鄂西南不同核用银杏品种叶中主要黄酮苷元及碳、氮元素含量比较研究

为了比较鄂西南不同核用银杏品种叶中主要黄酮苷元含量,并进一步探讨影响其含量的因素,采用RPHPLC法对样品中黄酮苷元进行定量分析,同时采用德国elementar vario MICRO CUBE元素分析仪测定样品中碳、氮等元素含量。结果表明:不同银杏品种叶片中黄酮含量存在差异,三种主要黄酮苷元组成比例在各品种间差异更加显著,恩银15号及恩银23号具有较好苷元比例,可以作为叶用银杏发展的优先考虑品种。进一步分析表明,叶片总黄酮含量与叶中氮含量之间显著正相关,提示合理施氮有助于改善三种苷元的比例关系,从而使其比例达到最佳。通过比较鄂西南不同银杏品种银杏叶中有效成分的含量,为提高银杏叶质量,优化银杏叶资源提供了理论依据。     

银杏萜内酯的分布与矮壮素对其生物合成的调节

银杏萜内酯分为银杏内酯A、B、C、J、M(ginkgolide A、B、C、J、M)和白果内酯(bilobalide),主要存在于银杏叶与根内,近年的研究指出银杏萜内酯分别在银杏叶和根中生物合成[1],Cartayrade等人[2]通过叶片生根实验发现生根叶片的银杏萜内酯含量显著高于未生根叶,因而认为银杏萜内酯是在根部合成,然后运输到叶中积累,目前对此还缺乏进一步的研究报道.     

银杏叶萜内酯含量的变化及其与叶绿素荧光特性的关系

为探究银杏(Ginkgo biloba)叶萜类内酯含量和光合同化作用的关系,对其内酯含量和叶绿素荧光特性进行了研究。结果表明,不同采收时间银杏叶中白果内酯和银杏内酯含量有显著差异,总体上,5月份含量较低,此后逐渐升高,8月份达到高峰,然后快速下降,10月底最低;与此同时,银杏叶片的光合色素以及叶绿素荧光参数也呈现周期性变化。白果内酯以及萜内酯含量与叶绿素荧光参数Y(NPQ)之间呈极显著正相关关系,因此,可以通过银杏叶片的叶绿素荧光参数预测白果内酯和萜内酯含量。     

不同植被地区天然黄檗生物碱含量对季节的响应

黄檗(Phellodendron amurense Rupr.)不仅为中国特有的濒危植物,还是我国著名中药材"关黄柏"的药源植物,由于其珍贵的药用价值而被过度开采。本研究采用HPLC检测不同植被地区天然黄檗种群中药根碱、掌叶防己碱和小檗碱等生物碱的含量,分析不同部位,不同季节对生物碱分布的影响。研究表明,药根碱在黄檗各部位的分布为:根皮茎皮多年生枝一年生枝叶片。掌叶防己碱含量分布为:茎皮多年生枝皮根皮一年生枝叶片。小檗碱在不同部位的分布规律表现为:根皮茎皮多年生枝一年生枝叶片。根皮和茎皮中的药根碱含量随着春、夏、秋季节的推移呈逐渐上升的趋势,表现为秋季夏季春季,而多年生枝皮、一年生枝、叶片中的药根碱则是秋季春季夏季。各部位的掌叶防己碱均随着季节推移而升高,表现为秋季夏季春季。根皮、茎皮和多年生枝皮中小檗碱含量随着季节变化表现为夏季秋季春季。一年生枝中小檗碱在夏季降低,而到了秋季再升高。     

前景诱人的银杏叶制剂

银杏叶中的 多种化学成分具 有很好的药效作 用。从60年代 至今,对银杏叶 成分的提取、药 理和临床应用的研究不断深入,银杏叶的药用价值日益看好。银杏叶制剂在医学上应用日渐广泛。 一、含银杏叶提取物的药剂 从银杏叶中提取的含黄酮苷和内酯的银杏叶提取物(即浸膏,EGb)主要用于制备防治心脑血管疾病的药剂。通常把德国斯瓦贝(W.Schwabe)公司生产的EGb761作为银杏叶的标准提取物,这种提取物中含有24％的黄酮苷和6％的内酯(银杏内酯和白果内酯)。药理试验表明:银杏黄酮类化合物用于豚鼠离休     

光强与光质对银杏光合作用及黄酮苷与萜类内酯含量的影响

对2年生银杏（Ginkgo biloba L.)苗进行遮荫和光膜处理,测定光合速率及碳水化合物,银杏黄酮苷与萜类内酯的含量。光合速率在自然光下测定时从大到小依次为：黄膜＞蓝膜和红膜＞绿膜＞紫膜和白膜,在光膜下测定时为：黄膜＞红膜＞蓝膜、紫膜和白膜＞绿膜。光强和光质对碳水化合物含量有显著影响。光质对萜类内酯的生物合成和积累有影响,紫膜处理的银杏萜类内酯含量最高,为3.89mg/g,比白膜（对照） 高85．23％,其次是绿膜,为2．80mg/g。覆膜和蔗荫显著减少银杏黄酮苷含量,这可能与紫外辐射强度减弱有关。     

黄芩的结构与黄芩苷含量的关系

应用解剖学、组织化学定位和植物化学技术,研究了一、二年生黄芩(Scutellaria baicalensis Georgi)营养器官的结构特征与黄芩苷积累的关系.结果表明:黄芩各营养器官的结构类似于一般草本双子叶植物,黄芩苷主要分布在各器官的薄壁组织细胞内,其中以维管组织的薄壁细胞为多.器官间含量的不同表现为根>叶>茎,这与其结构特征相对应,根中维管组织所占比例最大,其中薄壁组织细胞又占主要部分,故根中黄芩苷含量最高.说明根部是黄芩苷的主要贮存部位,符合黄芩以根入药的传统.不同生长期黄芩苷含量测定结果表明,两年生营养生长前期春季根内含量最高,所以春季采挖为好.     

黄芩的结构与黄芩苷含量的关系

应用解剖学、组织化学定位和植物化学技术,研究了一、二年生黄芩（Scutellaria baicalensis Georgi）营养器官的结构特征与黄芩苷积累的关系。结果表明：黄芩各营养器官的结构类似于一般草本双子叶植物,黄芩苷主要分布在各器官的薄壁组织细胞内,其中以维管组织的薄壁细胞为多。器官间含量的不同表现为根〉叶〉茎,这与其结构特征相对应,根中维管组织所占比例最大,其中薄壁组织细胞又占主要部分,故根中黄芩苷含量最高。说明根部是黄芩苷的主要贮存部位,符合黄芩以根入药的传统。不同生长期黄芩苷含量测定结果表明,两年生营养生长前期春季根内含量最高,所以春季采挖为好。     

不同银杏无性系叶药用成分差异及聚类分析

运用HPLC技术分析了54个银杏(Ginkgo biloba)无性系叶总黄酮和萜内酯及其组分含量的差异,并进行了聚类。结果表明,银杏无性系间叶中总黄酮、萜内酯及其组分含量存在遗传变异,且萜内酯及其组分含量的变异系数明显高于总黄酮及其组分。总黄酮含量较高的无性系有18、42、32和50号,其槲皮素、异鼠李素、山奈酚含量均较高。萜内酯含量较高的无性系为13、42、33、51和65号,其银杏内酯A(GA)、银杏内酯B(GB)、银杏内酯C(GC)及白果内酯(BB)含量均较高。通过对总黄酮-萜内酯进行联合复选,显示叶中总黄酮和萜内酯含量均较高的无性系为13、65、33、51、18、32和42号。这些无性系可通过嫁接、扦插直接在银杏采叶园进行推广种植,或作为叶用银杏新品种的育种材料。     

荞麦中总黄酮和芦丁含量的变化

苦荞、甜荞叶中总黄酮平均含量达5.3％,芦丁平均含量达4.9％,井在开花结实期达最高峰,后期下降;茎中的含量较低,平均值分别为1.0％和0.7％,生育期中无明显变化。叶、茎中黄酮成分以芦丁为主,占70％～90％。同一时期发育不同的生殖器官总黄酮及芦丁含量的大小顺序为蕾>花>胚乳未充实种子>成熟种子。生殖器官中黄酮成分与芦丁比重因荞麦种别而异。     

盐胁迫对空心莲子草生长和光合作用的影响

用NaCl浓度为0(对照)、50、100、150、200、250、300、350mmol/L处理空心莲子草[Alternantheraphiloxeroides(Mart.)Griseb]。结果表明:盐胁迫下,植株鲜重、干重和根冠比都下降,含水量和肉质化程度先略高于对照,而后逐渐下降;根、茎和叶中Na 含量呈上升趋势,而K 含量呈下降趋势,且在同一浓度的盐处理下,叶的Na 和K 含量最高,茎的次之,根的最低;游离氨基酸(free amino acid,FAA)逐渐减少,脯氨酸(proline,Pro)含量先略低于对照,而后则急剧上升,可溶性糖含量(soluble sugar,SS)的变化正相反;净光合速率(net photosynthetic rate,Pn)、气孔导度(stomatal conductance,Gs)和蒸腾速率(transpirationrate,Tr)呈下降趋势,胞间CO2浓度(intercellular CO2concentration,Ci)呈上升趋势;膜稳定性呈下降趋势。因此,空心莲子草是一种盐生植物,且最适盐浓度较低;Na 主要积累在地上部的茎和叶中。推测它有可能向盐渍土壤蔓延。     

The Effect of Number of Shoots on the Quantity and Distribution of Increment in Young Apple-trees: With three Figures in the Text

It is shown that the shoots of a young tree act additively ratherthan competitively, that is, each extra shoot produces a definiteextra increment in total weight, not that a constant incrementis divided among the shoots of the young tree. One-year apple-trees of 3 varieties were rigorously selectedfor size and weight, and in the spring disbudded to 1, 2, 3,or n, the natural number of shoots per plant. The treatmentswere applied in the 1st or 2nd year after planting and the incrementduring the treatment year was determined. Provided not morethan a few secondary shoots were produced on the current shoots,each additional primary shoot produced an increase in weight.In one variety plants with 1 primary shoot produced many secondariesand these plants were heavier than those with 2 primaries. The largest shoot was not greatly affected in size by the presenceof other shoots except in the variety which produced secondaryshoots readily. These were most abundant on plants with 1 primaryshoot, fewer on plants with 2, and almost negligible on plantswith 3 and n shoots. Treatment and varietal effects on the percentage distributionof increment as leaves, new stem, old-stem increment, and root,were small. The percentage of leaves in the 2nd year was abouthalf what it was in the 1st year; the percentage of root wasnearly the same in both years.     

温室内长春花总黄酮含量的动态变化研究

以长春花为试材,应用超声提取和分光光度法测定和分析了不同发育阶段长春花不同部位总黄酮含量的动态变化。结果表明：长春花不同时期各部位总黄酮含量由高到低的排列顺序是：果、叶、花、茎、根;不同叶位总黄酮含量是花叶大于果叶,果叶大于营养叶,不同枝位总黄酮含量是果枝大于叶枝,叶枝大于茎,形成由上到下的递减趋势;侧枝各部位总黄酮含量高于主枝,须根总黄酮含量高于主根,形成由外到内的递减趋势。     

牛角花齿蓟马为害对苜蓿无性系根茎叶及同化产物分配的影响

为探索同化产物分配利用与苜蓿耐蓟马的关系,本试验以扦插的抗蓟马苜蓿无性系R-1和感蓟马苜蓿无性系 I-1为材料,研究不同虫口牛角花齿蓟马为害对苜蓿的抗性、根、茎和叶生长特性及可溶性糖含量的影响.结果表明: 随着虫口压力的增大,R-1和I-1苜蓿的受害指数升高;在相同虫口压力下,R-1苜蓿的受害指数显著低于I-1.受蓟马为害后,R-1和I-1苜蓿株高降低、叶面积减少、茎秆变细、节间长变短、节间数增加,根颈和主根直径加粗、侧根增多.在低虫口密度下,随虫口压力增大,R-1和I-1苜蓿地上部生物量增加,根冠比下降,分配到茎的生物量比例升高;在高虫口密度下,地上部生物量随虫口压力增大而减少,根冠比增加,分配到根系的生物量比例升高;R-1根冠比和茎生物量比例随虫口压力变化曲线的拐点均为每枝条5头,I-1根冠比和茎生物量比例随虫口压力变化曲线的拐点均为每枝条3头.在低虫口压力下,R-1苜蓿茎和叶中的可溶性糖含量随虫口压力增加而升高;在高虫口压力下,茎和叶中的可溶性糖含量随虫口压力增加而下降;根中可溶性糖含量随虫口压力增加持续下降.I-1根、茎和叶中的可溶性糖含量均随虫口压力增加持续下降.牛角花齿蓟马为害后,R-1根、茎和叶的农艺性状及抗性比I-1好,对同化产物的分配利用率高.     

Occurrence of iridoid glycosides in in vitro cultures and intact plants of <Emphasis Type="Italic">Scrophularia nodosa</Emphasis> L.

Shoot, root, and callus cultures of Scrophularia nodosa L. (Scrophulariaceae) were established and cultivated in vitro. Iridoid glycosides, such as harpagoside, aucubin, and catalpol were identified by LC-ESI-MS and their contents determined by HPLC. For comparison intact plants of S. nodosa were analysed. In shoot cultures slightly lower amounts of detectable iridoid glycosides (4.36% dry weight) were determined than in the field grown plants (4.88%). Concentration of harpagoside was highest in leaves of field plants (1.05%) and in flowers of in vitro plantlets (1.10%). For aucubin the highest amount was found in the leaves of in vitro plantlets (1.67%) whereas the levels of aucubin in the leaves of field plants were remarkably lower. Catalpol was produced as a trace compound in intact plants and shoot cultures. Callus and root cultures were apparently not able to synthesise iridoid glycosides.     

Effect of salinisation of soil on growth, water status and general nutrient accumulation in seedlings of Delonix regia (Fabaceae)

Greenhouse experiments were conducted to assess the effect of salinisation of soil on emergence, growth, water content, proline content and mineral accumulation of seedlings of Delonix regia (Hook.) Raf. (Fabaceae). Sodium chloride (NaCl) was added to the soil and salinity was maintained at 0.3, 1.9, 3.9, 6.0 and 7.9 dS m⁻¹. A negative relationship between seedling emergence and salt concentration was obtained. Salinity caused reduction in water content and water potential of tissues (leaves, stems, tap roots and lateral roots) that resulted in internal water deficit to plants. Consequently, shoot and root elongation, leaf expansion and dry matter accumulation in leaves, stems, tap roots and lateral root tissues of seedlings significantly decreased in response to increasing concentration of salt. Proline content in tissues was very low. There were no effective mechanisms to control net uptake of Na on root plasma membrane and subsequently its transport to shoot tissues. Potassium content significantly decreased in tissues in response to salinisation of soil. This tree species is a moderate salt-tolerant glycophytic plant. Nitrogen and calcium content in tissues significantly decreased as soil salinity increased. Phosphors content in tissues exhibited a declining trend with increase in soil salinity. Changes in tissues and whole-plant accumulation pattern of other elements tested, as well as possible mechanisms for avoidance of Na toxicity in this tree species in response to salinisation, are discussed.     

Effect of salinisation of soil on growth, water status and general nutrient accumulation in seedlings .of Delonix regia (Fabaceae)

Greenhouse experiments were conducted to assess the effect of salinisation of soil on emergence, growth, water content, proline content and mineral accumulation of seedlings of Delonix regia (Hook.) Raf. (Fabaceae). Sodium chloride (NaCl) was added to the soil and salinity was maintained at 0.3, 1.9, 3.9, 6.0 and 7.9 dS m^?1. A negative relationship between seedling emergence and salt concentration was obtained. Salinity caused reduction in water content and water potential of tissues (leaves, stems, tap roots and lateral roots) that resulted in internal water deficit to plants. Consequently, shoot and root elongation, leaf expansion and dry matter accumulation in leaves, stems, tap roots and lateral root tissues of seedlings significantly decreased in response to increasing concentration of salt. Proline content in tissues was very low. There were no effective mechanisms to control net uptake of Na on root plasma membrane and subsequently its transport to shoot tissues. Potassium content significantly decreased in tissues in response to salinisation of soil. This tree species is a moderate salt-tolerant glycophytic plant. Nitrogen and calcium content in tissues significantly decreased as soil salinity increased. Phosphors content in tissues exhibited a declining trend with increase in soil salinity. Changes in tissues and whole-plant accumulation pattern of other elements tested, as well as possible mechanisms for avoidance of Na toxicity in this tree species in response to salinisation, are discussed.     

盐胁迫下沙棘的渗透调节效应

分别用含有0、100、200和300mmol LNaCl的Hoagland培养液处理1年生沙棘(HippophaerhamnoidesL.)苗30d后,测定其鲜重,干重,含水量,可溶性糖、脯氨酸和无机离子(Na 、Cl-)的含量及叶片渗透势和渗透调节能力。结果表明:100mmol LNaCl处理的沙棘地上部和根的鲜重和干重最大,其含水量也最大;NaCl浓度超过100mmol L时,沙棘地上部分和根的鲜重和干重随盐浓度增加而逐步下降,其下降的趋势为地上部大于根部。随NaCl浓度不断升高,沙棘体内Na 和Cl-浓度随之升高,茎叶和根系中Cl-含量明显高于Na ,对Na 的相对吸收量多于Cl-。沙棘对盐胁迫有一定的适应能力,随NaCl浓度的升高,沙棘叶内脯氨酸含量升高,可溶性糖含量增加,渗透势降低,渗透调节能力增强。本结果可为盐碱地营造沙棘林提供依据。     

The effect of rhizoctonia root disease and applied nitrogen on growth,nitrogen uptake and nutrient concentrations in spring wheat

Root disease caused by Rhizoctonia solani is a common problem of spring wheat in South Australia. There are reports that nitrogen applications can reduce the incidence and severity of the disease. A glasshouse trail in pots examined the effects of disease and of applied nitrogen on wheat growth, and evaluated the utility of the basal stem nitrate concentration in diagnosing deficiency in plants with and without root disease. Plants were harvested at the mid-tillering stage. Shoot growth was increased by applied nitrogen until a maximum yield was attained, after which additional N had no effect on shoot yield. Root growth, however, responded positively only to low levels of applied N, after which it declined, and in the highest N treatment root mass was less than in the plants without applied N. Root disease caused severe reductions in plant growth, and both root and shoot mass were affected similarly. Even though growth of diseased plants responded positively to applied nitrogen the response was less than that of disease-free plants. The critical concentration of basal stem nitrate-N did not appear to be affected by root disease, and was estimated at 1200 mg kg^-1, consistent with other glasshouse data. The basal stem nitrate-N concentration, either in fresh or dried tissue, appeared a better diagnostic tool of N stress than did total shoot N concentration or content, because of sharper definition of critical concentrations. Concentrations of other nutrients in shoot tissue were affected differentially by both applied nitrogen and root disease, but generally did not reach critical levels, although phosphorus and magnesium appeared deficient in very disease-stressed plants.