• Mycobiology
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• v.51 no.3
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• pp.186-194
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• 2023

In July 2021, wilting symptoms were observed in adult and seedling hemp (Cannabis sativa L. cv. Cherry Blossom) plants grown in a greenhouse. As the disease progressed, yellowing and wilting symptoms on the leaves developed, resulting in whole plant death. In seedling plants, typical damping-off symptoms were observed. To identify the pathogen, the roots of diseased plants were sampled, surface sterilized, and cultured on potato dextrose agar (PDA) media. From the culture, 4 different fungal isolates were recovered and purely cultured. Each fungal isolate showed distinct growth shapes and color development on malt extract agar, oatmeal agar, sabouraud dextrose agar, and PDA media. Microscopic observation and molecular identification using ribosomal DNA internal transcribed spacer sequencing identified them as 3 Fusarium spp. and 1 Thielaviopsis paradoxa. Additional sequencing of elongation factor 1-alpha and b-tubulin regions of 3 Fusarium spp. revealed that 2 of them are Fusarium solani, and the other one is Fusarium proliferatum. To examine which isolate can act as a causal agent of wilt disease of hemp, each isolate was tested for their pathogenicity. In the pathogenicity test, F. solani AMCF1 and AMCF2, and F. proliferatum AMCF3, but not T. paradoxa AMCF4, were able to cause wilting disease in hemp seedlings. Therefore, we report that F. solani AMCF1 and AMCF2, and F. proliferatum AMCF3 as causal agents of Fusarium wilt of hemp plants. To our knowledge, this is the first report of the wilt disease of C. sativa L. caused by Fusarium spp. in Korea.

• Food Science and Preservation
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• v.17 no.6
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• pp.867-873
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• 2010

The total phenolic contents and the antioxidant activities of methanolic extracts of different parts (fruit, calyx, leaf, stem, and root) of Physalis alkekengi var. francheti were investigated using established in vitro systems including DPPH radical-scavenging, nitrite-scavenging, superoxide anion radical-scavenging activity, measurement of reducing power, and assessment of the metal-chelating effect. The highest extraction yield was from fruit (52.55%), whereas the lowest levels were obtained from root (10.49%) and stem (12.88%).The leaf extract had the highest total phenolic (58.47 mg/g) and total flavonoid (4.83 mg/g) contents, plus the greatest antioxidant activity, as shown by the DPPH radical-scavenging assay, and the highest levels of reducing power at concentrations of 1 and 5 mg/mL. In addition, the calyx also showed good antioxidant activity.These findings indicate that methanolic extracts of leaf and calyx may be useful in the food manufacturing and nutraceutical industries.

• Korean Journal of Poultry Science
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• v.28 no.3
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• pp.289-295
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• 2001

The objectives or this study were to improve duck meat qualify during storage period in onion-red ducks which contained antioxidants. Experimental animals (1 day old, Cherry Valley $F_{1}$, 360 chicks) were randomly assigned in eight treatment group. Treatments were control, 3%, 6% of chopped onion-fed, 5%, 10% of onion extract fed, 6% of onion meal, 3%, 6% of fermented onion-fed. pH was significantly high (P<0.05) in treatment group after 3 day storage in pectoralis muscle. Meat color was low in r* and a* value. TBA value was not different in day 1, was significantly low (P<0.05) 6% chopped and 6% fermented group after day 3 storage. Also, TBA value was significantly high (P<0.05) in control group and was significantly low in 3% chopped, 5%, 10% extract after day 6 storage. VBN value was lower in all treatment groups except 5% ferment group than control group. Meat order was high score in 3% and 6% chopped group and duck specific smell was reduced in all treatment groups. Meat appearance was higher score in treatment groups than in control group during 9 day storage. In result, onion feeding was reduce duck specific smell and improve meat quality during long period storage in ducks.

• Korean Journal of Poultry Science
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• v.28 no.3
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• pp.207-213
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• 2001

The objectives or this study were to examine reed value or waste onion in duck. Experimental chicks (Cherry Valley F$_1$, 1day old, 350 chicks) were randomly assigned in 8 treatment groups, each 45 chicks, and man-aged for 7 weeks (3 kg BW, 49 days old). Treatments were control, 3%, 6% of chopped onion-fed, 5%, 10% of onion extract fed, 6% of onion meal, 3%, 6% of fermented onion-fed. Feed intake was significantly (P<0.05) high in control group, but ADG was high in 3% chopped onion-fed group. Feed requirement was very efficient in all treatment groups except 6% fermented onion-fed group. Dressing rate was high in 5% onion extract-fed group, but it was not significant. Abdominal fat was the highest in control and 6% fermented onion-fed group and lowest in 6% chopped onion-fed group. Cholesterol content was lower in all treatment groups than in control group, but it was not significantly different. Stearic acid ($C_{18:0}$) content was significantly low in all treatment group (P<0.05). However, arachidonic acid ($C_{20:4}$) content was higher in treatment group than in control group. In result, onion diet was not significantly effect on palatability, feed intake, ADG in ducks. Duck meat of onion-fed contained low cho-lesterol and high unsaturated fat content.

• The Korean Journal of Pesticide Science
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• v.17 no.2
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• pp.107-116
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• 2013

Polar pesticides like pymetrozine (log $P_{ow}$: -0.18) are known to be difficult to analyze. The analytical method of pymetrozine using hydromatrix included in the official method of KFDA was uncommon and provided ambiguous evidence to confirm both the identity and the quantity. Therefore, precise single residue analytical method was developed in representative crops for using liquid-liquid extraction (LLE). The pymetrozine residue was extracted with methanol from 11 representative crops which comprised apple, blueberry, broccoli, cabbage, cherry, crown daisy, hulled rice, Korean cabbage, potato, rice and watermelon. The extract was purified serially by liquid-liquid extraction (LLE) and silica solid phase extraction (SPE). For rice and hulled rice samples, n-hexane partition was additionally adopted to remove nonpolar interferences, mainly lipids. The residue levels were analyzed by HPLC with DAD, using $C_8$ column. LOQ (limit of quantitation) of pymetroizinie was 1 ng (S/N > 10) and MQL (method quantitation limit) was 0.01 mg/kg. Mean recoveries from 11 crop samples fortified at three levels (MQL, 10 ${\times}$ MQL and 50 ${\times}$ MQL) in triplicate were in the range of 83.1~98.5% with coefficients of variation (CV) of less than 10%, regardless of sample type, which satisfies the criteria of KFDA. The method established in this study could be applied to most of crops as an official and general method for analysis of pymetrozine residue.