• 한국작물학회지
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• 제50권5호
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• pp.336-339
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• 2005

Common thistle contains water-soluble substances that are antioxidative to foods. Antioxidant activities measured by DPPH method for the ground samples were the greatest in leaves, although was less than that of commonly used antioxidants, BHT and ascorbic acid. Methanol extracts and fractions from Xanthium occidentale plants dose-dependently increased DPPH free radical scavenging activity, in vitro test. The extracts from leaves showed the strongest antioxidant activity. DPPH scavenging activity of the individual fraction was in order of n-butanol>water>ethyl acetate>n-hexane fraction. By means of HPLC analysis, leaf samples of Xanthium occidentale had the highest amount of phenolic compounds, related with antioxidant activity, and followed by stems and roots. Total content of these antioxidant phenolic com­pounds for leaves extracts were detected in water fraction (36.7 mg 100 $g^{-1}$) as the greatest amount, especially chlorogenic acid (39.4 mg 100 $g^{-1}$) was the greatest component. These results suggest that Xanthium occidentale plants had potent antioxidant activity, and their activities were differently exhibited depending on plant part and fraction.

• Plant Resources
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• 제8권2호
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• pp.116-121
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• 2005

Compositae plants are known to contain biologically active substances that are allelopathic to agricultural crops as well as weed species. Aqueous or methanol extracts and plant residues from leaves of Xanthium occidentale were assayed against alfalfa (Medicago sativa) to determine its allelopathic effects, and the results showed that the extracts applied onto filter paper significantly inhibited seed germination as well as root growth of alfalfa. Aqueous leaf extracts of $40g\;L^{-1}$ were completely inhibitory on root growth of alfalfa, while root growths of barley (Hordeum vulgare L.) and soybean (Glycine max L.) were less sensitive. Leaf residue incorporation at $100g\;kg^{-1}$ into soil on seedling growth of barnyard grass (Echinochloa crus-galli Beauv. var. oryzicola Ohwi) inhibited both shoot and root fresh weights of barnyard grass by 94 and $96\%$, respectively. Methanol extracts from BuOn and EtOAc fractions of X. occidentale reduced alfalfa root growth more than did those from hexane and water fractions. The results based on bioassay of extracts and residues show that X. occidentale had potent an allelopathic activity against other plant species.

• 한국작물학회지
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• 제49권1호
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• pp.30-35
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• 2004

Compositae plants are known to contain biologically active substances that are allelopathic to agricultural crops as well as weed species. Aqueous extracts from leaves of Xanthium occidentale were assayed against alfalfa (Medicago sativa) to determine their allelopathic effects, and the result showed that the extracts applied onto filter paper significantly inhibited seed germination as well as root growth of alfalfa. Untreated seeds germinated in 60h, but extract concentrations greater than 30g $\textrm{L}^{-1}$ delayed seed germination. The extracts significantly inhibited seed germination of alfalfa, and $\beta$-amylase activity of alfalfa and barley seeds during 24-36 hours after treatment. Aqueous extracts of 40 g $\textrm{L}^{-1}$ from X. occidentale were completely inhibited the hypocotyl and root growth of alfalfa. Aqueous leaf extracts showed the highest inhibitory effect and followed by root and stem extracts. Early seedling growth of both alfalfa and barnyard grass (Echinochloa crus-galli) was significantly reduced by methanol extracts. By means of high-performance liquid chromatography, chlorogenic acid and trans-cinnamic acid were quantified as the highest amounts from water and EtOAc fractions, respectively. BuOH and EtOAc fractions of X. occidentale reduced alfalfa root growth more than did hexane and water fractions. The findings of the bioassays for aqueous or methanol extracts reflected that the inhibitory effect of extract was closely related to the level of responsible allelochemicals found in plant extracts.

• 한국잡초학회지
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• 제30권1호
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• pp.1-16
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• 2010

농경지에 발생하는 주요 잡초에 대한 유묘기 검색방법을 개발하기 위하여 주요 잡초 60종에 대한 양적, 질적형질을 조사하였다. 잡초 유묘를 동정하는 형질로는 질적형질이 양적형질에 비해 보다 더 유용하였다. 자엽의 형태는 타원형과 광타원형이 가장 많았다. 차풀과 큰메꽃은 자엽의 형태가 넓은 직사각형이었다. 자엽의 형태가 횡광타원형인 초종은 4종이었다. 취명아주 등 22종의 잡초는 자엽의 형태가 1개 이상이었다. 이 중 자엽의 형태가 3가지 이상인 초종은 4종으로서 마디풀과의 참소리쟁이와 여뀌 그리고 대극과의 애기땅빈대와 깨풀이었다. 새팥은 자엽이 지면아래의 종자 속에 남아 있었다. 자엽의 엽두는 원두가 가장 많았다. 자엽의 엽저는 쐐기저가 가장 많았다. 환삼덩굴과 마디풀은 자엽의 엽저가 무엽병저였다. 일부 초종은 제 1본엽기와 제 2본엽기때 본엽의 형태가 각각 상이한 경우도 있었다. 돌콩, 새팥 및 매듭풀은 제 1본엽이 각각 광란형, 심장형, 원형 또는 광도란형이었나 제 2본엽에서는 3초종 모두 3출엽으로 전개되었다. 그리고 자귀풀과 차풀은 제 1, 2본엽의 형태가 우수우상복엽이었다. 본엽의 가장자리는 주로 전연이었으나, 큰도꼬마리를 포함한 6종은 제 1, 2본엽의 엽연이 치상거치였다. 애기땅빈대는 제 1본엽의 엽연이 전연, 제 2본엽의 엽연이 치상거치였다. 명아주과의 흰명아주와 좀명아주의 엽연은 제 1본엽기에는 전연, 제 2본엽기에는 불규칙거치였다. 잡초 유묘 자엽의 양적형질은 질적형질에 비해 종 동정 시 활용도는 떨어지나 초종에 따라서는 매우 유용한 경우도 있었다. 농경지 주요 광엽잡초 유묘에 대한 자엽 및 본엽의 질적 형질을 이용하여 간이 식별법을 제시하였다. 식법법 작성 시 자엽의 형태가 1개 이상인 잡초종에 대해서는 각각의 자엽 형태를 이용하여 종 동정이 가능하도록 하였다.