• Current Research on Agriculture and Life Sciences
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• v.31 no.4
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• pp.280-285
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• 2013

This study supplies basic data to develop a greenhouse model for reducing the damage to single-span greenhouses caused by strong winds and heavy snow. Single-span plastic greenhouses are predominantly used for growing crops in Korea. Thus, the safety wind speeds for single-span greenhouses were calculated and compared with the actual wind speeds and snow depths over a period of 8 years in different regions to analyze the structural safety of single-span greenhouses. The unit wind load and unit snow load were applied to different designs of single-span greenhouse according to the cultivated crop to achieve a structural analysis. As a result, the maximum section force for the wind and snow load was greatest for leaf and root vegetables, where the safety wind speeds for single-span greenhouses according to the cultivated crop were 17.7 m/s(leaf vegetables), 20.2 m/s (fruit vegetables), and 22.3 m/s (root vegetables). Thus, the single-span greenhouses were not found to be safe for the wind load in most regions, except for Hongcheon, Icheon and Sungju. Plus, the safety snow depths for single-span greenhouses according to the crop were 8.8 cm (leaf vegetables), 9.4 cm (fruit vegetables), and 11.8cm (root vegetables). Thus, when comparing the safety snow depths with the actual snow depths, the single-span greenhouses were not found to be safe. Therefore, to improve the safety of single-span greenhouses, the structures need reinforcement by reducing the interval between rafters or increasing the size of the pipes. However, additional research is needed.

• Korean Journal of Plant Resources
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• v.28 no.5
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• pp.656-664
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• 2015

To produce high quality watermelon, three tetraploid watermelon breeding lines (‘SA03-1’, ‘SA06-1’ and ‘SB01-1’) were developed by treatment with different chromosome doubling reagents. To identify the optimal tetraploid inductive conditions, the three watermelon breeding lines were selected by counting the number of doubled chloroplasts in guard cells. Tetraploid induction rates differed depending on the genotypes and treatment with doubling reagents. However, the highest induction rate occurred with 1.0% colchicine (82.2%). These putative tetraploid lines were re-confirmed for ploidy using flow cytometric analysis and chromosome counting. The internode length of the tetraploid breeding lines was different when the leaf size was larger in all three tetraploid lines compared to their diploids. The fruit weight of the tetraploid fruits for ‘SA03-1’ and ‘SB01-1’ was lower than for their diploid, and the rind thickness and total sugar content (°Brix) of tetraploid SB01-1 were significantly different from those of its diploid. Tetraploid lines were sterile, yielded a lower number of seeds per fruit for ‘SA03-1’ (21), ‘SA06-1’ (62), and ‘SB01-1’ (34.7), and the seeds were larger and thicker than those of their diploids. These tetraploid breeding results will be useful for breeding new seedless watermelon cultivars.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.269-274
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• 2007

This study was performed to estimate the efficacy of three commercial mating disruptors for the control of oriental fruit moth, Grapholita molesta (Busck), using a food-baited trap to collect field females. Mated female ratios estimated in the mating disruptor-treated areas were compared with the estimates of male trap captures, and both estimates were evaluated on the basis of crop damage measured by shoot tip damage caused by G. molesta. Both males and females were attracted to the food trap-baited with terpinyl acetate in apple orchard. Spermatophore of G. molesta was similar to female bursa copulatrix in size. Though there was more than 95% reduction in male trap captures indicating significant mating disruption, significant crop damage occurred on apple leaf buds, in which more than 35% of captured females were mated. This study demonstrates that assessment of the mated females would be more reasonable to represent the efficacy of mating disruptor(s) than the assessment of the male captures in G. molesta.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.253-257
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• 2011

This study was carried out to investigate the effect of different light emitting diode (LED) irradiation on the growth of paprika (Capsicum annuum 'Cupra'). The plants were irradiated by red (660 nm), blue (460 nm) and red + blue (4 : 1) light emitting diodes above 50 cm for 5 hours after sunset. Photosynthetic photon flux (PPF) irradiated by red, blue and red + blue LED were $79{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, $75{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and $102{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ respectively. Leaf temperature of paprika grown under blue LED irradiation was the highest of $18.6^{\circ}C$. Fruit temperature was the highest under in the control (no irradiation) but it was lower than leaf temperature. There was influence of LED irradiation on the paprika plants height; under blue irradiation the plant height was the shortest, while under in the control plant height was the highest. The leaf size of under different LED irradiation was bigger than that of in the control. Mean fruit weight under different LED irradiation was significantly increased; however number of fruits and marketable yield per plant were significantly decreased as compared to the control.

• Journal of Life Science
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• v.18 no.4
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• pp.447-453
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• 2008

Zinc is an essential trace element in Human Being. Highly zinc containing yeast strain isolated from the tropical fruit, rambutan and the zinc concentration in this yeast strain was 306 ppm (30.6 mg%)per dry matter basis. This strain was found to be a rounded type, normal size, and multi-polar budding. Phylogenetic analysis using the ITS1-5.85 rDNA sequences from isolated strain is most similar to yeast Saccharomyces cerevisiae at the level of nucleotide sequence identity at 99%. This strain was produced alcohol by about 12% using fully colonized koji-rice with Aspergillus oryzae. In conclusion, the isolated strain was found to be closely related to the S. cerevisiae based on its morphological and physiological properties, and alcohol fermentation. The phylogenetic analysis of strain FF-10 using ITS 5.8S rDNA sequence data also supported the closely related to the S. cerevisiae. Accordingly, the isolated yeast was named as S. cerevisiae FF-10. Further studies on the best culture conditions for zinc production from zinc-enriched S. cerevisiae FF-10 are under investigation.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.478-490
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• 2021

We aimed to generate basic breeding data for melon (Cucumis melo L.). A total of 219 melon accessions conserved at the National Agrobiodiversity Center (NAC) in Rural Development Administration (RDA) were used in this study, of which 72 (33%) were collected from India. The majority of accessions showed orange (42%) and white (36%) flesh color. In addition to phenotypic evaluations, the accessions were genotyped using a molecular marker for the carotenoid biosynthesis gene CmOr. DNA fragments of the expected size were amplified in 205 out of 219 accessions. Digestion of the PCR products with HinfI restriction endonuclease showed 100% concordance between phenotype and genotype in green-fleshed accessions, but 98%, 97%, and 80% concordance in orange-, white-, and creamy-fleshed accessions, respectively. Sequence analysis revealed single nucleotide changes in the three positions of SNP1, SNP2 and SNP1int in the CmOr gene among accessions. These newly found alleles suggest that there are multiple mechanisms in determining fruit flesh color in melon. Also, the phenotype data of diverse accessions obtained in this study will be a valuable source for melon breeding.

• Journal of Life Science
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• v.31 no.6
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• pp.537-542
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• 2021

Schisandra nigra Max., a dioecious plant native to Jeju Island in Korea, is cultivated on a small scale for fruit production. As fruit-producing female individuals are generally considered to be more valuable than male, early identification of plant sex at the seedling stage is important. In this study, a sequence-characterized amplified region (SCAR) marker associated with a female-specific region in the genome of S. nigra was investigated. Of 120 randomly amplified polymorphic DNA (RAPD) primers, one primer (OPB-03) consistently amplified a 749 bp band in female plants. The female-specific PCR product was isolated and cloned, and the nucleotide sequences were then determined. Southern hybridization performed using the female-specific fragment as a probe produced positive signals only in genomic DNA from the female plants. This result revealed that the 749 bp segment of DNA was present in the genome of female plants but absent in the genome of male plants. A SCAR primer pair was designed based on the RAPD marker to amplify a 436 bp fragment in the genomic DNA of female plants. This primer pair amplified the expected size of DNA fragment in female plants and four monoecious individuals collected from a natural population. The SCAR marker identified in this study can be used to distinguish female-flowering individuals at the seedling stage.

• Korean Journal of Plant Resources
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• v.35 no.4
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• pp.464-470
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• 2022

In this study, the morphological characteristics of flower and fruit in five varieties (Hancho 915ho, 930ho, 10ho, 1020ho, 1030ho) from Zanthoxylum schinifolium were investigated as new varieties with different fruiting seasons. Qualitative and quantitative characteristics were investigated, spectively. For quantitative characteristics can be measured numerically, such as size and number, the varieties were identified using ANOVA and Scheffe's multiple range test. In addition, the validity of whether the quantitative characteristics of five varieties can be explained by factor analysis was reviewed. Using UPGMA, the relationship between the five varieties was confirmed by dendrogram. As a result of ANOVA and Scheffe's multiple range test there was significant difference in inflorescence width and female flower length. It had a high contribution to distinguishing varieties, which was similar to the PCA results using factor analysis. As a result of dendrogram using cluster analysis, Hancho 915ho, 1020ho and 1030ho were similar, but there was a distinct difference in the characteristics of different flowering and fruiting periods, confirming that they were different varieties.

• Journal of the Korean Wood Science and Technology
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• v.42 no.4
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• pp.428-438
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• 2014

Functional effects of cauliflower mushroom (Sparassis latifolia) have been magnified by various media and internal and external research papers, recently. So, optimum condition of wood chip particle size and cultivation method of high ${\beta}$-glucan content for bulk cultivation generalization of cauliflower mushroom farms researched. As a result, T7 (1~2 mm 25%, 2~4 mm 50%, over 4 mm 25%) media as mixed media of certain ratio of particle size, showed excellent growth at $11.5{\pm}1.0$ cm / 44 days. Also, production of fruit body found higher than control and marketable pileus part took 85% ratio. The ${\beta}$-glucan content at media composition condition showed 1.4~2.4 times higher content in stipe part than pileus part. Also, PCF300 medium found 59.5% highest ${\beta}$-glucan content in stipe part. While ${\beta}$-glucan content showed 33.0% low content in pileus part. Therefore it needed additional study that ${\beta}$-glucan content improved in pileus part. In conclusion, production of high ${\beta}$-glucan content cauliflower mushroom was possible by T7 condition (wood chip particle size: 1~2 mm 25%, 2~4 mm 50% and over 4 mm 25%, composition: corn powder, flour and 300 ppm yeast).

• Research in Plant Disease
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• v.14 no.1
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• pp.57-60
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• 2008

A rhizopus soft rot caused by Rhizopus stolonifer occurred sporadically on apple fruits (Malus pumila var. dulcissima Koidz.) at a wholesale market of agricultural products in Jinju, Korea in 2006 and 2007. Infected fruits were rapidly water-soaked, softened and rotted. The symptoms were initiated mainly from wounds or cracks occurred at harvest time. Sporangiophores were $950{\sim}1,900\;{\mu}m$ in length and $12{\sim}22\;{\mu}m$ in width. Sporangia were globose or hemispheric and $82{\sim}185\;{\mu}m$ in size. The color of sporangia was white and cottony at first and gradually turned to brownish black, bearing abundant spores when matured. Columella were hemispheric and $70{\sim}85\;{\mu}m$ in size. Sporangiospores were irregular round or oval, brownish-black streaked and $8{\sim}18{\times}7{\sim}8\;{\mu}m$ in size. Optimum temperature for mycelial growth of the fungus on PDA was $25^{\circ}C$. On the basis of mycological characteristics and pathogenicity to apple the causal fungus was identified as Rhizopus stolonifer (Ehrenb.) Vuill. This is the first report of Rhizopus soft rot by R. stolonifer on Fuji apple in Korea.