桑树叶肉原生质体培养再生植株

近年来,木本植物原生质作诱导再生植株的研究越来越受到国内外学者关注。但在林木树种中,迄今成功的种类仍然不多,在文     

桑白皮中抗人爱滋病病毒（HIV）成分研究

从中药桑白皮（ＭｏｒｕｓａｌｂａＬ．）的根皮中分离到６个成分,它们是：ｍｏｒｕｓｉｎ（１）,ｍｕｌｂｅｒｒｏｆｕｒａｎＤ（２）,ｋｕｗａｎｏｎＨ（３）,ｍｕｌｂｅｒｒｏｆｏｒａｎＫ（４）,ｋｕｗａｎｏｎＧ（５）,ｍｕｌｂｅｒｒｏｆｕｒａｎＧ（６）;并制备了它们的乙醚化合物和葡萄糖成;还测定了这些化合物的体外抗人爱滋病病毒（ＨＩＶ）活性和对人淋巴细胞的细胞毒活性,发现其中黄酮ｍｏｒｕｓｉｎ,ｋｕｗａｎｏｎＨ和ｍｏｒｕｓｉｎ４＇－ｇｌｕｃｏｓｉｄｅ具有一定的抗ＨＩＶ活性。     

Alternative pathways of liana communities in the forests of northwestern Argentina

Liana dynamics in secondary and mature forests are well known in tropical areas dominated by native tree species. Outside the tropics and in secondary forests invaded by exotic species, knowledge is scarce. In this study, we compare liana communities between secondary and mature forests dominated by native species in a subtropical montane area of Sierra de San Javier, Tucuman, Argentina. Additionally, we evaluate changes of liana communities in secondary forests with increasing densities of Ligustrum lucidum and Morus alba, two of the most invasive exotic trees of the area. We surveyed liana species richness and density in three 30-year secondary patches, four 60-year secondary patches, and four mature patches dominated by native tree species, to analyze changes in liana communities with forest age. Within each patch, we sampled 10–25 20 × 20 m quadrats. Additionally, we surveyed liana density and species richness in secondary forest patches with different densities of L. lucidum and M. alba. In native-dominated forests, liana species richness increased and showed a tendency of increasing basal area from 30-year secondary forests to mature forests. Liana density was highly variable, and most of the species were shared between native-dominated secondary and mature forests. Liana density and species richness decreased with L. lucidum density, whereas in secondary forests highly dominated by M. alba, lianas increased in density. Overall, lianas followed different pathways influenced by native forest succession and exotic tree invasions.     

桑叶细脉中伴胞的超微结构研究

为了解桑叶细脉中伴胞的超微结构,采用透射电子显微技术对桑叶细脉中伴胞进行观察,着重伴胞与相邻细胞界面上胞间连丝发生频率.结果表明,(1)伴胞含丰富细胞器,细胞壁光滑,无壁内突;(2)伴胞细胞壁上具有大量胞间连丝,胞间连丝通常聚集,并常发生分枝;(3)伴胞与不同类型细胞界面上的胞间连丝发生频率有差异,伴胞-维管束鞘细胞界面上发生频率为25.12±1.83个/μm²,伴胞-伴胞界面上20.18±1.7个2/μm²,伴胞-维管薄壁细胞界面上5.42±0.6个/μm².基于上述观察,认为桑叶细脉中的伴胞属于1-2a型,韧皮部装载途径属于共质体类型.     

Cytological changes during cell wall sac formation in mulberry idioblasts

Summary. When calcium carbonate crystals are formed in mulberry (Morus abla) idioblasts, they are deposited in newly formed cell wall sacs. The initial cytological events leading to cell wall sac formation were observed in the distal end of young idioblasts and tentatively categorized into four stages. The first indication of formation was the separation of the innermost cell wall layer from the cell wall, which is followed by the deposition of egg-shaped polysaccharide on the inner cell wall surface. The size of the deposit area increased, while the thickness of the cell wall significantly decreased during the next stage. Finally, the condensed cellulosic lamella was invaginated into the deposition area, resulting in the formation of an elongated cell wall sac. The internal cell wall sac was composed of numerous fibers with different morphologies. Application of gelatin-methenamine-silver staining allowed us to observe the spatial distribution of cellulosic polysaccharides as electron-dense images. Correspondence and reprints: Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo, Kyoto 606-8585, Japan.     

Photosynthetically versatile thin shade leaves: A paradox of irradiance-response curves

Thick sun leaves have a larger construction cost per unit leaf area than thin shade leaves. To re-evaluate the adaptive roles of sun and shade leaves, we compared the photosynthetic benefits relative to the construction cost of the leaves. We drew photosynthetically active radiation (PAR)-response curves using the leaf-mass-based photosynthetic rate to reflect the cost. The dark respiration rates of the sun and shade leaves of mulberry (Morus bombycis Koidzumi) seedlings did not differ significantly. At irradiances below 250 μmol m⁻² s⁻¹, the shade leaves tended to have a significantly larger net photosynthetic rate (P _N) than the sun leaves. At irradiances above 250 μmol m⁻² s⁻¹, the P _N did not differ significantly. The curves indicate that plants with thin shade leaves have a larger daily CO₂ assimilation rate per construction cost than those with thick sun leaves, even in an open habitat. These results are consistently explained by a simple model of PAR extinction in a leaf. We must target factors other than the effective assimilation when we consider the adaptive roles of thick sun leaves.     

Simultaneous determination of five characteristic stilbene glycosides in root bark of Morus albus L. (Cortex Mori) using high-performance liquid chromatography

Introduction – Cortex Mori, one of the well‐known traditional Chinese herbal medicines, is derived from the root bark of Morus alba L. according to the China Pharmacopeia. Stilbene glycosides are the main components isolated from aqueous extracts of Morus alba and their content varies depending on where Cortex Mori was collected. We have established a qualitative and quantitative method based on the bioactive stilbene glycosides for control of the quality of Cortex Mori from different sources. Objective – To develop a high‐performance liquid chromatography coupled with ultraviolet absorption detection for simultaneous quantitative determination of five major characteristic stilbene glycosides in 34 samples of the root bark of Morus alba L. (Cortex Mori) from different sources. Methodology – The analysis was performed on an ODS column using methanol‐water‐acetic acid (18: 82: 0.1, v/v/v) as the mobile phase and the peaks were monitored at 320 nm. Results – All calibration curves showed good linearity (r ≥ 0.9991) within test ranges. This method showed good repeatability for the quantification of these five components in Cortex Mori with intra‐ and inter‐day standard deviations less than 2.19% and 1.45%, respectively. Conclusion – The validated method was successfully applied to quantify the five investigated components, including a pair of cis‐trans‐isomers 1 and 2 and a pair of isomers 4 and 5 in 34 samples of Cortex Mori from different sources. Copyright © 2010 John Wiley & Sons, Ltd.     

龙桑一号桑叶精油的挥发性组分(英文)

桑品种龙桑一号(Morus alba)栽培于中国东北黑龙江省齐齐哈尔市甘南林场桑产业科技示范园。2009年7月、8月和9月的桑品种龙桑一号干桑叶精油中的挥发性组分经水蒸馏提取后进行了气相色谱-质谱(GC-MS)分析。结果表明桑叶精油的共有组分是植醇(醇类化合物)、六氢金合欢丙酮(酮类化合物)、二十七烷和二十五烷(烃类化合物)。棕榈酸为7月和8月采集桑品种龙桑一号干桑叶精油的共有第一主成分。顺式-β-金合欢烯、反式-β-金合欢烯、β-甜没药烯、反式-α-佛手柑油烯和α-姜黄烯是9月采集桑品种龙桑一号干桑叶精油的主要芳香组分。萜类化合物相对含量较高的9月份采集的干桑叶精油具有药用价值。     

Morphological and Molecular Variation of Morus laevigata in India

Morus spp., commonly known as mulberry, is significantly associated with human civilization and spread of silk-culture from Asia to Europe, Africa and Latin America. One of its species, Morus laevigata, traditionally well known for its timber value, forage use and silkworm's feed, is widely distributed in India extending from Himalayan foothill to Andaman islands. The variability occurring for 12 morpho-biochemical parameters and RAPD profiles, generated with 13 selected RAPD primers, for M. laevigata accessions from six different zones were investigated. Analyses revealed high degree of genotypic similarity of collection from Himalayan foothill (West Bengal) with those from Andaman Islands. Specific accessions from central India and south India also revealed genotypic similarities with specific accessions from north-east India. These observations are discussed in the context of clonal propagation of mulberry and evolutionary perspective of dispersal of this species, through human activities