Jeollanam do Agricultural Research and Extension Services

Naju, South Korea

Jeollanam do Agricultural Research and Extension Services

Naju, South Korea
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Lee J.H.,Chonnam National University | Ma K.C.,Jeollanam do Agricultural Research and Extension Services | Ko S.J.,Jeollanam do Agricultural Research and Extension Services | Kang B.R.,Jeollanam do Agricultural Research and Extension Services | And 2 more authors.
Current Microbiology | Year: 2011

Bacterial culture filtrates of an aggressive rhizobacterium, Pseudomonas chlororaphis O6, displayed strong nematicidal activity. The nematicidal activity of P. chlororaphis O6 was markedly reduced in the gacS mutant of P. chlororaphis O6 grown in the presence of glycine, but no reduction of nematicidal activity in the gacS mutant was noted in the absence of glycine. The results of bioassay with P. chlororaphis O6 mutants showed that phenazine and pyrrolnitrin production was not a major factor, but the effects of glycine in the culture medium suggest that formation of hydrogen cyanide might be important. Assessments in greenhouse studies with tomatoes growing in nematode-infested soils confirmed that the application of P. chlororaphis O6 resulted in the control of the root-knot nematode. Our results demonstrated that P. chlororaphis O6 could be employed as a biocontrol agent for the control of the root-knot nematode, and the global regulator, GacS, functions as a positive regulator of the expression of nematicidal compounds and enzymes in P. chlororaphis O6. © 2010 Springer Science+Business Media, LLC.


Joung Y.H.,Chonnam National University | Picton D.,U.S. Department of Agriculture | Park J.O.,Jeollanam do Agricultural Research and Extension Services | Roh M.S.,U.S. Department of Agriculture
Horticulture Environment and Biotechnology | Year: 2011

The hybrid origin of Ilex × wandoensis C. F. Mill. & M. Kim was studied by polymerase chain reaction (PCR) using taxa-specific primers, restriction fragment length polymorphism (RFLP) analysis of the internal transcribed spacer 2 (ITS2) regions, and sequence analysis of PCR amplicons of the ITS region. Five accessions of I. integra Thunb., three accessions of I. cornuta Lindl. & Paxton and 22 accessions of I. × wandoensis, tentatively characterized based on morphological characters, were selected and subjected to PCR analysis. Amplified products of the selected accessions were sequenced. Significant variations were observed in leaf morphology of I. × wandoensis accessions based on the presence of single or multiple teeth and cuneate or rounded base of the leaf blade. Based on the PCR amplifications, sequence and RFLP analysis using HhaI and HaeIII restriction enzymes, the hybrid origin of I. × wandoensis was confirmed. Some accessions appeared to be introgressant and either crossed back to I. integra or to I. cornuta based on the RFLP polymorphisms. Analysis of the ITS2 region of the nuclear ribosomal DNA (nrDNA) using primers specific to certain taxon or taxa, and RFLP analysis of PCR amplicons proved to be useful tools to study the nature of interspecific hybridization and introgressions in complement with morphological characters. © 2011 Korean Society for Horticultural Science.


Lim K.-H.,Jeollanam do Agricultural Research and Extension Services | Gu M.,Texas AgriLife Research Center | Kim B.-S.,Jeollanam do Agricultural Research and Extension Services | Kim W.-S.,Chonnam National University | And 6 more authors.
Journal of Horticultural Science and Biotechnology | Year: 2015

A study was conducted to compare the effects of an open-field or rain-shelter system on the physiological responses of four Asian pear (Pyrus pyrifolia Nakai) cultivars (‘Hanareum’, ‘Wonhwang’, ‘Manpungbae’, and ‘Niitaka’) in an organic orchard in 2013 and in 2014. The rain shelter was covered with polyethylene film between 31 March - 4 July each season, then uncovered during the remainder of each growing season. The incidences of fruit disease and insect pests, and fruit quality were measured in 2013. The rain-shelter system increased leaf chlorophyll contents to a SPAD value of 44.0 and rates of CO2 assimilation to 17.0 µmol m-2 s-1 in all four cultivars. It also increased leaf total nitrogen concentrations and dry weights in ‘Wonhwang’ and ‘Niitaka’ trees compared to the open field. Freezing temperatures were observed in the open field during flowering. The rain-shelter system resulted in a 10.3% delay in completion of current year shoot extension in all cultivars on 7 August 2014. It also significantly increased fruit yields (22,900 kg ha-1), mean fruit fresh weights (582 g), fruit size (94 mm in length and 105 mm in diameter), and total soluble solids contents (12.7 ºBrix) in 2013 and 2014. The incidence of scab on fruit was reduced by 3.3% in the rain-shelter system in 2013, but scab and rust on leaves and fruit were not completely prevented by this system in September 2014. The incidence of green chafers on leaves was significantly reduced from 23.3% to 51.0% by the rain-shelter system on 15 July 2014. The average income from fruit production in both seasons increased by approx. 138%, 167%, 326%, and 215% for rain-sheltered ‘Hanareum’, ‘Wonhwang’, ‘Manpungbae’, and ‘Niitaka’ trees, respectively, compared to open-field production. © 2015, Headley Brothers Ltd. All rights reserved.


Lee M.-S.,Chonnam National University | Kang B.-M.,Chonnam National University | Lee J.-E.,Chonnam National University | Choi W.-J.,Chonnam National University | And 9 more authors.
Agriculture, Ecosystems and Environment | Year: 2013

Despite the growing body of evidence that ongoing warming modifies the cereal quality of several crop species, little is known about how it interacts with other climate change drivers. Here, we examined how elevated [CO2], warming, and extreme wet events (EWEs) would affect the grain quality of a temperate rice (Oryza sativa L.). In 2009 and 2010, plants were grown at two levels of [CO2] (c. 390 and 650μll-1) and three levels of warming (ambient, +1.2°C and +2.2/2.4°C) over the seasons in six independent temperature gradient field chambers (three each for ambient and elevated [CO2]). From 20 days after heading, plants were exposed to EWE with a simulated rainfall of 30mm a day and cloud cover by shading (c. 18% of full sunlight) for 10 consecutive days. There were also control plots, which were non-treated (NT) in terms of EWE. We found that warming and EWE, both independently and in their interaction, lead to a significant reduction in the percentages of sound grains, whereas elevated [CO2] does not seem to do so. Not only warming and EWE, but also elevated [CO2] resulted in a significant increase of immature chalky grains (ICGs), which mostly consisted of milky-white chalky grains, degrading the grain quality. In addition, warming interacted positively with elevated [CO2] on ICGs, whereas the warming sensitivity of IGCs was moderated in EWEs: e.g., on average, the % of ICGs in ambient vs. elevated [CO2] were 8.5% vs. 9.4%, 10.7% vs. 18.1% and 17.8% vs. 29.8% at ambient (24.7°C), +1.2°C and +2.4°C, respectively, whereas they in NT vs. EWE were 1.2% vs. 16.6%, 7.7% vs. 21.1% and 19.4% vs. 28.2%. Our results tightly confirmed that elevated [CO2] leads to a significant reduction in rice grain protein content (PC). While warming had little effect on the PC, EWE had a significant positive effect, and the EWE-induced increase in PC was smaller in elevated (+3.3%) than in ambient [CO2] (+10.9%). Given the rice quality predictor of ICGs and PC, our findings imply that expected climate change and weather extremes have a great potential to degrade the quality of rice, in terms of its milling, cooking, eating, and nutritional quality, as well as market value. © 2013 Elsevier B.V.


Kim R.J.,Chonnam National University | Jo Y.H.,Chonnam National University | Oh S.H.,Chonnam National University | Park C.H.,Chonnam National University | And 6 more authors.
Genes and Genomics | Year: 2010

Hemolin has been known to play a key role in insect innate immunity. In an attempt to examine expression pattern of the Hemolin gene in the diamondback moth, Plutellea xylostella, the full-length cDNA of Hemolin was cloned using 5′-RACE PCR technique. The cDNA contained a 5′ untranslated region of 48 nucleotides and a 3′ untranslated region of 198 nucleotides, including a stop codon (TAA) and a poly (A) tail. It consists of 1,401 bp with an open reading frame of 1,245 bp, encoding 414 amino acids. The deduced amino acid sequence of PxHemolin has relatively low identities (35-42%) to various insect Hemolins. However, it has high three-dimensional structural similarity to Hemolin. Interestingly, analysis of spatial expression pattern of Px Hemolin shows that it was highly expressed in the Malpighian tubule and the silk gland although it was also detected in fat body and gut. Furthermore, Px Hemolin mRNA was highly induced 3 hr after immune-challenging with lipopolysaccharide and was gradually up-regulated after laminarin treatment. These data suggest that PxHemolin may play a role in innate immune responses although it remains to further elucidate the precise biological © The Genetics Society of Korea and Springer 2010.


Jung H.-J.,Sunchon National University | Jung H.-J.,Jeollanam do Agricultural Research and Extension Services | Ahmed N.U.,Sunchon National University | Park J.-I.,Sunchon National University | And 4 more authors.
PLoS ONE | Year: 2012

The self-incompatibility (SI) system is genetically controlled by a single polymorphic locus known as the S-locus in the Brassicaceae. Pollen rejection occurs when the stigma and pollen share the same S-haplotype. Recognition of S-haplotype specificity has recently been shown to involve at least two S-locus genes, S-receptor kinase (SRK) and S-locus protein 11 or S locus Cysteine-rich (SP11/SCR) protein. Here, we examined the function of S60, one SP11/SCR allele of B. rapa cv. Osome, using a RNAi-mediated gene silencing approach. The transgenic RNAi lines were highly self-compatible, and this trait was stable in subsequent generations, even after crossing with other commercial lines. These findings also suggested that the resultant self-compatibility could be transferred to commercial cultivars with the desired performances in B. rapa. © 2012 Jung et al.


Kim B.-S.,Jeollanam do Agricultural Research and Extension Services | Gu M.,Texas AgriLife Research Center | Cho K.-C.,Jeollanam do Agricultural Research and Extension Services | Yun B.-K.,Jeollanam do Agricultural Research and Extension Services | And 2 more authors.
Journal of Horticultural Science and Biotechnology | Year: 2015

The physical and chemical properties of the soil and the growth and fruit yields of mature ‘Fuyu’ persimmon (Diospyros × kaki Thunb.) trees were measured as responses to the frequency of mowing in an organic orchard from 2011 to 2013.Treatments included zero, two, three, or four mowings per annum of the natural vegetation in the orchard to which organic fertiliser was applied annually. The four-fold mowing treatment increased the biomass of the cut vegetation to 8.4 metric tonnes (MT) ha-1 year-1, followed by the three-fold (6.4 MT ha-1 year-1), two-fold (5.7 MT ha-1 year-1), and zero mowings (3.4 MT ha-1 year-1) and the corresponding supply of macro-nutrients from the biomass.The four-fold mowing treatment reduced the bulk density of the soil from 1.3 kg m-3 to 1.1 kg m-3 and increased soil porosity to 59% (measured as air-filled space) as well as increasing the soil organic matter content to 25 - 30 mg kg-1 in March and September 2011 and 2012. Foliar macro-nutrient concentrations, except for foliar P, increased in the two-, three-, and four-fold mowing treatments in 2012. An increased mowing frequency stimulated the number of watersprout shoots, and reduced light transmission into the tree canopy in 2012 and in 2013. The three- and four-fold mowing treatments increased average fruit yields by 28.1 - 29.4 MT ha-1 and average fruit fresh weights (FWs) to 209 - 211 g compared to zero mowing (23.3 MT ha-1 fruit yield and 197 g fruit FW) over the 3 years. The estimated average gross income from fruit sales increased by 183% in the three- and four-fold mowing treatments compared to the zero-mowing treatment over the 3 years. © 2015, Headley Brothers Ltd. All rights reserved.


Kim B.S.,Jeollanam do Agricultural Research and Extension Services | Pagay V.,Oregon State University | Cho K.-C.,Jeollanam do Agricultural Research and Extension Services | Na Y.-G.,Jeollanam do Agricultural Research and Extension Services | And 4 more authors.
Journal of Horticultural Science and Biotechnology | Year: 2015

Various amounts of pelletised oil cake were applied to mature, non-astringent ‘Fuyu’ persimmon (Diospyros×kaki Thunb.) trees from 2011 to 2013, to evaluate the most appropriate rate of application of the organic fertiliser to improve tree vigour and reproductive growth. Treatments included application of 0, 25, 50, 75, or 100% of the recommended amount (RA) of oil cake, respectively. Oil cake application at 50%, 75%, or 100% of the RA increased dry matter (DM) production by > 1,500 kg ha-1 compared to the 0% RA control. All rates of application of oil cake increased the pH, organic matter content, macro-nutrient concentrations, cation exchange capacity, and electrical conductivity of the soil at depths of 0-20 cm in 2012 and in 2013. Consequently, all applications of oil cake increased leaf N concentrations by > 1%, and resulted in more than four water sprouts (shoots) per tree compared to the 0% RA treatment in 2012 and in 2013. Light interception by the central region of the canopy of each tree was reduced as rates of application of oil cake increased (R2 = 0.559). All rates of application of oil cake increased mean fruit weights by > 8 g, and fruit firmness values by > 1.4 N, compared to the 0% RA controls. The 3-year average fruit yield was highest (29,110 kg ha-1) in the 50% RA treatment. Gross incomes from the 50% RA treatment in 2012 and in 2013 were approx. 19% higher than those from the 0% RA controls. Together, these results indicate that 50% RA was the optimum rate of application of oil cake to increase fruit yields, nutrient levels, and the profitability of non-astringent persimmon trees. © 2015, Headley Brothers Ltd. All rights reserved.


Seo J.-B.,Jeollanam do Agricultural Research and Extension Services | Shin G.-H.,Jeollanam do Agricultural Research and Extension Services | Lee Y.-S.,Jeollanam do Agricultural Research and Extension Services | Jang M.-H.,Jeollanam do Agricultural Research and Extension Services | And 4 more authors.
Korean Journal of Horticultural Science and Technology | Year: 2014

‘Hei-G’ is a new tomato cultivar originating from the cross of two inbred lines, the maternal plant TKUI-3 separated from ‘Kame’ in 2007, and the paternal plant AL-1 developed by pedigree breeding. The new cultivar was registered as ‘Hei-G’ named ‘JTB026 (Jeonnam-2)’ based on characteristics and yield trials carried out in the spring of 3 years, from 2010 to 2012. ‘Hei-G’ is an indeterminate type with strong plant vigor. The fruit is round and the ripening fruit is blackish red. The average fruit weight of ‘Hei-G’ is about 43.4 g, and its marketable yield is 4,944 kg·10 a-1. The lycopene content of ‘Hei-G’ (11.8 mg?100 g-1)is higher than that of other tomatoes (e.g., cv. Rapido, 3.1 mg). In addition, ‘Hei-G’ is suitable for environment-friendly protected cultivation because of its resistance to powdery mildew. © 2014 Korean Society for Horticultural Science.


Shin G.-H.,Jeollanam do Agricultural Research and Extension Services | Seo J.-B.,Jeollanam do Agricultural Research and Extension Services | Kim D.I.,Jeollanam do Agricultural Research and Extension Services | Seung-Koo Y.,Jeollanam do Agricultural Research and Extension Services | And 3 more authors.
Acta Horticulturae | Year: 2014

In the environment-friendly farming system, Fusarium wilt and crown brown rot occurred during the planting period and powdery mildew and gray mold during the harvesting. They have been causing serious damages at strawberry cultivation regions in Korea. Fusarium wilt caused by the soil-borne pathogen Fusarium oxysporum f. sp. fragariae Winks & Williams, was harmful at early growth stage of strawberry. Control of Fusarium wilt causing soil-borne disease was tried by soil drenching after addition of rice and wheat bran (1-2 t/10 a). The density of Fusarium wilt decreased and disease occurrence also decreased after strawberry plantation. Antagonistic microorganisms were tested with respect to the control of gray mold and powdery mildew on strawberry. Bacillus velezensis isolate successfully inhibited mycelium growth of gray mold. Liquid formulation of B. velezensis antagonist was treated three times (1/week) for three weeks on gray mold in the field, resulting in higher control efficacy (50.2%) than registered bio-pesticide. When B. velezensis antagonist was sprayed three times with 5-day intervals on powdery mildew in the field, the disease was successfully controlled with control efficacy of 88.7%.

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