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Pilea carautae M. D. M. Vianna & R. J. V. Alves (Urticaceae) is described and illustrated. This new species is endemic to the Cabo Frio region in Rio de Janeiro State, Southeastern Brazil. P. carautae is considered threatened by IUCN standards due to its extremely restricted geographic area of occurrence.  相似文献   

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A new species, Lockhartia viruensis, is described and illustrated from the state of Roraima, in the Brazilian Amazon, and its affinities are discussed. The new species is similar to L. imbricata, but differs by having an entire lip with an obtuse to rounded apex, a callus on the disk of the lip with a longitudinal row of papillae with a rounded apex, and the margin of the column wings entire.  相似文献   

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A new species, endemic to the Flora Iranica area, Gagea robusta (Liliaceae) is described and illustrated. It differs from G. reticulata (Pall.) Schult. & Schult. f. in having a puberulent indumentum on the basal leaf and from G. setifolia Baker ex Aitch. in having a long neck (up to 12 cm long). Its ecology, distribution and conservation status are discussed.  相似文献   

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We describe and illustrate Capparidastrum tuxtlense, a narrow endemic, known only from the eastern slopes of Volcán San Martín, (10–450 m), Veracruz, Mexico. Capparidastrum tuxtlense is similar to Capparidastrum discolor, but differs by foliar, floral, and fruit characters. A discussion of putative relatives and a key to the Central American species of Capparidastrum are included.  相似文献   

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“Mallín” (plural mallines) is a particular kind of wetland occurring in Patagonian steppe and forests. In Northwest Patagonia, mallines are humid meadows with high net primary production. It was previously found that a mallín soil in the steppe devoid of actinorhizal plants had a higher Frankia nodulation capacity in Ochetophila trinervis (sin. Discaria trinervis) than other soils in the region. Under the hypothesis that mallín wetland meadows are reservoir of infective Frankia, we studied the Frankia nodulation capacity in O. trinervis of 12 mallín and their neighbouring steppe soils, by using plant bioassays. A qualitative plant bioassay showed that infective Frankia was present in most soils. The number of nodules per plant in seedlings inoculated with mallín soils was negatively correlated with soil water content while the opposite was true for plants inoculated with soils from neighbouring steppe. A quantitative bioassay was performed with eight representative soils, selected according to the number of nodules per plant produced in the qualitative assay and to the presence or not of different actinorhizal plants at the sites. Frankia nodulation units per cm3 of soil (NU) in mallín soils were higher than those in steppe. Water and organic matter content of soils were correlated with the higher nodulation capacity of mallines, which may account for the saprotrophic growth of Frankia in soils. The symbiosis was effective in plants inoculated with all soil samples. These results suggest that Northwestern Patagonian mallín wetland meadows are reservoirs of infective and effective Frankia propagules in O. trinervis.  相似文献   

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Following a re-examination of the material treated under Barleria brevispina (Fiori) Hedrén in the recent Flora of Somalia account of the Acanthaceae, it is concluded that two distinct species are involved and Barleria compacta Malombe & I. Darbysh. is described here from north-eastern Somalia. Its affinities and conservation status are discussed.  相似文献   

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The root endophytic fungus Piriformospora indica is a prime candidate to improve the growth and yield of plants. It also acts as a growth promoter and bioprotector, as well as combating environmental stress in a range of plant species. In the present investigation impact of a P. indica culture filtrate was studied on Helianthus annus Sun gold and H. annus Japanese gold varieties in the greenhouse. Treatment with the P. indica culture filtrate promoted overall growth and seed production of the plants. Moreover, the oil content of the seeds increased by 50% to 70% in these two varieties of H. annus plants. The possible reasons for these effects are discussed.  相似文献   

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Juniperus navicularis Gand (= J. oxycedrus L. subsp. transtagana Franco) is an endemic dioecious shrub from the Plio-Plistocene transition sands of the west Portuguese coast line. It grows in sole or mixed stands along with Pinus pinea and P. pinaster and, more rarely, with Quercus lusitanica. In order to reduce fire incidence in these Mediterranean mixed stands, forest management practices of mechanical or chemical treatments, have drastically reduced J. navicularis populations. In addition, the fast expansion of touristic areas along with a low seed germination rate further endangers this species. In this study we developed a protocol for micropropagation of adult J. navicularis. Microcuttings were obtained from lateral and apical twigs of both female and male mature plants, and used as explants. Microcuttings with axillary buds were grown on different media and plant growth regulators combinations. Developmental parameters were evaluated to define the best medium and plant growth regulator concentration for shoot bud induction during the multiplication cycles. Olive Medium and Gupta and Durzan medium, both supplemented with 0.45 μM 6-benzyl-amino-purine, were the most favourable of all combinations tested achieving more than 3 new shoots per explant. The highest rooting (60%) was obtained in microshoots cultured in Olive Medium when supplemented with indole-3-butyric acid at 12.3 μM. With this multiplication protocol, it was possible to obtain more than 500 shoots from the initial 20, after three multiplication cycles in 3 months.  相似文献   

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Boletus kermesinus, a new species of Boletus section Luridi, is fully described and illustrated based on the materials collected in subalpine coniferous forests of central Honshu, Japan. It has distinctive features of dark-red basidiomata having distinct viscidity in the pileus surface, usually unchanging flesh, discolorous red pores, and an entirely reticulate stipe becoming coarsely lacerate-rimose with age.  相似文献   

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Valeriana neglecta R. Bernal (Valerianaceae) from the Sierra Nevada de Santa Marta, in northern Colombia, is described as new, and illustrated, based on two specimens collected in 1844. It belongs to subgenus Valeriana sect. Porteria (Hook.) Benth. & Hook f., and differs from other species of the group in its corymboid inflorescence, with dense, capitoid, partial inflorescences, and in its narrowly spathulate leaves that are remotely dentate towards apex.  相似文献   

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A new corticolous species of Byssoloma, B. rubromarginatum Messuti and de la Rosa from Nothofagus dombeyi forests is described and illustrated. The new species is characterized by the morphology of the thallus and apothecia, the 3–5 (7)-septate ascospores, the presence of an anthraquinone in the exciple, and its ecology. It is the first species within the genus known to have gyrophoric acid in the apothecial margin. A key to Byssoloma species known from Nothofagus temperate forests in South America is provided.  相似文献   

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The intron sequence of chloroplast rpS16 and the secondary structure of its pre-mRNA were characterized for the first time in 26 Allium sativum accessions of different ecologo-geographical origins and seven related Allium species. The boundaries and main stem-loop consensus sequences were identified for all six domains of the intron. Polymorphism was estimated for the total intron and its regions. The structural regions of the rpS16 intron proved to be heterogeneous for mutation rate and spectrum. Mutations were most abundant in domains II and IV, and transition predominated in domains I, III, V, and VI. In addition to structural elements and motifs typical for group IIB introns, several Allium-specific micro- and macrostructural mutations were revealed. A 290-bp deletion involving domains III and IV and part of domain V was observed in A. altaicum, A. fistulosum, and A. schoenoprasum. Several indels and nucleotide substitutions were found to cause a deviation of the pre-mRNA secondary structure from the consensus model of group II introns.  相似文献   

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Summary   Psychotria kupensis Cheek is described as a new species in Psychotria sect. Confertiflorae Hiern. Attention is drawn to its monopodial, dwarf, litter-gathering and adventitious root-forming habit and to its anomalous stipules. The species appears to be endemic to the submontane evergeen forest of Mt Kupe in Cameroon. Its conservation status is assessed.  相似文献   

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Managing populations, either for conservation, harvesting, or control, requires a mechanistic or semi-mechanistic understanding of population dynamics. Here, we investigate how time-since-fire affects demographic transitions in an endangered plant, Dicerandra frutescens ssp. frutescens (Lamiaceae), which is specialized to gaps created by fire. We used a hierarchical Bayesian model to estimate transition probabilities (i.e., the elements of population projection matrices) as a function of time-since-fire and random effects, from 13 years of data on marked individuals in five populations. Using a standard Bayesian criterion to compare models, we find that death becomes increasingly probable and progression increasingly improbable with time-since-fire. The magnitude of some of the time-since-fire effects is substantial: death is 3–5 times more likely for flowering plants >6 years versus 3–6 years post-fire, 3-step progression is almost 7 times less likely, and large flowering plants are more than 6 times more likely to stop flowering. These insights inspire new hypotheses about the underlying cause of decline with time-since-fire, and how it can be managed. Our approach can be used by others who wish to model the effect of an exogenous factor on demography, while rigorously accounting for uncertainty and variability. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

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Stylogyne carautae Carrijo & M. F. Freitas is described and illustrated as a new endemic species from south-eastern Brazil. The relationships between S. carautae and S. depauperata Mez are discussed, and comments on their ecology and conservation are provided.  相似文献   

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