Ontogeny of Staminate and Carpellate Flowers of Schisandra sphenanthera(Schisandraceae)

The ontogenetic process of the staminate and carpellate flowers of Schisandra sphenanthera Rehd. et Wils., an endemic species to China, was observed for the first time under the scanning electron microscope (SEM). In the staminate flowers, the perianth units and stamens were initiated acropetally in a continuous fasion with 2/5 spiral phyllotaxis, while no female structures were formed. Anthers were differentiated prior to the filaments formation. Throughout all the stages were the stamens arranged spirally on a columniform receptacle. In the carpellate flowers, the initiation sequence of the perianth units and carpels were similar to that of the staminate flowers. In contrast, no male structures were formed. Shortly after initiation, the carpel primordia began their marginal growth besides the apical growth and then appresses were formed on the adaxial surfaces of the primordia. However the lower margins of these appresses were inconspicuous, resulting in conduplicate carpels. Two ovules were developed on the inner surface near either lateral margins of the carpel, shaping laminar placentae. Compared with S. glabra (Brickell) Rehd., a related American species, the evolutionary trend of phyllotaxis of androecia is considered that stamens may change from spiral to approximately whorled arrangement, accompanying with the change of receptacle from a column to a flattened shield. It was also suggested that the stamens being numerous and uncertain in number become certain and decrease in number to 5 (4－7). Sterile stamens are observed and the unisexual nature of the flowers is discussed. Two types of carpel primordia are categorized, corresponding to two types of carpels, namely, ascidiate and conduplicate carpels, respectively.     

细裂槭与其近缘种的比较形态学及分类学研究

通过对细裂槭与其近缘种大叶细裂槭、疏毛槭的表型性状及叶片微形态进行比较研究,探讨细裂槭在植物分类学上的地位。结果表明:(1)不同产地细裂槭表型性状变异主要来源于居群内。(2)同一产地细裂槭与其近缘种的一些表型性状存在较大的差异。(3)反映叶片大小和翅果形状指标的平均变异系数相对较大,不能准确反映种间关系,故不支持《中国植物志》、Flora of China以及各类地方植物志中以叶片大小和双翅连接角度作为细裂槭、大叶细裂槭和疏毛槭的主要分类依据。(4)疏毛槭叶上表皮和下表皮均具表皮毛,且生活周期内不脱落,与《中国植物志》和Flora of China对疏毛槭的记载略有不同。依据许炳强提出的植物叶脉序演化关系,细裂槭与大叶细裂槭的叶脉序特征基本一致,而疏毛槭较细裂槭和大叶细裂槭原始,该研究结果支持Flora of China对细裂槭和大叶细裂槭的合并处理,并将细裂槭作为疏毛槭的变种处理。     

大血藤不同器官黄酮类化合物含量的季节变化

大血藤〔Ｓａｒｇｅｎｔｏｄｏｘａｃｕｎｅａｔａ (Ｏｌｉｖ .)Ｒｅｈｄ .ｅｔＷｉｌｓ.〕隶属木通科 (Ｌａｒｄｉｚａｂａｌａｃｅａｅ)大血藤属 (ＳａｒｇｅｎｔｏｄｏｘａＲｅｈｄ .ｅｔＷｉｌｓ.) ,为落叶木质藤本 ,根和藤可入药 ,有强筋骨、活血散瘀、止痛、通经之效 ,并可治疗阑尾炎、风湿性关节炎等 ,又可用作杀虫剂[1] 。大血藤是中国特有中药材 ,入药部位为一年生嫩茎 ,但在中医临床应用上并不广泛。有关大血藤次生代谢产物的研究较少。Ｒｏｍｋｅｒ等从大血藤分离出三萜类皂素如儿茶素等 ,并发现在体内具有明显的抗病毒效应[2 ] …     

蓣知子的化学成份研究（Ⅲ）

从木通科木通属植物白木通[Akebia trifolinta (Thunb.) Koidz. var. australis(Dies)Rehd]的种子(蓣知子)抗肿瘤活性的乙醇提取物中以硅胶层析等方法分得一种三萜皂甙。经波谱分析及酸碱水解确定了其化学结构,命名为:3-O-α-L-吡喃阿拉伯糖常春藤皂甙元-28-O-β-D吡喃葡萄糖-(1→6)-β-D-吡喃葡萄糖甙(即Saponin D),为首次自该植物中获得。     

安徽黄山华中五味子次生木质部的生态解剖

对安徽黄山海拔420～1840m的华中五味子茎的次生木质部进行了生态解剖学研究。结果表明,茎的次生木质部为散孔材,导管分子长741.7～1025.2μm,直径为152.4～191.9μm;导管频率60.6～70.2mm-2。纤维管胞长925.2～1046.3μm;木射线类型为异形ⅡA和ⅡB,单列射线高682.1～778.4μm,多列射线高度为1093～1208μm,多列射线宽63.6～92.6μm,射线频率9.2～12.8mm-1。次生木质部解剖特征随异质生境而表现出一定的可塑性,其中,多列射线宽、射线频率、导管分子长度、导管直径等性状的可塑性较大。多重回归分析表明,水分和温度是影响华中五味子次生木质部解剖特征的主导因子。随着空气相对湿度的增加,导管分子长度和直径均增大,射线频率减小。随着降雨量的增加,纤维长度增加。随着最冷月温度的增加,导管频率增加,多列射线宽度减小。随着年较差的增加,单列射线和多列射线高度均减小。     

Relaxant effects of Schisandra chinensis and its major lignans on agonists-induced contraction in guinea pig ileum

In this study, the herbal extracts of Schisandra chinensis were demonstrated to inhibit the contractions induced by acetylcholine (ACh) and serotonin (5-HT) in guinea pig ileum, and the 95% ethanol extract was more effective than the aqueous extract. Analysis with High Performance Liquid Chromatography (HPLC) indicated that schisandrin, schisandrol B, schisandrin A and schisandrin B were the major lignans of Schisandra chinensis, and the ethanol extract contained higher amount of these lignans than the aqueous extract. All four lignans inhibited the contractile responses to ACh, with EC₂₀ values ranging from 2.2 ± 0.4 μM (schisandrin A) to 13.2 ± 4.7 μM (schisandrin). The effectiveness of these compounds in relaxing the 5-HT-induced contraction was observed with a similar magnitude. Receptor binding assay indicated that Schisandra lignans did not show significant antagonistic effect on muscarinic M3 receptor. In Ca²⁺-free preparations primed with ACh or KCl, schisandrin A (50 μM) attenuated the contractile responses to cumulative addition of CaCl₂ by 37%. In addition, schisandrin A also concentration-dependently inhibited ACh-induced contractions in Ca²⁺-free buffer. This study demonstrates that Schisandra chinensis exhibited relaxant effects on agonist-induced contraction in guinea pig ileum, with schisandrin, schisandrol B, schisandrin A and schisandrin B being the major active ingredients. The antispasmodic action of schisandrin A involved inhibitions on both Ca²⁺ influx through L-type Ca²⁺ channels and intracellular Ca²⁺ mobilization, rather than specific antagonism of cholinergic muscarinic receptors.     

红豆杉种子发育及幼苗生长动态

对红豆杉〔Ｔａｘｕｓｃｈｉｎｅｎｓｉｓ（Ｐｉｌｇｅｒ）Ｒｅｈｄ．〕种子发育及１～５年生实生苗生长动态进行了观测,在秦岭山区,红豆杉成年树３～５月开花,５～９月胚珠逐渐发育,９月下旬种子成熟。实生苗在２龄内地上部生长缓慢,根系生长迅速;自第３年起地上部生长旺盛,地下部则稳定生长。文中就红豆杉人工育苗及家化栽培的问题进行了讨论。     

生长在太白山上的紫萼丁香木材的生态解剖

生长在秦岭太白山北坡的紫萼丁香(Syringa oblata var.giraldii Rehd.)的木材结构随着海拔高度的增加而变化。其年轮宽度,导管分子长度、直径;纤维管胞长度、宽度;射线高度等值逐渐增加。导管频率、射线频率、单孔率值则逐渐减少。导管、纤维管胞的壁减薄,其次生壁上的螺纹加厚由明显到不明显。