广西鹅耳枥属一新种

<正> 灌木,高2—3米;树皮灰褐色;小枝紫褐色,无毛,疏生小皮孔;托叶条形,纸质,长5—7毫米。叶卵状披针形,长2.5—4.2厘米,宽1—1.5厘米,先端渐尖或尾状渐尖,基部圆楔形,有时稍不对称,边缘有锯齿,有时为重锯齿,齿端有腺体,上面无毛,下面沿中、侧脉略被毛,中脉和侧脉在上面凹陷,在下面突起,侧脉每边13—18条,网脉细密,在上面明显突起,下面不明显,叶柄长3—5毫米,无毛或被微小柔毛。果序长2—4厘米,果序轴纤细,无毛;果稀少;果苞长1—1.3厘米,半卵形或半宽卵形或长圆形,先端钝尖,外侧边缘具不规则的锯齿,内侧边缘全缘,直或微弯;小坚果宽卵形,长2.5—3毫米,宽3.5毫米,先端被柔毛,其余无毛,有明显的肋7—9条。     

云贵鹅耳枥群落乔木种群生态位初探

木文应用Ｌｅｖｉｎ公式和王刚改进公式分别计测了贵阳喀斯特山地云贵鹅耳枥群落中乔木种群的生态位宽度和生态位重叠,并对这些种群的生态位关系及其对群落结构和动态的影响进行了分析。     

Comparison of allometric relationships and morphological differences in Tilia cordata Mill. outer leaves exposed to different environmental conditions

The study is based on four leaf parameters: leaf width (LW), lobe length (LL), leaf size (LS) and leaf shape which is calculated as LW to leaf length (LW/LL) ratio. Under different environmental conditions, LL is an isometric character, LW shows positive allometry, whereas LW/LL shows negative allometry. Regression analysis results indicated that there is no significant difference either in slopes or in regression coefficients between investigated sites. Thus, in this study, we found that allometric relationships between leaf parameters and LS are character specific and that they tended not to differ significantly between Tilia cordata Mill. outer leaves exposed to different environmental conditions. Also, there are no significant interpopulation differences for both principal component PC1 and PC2 scores. The stepwise discriminant functional analysis results allowed us to identify a set of two leaf parameters (LS and LL) with a moderate discriminating ability (59.8%). T. cordata outer leaves are significantly larger and broader in the reference area (R-leaves) than leaves from polluted (P-leaves) site. The data also indicated that there is a relatively larger petiole size in R-leaves than in P-leaves. We found that in P-leaves, LW increased faster with increasing LS than in R-leaves.     

干旱胁迫对欧洲鹅耳枥幼苗生理生化特征的影响

以一年生欧洲鹅耳枥幼苗为材料,通过盆栽控水试验,设置5个土壤含水量梯度,研究不同梯度干旱胁迫对其幼苗生理生化指标的影响,以明确欧洲鹅耳枥的耐旱特性。结果显示:（1）随着干旱胁迫的加剧,欧洲鹅耳枥幼苗受到损害程度逐渐加重,形态表现出明显的缺水特征,叶片相对含水量和叶绿素总量随着干旱胁迫程度的增加而下降,且胁迫强度越强、时间越久其变化幅度越大。（2）幼苗叶片SOD活性、POD活性、可溶性糖含量和可溶性蛋白含量均随着干旱程度的增加表现出先升高后降低的趋势。（3）随着干旱胁迫程度的增加和干旱时间持续,幼苗叶片MDA含量和相对电导率总体上呈增大趋势,并在干旱末期达到最大值。研究表明,欧洲鹅耳枥幼苗在短期和轻度（田间最大持水量的60%）、中度（田间最大持水量的45%）干旱胁迫下能通过调节自身保护酶活性和渗透调节物质含量来减轻干旱造成的危害;而在重度（田间最大持水量的30%）干旱胁迫下,幼苗自我调节能力受影响,极度（田间最大持水量的15%）干旱胁迫对其造成一定的损害。研究认为,欧洲鹅耳枥具有一定的抗干旱特性,可在园林中推广运用。     

Anti-bacterial and anti-inflammatory effects of ethanol extract from Houttuynia cordata poultice

Houttuynia cordata (HC) has been commonly used as many traditional remedies in local areas of Japan. Although many pharmacological activities of HC have been reported, the mechanism underlying the effect of HC remains unknown. We conducted the interview survey in Japan to verify how HC was actually used. The interview survey revealed that HC poultice (HCP) prepared from smothering fresh leaves of HC was most frequently used for the treatment of purulent skin diseases including furuncle and carbuncle with high effectiveness. Ethanol extract of HCP (eHCP) showed anti-bacterial effects against methicillin-resistant Staphylococcus aureus (MRSA), and showed an anti-biofilm activity against MRSA. eHCP showed dose-dependent inhibition of S. aureus lipoteichoic acid (LTA)-induced interleukin-8 and CCL20 production in human keratinocyte without any cytotoxicity. These results suggest that HCP is effective for skin abscess and its underlying mechanism might be the complicated multiple activities for both bacteria and host cells.     

Cortical development in roots of the aquatic plant Pontederia cordata (Pontederiaceae)

Adventitious roots of marsh-grown Pontederia cordata were examined to determine cortical development and structure. The innermost layer of the ground meristem forms the endodermis and aerenchymatous cortex. The outermost layer of the early ground meristem undergoes a precise pattern of oblique and periclinal cell divisions to produce a single or double layer of prohypodermis with an anchor cell for each radial file of aerenchyma cells. At maturity, endodermal cell walls are modified only by narrow Casparian bands. The central regions of the ground meristem become proaerenchyma and exhibit asymmetric cell division and expansion. They produce an aerenchymatous zone with barrel-shaped large cells and irregularly shaped small cells traversing the aerenchyma horizontally along radii; some crystalliferous cells with raphides are present in the aerenchyma. The walls of the hypodermis are modified early by polyphenols. The outermost layer of the hypodermis later matures into an exodermis with Casparian bands that are impermeable to berberine, an apoplastic tracer dye. The nonexodermal layer(s) of the hypodermis has suberin-modified walls. Radial files of aerenchyma are usually connected by narrow protuberances near their midpoints, the aerenchyma lacunae having been produced by expansion of cells along walls lining intercellular spaces. We are terming this type of aerenchyma development, which is neither schizogenous nor lysigenous, "differential expansion."     

Adjustment of foliage structure and function to a canopy light gradient in two co-existing deciduous trees. Variability in leaf inclination angles in relation to petiole morphology

 Foliar inclination angles, petiole morphology and dry matter partitioning between assimilative and support biomass were studied in shade-intolerant Populus tremula L. and shade-tolerant Tilia cordata Mill. along a natural light gradient across the canopy. The leaves of sub-canopy species T. cordata were on average exposed to lower irradiances, and they were also more horizontal with greater blade inclination angles (ϕ_B, defined as the angle between the leaf fall-line and the horizon; ϕ_B was positive for the leaves inclined upwards, and negative for the leaves inclined downwards) than those in P. tremula. Seasonal average daily integrated quantum flux density (Q _int, mol m^–2 day^–1) and ϕ_B were not related in T. cordata, and only a weak negative effect of Q _int on ϕ_B was detected in P. tremula. Nevertheless, when both species were pooled, there was a strong negative relationship between Q _int and ϕ_B, implying that the leaves became progressively vertical with increasing height in the canopy. Interspecific differences in foliage inclination were mainly related to petiole morphology, in particular to petiole length, rather than to contrasting biomass investment patterns between assimilative and support tissues within the leaf. It was suggested that more horizontal leaves, resulting from the species-specific structure of petioles, partly explain the superior performance of shade-tolerant T. cordata in the understory and the sub-canopy. Received: 13 November 1997 / Accepted: 6 March 1998     

三白草不同部位及鱼腥草挥发油成分的GC-MS比较分析

采用水蒸气蒸馏法提取,气相色谱-质谱联用技术(GC-MS)对三白草不同部位及鱼腥草挥发油化学成分进行定性和定量分析。共分离鉴定出88个化合物,从三白草地上部分鉴定出36个,根茎中鉴定出31个,分别占挥发油总量的73.38%和95.53%,其中仅13个共有成分;从鱼腥草中鉴定出50个化合物,占挥发油总量的74.59%。三白草地上部分与根茎挥发油中化学成分含量和组成有明显差异,且均不含有甲基正壬酮。     

中药博落回的药理实验研究

博落回对四氯化碳、半乳糖胺所致急性肝损伤模型,均有显著改善肝脏功能作用;对四氯化碳所致慢性肝损伤大鼠模型,博落回可显著降低血清LDH水平。降低动物死亡率。提高血清A/G比值,有效保护肝细胞胰。抑制肝脏纤维化;博落回还可显著增强T和B淋巴细胞功能。     

梯度水分对鱼腥草生长及生理特征的影响

以不同的施水量,模拟自然生境中林下鱼腥草不同水分条件,设置了8个水分梯度,研究梯度水分对鱼腥草生长和生理特征的影响,以建立鱼腥草生态栽培模式。结果表明:水分的减少或增加均显著减少生物量,中度、重度干旱和水淹明显降低株高和叶面积指数。重度干旱显著提高根冠比。除轻度湿润组外,水分的减少或增加,均显著提高MDA含量;与对照组相比,各干旱处理组SOD和CAT活性和MDA含量明显增强;除脯氨酸含量以外,湿润各处理组CAT、POD、SOD活性和MDA含量均明显低于干旱各处理组;水淹时,CAT、POD、SOD活性、MDA和脯氨酸含量均较低。说明中度干旱或中度湿润已对鱼腥草形成逆境胁迫。栽培鱼腥草的水分条件可以控制在轻度干旱和轻度湿润之间。