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111.
2-(2-Phenylethyl) chromones are the major constituents responsible for the quality of agarwood, which is one of the most valuable non-timber products used as incenses, perfumes, traditional medicines and other products. In this study, cell suspension culture of Aquilaria sinensis (Lour) Gilg was used to monitor the eliciting effects of crude fungal extracts on cell growth and chromones production. Crude extracts of Melanotus flavolivens (B. etc) Sing. prepared with different solvents were used to elicit the production of 2-(2-phenylethyl) chromones in cell suspension cultures of A. sinensis. Four 2-(2-phenylethyl) chromones,␣6,7-dimethoxy-2-(2-phenylethyl) chromone (1), 6,7-dimethoxy-2-[2-(4′-methoxyphenyl)ethyl] chromone (2), 6-methoxy-2-[2-(4′-methoxyphenyl)ethyl] chromone (3) and 6-methoxy-2-(2-phenylethyl) chromone␣(4),␣were detected by LC–MS in the cell suspension culture of A. sinensis elicited with crude extracts of M. flavolivens. Three hundred and seventy eight, 196 and 31 μg g−1 DW of 2-(2-phenylethyl) chromones were obtained in the cell cultures induced by water extracts, 50 and 95% ethanol extracts of M. flavolivens, respectively. The results show that water-soluble materials in the crude extracts are the main components inducing the production of 2-(2-phenylethyl) chromones in the cell cultures.  相似文献   
112.
皂荚天然群体间种实表型特性及种子萌发的差异分析   总被引:1,自引:0,他引:1  
对位于湖北京山、湖南城步、贵州兴义、重庆秀山、四川成都、广西桂林、山东费县和甘肃天水的8个皂荚(Gleditsia sinensis Lam.)天然群体间果实和种子表型特性及种子萌发率的差异进行了研究,在此基础上,对种子特性与萌发率的相关性进行了分析。结果表明:不同皂荚群体间荚果的长度、宽度、厚度和质量以及种子长度、宽度、厚度和百粒质量均存在极显著差异(P〈O.01);在低纬度、高降雨量和干扰程度相对大的区域产生的荚果及种子均较大。在不同温度(昼/夜温度35℃/20℃、30℃/15℃、25℃/10oC和15℃/5℃)条件下,8个皂荚群体间种子萌发率无显著差异,平均萌发率为7.70%;种皮经人为损伤后种子萌发率总体上有所提高且在不同温度条件下差异显著,其中在昼/夜温度15℃/5℃的条件下种子萌发率低于其他处理温度。在不同温度条件下,种子的长度、宽度、厚度和百粒质量与萌发率均呈正相关,但总体上相关性不显著。研究结果说明:不同皂荚群体的荚果和种子特性变异较大,且在降雨量高的地区其果实和种子较大;低温对皂荚种子的萌发有一定抑制作用;种皮损伤处理可解除皂荚种子的物理性休眠,但皂荚种子还可能存在生理休眠现象;一定程度的种子复合休眠可能是皂荚群体适应不同生境的重要生存策略之一。  相似文献   
113.
为了解柯拉斯那(Aquilaria crassna)的化学成分,从其所产沉香中分离得到10个化合物,经波谱分析分别鉴定为:6,8-羟基-2-(2-苯乙基)色酮(1),6,8-二羟基-2-[2-(4-甲氧基苯)乙基]色酮(2),rel-(1a R,2R,3R,7b S)-1a,2,3,7b-tetrahydro-2,3-dihydroxy-5-(2-phenylethyl)-7H-oxireno[f][1]benzopyran-7-one(3),rel-(1a R,2R,3R,7b S)-1a,2,3,7b-tetrahydro-2,3-dihydroxy-[2-(4-methoxyphenyl)-ethyl]-7H-oxireno[f][1]benzopyran-7-one(4),rel-(1a R,2R,3R,7b S)-1a,2,3,7b-tetrahydro-2,3-dihydroxy-5-[2-(3-hydroxy-4-methoxyphenyl)-ethyl]-7H-oxireno[f][1]benzopyran-7-one(5),oxidoagarochromone B(6),oxidoagarochromone C(7),(5S,6R,7S,8R)-2-[2-(3′-hydroxy-4′-methoxyphenyl)ethyl]-5,6,7,8-tetrahydroxy-5,6,7,8-tetrahydrochromone(8),6,7-cis-dihydroxy-2-(2-phenylethyl)-5,6,7,8-tetrahydrochromone(9),N-trans-feruloyltyramine(10)。化合物3~5和8~10为首次从柯拉斯那沉香中分离得到。化合物1,3,6,7,9和10对乙酰胆碱酯酶具有一定的抑制活性,化合物4对人慢性髓原白血病细胞株K-562和人胃癌细胞株SGC-7901均具有较小的抑制作用,化合物1和3对人肝癌细胞株BEL-7402也有抑制活性。  相似文献   
114.
小叶锦鸡儿研究概况   总被引:3,自引:0,他引:3  
综述了小叶锦鸡儿(Caragana microphylla Lam.)的分布、化学成分及药理作用.  相似文献   
115.
黄芪复合体(豆科)核型资料的聚类分析   总被引:2,自引:0,他引:2  
史刚荣 《植物研究》2003,23(2):220-223
在平均欧氏距离系数基础上,运用UPGMA法,对黄芪复合体5个类群11个居群的核型资料进行了Q型聚类分析,结果表明,膜荚黄芪Astragalus membranaceus和A. penduliflorus的不同居群在核型上存在明显的差异,但二者之间以及它们与民和黄芪、淡紫花黄芪的居群之间具有一定的连续性。蒙古黄芪在核型上与其它类群均存在一定的差异,且存在明显的间断。因此,本文作者认为:A. penduliflorus应视为膜荚黄芪的异名,黄芪复合体应包括2种:膜荚黄芪(A. membranaceus(Fisch)Bunge)和蒙古黄芪(A. monghulicus Bunge)、2亚种:膜荚黄芪(A. membranaceus spp. membranaceus)、民和黄芪(A. membranaceus spp. minhensis)和1变种:淡紫花黄芪(A. membranaceus var. purpurinus Y.C.Ho)。黄芪复合体核型的进化趋势是从对称向不对称发展,与Stebbins的观点一致。  相似文献   
116.
This investigation was undertaken to ascertain the antinociceptive activity of Caragana microphylla Lam. seeds and isolate and characterize the constituents. Antinociceptive activity was screened using acetic acid-induced abdominal constriction in ICR mice. The 75% ethanol extract and some fractions showed analgesic activity, but the antinociceptive activity of chloroform fraction was the strongest and was more productive than other fractions. Seven compounds were isolated from it and identified as: (1) machaeric acid, (2) beta-sitosterol, (3) stigmasterol, (4) pratol, (5) dehydrocavidine, (6) formononetin and (7) sucrose. Caragana microphylla Lam. seeds showed analgesic activity, with the chloroform fraction showing the strongest analgesic activity among the fractions.  相似文献   
117.
Calonyctin, a natural plant growth regulator extracted from the leaves of Calonyction aculeatum (L.) House, can promote crop growth and increase crop yield. The specific reasons for this response are unknown. This study was conducted to determine the effect of calonyctin treatment on the free sugars of sweet potato [Ipomoea batatas (L.) Lam.] as related to starch accumulation. The sweet potatoes were grown in the field in 1992, treated by foliar spray with Calonyctin concentrations of 0 (control) and 0.1 activity unit (CTSP) at 20 days after planting (DAP) at the rate of 190 liters of diluted solution/ha., and sampled periodically to determine free sugars. The response of sweet potato to calonyctin was first detected at 40 days after treatment (on 60 DAP). Data indicated that calonyctin treatment significantly increased starch synthesis in storage roots, decreased the fluctuation tendency of total sugar level during the growth period, and kept the sugar level relatively constant with a gradual rise regardless of variations in weather. The level of the reducing sugars in CTSP leaves was higher at 60 and 160 DAP and lower at 100, 120, and 140 DAP. During rainy days (100 DAP), the reducing sugars in CTSP storage roots remained at a lower level when those in controls reached high levels. The sucrose content in CTSP leaves was 40–138% greater than that in controls except at 80 and 120 DAP, and the ratio of sucrose to total nonreducing sugars remained at 100% in CTSP leaves even on rainy and cool days and above 96% in CTSP storage roots except on cool days (140 and 160 DAP), suggesting that calonyctin treatment promoted the synthesis and transfer of sucrose and supplied abundant sugar precursors for starch accumulation in storage roots.Abbreviations DAP days after planting - CTSP calonyctin-treated sweet potato with 0.1 activity unit  相似文献   
118.
Summary Significant differences in total dry matter yields of shoots and roots were found between 11 ryegrass (Lolium) cultivars grown in a glasshouse. Although shoot yield varied significantly between individual cultivars there was no overall difference between the annual and perennial cultivars; whereas for roots, the yields of the perennial plants were much smaller than those of the annual types. Water use (g H2O g total DM–1) also varied significantly between cultivars. However, there was no relationship between efficient water use and dry matter production.No significant differences were found in shoot composition between the cultviars for nitrogen, phosphorus, and potassium; however, concentrations of sulphur, magnesium, calcium, and sodium varied significantly. Sodium concentrations were generally higher in the annual compared to the perennial cultivars. For roots only nitrogen, phosphorus, and sulphur differed significantly between cultivars. Of the elements only calcium in the shoots was shown to be related to water use. Thus cultivars which were low users of water also had significantly lower calcium concentrations in their shoots. Water use appeared to affect the absorption of calcium by the root to a far greater extent than the transport from roots to shoot. An apparent relationship between magnesium concentration in the shoots and water use was shown to be due to the close association of magnesium with calcium in the plant.  相似文献   
119.
Transformation of sweet potato tissues with green-fluorescent protein gene   总被引:3,自引:0,他引:3  
Summary The expression of the green-fluorescent protein (GFP) gene from Aequorea victoria (jellyfish) was analyzed by transient and stable expression in sweet potato Ipomoea batatas L. (Lam.) ev. Beauregard tissues by electroporation and particle bombardment. Leaf and petiole segments from in vitro-raised young plantlets were used for protoplast isolation and electroporation. Embyrogenic callus was also produced from leaf segments for particle bombardment experiments. A buffer solution containing 1×106 protoplasts ml−1 was mixed with plasmid DNA containing the GFP gene, and electroporated at 375 V cm−1. Approximately 25–30% of electroporated mesophyll cell protoplasts subsequently cultured in KM8P medium regenerated cell walls after 48 h. Of these, 3% emitted bright green fluorescence when exposed to UV-blue light at 395 nm. Transformed cells continued to grow after embedding in KM8P medium solidifed with 1.2% SeaPlaque agarose. Stable expression of GFP was observed after 4 wk of culture in approximately 1.0% of the initial GFP positive cells (27.5 GFP positive micro callases out of 3024 cells which transiently expressed GFP 48 h after electroporation). In a separate experiment, 600–700 bright green spots were observed per plate 48 h after bombarding leaf segments or embryogenic cellus. In bombarded cultures, several stable GEP-expressing sectors were observed in leafderived embryogenic callus grown without selection for 4 wk. These results show that GFP gene expression can occur in various sweet potato tissues, and that it may be a useful sereenable marker to improve transformation efficiency and obtain transgenic sweet potato plants.  相似文献   
120.
The economic importance of gaharu is assessed in three villages on the Bahau River in north-central Borneo to gain insights about the incentives for harvesting and management of a valuable nontimber forest product. Three indicators of economic value—level and proportion of income, returns to labor, and proportion of gaharu collecting households per village—are used to demonstrate the multiple incentives that NTFP income can generate. The concept of incentive logic is developed as an analytical technique to show how economic values can be linked to incentives for different types of management actions. The article discusses how incentives from gaharu income were most likely linked to the stake local people had in the resource, their preferences about which forest product to harvest, and their willingness to engage in collective action. These incentives contributed to sustainability to the extent they induced actions that reduce threats to the resource. The article suggests that an understanding of the influence of economic incentives on people’s resource management can be improved by recognizing three factors: the multiple incentives created by an income, the logical link of those incentives to a management action, and the influence of other sociocultural and biophysical factors on management.  相似文献   
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