• Research in Plant Disease
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• v.19 no.2
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• pp.90-94
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• 2013

Potato cv. 'Haryeong' was bred with high solids, resistance to late blight and good culinary quality. It has been registered as new potato variety in 2005. Tuber necrosis symptoms such as severe superficial necrosis, raised surface lesions and ringed necrotic areas were found in tubers of 'Haryeong' during storage of seed potatoes in 2010. Potato virus Y (PVY) was detected from these symptomatic tubers by the analysis of RT-PCR using a primer set specific to coat protein gene of PVY. The nucleotide sequence of RT-PCR product ($PVY^{Hkr}$) was determined and compared to those of other strains, such as $PVY^{Kor}$, $PVY^N$, $PVY^{NTN}$, $PVY^O$, and $PVY^C$ registered in GeneBank. The result showed that $PVY^{Hkr}$ was exactly the same as $PVY^{Kor}$, Korean isolate reported in 2005, except two nucleotides. To verify the PVY was responsible for the tuber necrosis symptoms shown in the tubers of 'Haryeong', a bioassay was done using two viruses (PVY and Potato leafroll virus) and five potato cultivars ('Haryeong', 'Superior', 'Atlantic', 'Dejima', and 'Chubaek'). As expected, the same necrosis symptom appeared in tubers of 'Haryeong' infected with PVY only during the storage period.

• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.295-299
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• 2007

Resistance to chestnut gall wasp (Dryocosmus kuriphilus) of Korean prevailing chestnut cultivars, new cultivars released by Korea Forest Research Institute (KFRI), and local cultivars by growers was investigated to select optimal cultivars suitable for main chestnut producing areas. During three years investigated from 2004 to 2006, we could find no damage by chestnut gall wasp in any cultivars of test sites located in Gongju and Chungju of the central area. However, most cultivars of Gwangyang, Sancheong and Hapcheon sites located in the southern area showed a lot of damage by chestnut gall wasp. Hapcheon was most severe in comparison with regional damage by chestnut gall wasp. From comparison among cultivars, Kwangeun, Sandae, Eunsan and Idae released by KFRI showed no damage suggesting the highest resistant cultivars. On the contrary, over 20% in total damage by chestnut gall wasp was investigated in Tanzawa, Riheiguri, Kurakata-amaguri, Pyeonggi, Gwangdeok, Seil, Sinipyeong and Yumabyuni suggesting susceptible cultivars. In damage by chestnut gall wasp according to investigated position within tree, weak shoot was more severe than bearing shoot. Damage by chestnut gall wasp of major cultivars in Gwangyang, Sancheong and Hapcheon sites was remarkably decreased in 2006, and it seems to be caused by biological control by natural enemies such as Torymus sinensis.

• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.116-122
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• 2013

We investigated characteristics and self-incompatibility genotypes of 11 crabapple cultivars to introduce a new pollinizer of 'Fuji' apple tree in Korea. Flowering dates of eleven crabapples were two to seven days earlier than that of 'Fuji'. The rate of pollen germination in vitro was ranged from 85.6% to 98.0% except 'Virginia'. Controlled pollination treatment with each crabapples to 'Fuji' increased fruit set rate about 20.4% to 34.4%, the number of seed per fruit about 13.8% to 42.3% and fruit weight about 7.4% to 16.7% compared to open pollination. Tested crabapples were resistant to peach fruit moth, brown leaf spot and sooty blotch in general. A PCR amplification method using S-RNase primers was carry out in eleven crabapples. S-alleles, $S_3$, $S_5$, $S_9$, $S_{10}$, $S_{20}$, $S_{26} from six crabapples were determinated. Through sequencing analysis, $S_5$ ('Manchurian', 'Virginia') and $S_9$ ('Yantaishagou') showed 100% homologous to previous result. Based on our results, it was recommended that 'Manchurian', 'Hopa A', 'Hanyaehanakaidou', 'Spectabilis' could be promising pollinzers for 'Fuji' apple cultivar.

• Journal of Mushroom
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• v.16 no.3
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• pp.175-179
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• 2018

The button mushroom 'A. bisporus' is the most commonly grown mushroom worldwide. The color of 'Agaricus bisporus' is white and brown. Recently, the consumption of brown button mushrooms has been increasing steadily. 'Danseok-1ho' was bred using the multi-spore random mating method and named after Danseok Mountain in Gyeongju, the region where 'A. bisporus' was first grown in Korea. The optimum temperature for mycelial growth was between $20^{\circ}C$ and $30^{\circ}C$, and the mushroom production temperature was between $15^{\circ}C$ and $20^{\circ}C$. The color and shape of 'Danseok-1ho' are medium brown and spherical, respectively. The width and thickness of the pileus are 45.1 mm and 23.5 mm, respectively. The hardness and L of chromaticity of 'Danseok-1ho' are $8,937g/{\Phi}5mm$ and 50.4, respectively. The incubation period is around 20 days and mushroom production takes about 18 days after casing. A typical characteristic of 'Danseok-1ho' is that the individual occurrence rate is high, so mushroom losses are low during harvest.

• Current Research on Agriculture and Life Sciences
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• v.31 no.4
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• pp.265-271
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• 2013

The objective of this study was to find out the optimum number of fruiting per a flower cluster on 5 domestic strawberry cultivars (Fragaria${\times}$ananassa Duch.), 'Daewang', 'Ssanta', 'Okmae', 'Seolhyang' and 'Maehyang'. Therefore, three ways of fruit thinning, 4~5 fruiting, 7~9 fruiting and all fruiting per a flower cluster were compared. After fruit thinning, the first fruit weights were increased from the second flower cluster on 'Seolhyang' and 'Maehyang', but from the third one on 'Daewang' and 'Ssanta'. There was no difference in first fruit weight by the flower thinning ways on 'Okmae'. The mean fruit weights of all the cultivars were increased and sugar contents also were increased, but acidities were decreased. The peduncle lengths were shortened by fruit thinning, but there was no difference in number of leaf, petiole length and crown diameter. Marketable yields by 4~5 fruiting per a flower cluster than all the fruit setting were higher 4.3% and 6.6% respectively on 'Daewang' and 'Maehyang'. In contrast, the yields were higher 3.1%, 3.5% and 9.1% in 7~9 fruiting per a flower cluster than all fruiting on 'Ssanta', 'Okmae' and 'Seolhyang' respectively. As the result, we could improve the fruit quality and could increase marketable yield by fruit thinning with matching flowering characteristics of those strawberry cultivars.

• 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.

• Weed & Turfgrass Science
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• v.3 no.1
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• pp.29-40
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• 2014

Research was initiated to investigate early establishment characteristics and germination pattern of Kentucky bluegrass (KB, Poa pratensis L.). Fifteen cultivars were evaluated under alternative conditions (8 hours light at $25^{\circ}C$ and 16 hours dark at $15^{\circ}C$). Significant differences were observed in germination characteristics and germination pattern among KB cultivars. A final germination percentage differed in cultivars, being 75.25 to 89.50%. The first germination was initiated between 6 and 9 DAS (days after seeding). As for the first germination percentage, 'Brilliant' and 'Midnight II' produced 14.50% and 23.00%, respectively, while the others were most below 5%. Days to 75% germination were between 15.08 and 28.80 DAS. 'Excursion', 'Midnight II', 'Odyssey', 'Midnight' and 'Courtyard' were fastest. The slowest cultivar was 'Voyager II', being over 28 DAS, which were 13 to 14 days slower than the fastest ones. Considering the first germination percentage, days to the first germination, days to 75% germination, and germination pattern, 'Midnight II', 'Excursion' and 'Midnight' were regarded as excellent cultivars under alternative conditions. From this study, information on differences in germination characteristics and patterns would be practically useful for a golf course construction when established with KB.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.833-836
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• 2013

'Hei' is a new cultivar of red with black flesh; originated from the cross of two inbred lines, mother plant, TKUI separated from 'Kame' in 2007 and father plant, TLB separated from tomato collected in Europe by pedigree breeding method. 'Hei' was tested for specific character and productivity of lines of tomatoes in spring for 2 years, 2008 to 2009. This variety had resistance to powdery mildew. 'Hei' is an indeterminate type. The fruit shape is round and the skin color is blackish red. The average fruit weight of 'Hei' is about 127.9 g and marketable yield is $5,715kg{\cdot}10a^{-1}$. Lycopene contents of 'Hei' are about $18.5mg{\cdot}100g^{-1}$, high compared with other tomato ($3.1mg{\cdot}100g^{-1}$). 'Hei' is suitable for environment-friendly protected cultivation because of resistance to powdery mildew.

• Journal of Mushroom
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• v.11 no.4
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• pp.244-248
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• 2013

"Hwaseong 5ho" was developed by the method of Di-mon mating between monokaryotic strains derived from "Hwaseong 1ho" and dikaryotic strain "PSC109". The color of pileus was dark grayish brown, the shape of pileus was convex or infundibuliform. The length of stipe was longer and the thickness of stipe was some thinner than Suhan 1ho. Material properties of stipe of "Hwaseong 5ho" was higher in strength, hardness, chewingness and brittleness than Suhan 1ho, but similar in elasticity and cohesion. RAPD using URP-primer showed not the same between two strains. Days of primordia formation period were 22-27 days after spawning, that was a little later than Suhan 1ho. In the trial using culture box containing composted cotton waste, yield index of 'Hwaseong 5ho' was 16.6% higher than Suhan 1ho. The farm field trial were showed stable productivity in each different growing conditions.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.303-309
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• 2014

The purpose of this study is to suggest indicators and proper standards to forecast the sensory quality of 'Hongisul' grape. Further, this study determines the optimum fruit load of 'Hongisul' grape reflecting consumer preference. Among several quality attributes, identified through instrumental and sensory evaluation, soluble solid-acid ratio was the most useful indicator of consumer preference for 'Hongisul' grapes. The ideal soluble solid-acid ratio for marketable grapes was found to be higher than 86.3. Analysis on the effects of fruit load control on fruit quality revealed a negative correlation where the latter increased as the former decreased. This trend is common for all grape species. The field with a fruit load of $1,400kg{\cdot}10a^{-1}$ exhibited a soluble solid-acid ratio of less than 86.3, uneven coloring and slow softening texture at the mature stage. However, fruit quality proved excellent in the field with a fruit load of $1,200kg{\cdot}10a^{-1}$ or less. It is therefore proposed that fruit load should be controlled to $1,200kg{\cdot}10a^{-1}$ or less when growing 'Hongisul' grapes to produce high quality grapes. We believe that this result can be used as a standard in judging harvest time and evaluating fruit quality.