Sacheon 6' and 'Dajinbori') showed KD of 6.2% to 8.8% and determined resistant, however 'Samdobori' and 'Daeyeongbori' demonstrating KD of 22.2-36.6% were highly susceptible. 'Jinyangbori', 'Danwonbori', 'Sinhobori' and 'Kwangmaegbori' showing KD of less than 15% were moderately resistant cultivar.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.3
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• pp.23-38
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• 2015

The study was initiated with Kentucky bluegrass (KB, Poa pratensis L.) to investigate germination and early establishment characteristics of new cultivars for a practical application to turfgrass establishment such as parks, athletic field and golf course etc. Fifteen cultivars were evaluated in different experiments. An alternative condition for a KB germination test required by International Seed Testing Association (ISTA) was applied in Experiment I, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA conditions). Experiment II was conducted under a room temperature condition of 5 to $25^{\circ}C$ (natural conditions). Seed germinating vigor, germination speed and germination peak time were measured in both experiments. Significant differences were observed in seed germinating vigor, germination speed and germination peak time. Seed germinating vigor was variable with different environments and cultivars. It was 75.25 to 89.50% under ISTA conditions and 75.75 to 90.25% under natural conditions. There were considerable variations in early germination characteristics among KB cultivars according to different environments. Early germination characteristics showed that all cultivars were 3 to 5 days faster in germination under ISTA conditions, when compared with natural conditions. The germination speed, measured as days to seed germination of 50% to 80%, was much faster with 'Midnight II', 'Excursion' and 'Midnight' under ISTA conditions. But it was faster with 'Midnight II', 'Excursion' and 'Odyssey' under natural conditions. Differences was also observed in germination peak time with cultivars and growing conditions. It ranged 5.94 to 14.88 days under ISTA conditions and 4.71 to 13.06 days under natural conditions. Regardless of the environment conditions, the shortest cultivars were 'Odyssey' and 'Midnight II'. The longest ones were 'Nuglade' under ISTA condition and 'Moonlight' under natural conditions. Considering germinating vigor, germination speed and germination peak time, 'Midnight II', 'Excursion', 'Midnight', and 'Odyssey' were regarded as excellent cultivars under ISTA conditions in terms of early establishment characteristics, while 'Midnight II', 'Excursion', 'Odyssey', and 'Courtyard' under natural conditions. These results suggest that an intensive germination test be needed prior to planting, for investigating the early germinating vigor, germination speed and germination peak time. Also, a proper cultivar selection and comprehensive site analysis for the growing environmental conditions should be done before turfgrass establishment such as golf course construction.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.45-56
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• 2009

Current status on the occurrence and the management of the major disease, insect and mite pests were investigated in the organic or non-chemical pest control orchards from 2005 to 2009. Numbers of certified organic or non-chemical apple orchards were increased from 14 in 2005 to 78 in 2008. Severe damages on leaves and fruits occurred by the several diseases such as marssonina blotch, bitter rot, white rot, sooty blotch and flyspeck, and the several insect pests such as apple leaf-curling aphid, woolly apple aphid, oriental fruit moth and peach fruit moth on the almost certified organic or non-chemical pest control orchards. About 10 and 18 environmental-friendly materials were used to control diseases and insect or mite pests respectively. But, lime sulfur and bordeaux mixture to diseases and machine oil, plant oil mixed with egg yolk, and pheromone mating disruptions to insect pests were effective to control under the adequate conditions. At present, it is extremely difficult to produce organic apples in Korea. Growers must consider about and solve so many conditions on the cultivar, weather, local site, marketing and so on, before when they decide to change from conventional or IPM(Integrated Pest Management) to organic or non-chemical pest control orchards.

• Journal of Plant Biotechnology
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• v.33 no.4
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• pp.271-276
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• 2006

Hypocotyl explants of Chinese cabbage (us. 'Jeong Sang' and 'Seoul') produced adventitious shoots on Murashige and Skoog (MS) basal medium supplemented with 4mg/L $AgNO_3$, 5 mg/L acetosyringone, 4 mg/L 6-benzyladenine and 3mg/L alpha-naphthaleneacetic acid (SI) after cocoultivation with strains of Agrobacterium tumefaciens (LBA4404) harboring the pCAMBIA1301 and the $_PPTN290$ containing hygromycin-resistance gene and paromomycin-resistance gene as a selectable marker genes, respectively. There was a significant difference in the frequency of transgenic plants depending on antibiotics and cultivars used. Paromomycin was better than hygromycin, and cultivar 'Jeong-sang' was higher than 'c.v. Seoul' in the frequency of transgenic plants. In particular, the highest frequency (0.70%) of transgenic plants was obtained from selection medium (SI) containing 100mg/L paromomycin in c.v., 'Jeong-sang' GUS positive response were obtained 9 plants and 3 plants from the cultivars, 'Jeong-sang' and 'Seoul', respectively. They were grown to maturity in a greenhouse and normally produced $T_1$ seeds. GUS histochemical assay for progeny $(T_1)$ revealed that the transgenes were expressed in the plant genome.

• Journal of Plant Biotechnology
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• v.33 no.4
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• pp.283-288
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• 2006

Discrimination of 5 rice cultivars (Sangjubyeo , Dongjinbyeo Simbaekbyeo , Hwamanbyeo , and Simbaek-hetero ) using metabolic profiling was carried out. Whole cell extracts from each cultivar were subjected to $^1H$ NMR spectroscopy. When spectral data were analyzed by principal component analysis, 5 cultivars were clustered into 3 groups: SJ, DJ + SB, and HM + SH. Thecultivars showed great difference in carbohydrate region of $^1H$ NMR spectra, suggesting that qualitative and quantitative differences in carbohydrate compounds play a major role in discrimination of the cultivars. In addition, it was readily possible to determine relative quantification of major carbohydrates including sucrose, glucose, maltose from spectral data of the cultivars. SJ showed 2 to 4 times higher content of maltose than the other rice cultivars. Overall results indicate that metabolic discrimination of rice cultivars using $^1H$ NMR spectroscopy combined by multivariate statistical analysis can be used for rapid discrimination of numerous rice cultivars and simple quantitative analysis system of major carbohydrate compounds in rice grains.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.58-65
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• 2016

Powdery mildew is an important disease of the melon (Cucumis melo L.). Seven isolates of powdery mildew fungi were collected from five locations in Korea; Anseong (DH487), Icheon (BN103, BN625, BN968), Yeongam (YA141), Changnyeong (CN582), and Suncheon (SN102). All 7 fungi had a similar trend of conidial chain and conidiophore development as Podosphaera xanthii with fibrosin bodies in mature conidia. Among them, 2 isolates of powdery mildew fungi; CN582 and SN102 showed similar responses to resistance against powdery mildew as the previously reported race 1 and race N2. The isolates YA141 and BN103 showed similar responses as like as race A. However, three isolates of powdery mildew fungi (BN625, BN968, and DH487) showed different responses compared to the previously reported races (1, N1, N2, A, S, and 5). Therefore, these three isolates could be designated as new races in melon. Nine out of 15 commercial melon cultivars in Korea showed resistance to race 1 (CN582). However, the new race BN968 invaded all 15 cultivars. Results of the two molecular markers were consistent in response to disease development by race 1 of Podosphaera xanthii in case of the above mentioned cultivars. This study confirmed the presence of new melon powdery mildew fungi in Korea which are similarly notorious as like as the previously reported race 1. Therefore, breeders can use these two molecular markers for breeding melon in Korea that is resistant to race 1 and as well as to some other races.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.303-311
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• 2017

In this study, random amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) analyses were used for evaluation of genetic diversity of 61 kiwifruit (Actinidia spp.) germplasms including domestic and overseas collection cultivars. Forty RAPD primers were detected in a total of 230 polymorphic bands with an average of 5.75. Thirty-two SRAP primer combinations were detected in a total of 204 polymorphic bands with an average 6.38. By unweighted pair-group method arithmetic average cluster analysis using 434 polymorphic bands, kiwifruit germplasms were classified in three groups with similarity value of 0.680. Cluster I consisted of 46 kiwifruit germplasms belonging to A. deliciosa, A. chinensis, A. deliciosa ${\times}$ A. arguta, A. chinensis ${\times}$ A. arguta, and A. chinensis ${\times}$ A. deliciosa. Cluster II consisted of seven germplasms belonging to A. arguta and 'Skinny Green', a cultivar derived from a cross between A. arguta and A. deliciosa. Cluster III consisted of seven germplasms belonging to A. rufa, A. hemsleyana, A. macrosperma, A. polygama, and A. eriantha. Genetic similarity values among tested kiwifruit germplasms ranged from 0.479-0.991, and average similarity value was 0.717. Similarity value was highest (0.991) between NHK0038 (A. deliciosa) and NHK0040 (A. deliciosa), and lowest (0.479) between 'Hayward' (A. deliciosa) and K5-1-22 (A. arguta).

• The Plant Pathology Journal
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• v.18 no.5
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• pp.259-265
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• 2002

Apple mosaic virus (ApMV), a member of the genus Ilarvirus, was detected and isolated from diseased 'Fuji' apple (Malus domestica) in Korea. The coat protein (CP) genes of two ApMV strains, denoted as ApMV-Kl and ApMV-K2, were amplified by using the reverse transcription and polymerase chain reaction (RT-PCR) and were analyzed thereafter. The objectives were to define the molecular variability of genomic information of ApMV found in Korea and to develop virus-derived resistant gene source for making virus-resistant trans-genic apple. RT-PCR amplicons for the APMVS were cloned and their nucleotide sequences were determined. The CPs of ApMV-Kl and ApMV-K2 consisted of 222 and 232 amino acid residues, respectively. The identities of the CPs of the two Korean APMVS were 93.1% and 85.6% at the nucleotide and amino acid sequences, respectively. The CP of ApMV-Kl showed 46.1-100% and 43.2-100% identities to eight different ApMV strains at the nucleotide and amino acid levels, respectively. When ApMV-PV32 strain was not included in the analysis, ApMV strains shared over 83.0% and 78.6% homologies at the nucleotide and amino acid levels, respectively. ApMV strains showed heterogeneity in CP size and sequence variability. Most of the amino acid residue differences were located at the N-termini of the strains of ApMV, whereas, the middle regions and C-termini were remarkably conserved. The APMVS were 17.(1-54.5% identical with three other species of the genus Ilarviyus. ApMV strains can be classified into three subgroups (subgroups I, II, and III) based on the phylogenetic analysis of CP gene in both nucleotide and amino acid levels. Interestingly, all the strains of subgroup I were isolated from apple plants, while the strains of subgroups II and III were originated from peach, hop, or pear, The results suggest that ApMV strains co-evolved with their host plants, which may have resulted in the CP heterogeneity.

• Korean Journal of Organic Agriculture
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• v.18 no.1
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• pp.75-82
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• 2010

The purpose of this study is to investigate an occurrence rate of rice stripe virus disease under different rice transplanting time and different rice cultivars. After final harvest, the yield of rice infected by rice stripe virus was obtained on Wangchal cultivar compared to uninfected rice. The results obtained as following: 1) Yield of rice infected by rice stripe virus was decreased by 64% with reduction of culm length, pancile length, number of spike, number of spikelet, and grain filling compared to uninfected rice, 2) An occurrence rate of rice stripe virus disease under different rice planting season was high as order of May 30 > June 15 > July 1. In additional, to reduce a rice stripe virus disease on higher disease occurrence region and susceptible cultivars, rice planting season will be accepted on and after June 15, and 3) Eighteen cultivars were resistance cultivars such as Hwayeongbyeo, Onnuri, Ilmibyeo, Nampyongbyeo, Dongjin2ho, Hopumbyeo, Hwangkeumnuri, Malgeumi, Saenuri, Pungmi1ho, Haechanmulgyeo, Hwangkeumnodeul, Chilbobyeo, Dongjinbyeo, Younganbyeo, Junambyeo, Samkwangbyeo, and Nakdongbyeo. Twenty-one cultivars were susceptible cultivars such as Odaebyeo, Unkwangbyeo, Shinungbong1ho, Manabyeo, Hopyongbyeo, Borami, Damibyeo, Hwangchalbyeo, Sulgengbyeo, Nongrim6ho, Sasanishigi, Yunishigari, Chungmubyeo, Dongjin1ho, Huknambyeo, Guromy, Shanghehanghulna, Heukchalbyeo, Heukhwangbyeo, and Aranghwangchalbyeo.

• Korean Journal of Weed Science
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• v.4 no.2
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• pp.143-148
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• 1984

Experiments were carried out to study the germination and emergence of the red rice(sare) as a weed, Mong-geun sare, Sal sare, Ginkarag sare, Galsaegsal sare, Galsaegkarag sare. The germination and emergence of red rice were not greatly affected by soil salinification, soil pH and air temperature. Especially, in deep molding volume, emergence of red rice was greater than rice cultivar. It was considered to be due to the vitality of the mesocotyl. Submergence was expected to be a better way to control the red rice because germination rate of red rice was low under submergence.