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21.
A novel yeast species was isolated from leaf litter of Macropanax dispermus obtained from the Cibodas Botanical Garden, West Java, Indonesia. The two strains of the species displayed typical characteristics of the genus Citeromyces. Phylogenetic analysis based on the gene sequences of the D1/D2 domains of large subunit (LSU) rDNA, internal transcribed spacer (ITS) including 5.8S rDNA, mitochondrial small-subunit rRNA gene (MtSm), and translation elongation factor-1α (EF-1α) showed that the novel strains were clearly separated from the other four existing species of the genus Citeromyces. Therefore, the two strains were proposed to represent a novel species within the genus Citeromyces, for which the name Citeromyces cibodasensis is proposed; the type strain is NBRC 110244T (= CBS 14272T?=?InaCCY703T?=?AK 01). 相似文献
22.
Bernard R. Baum 《Plant Systematics and Evolution》1989,166(3-4):197-210
Aristotelian principles still dominate botanical classification. Biological classification has undergone a major transformation during the period fromAdanson (1763) toDarwin (1859), from essentialism and the practice of downward classification, to empiricism and upward classification. The polythetic class was conceptualized during the 1950s. Interest in the species problem generated data from many different disciplines, the most recent being DNA systematics. These many disciplines have contributed to our understanding of evolutionary processes and to improved classifications. Many different phylogenetic models were developed and for different kinds of data. These models formed the basis of many algorithms to infer phylogenetic trees, some widely available in computer packages. This became possible with rapid growth of computer technology. These developments in turn catalyzed the formulation of divergent philosophical principles and approaches to classification. For instance, should methodological principles be divorced from knowledge about evolutionary processes? These approaches are discussed along with problems of reticulate evolution, intra-OTU-variation, homology, and other issues in the light of existing methodologies and their impact on classification. The next important direction in addition to development of new classificatory algorithms is the synthesis of various elements of different methodologies presently used in isolation. 相似文献
23.
- Aploneura lentisci (Passerini ) (Homoptera, Aphididae) forms kidney-shaped galls on the leaflets of its primary host, Pistacia lentiscus (Anacardiaceae). Observations on its population dynamics and ecology werecarried out in 1980–1985.
- The galls are formed annually on newly-growing shoots of the same year. Each gall is founded by a single nymph and contains its parthenogenetic offspring. The infestation period (late March-early April) is short relative to the period of appearance of new shoots. The distribution of galls on the shoots is non-random (“clumped”). Early shoots emerging near pruning cuts, when the rest of the buds are still dormant, are often very heavily infested.
- Clone size within galls increases from 1 in April to several hundred in September (at least 2 parthenogenetic generations). Alates of the last generation leave the galls gradually as they form. By the following March, previous-year galls contain no live aphids.
- Population density of galls varied greatly among years. Possible causes of this variation are discussed.
24.
Rolf Singer 《Plant Systematics and Evolution》1987,156(3-4):177-181
Changes in the rules are contraproductive and in contradiction to the Preamble of the International Code of Botanical Nomenclature (Voss & al. 1983), especially if the consequences are insufficiently researched before binding, basic, retroactive alterations are introduced. The most confusing and upsetting alterations concern those accepted at Sydney with regard to the starting point rule, Art. 13.1 (d). It is recommended that Proposal 42 (Taxon 1984) be accepted at Berlin. 相似文献
25.
Old sleeping Sicilian beauty: seed germination in the palaeoendemic Petagnaea gussonei (Spreng.) Rauschert (Saniculoideae,Apiaceae) 下载免费PDF全文
O. De Castro L. Gianguzzi F. Carucci A. De Luca R. Gesuele M. Guida 《Plant biology (Stuttgart, Germany)》2015,17(5):1095-1098
Petagnaea gussonei (Apiaceae) is a perennial herbaceous species endemic to northeast Sicily (Nebrodi Mountains). It is considered a remnant of the Sicilian Tertiary flora, and is endangered according to the Red List. There is no information in the literature about the germinability of its seeds, even though seed production is know to occur. The aim of this study was to obtain data to better understand seed germination of this species and its biological implications. Thus, several approaches were employed: vitality analyses, gibberellic acid supply, germination and soil microbial flora analyses via end‐point and qPCR. The results suggest that seed germination occurs after ca. 1.5 years at a rate of ca. 11%. The seeds can be classified as physiologically dormant, and probably require prolonged cold stratification for germination. Because seed germination is low, it is likely that agamic reproduction represents an important mean for its conservation and survival. These results have important implications for P. gussonei survival and should be considered in possible re‐introduction attempts aimed at restoring threatened populations. 相似文献
26.
Marcelo H. O. Pinheiro Luiz C. Almeida De Neto Reinaldo Monteiro 《Biodiversity and Conservation》2006,15(8):2747-2764
The International Union for Conservation of Nature and Natural Resources (IUCN) and the World Wide Fund for Nature (WWF) advocates
an increase of the number of botanical gardens throughout the world as one of the measures that can help to preserve the world's
biodiversity. To implement this strategy, the present work brings forward a suggestion particularly suited to tropical regions:
establishing municipal botanical gardens. It refers to the experience of a newly opened municipal botanical garden in Brazil,
comparing its attractive power on visitors to that of other botanical gardens included in the Brazilian network of Botanical
Gardens. It also presents considerations on in situ conservation in small remnants and on the importance of urban reserves to preserve the regional biodiversity and spread the
conservationist philosophy. The present proposal promotes the participation of local communities making the public opinion
more aware and active, besides being able to counterbalance proposals that support protecting the world biodiversity through
interventionist actions. It assumes that, through actions planned and coordinated by regional and national botanical garden
networks, the measure proposed can mitigate the anthropic actions exerted on important natural reserves all over the world. 相似文献
27.
The Kentucky coffeetree (Gymnocladus dioicus, Fabaceae) is an ecological paradox. A rare tree in nature in eastern and central North America, G. dioicus produces legumes that are only known to be dispersed by water, but appear similar to fruits consumed and dispersed by elephants
and rhinoceros. One would expect the pods to be consumed by livestock, but the pulp and seeds are toxic to cattle and sheep.
We examine the puzzle of G. dioicus dispersal in light of its other reproductive and life history characteristics and find that it probably is a botanical anachronism,
in terms of both a set of dispersal agents long extinct and habitats, including what we term megafaunal disclimaxes, which
have disappeared. Large seeds, the megafaunal gestault of the fruit, a dioecious mating system, and shade-intolerance combined
with vigorous cloning suggest a widely dispersed pioneer of Miocene through Pleistocene habitats profoundly altered by large-mammal
herbivory. As to what ate it, we can only say there were once many candidates. We hypothesize that the plant is an ecological
anachronism, sinking to extinction in the wild. 相似文献
28.
西双版纳热带植物园引种植物物候特征比较 总被引:2,自引:0,他引:2
迁地保护是生物多样性保护的重要手段之一,前期的植物引种研究呵为迁地保护提供必要的理论支持。通过对西双版纳热带植物园内不同来源的引种植物和本地植物的4个物候期(萌叶期、落叶期、开花期和果熟期)分布格局及其气候影响因子进行对比,阐明引种植物对环境的适应性和对策。结果表明,引种植物比本地植物萌叶生长盛期更长,但对低温和干旱更加敏感的引种植物,在旱季其落叶比例明显高于本地植物,而3、4月由于气温的回升,使引种植物和本地植物在雨季之前就进入了萌叶盛期。而在繁殖物候方面,由于受气候因子影响较小,引种植物和本地植物的开花期和果熟期格局季节性表现都不明显。且规律性不强。总体上,各来源地的引种植物能根据环境的改变形成相应的生长与繁殖适应对策,可较好地适应西双版纳的环境。 相似文献
29.
Stimulation of soil nitrification and denitrification by grazing in grasslands: do changes in plant species composition matter? 总被引:2,自引:0,他引:2
Stimulation of nitrification and denitrification by long term (from years to decades) grazing has commonly been reported in different grassland ecosystems. However, grazing generally induces important changes in plant species composition, and whether changes in nitrification and denitrification are primarily due to changes in vegetation composition has never been tested. We compared soil nitrification- and denitrification-enzyme activities (NEA and DEA, respectively) between semi-natural grassland sites experiencing intensive (IG) and light (LG) grazing/mowing regimes for 13 years. Mean NEA and DEA (i.e. observed from random soil sampling) were higher in IG than LG sites. The NEA/DEA ratio was higher in IG than LG sites, indicating a higher stimulation of nitrification. Marked changes in plant species composition were observed in response to the grazing/mowing regime. In particular, the specific phytomass volume of Elymus repens was lower in IG than LG sites, whereas the specific volume of Lolium perenne was higher in IG than LG sites. In contrast, the specific volume of Holcus lanatus, Poa trivialis and Arrhenatherum elatius were not significantly different between treatments. Soils sampled beneath grass tussocks of the last three species exhibited higher DEA, NEA and NEA/DEA ratio in IG than LG sites. For a given grazing regime, plant species did not affect significantly soil DEA, NEA and NEA/DEA ratio. The modification of plant species composition is thus not the primary factor driving changes in nitrification and denitrification in semi-natural grassland ecosystems experiencing long term intensive grazing. Factors such as trampling, N returned in animal excreta, and/or modification of N uptake and C exudation by frequently defoliated plants could be responsible for the enhanced microbial activities. 相似文献
30.
D.M. Anderson E.L. Fredrickson P. Nachman R.E. Estell K.M. Havstad L.W. Murray 《Animal Feed Science and Technology》1998,70(4):1905
Filtrate from pre- and post-digested plant material was exposed to 355-nm pulsed laser light and the subsequent laser-induced fluorescence (LIF) was recorded. Similarities and differences among spectra from 20 materials are discussed. Each material was replicated once, dried, ground, and exposed to chloroform (CHCl3) for 24 h. The material represented aged (1 to 18 years old) plants from different herbaceous (grasses and forbs) and woody plant life forms. Mean peak fluorescence recorded among materials differed (P<0.0001) in both wavelength and peak amplitude (counts) across the spectral range (387 to 788 nm). Peak fluorescence was evaluated within each of three arbitrary color categories, blue near 455 nm and red near 674 nm, while only 16 of the materials produced a green peak near 528 nm. In general, the blue and green fluorescence peaks were broad while the red peak was narrow. Mean peak counts were largest in the red range. Varying amounts of laser beam absorption occurred among the materials evaluated due to different concentrations of filtrate and different absorption efficiencies; therefore, amplitude data (counts) were not used to determine statistical differences among materials. To overcome difficulties attributed to the raw count data, red/blue, red/green and blue/green count ratios within replicates were calculated. Using all three count ratios in a multivariate analysis of variance, the 16 materials could be separated into nine different (P<0.05) material groupings. The LIF technique may provide a reliable means to separate ground pre- and post-digested plant materials following further research into determining what fluorophores are producing the spectral signatures and how sample preparation affect peak wavelengths. 相似文献