• The Plant Pathology Journal
• /
• v.26 no.4
• /
• pp.353-359
• /
• 2010

In order to control postharvest spoilage of satsuma mandarin fruits, rhizobacteria were isolated from soil samples. The Pantoea agglomerans strain 59-4 (Pa 59-4) which suppresses the decay of mandarin fruit by green and blue mold, was tested for the control efficacy and its mode of action was investigated. Pa 59-4 inhibited infection by green and blue mold on wounded mandarins, which were artificially inoculated with a spore suspension of Penicillium digitatum and P. italicum with control efficacies of 85-90% and 75-80%, respectively. The biocontrol efficacy was increased by raising the concentration of cells to between $10^8$ and $10^9\;cfu/ml$, and pretreatment with the antagonist prevented subsequent infection by green mold. The population of Pa 59-4 was increased more than 10 fold during the 24 hr incubation at $20^{\circ}C$, indicating that colonization of the wound site might prevent the infection by green mold. Despite poor antifungal activity, the Pa 59-4 isolate completely inhibited the germination and growth of P. digitatum spores at $1{\times}10^8\;cfu/ml$. We argue that the control efficacy was mediated by nutrient competition. Overall, the effective rhizobacterium, Pa 59-4, was shown to be a promising biocontrol agent for the postharvest spoilage of mandarin fruits by green and blue mold.

• Horticultural Science & Technology
• /
• v.31 no.3
• /
• pp.299-307
• /
• 2013

A radish (Raphanus sativus L.) polygalacturonase-inhibiting protein (PGIP) gene was cloned and compared to the PGIP gene (BrPGIP2) from Chinese cabbage (Brassica rapa ssp. pekinensis) in order to gain more information on controlling a disease and improving produce quality. To clone the radish PGIP gene, primers were designed based on conserved sequences of two PGIP genes (BnPGIP1 and BnPGIP2) from rape (B. napus L. ssp. oleifera), Chinese cabbage and Arabidopsis thaliana. PCR cloning was performed with cDNA from the stigma of radish 'Daejinyeoreum' as a template to confirm DNA fragments which were about 600 base pair in size. Sequence analysis revealed 84.1% homology with BrPGIP2 and 70.1% with BnPGIP1. DNA walking was conducted to confirm the open reading frame of 972 bp, and the gene was named RsPGIP1. RsPGIP1 consisting with 323 amino acids (aa) has a high leucine content (54/323) and contains 10 leucine-rich repeat domains, as do most BrPGIPs of Chinese cabbage. The gene expression of RsPGIP1 was induced by abiotic stresses and methyl jasmonate. It showed enrichment in the stigma and the primary root than a leaf. Cloning RsPGIP1 will aid to further apply practices on postharvest quality maintenance and disease control of the root.

• The Plant Pathology Journal
• /
• v.25 no.4
• /
• pp.361-368
• /
• 2009

The efficacy of the combination of Burkholderia cepacia B23 with 0.75% chitosan and 3% calcium chloride ($CaCl_2$) as a biocontrol treatment of anthracnose disease of papaya caused by Colletotrichum gloeosporioides, was evaluated during storage. The growth of B. cepacia B23 in papaya wounds and on fruit surfaces was not affected in presence of chitosan and $CaCl_2$ or combination throughout the storage period. The combination of B. cepacia B23 with chitosan-$CaCl_2$ was more effective in controlling the disease than either B. cepacia B23 or chitosan or other combination treatments both in inoculated and naturally infected fruits. Combining B. cepacia B23 with chitosan-$CaCl_2$ gave the complete control of anthracnose infection in artificially inoculated fruits stored at $14^{\circ}C$ and 95% RH for 18 days, which was similar to that obtained with fungicide $benocide^{(R)}$. Moreover, this combination offered a greater control by reducing 99% disease severity in naturally infected fruits at the end of 14 days storage at $14^{\circ}C$ and 95% RH and six days post ripening at $28\pm2^{\circ}C$, which was superior to that found with $benocide^{(R)}$ or other treatments tested. Thus, postharvest application of B. cepacia B23 with chitosan-$CaCl_2$ as enhancers represents a promising alternative to synthetic fungicides for the control of anthracnose in papaya during storage.

• The Plant Pathology Journal
• /
• v.29 no.2
• /
• pp.168-173
• /
• 2013

Apple ring rot disease, caused by Botryosphaeria dothidea (Moug. ex. Fr) Ces. et de Not., is one of the most important diseases on apple fruits. In this study, strain 9001 isolated from healthy apple fruits from an infested orchard was evaluated for its biocontrol activity against apple ring rot in vitro and in vivo. Strain 9001 showed obvious antagonistic activity to B. dothidea YL-1 when plated on potato dextrose agar. Soaking healthy apples in the bacterial suspensions of strain 9001 prior to artificial inoculation of fungal pathogen resulted in a dramatic decrease in disease incidence when compared to the control. Moreover, either field application in the growth season or postharvest treatment of apples from infected orchards with bacterial suspensions of strain 9001 resulted in significantly reduced disease incidence within the storage period for 4 months at room temperature. Based on the phylogenetic analysis of 16S rRNA and the gyrA gene, strain 9001 was identified as Bacillus amyloliquefaciens. These results indicated that B. amyloliquefaciens 9001 could be a promising agent in biocontrol of apple ring rot on fruit, which might help to minimize the yield loss of apple fruit during the long postharvest period.

• Korean Journal of Agricultural Science
• /
• v.39 no.1
• /
• pp.117-123
• /
• 2012

Pathogenic fungi and bacteria such as Pectobacterium atrosepticum, Clavibacter michiganensis subsp. sepedonicus, Verticillium albo-atrum, and Rhizoctonia solani were the major microorganism which causes diseases in seed potato during postharvest process. Current detection method for disease-infected seed potato relies on human inspection, which is subjective, inaccurate and labor-intensive method. In this study, a reflectance spectroscopy was used to classify sound and disease-infected seed potatoes with the spectral range from 400 to 1100 nm. Partial least square discriminant analysis (PLS-DA) with various preprocessing methods was used to investigate the feasibility of classification between sound and disease-infected seed potatoes. The classification accuracy was above 97 % for discriminating disease seed potatoes from sound ones. The results show that Vis/NIR reflectance method has good potential for non-destructive sorting for disease-infected seed potatoes.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2007.11a
• /
• pp.65-72
• /
• 2007

Phytochemicals have long been known to hold a number of physiological benefits, including antioxidant, anticardiovascular activities and anticancer. The profitable effects of phytochemicals from food sources such as vegetables and fruits, with respect to neurodegeneration, are only beginning to receive increased attention. Alzheimer's disease (AD) is one of the major neurodegenerative diseases for which no treatment is available, and characterized by loss of cognition and memory. Many recent studies show that the brain of AD patient is subjected to increased oxidative stress resulting from free radical damage, and the resulting cellular malfunctions are widely believed to be responsible for neuronal degeneration in AD. In this study, the relative relation between AD and phytochemicals were surveyed.

• Research in Plant Disease
• /
• v.9 no.4
• /
• pp.201-204
• /
• 2003

This study was conducted to identify optimum ripening condition for kiwifruits (Actinidia deliciosa) to prevent postharvest fruit rots caused by Botryosphaeria dothidea, Diaporthe actinidiae and Botrytis cinerea. The optimum temperatures for mycelial growth of B. dothidea, D. actinidiae and B. cinerea were $26{\sim}35^{\circ}C$, $26{\sim}29^{\circ}C$ and $20{\sim}26^{\circ}C$, respectively, and the incidence was closely related with the temperature. Although kiwifruits ripened faster at higher temperatures, the rates of diseased fruits increased with the rates of ripened fruits increased. Optimum conditions for ripening of kiwifruit were 20-day at 17C.

• Research in Plant Disease
• /
• v.9 no.4
• /
• pp.205-208
• /
• 2003

Fungicides of tebuconazole wp, iprodione wp and flusilazole wp were applied for the control of postharvest fruit rots of kiwifruit (Actinidia deliciosa) in the field in 2000 and 2001. More than 3 consecutive applications of these fungicides from the late June with 10-day-interval successfully controlled the diseases. It was found in the field trial in 2002 that 4 consecutive spays from mid of June with 10-day-interval was found to be the most effective application program for tebuconazole wp, iprodione wp and flusilazole wp, The results suggested that currently registered fungicides of benomyl wp and thiophanate-methyl wp can be substituted by tebuconazole wp, iprodione wp and flusilazole wp for the control of the diseases in Korea. Use of these fungicides can restrain emergence of fungicide resistant strains of postharvest fruit rot pathogens with benefit of reduced application of chemicals for food safety and environmental conservation.

• Research in Plant Disease
• /
• v.24 no.3
• /
• pp.175-181
• /
• 2018

Incidence rates of bacterial canker, bacterial leaf spot and postharvest fruit rot on the Korean yellow-fleshed kiwifruit cv. Haegeum were compared with those on the most popular green-fleshed kiwifruit cv. Hayward grown in several naturally infected kiwifruit orchards in 2013 and 2014. The percentages of diseased leaves caused by bacterial canker were 18.5% and 17.3% on Hayward in 2013 and 2014, but those on Haegeum were 1.2% and 0%, respectively. The percentages of diseased leaves caused by bacterial leaf spot on Hayward were 63.5% and 16.2% in 2013 and 2014, respectively, but no bacterial leaf spots were observed on Haegeum in both years. The average percentages of diseased fruits caused by postharvest fruit rot were 24.2% and 20.5% on Hayward in 2013 and 2014, while 6.3% and 4.4% and Haegeum, respectively. Botryosphaeria dothidea was turned out to be the major pathogen of postharvest fruit rot on both cultivars.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.2
• /
• pp.315-321
• /
• 1994

In order to prevent the postharvest decay and to promote the freshness retention of fruits and vegetables grapefruit seed extract(GFSE), natural microorganism control agent, was applied to the preservation of fresh fruits and vegetables. Freshfruits and vegetables treated with GFSE and stored in polyethylene film (0.1mm) at 1$0^{\circ}C$-15$^{\circ}C$ of natural low temperature low kept better qualities in color and texture than the GFSE -not- treated control. The treatment using GFSE ina 250ppm to 500ppm concentration seemed to be an effective one for the control of Botrytis cinerea isolated in red wine grapes. After 4 weeks of storage the firmness rate of cucumbers treated with the dilute GFSE was four times higher than that of non-treated ones. GFSE showed effective inhibitory action towards plant pathological bacteria and fungi which were involved in the decay of fruits and vegetables. Minimum inhibitory concentrations of GFSE towards them were in the range of 250ppm to 500ppm .Direct visualization of microbial cells and spores using electron microscopy showed microbial cells and fungal spores the function of which was destroyed by treating with the dilute solutions of GFSE. It was observed that GFSE would reduced disease damages and have bactericide & fungicide properties during the storage of such fruits and vegetables as egg plant, wild edible greens , kumquat, and kiwi fruit.