• Korean Journal of Food Science and Technology
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• v.49 no.5
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• pp.519-523
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• 2017

We investigated the applications of functional materials through the examination of a variety of physiological activities of Ipomoea aquatica extract. I. aquatica extract showed low cytotoxicity against murine melanoma B16F10 cells. At concentrations that exerted little or no cytotoxicity to the cells, I. aquatica extract showed high DPPH radical scavenging activity ($ID_{50}$, $7.84{\mu}g/mL$), inhibited tyrosinase activity ($ID_{50}$, $106.56{\mu}g/mL$), and decreased melanin content ($ID_{50}$, $41.75{\mu}g/mL$). The treatment of B16F10 cells with I. aquatica extract suppressed the protein expression of tyrosinase in a dose-dependent manner. These findings suggested that I. aquatica extract inhibited melanin synthesis in murine melanoma B16F10 cells through the suppression of intracellular tyrosinase expression, as well as the simultaneous direct inhibition of tyrosinase activity. Additionally, I. aquatica extract promoted the expression of involucrin, which is related to skin barrier protection. These results indicate that I. aquatica extract may be an appropriate material for the improvement of skin barrier function.

• Fisheries and Aquatic Sciences
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• v.24 no.12
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• pp.415-427
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• 2021

Wetland ecosystems act as natural freshwater purification systems, but their rich biodiversity is being threatened with the introduction of the non-native freshwater snail, Pomacea canaliculata. This study was conducted to measure the herbivory effects and growth rate of P. canaliculata on common macrophytes: Ipomoea aquatica, Ipomoea batatas, Pandanus amaryllifolius and Cucurma longa. In separate experiments, the macrophyte species were served as the snails' food as individual species and simultaneously. In the individual treatment, the growth pattern and rate were based on the snails' weight (mg/snail/day; n = 9) while the individual feeding consumption (mg/snail/day) was calculated from the leftover food. In the simultaneous treatment, the herbivory effects were evaluated as the feeding preference (%) from observations every two hours, while the total feeding consumption (mg) was calculated based on the food remaining after a 12-hour experiment (3 replicates: total n = 27). The results indicated that the growth pattern was significant for snails grazing on I. aquatica but not when other macrophyte species were eaten. The individual feeding consumption was higher when using I. aquatica than P. amaryllifolius but the growth rate for snails grazing on I. aquatica and P. amaryllifolius did not differ significantly. Meanwhile, the consumption of C. longa deterred the snails' growth rate. Although the snails consumed all the macrophytes in the individual experiment, when given the species simultaneously, the feeding preference and total feeding consumption were directed significantly more toward I. aquatica than P. amaryfollius and C. longa. We conclude that P. canaliculata is a generalist feeder given a limited choice of food but tends to show a strong feeding preference after being introduced to more food choices. These findings indicate that the introduction of P. canaliculata into wetland ecosystems may increase the herbivory effects on macrophytes, making these ecosystems vulnerable to the impact of eutrophication and biodiversity reduction.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.367-372
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• 2022

Leaf spot symptoms were observed in water spinach (Ipomoea aquatica) plants growing in fields in Ansan and Hongseong, Korea, during disease surveys in 2019 and 2020. The symptoms appeared as brown to dark brown circular or irregular spots on the leaves of the plants. The disease incidence on the plant leaves in the fields investigated at the two locations ranged from 1% to 20%. Five single-spore isolates of Phoma sp. Were obtained from lesions of the diseased leaves. All the isolates were identified as Ectophoma multirostrata based on their cultural and morphological characteristics, as well as molecular analysis. Two isolates of E. multirostrata were tested for pathogenicity on water spinach leaves using artificial inoculation. The tested isolates caused leaf spot symptoms in the inoculated plants. These symptoms were similar to those observed in plants from the investigated fields. To our knowledge, this is the first report of E. multirostrata causing leaf spot in water spinach.

• Research in Plant Disease
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• v.26 no.4
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• pp.272-278
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• 2020

The severe lettuce damage caused by Paratylenchus projectus was first reported in 2019 in Korea. To find high-value rotation crops for the control of P. projectus, nine vegetables, Brassica juncea (leaf mustard), B. rapa subsp. nipposinica (kyona), B. oleracea var. italica (broccoli), B. rapa subsp. chinensis (bok choy), B. oleracea var. viridis (kale), B. oleracea var. gongylodes (kohlrabi), Cichorium endivia (endive), C. intybus (chicory), Ipomoea aquatica (morning glory) were planted in d-10-cm clay pots in greenhouse. The growth of vegetables was compared between inoculated with 3,000 P. projectus per 100 ㎤ of soil and non-inoculated. Treatments were replicated 10 times. After 100 days, the reduction of fresh top weight was 30.4% in C. intybus, 35.1% in I. aquatica, 36.9% in B. oleracea var. acephala, 40.5% in C. endivia, 42.1% in B. rapa, 47.5% in B. rapa subsp. nipposinica, 50.4% in B. oleracea var. gonglodes, 56.3% in B. oleracea var. italica, and 66.0% in B. juncea. Nematode multiplication rates (Pf/Pi) were lower in I. aquatica (0.64) and C. endivia (1.1), but higher in B. oleracea var. gongylodes (2.54). Considering these results, I. aquatica is suitable for the rotation crop with lettuce until better rotation crops developed.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.8
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• pp.1292-1297
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• 1999

A preference test on feed and nutrient intakes were conducted on four male ($1.25{\pm}0.08kg$) and four female ($1.21{\pm}0.15kg$) lesser mouse deer (Tragulus javanicus) in captivity. Each animal was kept in individual cages placed in a well-ventilated animal house. The experiment was conducted in two weeks, where the first week was for adaptation to the feeds and the second week for measurements of nutrient intake, nutrient digestibility and nitrogen balance. The feeds offered were kangkong (Ipomoea aquatica), long bean (Vigna sinensis) and french bean (Phaseolus vulgaris) as roughages and proteinaceous feeds; sweet potato (Ipomoea batatas) and carrot (Daucus carota) as carbohydrate-rich feeds; and commercial rabbit pellet (0.3 cm diameter and 0.5 cm long) as a complete feed. The dry matter (DM) content of each feed in the order mentioned above was 7.1, 6.1, 3.9, 18.5, 6.2 and 87.6%, respectively. Long bean had the highest protein (CP) content (29.7%), while sweet potato had the lowest (6.2%). The CP contents of other feeds were within the range of 14.2 - 25.1%. Among the feeds, carrot had the lowest energy content (3.83 kcal/g) and long bean the highest (4.67 kcal/g). When fresh weight of the feed was considered, the male mouse deer consumed sweet potato the most ($86.3{\pm}12.90g/d$), but the female had a high preference for carrot ($79.2{\pm}9.76g/d$). The other feeds were consumed in lesser amounts. However, in terms of DM of the feed, the amount of commercial pellet consumed was the highest for both male ($45.0{\pm}5.10%$) and female ($44.7{\pm}7.38%$) mouse deer, followed by sweet potato ($33.1{\pm}4.43%$ and $22.4{\pm}7.73%$ for male and female, respectively). Significant (p<0.05) differences in DM, organic matter (OM) and gross energy (GE) intakes were observed between male and female mouse deer. The male consumed higher amount of DM, OM and GE than the female. The total DM intake was $40.7{\pm}2.24g/d/kg$ $W^{0.75}$ for male and $35.9{\pm}1.72g/d/kg$ $W^{0.75}$ for female mouse deer. Percentage digestibilities of DM, OM, CP and GE were within 72.7~80.8% and were not significantly different between male and female mouse deer. However, male mouse deer had significantly (p<0.05) higher digestible DM, OM and GE intakes than the female. Both male and female mouse deer were in positive nitrogen balance (0.6 g N/d/kg $W^{0.75}$). The male mouse deer gained $7.6{\pm}3.45g/d$, while the female gained $4.3{\pm}2.40g/d$.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.8
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• pp.1171-1177
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• 2008

The performance of growing rabbits fed Ruzi grass (Brachiaria ruziziensis), head lettuce (Lactuca sativa) residue, Mimosa pigra and water spinach (Ipomoea aquatica) was studied in an experiment using 64 rabbits (4 males and 4 females per treatment) of 2 breeds, New Zealand White and a crossbred between New Zealand White and native breed. The rabbits had an average initial weight of 668 g, were about 6 weeks old and were housed in individual pens. The foliages were fed ad libitum and a commercial concentrate was fed at a restricted level of 2% of body weight on a dry matter (DM) basis. In the digestibility experiment, the rabbits, 4 per foliage and males only, were fed the same foliages as in the growth experiment but without concentrate. Daily weight gain was lower in the group fed Ruzi grass, 14.8 g/d (p<0.001) compared to 17.6, 18.5 and 18.4 g/d for head lettuce, Mimosa pigra and water spinach, respectively. Feed intake and feed conversion ratio were lowest for the rabbits fed water spinach, 66 g DM/d and 3.6 kg DM/kg live weight, respectively. The New Zealand White breed had a higher daily gain than the crossbred rabbits (p<0.05), 18.0 and 16.7 g/d, respectively. There were no significant differences in feed intake, growth or feed conversion ratio due to sex. The digestibility coefficients of DM, organic matter, crude protein, crude fiber, neutral detergent fiber and acid detergent fiber were significantly lower (p<0.001) in the rabbits fed Ruzi grass. Breed and sex had no effect on digestibility. In conclusion, feeding head lettuce residue, Mimosa pigra and water spinach resulted in higher growth rate and digestibility than feeding Ruzi grass and can be recommended as alternative feeds.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.986-993
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• 2001

In balance experiments with rats either 25 or 50% of the casein protein in the control diet was replaced with one of the following eight sun-dried tropical biomass products: water spinach plants (WS) (Ipomoea aquatica Forsk), leucaena leaves (LL) (Leuceana leucocephala), duckweed plants (DW) (Lemma minor L.), groundnut foliage (OF) (Arachis hypogaea L.), trichantera leaves (Tric) (Trichantera gigantea), indicago leaves (Ind) (Indigofera hirsuta), mungbean foliage (Mb) (Phaseolus aureus), and cassava leaves (CL) (Manihot esculenta Crantz). The experiment included 102 rats with six individuals per treatment group. In three of the 16 biomass treatment groups, feed intake and weight gain of the rats were unacceptably low, and therefore they were excluded from the statistical evaluation, The crude protein (CP) content of the biomass products varied between 20.9% (Tric) and 33.2% (DW), whereas the content of NDF varied between 18.5% (Ind) and 32.2% (DW) of dry matter (DM). The total content of essential amino acids (g/16 g N) was comparable with that of alfalfa meal, except for GF and Tric, which were inferior. Between plant species, differences in dietary digestibility of organic matter (dOM) and CP (dCP) were observed (p<0.001). Also, the replacement level negatively influenced dOM and dCP (p<0.001). The lowest values for dOM (p<0.001) were observed for diets including biomass products with the highest content of NDF (OF, Tric, Mb, LL). Digestibility of CP was negatively affected by level of protein replacement. Significant (p<0.001) differences were found in N-retention and biological value among diets with different biomass products. The most favourable overall results were obtained for DW, WS and CL. The main factors affecting the nutritive value of the diets tested were their NDF content, dCP and AA profile of the biomass. Also antinutritive component(s) may have influenced the process of digestion and metabolism of some of the biomass products.

• Korean Journal of Environmental Agriculture
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• v.36 no.2
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• pp.67-72
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• 2017

BACKGROUND:Cultivation of alternative crops in paddy fields is necessary because of the decrease in rice consumption and the increase in excess stock of rice. The study was conducted to investigate the effects of alternative crops cultivation in paddy fields on soil physico-chemical characteristics and crop yield. METHODS AND RESULTS: Soybean (Glycine max), red-clover (Trifolium pratense), and water convolvulus (Ipomoea aquatica) were selected for alternative crops in the first and/or second year and rice was planted in the third year. When alternative crops were cultivated in the previous year, soil bulk density, soil hardness, and water content were lower than those for rice cultivation. Water-depth decreasing rate and aggregate content were greater for the upland-upland-paddy cropping system than upland-paddy-paddy cropping system. Cultivation of red-clover and water convolvulus for two years resulted in the high soil organic matter content. In the third year, available phosphate, exchangeable potassium, and soil cation exchange capacity were relatively high when soybean was cultivated in the previous year. In the first year, water convolvulus cultivation showed greater productivity than red-clover cultivation while the opposite pattern was found in the second year. Rice yield in the third year was greater for soybean or red-clover as a previous crop than for water convolvulus as a previous crop. CONCLUSION: The results suggest that cultivation of alternative crops in paddy fields can improve soil physical properties including bulk density, hardness, water content, and aggregate content as well as rice productivity.