• Korean Journal of Organic Agriculture
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• v.29 no.1
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• pp.97-109
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• 2021

Plant parasitic nematodes are causing significant damage in crop production. There is a need to develop eco-friendly nematicide that reduces the damage of nematode and has little effect on the environment and human. In this study, we have isolated a substance having nematicidal activity from Ginkgo biloba L. outer seedcoat. Studies of G. biloba L. outer seedcoat are insufficient compared to the seed and leaves due to their odor and toxicity. The dried G. biloba L. outer seedcoat was extracted with dichloromethane:methanol (1:1) and fractionated into hexane, ethyl acetate and H₂O. Four steps TLC were performed from EtOAc fraction to purely isolate GB4-3 with nematicidal activity. To compare nematicidal activity, G. biloba L. seedcoat methanol extract and purified GB4-3 were investigated in terms of treatment concentration and time. As a result, the nematicidal activity increased with concentration and time. In the place treated with 20 ㎍/mL of crude G. biloba L. seedcoat MeOH extract, strong activity appeared after 12 hours, and 46% nematicidal activity shown after 18 hours. About 69% of nematicidal activity was confirmed in the place where GB4-3 purified from outer seedcoat was treated with 20 ㎍/mL, and the possibility of development as nematicide was very high. This study could be used as a basic data for the development of a nematode preparation from G. biloba L. outer seedcoat.

• The Plant Pathology Journal
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• v.31 no.1
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• pp.61-66
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• 2015

From study of antifungal actions on the rice sheath blight by using the extract of Ginkgo biloba outer seedcoats, we found that the extracts of Ginkgo biloba outer seedcoats of all treatment concentrations had inhibited the rice sheath blight. Among them, the most effective concentration was 250 mg/l at which the growth of microbe was 26 mm and even at the packaging test, when sprayed the G. biloba outer seedcoats at the level of 250 mg/l, the damage rate of the rice sheath blight was identified as 13%. As a result investigating the antifungal activity by separating polysaccharides from G. biloba outer seedcoats, it showed that the clear zone of 14 mm or more was formed at the concentration of 250 mg/l or higher. Based on these results, we concluded that the G. biloba outer seedcoat is a natural substance with the antifungal activity on the rice sheath blight.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.7-13
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• 2011

This study was conducted to investigate the antimicrobial activity of Ginkgo biloba L. leaves, seed and outer seedcoat against bacteria. Antimicrobial effects of Ginkgo biloba L. leaves (GBL), seed (GBS) and outer seedcoat (GBO) were examined by paper disc method and optical density method to determine minimum inhibition concentration (MIC), and observed by scanning electron microscope (SEM) to figure out the morphological change on the surface when Ginkgo biloba leaves extract was treated. The extracts of GBL, GBS and GBO were extracted by solvents such as methanol, ethanol, water. The methanol extract of GBL and GBO showed the highest antimicrobial activity against Bacillus cereus, Bacillus subtilis, Klebsiella pneumoniae, Listeria monocytogenes, Salmonella Typhimurium, Staphylococcus aureus, Yersinia enterocolitica except Escherichia coli and thus was further fractionated. The MICs of the chloroform fraction of GBL methanol extract were $125{\mu}g$/mL against B. subtilis, and L. monocytogenes; GBO methanol extract were $62.5{\mu}g$/mL against B. cereus and $125{\mu}g$/mL against B. subtilis, and L. monocytogenes. The microorganisms were treated with chloroform extracts ($2000{\mu}g$/mL) of GBL and GBO methanol extracts. It was observed by scanning electron microscope (SEM). The cells were expanded and a part of cell wall was completely destructed by GBL and GBO. Thus Ginkgo biloba L. leaves and outer seedcoat could be further developed into a natural antimicrobial agent.

• Korean Journal of Plant Resources
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• v.3 no.1
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• pp.31-40
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• 1990

Pericarp and seedcoat removal treatments were tested to determine their effectiveness in the hard-to-germinate botanical seeds of jerusalem artichoke. Fresh seed of five Helianthus tuberosus L.varieties were (A)untreated (B)water soaked overnight (C) soaked overnight followed by renoval of pericarp or (D) soaked overnight followed by renoval of pericarp and seedcoat. The results indicate that treatments which removed the pericarp and seedcoat were the very effective, giving germination of over 90%. A considerable increase in germination did not follow only the peri-carp removal treatments. The factors inhibitory to germination of fresh jerusalem artichoke seed is associated withthe seedcoat. The removal treatment of pericarp and seed-cost is recommended despite its complexity because it givesa high germination percentage and varies least from varietyto variety. Heliarthus tuberosus L., a biomass potential crop, is a member of the family compositae. The genus Helianthushas provided man with two food plants, the sunflower (H.annus) and the jerusalem artichoke or topinambour (H. tube-rosus) . (3) The jerusalem artichoke grown for its tubers, has always been an extremely minor crop, but it is stillgrown in many places as a food for man or livestock and forthe production of alcohoL. Though tubers are used for pro-pagation jerusalem artichoke also flower and produce seedin head-like in florescences. Flowers are developed acro-petaLly on flattened receptacles such that outermost flowers are oldest. Each of these epigynous flowers may develop an achene-type fruit in which outer layers of the overy wallpersist, while inner layers become disorganized. Insidethe ovary wall of mature fruit, there is a papery seedcoat, probably composed of compact cells from endosperm, integu-ments, and nucellus.In general, the efforts to improving this crop havebeen hampered by the hard-to-germinate botanical seed.Seeds did not germinate for at least IL months after harvest.Fresh seeds of some varieties require one year more to gar-minate. (5) Since the time factor between generations isof concern in a prospective breeding program of jerusalemartichoke , these observations led to investigation of thenature of delayed seed germination in jerusalem artichokeas a biomass potential crop.