A novel cytotoxic flavonoid glycoside from Physalis angulata.

A new flavonol glycoside, myricetin 3-O-neohesperidoside (1) was isolated from a cytotoxic MeOH extract of the leaves of Physalis angulata. Compound 1 showed remarkable cytotoxicity in vitro against murine leukemia cell line P-388, epidermoid carcinoma of the nasopharynx KB-16 cells, and lung adenocarcinoma A-549 with ED(50) values of 0.048, 0.50 and 0.55 microg ml(-1), respectively.     

Antimicrobial activity of licorice flavonoids against methicillin-resistant Staphylococcus aureus

Nineteen flavonoids isolated from licorice (Glycyrrhiza glabra, G. inflata and G. uralensis) were tested for their antimicrobial activities against methicillin sensitive Staphylococcus aureus, methicillin resistant S. aureus, Micrococcus luteus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa.     

Hydraulic architecture and water relations of a flood-tolerant tropical tree, Annona glabra

Hydraulic architecture parameters, water relation parameters and wood anatomy were studied in roots and shoots of the flood-tolerant tree Annona glabra L. on Barro Colorado Island, Panama. Hydraulic conductivity, leaf specific conductivity, and Huber value were similar to the corresponding values for tree species living in non-flooded habitats. The vulnerability of stems to loss of hydraulic conductivity resulting from embolism was low (50% loss of conductivity at -3.3 MPa). The lowest leaf water potential measured in the field was about -1.0 MPa, indicating that A. glabra has a large margin of safety from embolism, which may provide protection against rare drought events, or may be an adaptation to brackish mangrove habitats. Low absolute conductivity of roots was compensated for by an increase in the number of roots. More than two-thirds of whole-plant resistance to water flow was located in the roots.     

杉木林冠下草珊瑚人工种植技术

草珊瑚应用广泛,经济效益良好,本文探索在杉木林冠下种植草珊瑚的可行性途径及关键技术措施,为改善杉木林经济效益增长方式提供一条途径,同时也为草珊瑚人工种植的规模化发展提供技术参考。     

海南油楠资源概况及其培育对策

油楠具有较大的开发利用价值,可生产生物柴油,在我国其野生资源仅分布于海南岛.文章概述了油楠的生物学特性、生长环境、资源分布,在种子的选择与处理、育苗方法等方面进行了总结和试验,对其资源培育进行了讨论.     

论我国南方林区草珊瑚的人工栽培

在介绍草珊瑚之价值的基础上,论述了我国南方林区人工栽培草珊瑚的意义和可行性.     

桉树+草珊瑚复合经营模式研究及其经济效益分析

为提高桉树人工林地的土地利用率,有效改善生态环境,项目在桂中平原低丘和高丘陵区两种立地条件下,采用随机区组试验设计方法,研究了桉树+草珊瑚两种复合经营模式、3种栽培模式下产量及其经济效益。结果表明：(1)桉树林下培育草珊瑚苗木复合经营比对照桉树纯林增值456623.73元·hm-2,增值率422.67%。(2)桉树人工林下套种草珊瑚的桉1+草1、桉1+草2、桉1+草3等复合经营模式分别比对照桉树纯林增值?1041.89元·hm-2、18934.23元·hm-2、20212.27元·hm-2,增值率分别是?3.95%、71.88%和76.73%,以桉1+草3复合经营模式经济效益最好。(3)桉树林下套种的草珊瑚生长5个月、16个月和25个月比对照桉树纯林分别增值2264.14元·hm-2、15823.69元·hm-2和42334.03元·hm-2,增值率分别是8.73%、49.64%和115.45%。研究结果表明,对于萌芽力强的多年生植物草珊瑚而言,随着生长时间延长,草珊瑚的分蘖数量和生物量增加,经济效益更好。     

敦煌李光杏低产原因及其防治措施初探

总结了由于受气候及果园综合管理水平等因素的制约,导致李光杏败育花比例上升和授粉品种、授粉昆虫减少,异花授粉受精受阻,开花多、结果稀少;提出了治理措施.     

不同林分类型林下套种草珊瑚生长比较

以16年生、25年生杉木人工林及22年生马尾松人工林林下套种的草珊瑚为研究对象,探讨不同林分类型、不同坡位对套种的草珊瑚生长量的影响。结果表明,不同林分类型套种的草珊瑚地径和当年抽高均表现为下坡位>中坡位>上坡位;同一林分类型下,不同坡位间草珊瑚地径生长量差异不显著,而当年抽高差异达极显著水平;16年生杉木人工林最有利于草珊瑚地径的生长,其次为25年生杉木人工林;16年生的杉木人工林最有利于草珊瑚的高生长,其次为22年生马尾松人工林。     

西印度樱桃的引种栽培和开发利用研究

新经济植物西印度樱桃引入西双版纳种植观测表明,该植物在引种地栽培长势良好,平均单株产量可达25 kg~30 kg。本文还就该物种的形态特征,营养价值及加工利用,栽培管理技术及发展前景作综述分析。     

光照、温度和沙藏对草珊瑚种子萌发的影响

在三明市三元区研究草珊瑚种子发芽率和发芽指数与光照、温度和沙藏时间的关系.结果表明,光照、温度和沙藏时间对草珊瑚种子的发芽率和发芽指数影响极显著,最高发芽率是最低的3.10倍,最高发芽指数是最低的8.63倍.有光照的草珊瑚发芽率显著高于无光照的发芽率;随着温度的增加,草珊瑚种子发芽率表现出先升后降的趋势,25℃时种子发芽率和发芽指数最高;沙藏时间对种子发芽率和发芽指数影响最大,沙藏90 d的种子发芽率在90.00％以上.影响草珊瑚种子发芽率的各因素作用大小依次为沙藏时间＞光照＞沙藏时间×光照＞温度＞沙藏时间×温度,影响发芽指数的各因素作用大小依次为沙藏时间＞光照＞温度＞沙藏时间×温度＞沙藏时间×光照.因此,草珊瑚种子宜分批采种、晾干后即沙藏,3月底到4月间播种,播种时宜浅播.     

三角花品种越冬抗寒性比较研究

对引进上海的三角花4个品种进行越冬冻害观察结果表明,各品种在相同的小环境条件下(风口露地与背风向阳露地)其冻害加重进程不一致;在不同栽培设施下,各品种间抗寒性差异明显;结合相关生理指标测定表明,光叶类三角花较毛叶类三角花品种抗寒,其品种的抗寒性顺序为亮叶三角梅>艳紫三角梅>红色三角梅>斑叶三角梅。     

草珊瑚组培中外植体消毒方法的研究

在建立草珊瑚组培快繁体系过程中,采用常规的表面消毒方法难以获得有效的无菌材料。本文报道了不同的表面消毒方法和抗生素结合使用对组培中污染菌的防除有较好作用。最有效的外植体消毒方案为:草珊瑚的幼嫩茎段经75%酒精处理30 s后,用0.1%升汞溶液消毒10 min,无菌水冲洗3~4次,然后浸于120 mg.L-1利福平溶液中振荡预培养2~4d,再用0.1%升汞溶液消毒10 min,无菌水冲洗3~4次,可以达到较佳的消毒效果,消毒成功率可达55.56%。     

海南尖峰岭油楠树脂油的主要理化特性

以海南尖峰岭油楠为研究对象,通过树干基部钻孔每个月定期收集树脂油,测定6份不同油样的16项理化指标,综合评价油楠树脂油不同样品间理化特性的变异及其关联。结果表明:树脂油的凝点、闭口闪点、馏程、总热值、净热值、碘值、硫含量和铜片腐蚀等理化指标比较稳定,受产油单株影响较弱,除铜片腐蚀为Ia外,其他7个指标变化范围分别为-27～-36℃,114～124℃,248～345℃,42～43MJ·kg-1,40～41MJ·kg-1,118～131gI2·(100g)-1,0.0005%～0.0093%;树脂油密度、运动黏度、冷滤点、水分、灰分、机械杂质、酸值、10%蒸余物残炭和十六烷指数在不同样品间产生显著变异,并与产油单株紧密关联,其变化幅度为812～957kg·m-3,24～48mm2·s-1,12～28℃,0.03%～2.74%,0.008%～0.055%,0～0.060%,0.35～2.23mgKOH·g-1,0.42%～5.46%和25～64;10%蒸余物残炭与闪点存在显著负相关,与碘值、灰分和冷滤点存在显著正相关,密度与运动粘度和机械杂质呈显著正相关、与十六烷指数呈显著负相关,这表明10%蒸余物残炭和密度是树脂...     

Effects of natural and induced pollution on the leaf wax structure of three cypress species

Severe damage was caused to coastal forest vegetation by the Libeccio, a sea wind blowing against the Italian coast from W-SW. The behaviour of common cypress (Cupressus sempervirens), smooth cypress (C. glabra) and Monterey cypress (C. macrocarpa) in response to the Libeccio windstorms of 1990 was compared with that due to treatments with the surfactant ABS (sodium dodecylbenzenesulphonate). As regards both the nature and the intensity of the damage to the leaf waxes, the surge damage caused by the windstorms differed little from that produced artifi-cially by ABS sprays.     

Ent-trachyloban-19-oic acid isolated from Iostephane heterophylla as a promising antibacterial agent against Streptococcus mutans biofilms

From the roots of Iostephane heterophylla, six known compounds, namely, ent-trachyloban-19-oic acid (1), the mixture of ent-kaur-16-en-19-oic acid (2) and ent-beyer-15-en-19-oic acid (3), xanthorrhizol (4), 16α-hydroxy-ent-kaurane (5) and 16α-hydroxy-ent-kaur-11-en-19-oic acid (6) were isolated using a bioassay-guided fractionation method. The known compounds (1-6) were identified by comparison of their spectroscopic data with reported values in the literature. In an attempt to increase the resultant antimicrobial activity of 1 and 4, a series of reactions was performed on ent-trachyloban-19-oic acid (1) and xanthorrhizol (4), to obtain derivatives 1a, 1b, and 4a-4d. All the isolated compounds (1-6) and the derivatives 1a, 1b, and 4a-4d were evaluated for their antimicrobial activity against two oral pathogens, Streptococcus mutans and Porphyromonas gingivalis associated with caries and periodontal disease, respectively. Compounds 1, 1b, 2+3, 4 and 4d inhibited the growth of S. mutans with concentrations ranging from 4.1 μg/mL to 70.5 μg/mL. No significant activity was found on P. gingivalis except for 4 with an MIC of 6.8 μg/mL. The ability of 1, 1b, 2+3, 4 and 4d to inhibit biofilm formation by S. mutans was evaluated. It was found that 1, 1b, 4 and 4d interfered with the establishment of S. mutans biofilms, inhibiting their development at 32.5, 125.0, 14.1 and 24.4 μg/mL, respectively.     

Seed germination of six mature neotropical rain forest species in response to dehydration

We studied effects of dehydration and rehydration on germination of seeds of six mature tropical rain forest species-Cupania glabra Swartz, Cymbopetalum baillonii Fries, Poulsenia armata (Miq.) Standl., Stemmadenia donnell-smithii (Rose) Woodson, Rheedia edulis Triana & Planch. and an understory palm Chamaedorea alternans H. Wendl.-from Veracruz, México. Before the seeds were sown, their water content was reduced by 0 (control), 30, 54 and 72% of their original water content. Dehydration affects the ability of seeds to rehydrate, as well as the rate and final percentage of germination when seeds are subsequently rehydrated. Seed survival and germination behavior showed three patterns: (1) C. baillonii, P. armata and S. donnell-smithii had greater tolerance to seed dehydration than C. glabra, C. alternans and R. edulis; (2) partial dehydration enhanced germinability of C. glabra and C. baillonii seeds; and (3) partial dehydration of C. alternans and R. edulis seeds resulted in delayed or sporadic germination. A relationship was found between the effects of dehydration on germination and the seasonality of seed production.     

草珊瑚栽培技术

介绍了草珊瑚采种、育苗、栽植、管理和采收等人工栽培的技术。     

草珊瑚林间栽培习性及收获模型

简介草珊瑚林间栽培适宜环境及鲜叶、地上鲜重、叶面积３个预估模型。     

草珊瑚林冠下播种育苗试验

草珊瑚播种育苗试验在杉木近熟林、阔叶树近熟林、毛竹林的林冠下进行,结果表明：不同树种林冠下的生长环境和土壤条件对草珊瑚种子的发芽率、苗木保存率及生长量均有显著影响;杉木近熟林林冠下较适宜草珊瑚的种子发芽率、苗木保存率、苗高、地径、主根长度、侧根长度、≥3 cm侧根条数7项指标平均达85.1%、83.6%、8.2 cm、0.18cm、5.3 cm、8.4 cm、4.2条。