刚竹属植物非笋期营养体分类的初步研究

刚竹属(PhyllostachysSieb. et Zucc.)是一个主产于中国,大约有60种的竹亚科大属,当前其属内种间的划分和鉴定主要依据秆箨和新秆的特征。然而,本属植物的笋期大多仅持续20~30 d,其他时间很难见到鲜笋或新鲜秆箨和新秆。应用现今流行的分种检索表和形态特征来鉴别处于非笋期营养生长状态的竹种往往作用不大,这就需要重新寻找更多的证据来解决这一问题。据长期的野外调查和栽培植物的定点观察,一些性状,如秆的节内距、小枝及叶的排列方式、叶耳及繸毛存在与否及其排列方式、叶舌是否伸出、叶片背面毛被状况等可以作为本属植物非笋期分类的重要依据。如果把握得恰当,利用这些性状和其他特征的组合可以在非笋期将本属现知的所有竹种划分开来,并据此编制了此期的分种检索表。     

大岩桐叶片培养再生植株的研究

以大岩桐（Ｓｉｎｎｉｎｇｉａ ｓｐｅｃｉｏｓａ Ｂｅｎｔｈ．ｅｔ Ｈｏｏｋ）叶片为试材,接种于ＭＳ附加不同激素组合的培养基上,成功地经愈伤组织至球状体至不定芽途径形成大量再生植株并移栽成活。在各种细胞分裂素中,６－苄基嘌呤（ＢＡ）的效果优于激动素（ＫＴ）。生长素萘乙酸（ＮＡＡ）与ＢＡ及ＫＴ配合使用时愈伤组织诱导、球状体分化及不定芽增殖均有明显的增效作用。其最适宜的培养基组成为：ＭＳ＋ＢＡ２．０ｍｇ     

The vegetation of roadside verges with respect to environmental gradients in southern New Zealand

Abstract. A survey of the vegetation of roadside verges was made across the southern part of the South Island of New Zealand. Samples were taken at 10-km intervals along selected roads providing a climatic range from the suboceanic conditions of the east coast into semi-arid Central Otago, and from Central Otago through the Southern Alps to the hyper-oceanic areas of high rainfall on the west Coast. The variation in the floristic composition is associated mainly with variation in rainfall, continentality, altitude, soil acidity, soil organic matter, and presence of forest. Sites in the arable and pastoral regions on the eastern side of the Southern Alps support a herbaceous vegetation consisting mostly of exotic species of European origin, with a few native grasses scattered through the drier and less fertile sites. A greater proportion of native species is found at higher altitudes. Roadside vegetation in the area of high rainfall to the west is characterized by indigenous ferns and woody species, although vegetation adjacent to cleared areas is more similar to that on roadsides adjacent to farmland on the east coast. The pattern of distribution of both native and exotic species is strongly related to altitudinal and climatic gradients, and the environmental responses of the exotic species are similar to those recorded in Europe. This suggests a colonization of all available sites by the exotic species, despite the relatively short time since their introduction to New Zealand, rather than an incomplete invasion.     

Vegetation change following exclusion of grazing animals in depleted grassland,Central Otago,New Zealand

Abstract. Models of semiarid vegetation dynamics were evaluated to explain changes in the grassland of interior South Island, New Zealand. Annual records were taken for six years of plant species height frequency and percentage ground cover in five plots established in 1986. One subplot at each site was fenced to exclude sheep, one to exclude rabbits and sheep, and one remained unfenced as a control. Records from 1986–1992 were analysed by ordination. The overall pattern of vegetation change shows considerable year-to-year variation. At some sites, variation in vegetation composition between years was as great as, or greater than, that between grazed and ungrazed subplots. Such variation is particularly evident in grazed vegetation, perhaps because it is under greater stress than ungrazed vegetation. At one site changes in vegetation total cover and species composition could be statistically related to rainfall during the first half of the growing season. The only general trends following cessation of grazing were for perennials to increase in frequency, and for year-to-year changes to become smaller with time. Total vegetation cover values seldom changed as a result of cessation of grazing, but tended to follow year-to-year changes in species frequency. The results do not in general support switch/state-and-transition models of semi-arid vegetation dynamics. Vegetation change follows changes in grazing and climate with little lag. This most closely conforms with the Pulse-phase dynamic model.     

丁香挥发油化学成分与抗菌活性研究

利用气相色谱—质谱(GCMS)法结合化学计量学方法对丁香挥发油化学成分进行了分析研究。得益于化学计量学分辨方法,从丁香花蕾与丁香果实中共鉴定了46种化合物。其中从丁香果实挥发油中鉴定了41种化合物,占挥发油总量的94.154%;从丁香花蕾挥发油中鉴定出30种化合物,占其挥发油总量的98.418%。2,3,4trimethoxyacetophenone和2methoxy4[2propenyl]phenolacetate为首次从丁香挥发油中鉴定得到。两种已经确认具有生物活性的化合物丁子香酚和石竹烯在丁香果挥发油分别为22.667%和7.147%,而在丁香花蕾挥发油中含量分别为和57.133%和14.408%,二者在相对含量上差异较大。体外抗菌试验结果表明,这两种挥发油对金黄色葡萄球菌和白色念珠菌十分敏感,对大肠杆菌和枯草杆菌敏感。而丁香花蕾挥发油对所有试验菌株都比丁香果挥发油表现出更强的抗菌活性,我们认为这可能是前者丁子香酚和石竹烯含量高的原因。     

石荠苧精油的GC-MS分析及其抑菌活性的研究

利用水蒸汽蒸馏法提取石荠芋（Mosla scabra（Thunb．）C．Y．Wu et H．W．Li]精油,得油率为1．2％。采用GC—MS方法分析了该挥发油的化学组成,检测到125个峰,共鉴定出其中67个化学成分并测定其相对含量。占总含量的95．25％。其中,（R）侧柏酮（26．11％）、（M）侧柏酮（13．66％）、石竹烯（8．89％）、桉叶油素（7．99％）、（R）-α-石竹烯（6．45％）、芹菜脑（5．43％）和β-荜澄茄油烯（4．51％）为主要成分。体外抑菌实验表明,该精油对7种供试细菌均有抑制作用,对金黄色葡萄球菌（Staphylococcus aureus Roenbach）、普通变形杆菌（Proteasv ulgarisHauser）、甘薯青枯假单胞菌（Ralstonia soanacearum E．F．Smith）、大肠杆菌（Esckrichia coli Castellani et Chalmers）和短小芽孢杆菌（Bacillus pumilus Meyer et Gottheil）的最低抑菌浓度（MIC）为2％,对枯草芽孢杆菌（Bacillus subtilis Cohn）和藤黄八叠球菌（Sarcina lutea Schroeter）的MIC为1％。     

Stimulation-Evoked Ca2+ Fluxes in Cultured Bovine Adrenal Chromaffin Cells Are Enhanced by Forskolin

Forskolin, 1 microM, increased acetylcholine (ACh)-stimulated 45Ca uptake by chromaffin cells. The stimulatory effects of forskolin decreased with increasing concentration of ACh. The attenuation of the effect of forskolin on 45Ca uptake as a function of ACh concentration correlated well with changes in the forskolin effect on ACh-evoked catecholamine (CA) release. Forskolin increased excess KCl- and veratrine-evoked CA release and 45Ca uptake. Forskolin by itself stimulated 45Ca efflux and enhanced ACh-, excess KCl-, and veratrine-stimulated 45Ca efflux. High doses of forskolin inhibited both ACh-evoked 45Ca uptake and CA release. The inhibitory action of forskolin was specific to receptor-mediated response because excess KCl- and veratrine-stimulated 45Ca uptake and CA release were not inhibited. Forskolin, 0.3-30 microM, dose-dependently increased caffeine-stimulated CA release and 45Ca efflux in the absence of Ca2+ in the medium, and the effects were mimicked by dibutyryl cyclic AMP. These results suggest that cyclic AMP increases stimulation-induced CA release by enhancing calcium uptake across the plasma membrane and/or altering calcium flux in an intracellular calcium store.     

A Study on the Genus Melocalamus Benth. (Bambusoideae) from China

Melocalamus Benth. consists of five species. Through a comprehensive study of history, morphology, and all specimens available, the authors confirm the occurrence in China of M. compactiflorus (Kurz.) Benth. et Hook f., the type of the genus, and two species, M. scandens Hsueh ct Hui, M. fimbriatus Hsueh et Hui, are described as new. A key to speciesis provided.     

红叶藤化学成分的研究

从红叶藤[Rourea microphylla(Hook.et Arn)Plan ch.]茎叶中分得11种化合物,经理化常数测定、光谱分析及化学方法鉴定为槲皮素-3-O-α-L-鼠李吡喃糖甙(Ⅰ)、金丝桃甙(Ⅱ),槲皮素(Ⅲ)、落新妇甙(Ⅳ)、β-谷甾醇(Ⅴ)、β-谷甾醇-β-D-葡萄吡喃糖甙(Ⅵ)、大黄素甲醚(ⅦI)、红灰青素(Ⅷ)、硬脂酸(Ⅸ)、软脂酸(Ⅹ)和正九烷(Ⅺ)。其中化合物Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅵ、Ⅶ、Ⅷ、Ⅸ、Ⅹ和Ⅺ为首次。从红叶藤属植物中分得。     

新疆天山三角草属(禾本科)一新种

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