647. RONDELETIA BUXIFOLIA

Rondeletia buxifolia Vahl (Rubiaceae) a critically endangered shrub, restricted to the Caribbean Island of Montserrat, is described and illustrated. Its distribution and conservation status are reviewed.     

Woody vegetation structure of xeric forest stands under different edaphic site conditions and disturbance histories in the Biosphere Reserve 'Parque Costero del Sur', Argentina

We studied stand structures and soil properties in an old-growth forest and two 30-yr-old second-growth stands. In the old-growth forest, the total density and basal area average 1566 trees > 1.25 m height ha^-1 and 46.73 m² ha^-1. The dominant trees are Scutia buxifolia and Celtis tala. Using multivariate techniques we distinguished three stands: PS1, dominated by S. buxifolia, is 1000 m far from the river. Its soil is shallow and loamy. PS2 and PS3, co-dominated by S. buxifolia and C. tala, are over 1200 m distant from the river. There the soil is deeper and has thicker texture and higher phosphorus and calcium concentrations than the near-the-river forest soil. Scutia buxifolia shows reverse J-shaped size-distributions and has morphological features of stress-tolerant species. Celtis tala shows oscillating decay size-curves that suggest recruitment pulses related to small gaps and it has morphological features of competitive species. Celtis tala was selectively cut in the past in the second-growth stands SNRD and SRD. The stand SNRD, 1000 m far from the river, is dominated by S. buxifolia. The second species is Schinus polygamus which presents the bell-shaped size-structure of the pioneer species. SNRD does not differ from its old-growth counterpart PS1 in total tree density, basal area and tree branching. The stand SRD, over 1200 m distant from the river, is co-dominated by S. buxifolia and by C. tala trees regenerated from stumps. SRD does not differ from its old-growth counterparts PS2 and PS3 in total tree density and basal area. As to tree branching, it does not differ from PS3, but differs from PS2. All the stands are being invaded by the exotic tree Ligustrum lucidum.The differences between the old-growth stands seem to be related to the gradients of soil texture and nutrient concentrations raising edaphic stress towards the river. In SNRD, the stress, the stress-tolerance of S. buxifolia, and the aptitude of S. polygamus to recruit in disturbed habitats seem to have prevented the post-logging recruitment of C. tala. In SRD, C. tala regenerated possibly due to a better competitive performance in a more favorable site. Under protection the second-growth stands recovered the old-growth quantitative features. We recommend the restoration of the qualitative features and the control of L. lucidum.     

Evidence for physiological seed dormancy cycling in the woody shrub Asterolasia buxifolia and its ecological significance in fire‐prone systems

• Dormancy cycling is a key mechanism that contributes to the maintenance of long‐term persistent soil seed banks, but has not been recorded in long‐lived woody shrub species from fire‐prone environments. Such species rely on seed banks and dormancy break as important processes for post‐fire recruitment and recovery.
• We used germination experiments with smoke treatments on fresh seeds and those buried for 1 year (retrieved in spring) and 1.5 years (retrieved the following late autumn) to investigate whether Asterolasia buxifolia, a shrub from fire‐prone south‐eastern Australia with physiologically dormant seeds, exhibited dormancy cycling.
• All seeds had an obligation for winter seasonal temperatures and smoke to promote germination, even after ageing in the soil. A high proportion of germination was recorded from fresh seeds. but germination after the first retrieval was significantly lower, despite high seed viability. After the second retrieval, germination returned to the initial level. This indicates a pattern of annual dormancy cycling; one of the few observations, to our knowledge, for a perennial species. Additionally, A. buxifolia’s winter temperature and smoke requirements did not change over time, highlighting the potential for seeds to remain conditionally dormant (i.e. restricted to a narrow range of germination conditions) for long periods.
• For physiologically dormant species, such as A. buxifolia, we conclude that dormancy cycling is an important driver of successful regeneration, allowing seed bank persistence, sometimes for decades, during fire‐free periods unsuitable for successful recruitment, while ensuring that a large proportion of seeds are available for recruitment when a fire occurs.

     

Antibacterial cyclopeptide alkaloids from the bark of Condalia buxifolia

The cyclopeptide alkaloid, named condaline-A, was isolated from the root bark of Condalia buxifolia Reissek (Rhamnaceae), along with the known compounds adouetine-Y', scutianine-B, and scutianine-C. Their structures were determined by spectroscopic analyses, with their antibacterial activities being evaluated by use of a direct bioautography method.     

Cyclopeptide alkaloids from Scutia buxifolia Reiss and their antimicrobial activity

The present study reports a cyclopeptide alkaloid, scutianine M, isolated from the methanolic root bark extract of Scutia buxifolia Reiss (Rhamnaceae) along with six known compounds, scutianines-B, -C, -D, -E, -F, and scutianene D. Its structure was established on the basis of spectroscopic analyses, including application of 2D NMR spectroscopic techniques. As part of a study of the bioactive compounds of medicinal plants from southern Brazil, we also compared the antimicrobial activity of the isolated compounds towards Gram (+), Gram (-) bacteria, and yeasts.     

52种热带药用植物抗烟草青枯菌的体外活性筛选

为寻找具有抗烟草青枯菌活性的热带药用植物,通过制备乙醇提取物,测定荔枝草、蜂巢草、光叶巴豆等52种热带药用植物对烟草青枯病菌的抑菌圈直径和最小抑菌浓度。结果表明：13种热带药用植物对烟草青枯菌具有抑制作用,其中酒饼簕、许树和光叶巴豆抑菌活性较强,样品浓度为100 mg/mL时抑菌圈直径分别为10.0、8.7、12.0 mm,最小抑菌浓度分别为1.56、3.31和3.31 mg/mL。     

Cytotoxicity, redox cycling and photodynamic action of two naturally occurring quinones

Two naturally occurring anthraquinones, barleriaquinone-I (BQ-I) and barleriaquinone-II (BQ-II), extracted from Barleria buxifolia, are tested for their cytotoxic action by aerobic incubation with human breast adenocarcinoma cells (MCF7). Cytotoxicities, measured as LD(50) (50% inhibition of colony formation) values, show BQ-II to be more active than BQ-I. Electron paramagnetic resonance studies confirm that BQ-II is reductively activated by NADH:cytochrome c reductase to superoxide anion radical. Cyclic voltammetric studies show one quasi-reversible redox couple for both BQ-I and BQ-II. Also, aerobic solutions of both BQ-I and BQ-II on visible illumination generate reactive oxygen species. Formation of O*-2 is studied by both EPR spin trapping and SOD-inhibitable cytochrome c reduction techniques. BQ-I generates more singlet oxygen as evidenced from the photobleaching of N,N-dimethyl-4-nitrosoaniline.     

Anatomy of the haustorium of Jodina rhombifolia (Santalaceae)

The structure of the haustorium of Jodina rhombifolia in material from Argentina was analysed. Self-haustoria and interespeciñc haustoria, the latter on Celtis tala and Scutia buxifolia , were detected. Different developmental stages of the haustorium were found, since immature to mature ones. Features such as the gland, the interrupted zone and the sucker were described. The gland was a constant feature of J. rhombifolia haustorium. A glandular activity was also observed in the clasping folds and in groups of meristematic cells disposed in the body of the haustorium. The presence of graniferous tracheary elements was confirmed under SEM. The interrupted zone was represented by few parenchyma cells as well as by large parenchyma cells. Self-haustoria were larger than interespeciñc ones. In the former, graft-like unions occurred at more mature stages.     

基于天然更新性能筛选海南岛木麻黄海防林混交树种

基于对海南木麻黄(Casuarina equisetifolia L.)海防林天然更新情况的实地调查,采用更新数量、更新分布范围和更新结构3项单目标评价方法和熵权综合评价方法,对不同树种在木麻黄林下的天然更新性能进行评价和排序,据此筛选出适宜在木麻黄林下天然更新的树种。结果显示,更新能力较强的树种有:乔木树种潺槁木姜子(Litsea glutinosa(Lour.)C.B.Rob.)、大叶相思(Acacia auriculiformis A.Cunn.ex Benth)、苦楝(Melia azedarace L.)和鹊肾树(Streblus asper Lour.);小乔木鸦胆子(Brucea javanica(Linn.)Merr.)、露兜树(Pandanus tectorius Sol.)和暗罗(Polyalthia suberosa(Roxb.)Thw.);灌木酒饼簕(Atalantia buxifolia(Poir.)Oliv.)、调料九里香(Murraya koenigii(L.)Spreng.)、刺篱木(Flacourtia indica(Burm.F.)Merr.)和基及树(Carmona microphylla(lam.)G.Don)。具有一定更新潜力的树种有:乔木树种榄仁树(Terminalia catappa L.)、红厚壳(Calophyllum inophyllum L.)等;小乔木粗糠柴(Mallotus philippensis(Lam.)Muell.Arg.)、八脉臭黄荆(Premna octonervia Merr.et Metc.)等;灌木苦郎树(Clerodendrum inerme(L.)Gaertn.)、九节(Psychotria rubra(Lour.)Poir.)等。小乔木和灌木是海防林的伴生树种,适当保留和种植可提高木麻黄林的物种多样性和层次结构。选用天然更新良好的树种与木麻黄混交,最终可实现海防林由人工林向“近自然”林的转化。     

Investigations into seed dormancy in Grevillea linearifolia, G. buxifolia and G. sericea: anatomy and histochemistry of the seed coat

BACKGROUND AND AIMS: Seeds of east Australian Grevillea species generally recruit post-fire; previous work showed that the seed coat was the controller of dormancy in Grevillea linearifolia. Former studies on seed development in Grevillea have concentrated on embryology, with little information that would allow testing of hypotheses about the breaking of dormancy by fire-related cues. Our aim was to investigate structural and chemical characteristics of the seed coat that may be related to dormancy for three Grevillea species. METHODS: Seeds of Grevillea linearifolia, Grevillea buxifolia and Grevillea sericea were investigated using gross dissection, thin sectioning and histochemical staining. Water movement across the seed coat was tested for by determining the water content of embryos from imbibed and dry seeds of G. sericea. Penetration of intact seeds by Lucifer Yellow was used to test for internal barriers to diffusion of high-molecular-weight compounds. KEY RESULTS: Two integuments were present in the seed coat: an outer testa, with exo-, meso- and endotestal (palisade) layers, and an inner tegmen of unlignified sclerenchyma. A hypostase at the chalazal end was a region of structural difference in the seed coat, and differed slightly among the three species. An internal cuticle was found on each side of the sclerenchyma layer. The embryos of imbibed seeds had a water content six times that of dry seeds. Barriers to diffusion of Lucifer Yellow existed at the exotestal and the endotestal/hypostase layers. CONCLUSIONS: Several potential mechanisms of seed coat dormancy were identified. The embryo appeared to be completely surrounded by outer and inner barriers to diffusion of high-molecular-weight compounds. Phenolic compounds present in the exotesta could interfere with gas exchange. The sclerenchyma layer, together with strengthening in the endotestal and exotestal cells, could act as a mechanical constraint.     

Chromosome numbers of dominican compositae

Chromosome numbers of 34 species of Dominican Compositae in 26 genera and nine tribes are reported. First counts are given forCoreopsis buchii (2n = 64),Lagascea mollis (2n = 34),Spilanthes urens (n = 16),Liabum subacaule (n = 18),Eupatorium sciatraphes (2n = 40),Hieracium gronovii (2n = 18),Vernonia buxifolia (2n = 34),V. sprengeliana (2n = 34),V. racemosa (2n = 28), andChaptalia leiocarpa (2n = 48,ca. 58). Our report forNarvalina domingensis (2n = 120) is the first for any species of this genus.     

Relationships in Patagonian species of Berberis (Berberidaceae) based on the characterization of rDNA internal transcribed spacer sequences

Sequence analysis of the internal transcribed spacer (ITS) of the 18S(ITS1)-5.8S-26S(ITS2) rDNA region was performed in order to analyse the phylogenetic relationships between 13 Patagonian species of the genus Berberis (Berberidaceae). The divergence values between the pairwise sequence in the studied Patagonian species were in the range 2.9–22.9%. The lengths of the ITS1 and ITS2 sequences were in the range 227–231 bp and 220–224 bp, respectively, and the 5.8S sequence was 159 bp throughout all species . B. microphylla sensu Landrum does not appear to be monophyletic based on current sampling. Indeed, we suggest that B. microphylla should be distinguished from B. buxifolia , B. parodii , and B. heterophylla . ITS sequences, together with data obtained from morphological, biochemical, amplified fragment length polymorphism, and cytological characterizations, support the existence of diploid and polyploid hybrid speciation in the genus.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 321–328.     

In vitro plant regeneration of Aristolochia indica through axillary shoot multiplication and organogenesis

Protocols for in vitro plant regeneration via axillary and adventitious shoot regeneration were established in an important medicinal plant, Aristolochia indica L. (Aristolochiaceae). Basal Murashige and Skoog's (MS) medium supplemented with 0.54 μM α-naphthaleneacetic acid (NAA) and 13.31 μM benzyladenine (BA) induced the maximum number of shoots (45-50) from shoot tip and nodal segment cultures. Phenolic accumulation in leaf and internodal stem derived callus cultured in MS medium containing NAA or 2,4-dichlorophenoxyacetic acid and BA or kinetin was controlled by the addition of 1.0 mg l^-1 phloroglucinol (PG) to the callus induction medium. Basal medium supplemented with 2.69 μM NAA, 13.31 μM BA and 1.0 mg l^-1 PG induced the best results in terms of shoot bud regeneration from leaf derived callus. Direct de novo development of shoots from leaf segments was achieved using 13.31 μM BA along with 50 mg l^-1 activated charcoal. The microshoots were rooted in White's medium supplemented with 2.46 μM indolebutyric acid. More than 85% of rooted plants survived in the soil. This revised version was published online in June 2006 with corrections to the Cover Date.     

Antioxidant activities of flavonol derivatives from the leaves and stem bark of Scutia buxifolia Reiss

This study evaluated the antioxidant activities in the leaves and stem bark fractions of Scutia buxifolia. Cerebral lipid peroxidation (TBARS) was induced by Fe(II) and radical-scavenging activity was determined by DPPH method. Folin–Ciocalteu was used to determine phenolic contents. Quercetin, quercitrin, isoquercitrin and rutin were isolated from leaf ethyl acetate fraction and their levels were measured by high performance liquid chromatography.-photodiode array detector.IC₅₀ (DPPH) varied from 4.35 ± 1.30 to 29.55 ± 0.54 μg/mL for stem bark and from 6.50 ± 0.40 to 30.54 ± 1.14 in the leaves. Ethyl acetate and butanolic fractions caused a sharp fall in TBARS production with IC₅₀ from 2.93 ± 2.17 to 40.46 ± 2.51 μg/mL for the leaves and 0.66 ± 0.17 to 27.3 ± 1.23 for the stem bark. Results obtained indicated that S. buxifolia has a great potential to prevent disease caused by the overproduction of free radicals and also it might be used as a potential source of natural antioxidant agents.     

The conserved nature and taxonomic utility of pollen morphology in Cantua (Polemoniaceae)

Pollen exine morphology of nine of the ten species of Cantua (Polemoniaceae) is examined using light and scanning electron microscopy. A total of 28 specimens of C. bicolor, C. buxifolia, C. candelilla, C. cuzcoensis, C. flexuosa, C. pyrifolia, C. quercifolia, C. volcanica, and an as yet undescribed species (Cantua sp. nov.) are examined using either fresh or herbarium material. Pollen grains are found to be spheroidal, pantoporate, and quite large; mean diameter varies from 62 to 87?μm. Mean number of pores varies from 4.5 to 21.2 and mean pore size varies from 4.86 to 12.40?μm. Pollen grains of all species have insulate semitectate sexines. This feature distinguishes the pollen of Cantua species from the remainder of the Polemoniaceae. Insulae are evenly distributed over the surface of the pollen grain, with the exception of C. flexuosa and occasionally C. buxifolia, where insulae are more sparsely and haphazardly distributed. The majority of the species examined have irregularly shaped tectal insulae, with the exception of the large rounded insulae in C. quercifolia and the elongated narrow insulae in C. volcanica. Cantua quercifolia and C. volcanica have supratectal verrucae, a possible synapomorphy. In comparison to close relatives, the pollen grains of Cantua are evolutionarily conserved, and show little variation among species.     

Brachyptera Group. Sp.32. C. Brachyptera. Sp.33. C.c RUFA. Sp.34. C. Troglodytes. Sp.35. C. Fulvicapilla.

A part from considerations as to where it is best wedged into the linear sequence, the brachyptera group is defined in general terms as a compact group of four small or very small species which resemble one another in many important specific characters and the other thirty-six species classified here as Cisticola in so many ways of form, coloration and behaviour as to make them best understood by classifying them also under that generic name.     

Andropause ou P.A.D.A.M.

Recently the word P.A.D.A.M. has been proposed to replace the term Andropause (Partiel Andrologen Deficiency in Aging Males). This implies that most if not all problems of the aging male are due to testosterone déficiency, which is not at all true when one considers the results of endocrine investigations in that group. So many other sociological and relational causes are involved that the term P.A.D.A.M. is clearly a misnomer.     

Species 29. Cisticola Carruthersi. Pl. XIV. fig. 59. Cisticola carruthersi O.-Grant, Bull. B. O. C. xxiii. 1909, p. 94: typ. loc. Mokia, L. George, Uganda.

The B. O. C. Ruwenzori expedition of 1906 brought home a single immature female of this species, obtained in a papyrus swamp near Lake George, and to Ogilvie-Grant's discrimination we owe the recognition of its specific distinction from galactotes , the species it so closely resembles in coloration, and which is certainly carruthersi s nearest ally.     

Species 1. Cisticola Juncidis. Pls. I. & II. The Common Fantail Waebler.

The only European and most familiar species * of the whole genus Cisticola , of which, according to ancient designation †, it is the representative type-species. It is also the species with the widest range.     

For debate . . . Individual contributions to multiauthor papers.

The curricula vitae of four candidates for a professorial appointment at Athens University were examined to estimate the actual contribution of each candidate to the papers of which he was a coauthor. A total of 879 research papers by the four candidates were analysed in terms of the number of authors, the sequence of names, and the year of publication. The four authors presented 364, 349, 96, and 70 papers. If an equal contribution of all coauthors is assumed, the actual number of papers (all papers divided by the number of authors), is about 106, 83, 28, and 26, respectively, so that the rank of the four candidates did not change. On the assumption that the contribution was related to the candidate''s position in the order of the coauthors'' names, the numbers of papers were corrected to 84, 95, 26, 33 using one statistical method and to 88, 94, 28, 31 using another. These assumptions may not be valid, however, especially as the last author may be more important than the intermediate ones. It is suggested that the journals require authors to state their specific contribution to a paper, such as original idea, planning, collecting data, writing up, etc.