Ultrastructural organization of vegetative hyphae of Tuber Albidum Pico

The ultrastructural organization of vegetative hyphae ofTuber albidum, an ectomycorrhizal fungus is described. Three zones are recognized: 1) an apical zone with cytoplasmic vesicles; 2) a subapical zone with protoplasmic organelles; 3) a vacuolated zone. This organization corresponds in its main features to the pattern just described for rapidly growing fungi.     

Identification of Tuber magnatum Pico DNA markers by RAPD analysis

Summary Different species of truffle were studied in order to identify species-specific markers. The isolation of two Tuber magnatum Pico markers is reported. One of these could be used as a probe in dot blot hybridization, allowing the development of a rapid test able to identify Tuber magnatum species.     

Lowland floristic assessment of Pico da Neblina National Park,Brazil

Pico da Neblina National Park, located in north-western Amazonia,Brazil, is characterized by considerable habitat diversity resulting from anorographic zonation of vegetation (from 100 to 3,014 m above sealevel) and a mosaic pattern of soil types with lowland primary tropicalrainforest being the predominant ecosystem. A tree inventory of the lowlandareas of the Park was conducted as part of an ecological study of primates. Twohectares of forest were inventoried within the limits of a 500 hectare studysite. There were 1569 trees with diameter at breast height 10 cm in the sample (minimum of 229 species in 45 families). Thetree species Eperua leucantha and Hevea cf.brasiliensis dominated the forest accounting for 29% of thesampled trees. Three forest types were represented: chavascal, terra firme andcaatinga. Caatinga was the least diverse forest (H = 0.9), andterrafirme the most diverse (H = 1.5). Low diversity in caatinga wasassociated with high species dominance by Eperua leucantha, Micrandrasprucei and Hevea cf. brasiliensis whichtogether accounted for 66% of all sampled trees in one caatinga plot.Compared to Amazonian forests elsewhere, the ranking order of plant families inPico da Neblina was peculiar in that Leguminosae sensulatuand Euphorbiaceae dominated the sample accounting for 52% of all markedtrees. Such families were represented by few tree species, all of which werecharacterized by dry, large-seeded sclerocarpic fruits. The consequentlow availability of fleshy fruits in the forest is suggested as a possiblecontributing factor to the observed low abundance and diversity of primates inthe lowlands of Pico da Neblina.     

Chytridiomycosis in Wild Frogs from Pico Bonito National Park, Honduras

Almost half of the endemic species of Honduran amphibians have declining populations; some of which seem to be extinct since they have not been seen in several years in places where they were once common. Disappearances in pristine and protected habitats have occurred in several highland localities throughout the country. The highland amphibian fauna of Pico Bonito National Park declined sometime between 1989 and 1995. An amphibian chytrid fungus, Batrachochytrium dendrobatidis has been linked to similar declines in other neotropical regions. We checked 19 specimens for this disease, which were collected in the park in 2003. The only Rana maculata examined was found to be infected, as were three of the six Eleutherodactylus aurilegulus surveyed for the disease. Two of the infected E. aurilegulus were collected at 120 m elevation and showed strong infections. One of these was lethargic and did not react when it was collected in the field, although it was still alive. A complete necropsy could help determine if the B. dendrobatidis infection was responsible for these symptoms, and further research might show how susceptible E. aurilegulus is to this pathogen at low altitudes. More research should be focused on the distribution of this pathogen in Honduras, and on how this disease has affected the local amphibian fauna.     

Mysteries of attraction: Giovanni Pico della Mirandola,astrology and desire

Although in his later years Giovanni Pico della Mirandola (1463–1494) vehemently rejected astrology, he earlier used it in a variety of ways, but primarily to provide further evidence for positions to which he had arrived by other means. One such early use appears in his commentary on his friend Girolamo Benivieni’s love poetry, the Canzone d’amore, of 1486–1487. In the passages discussed here, Pico presents an intensive Platonic natural philosophical analysis based on a deep astrologically informed understanding of human nature as he attempts to explain a perennial question, namely, why one person is attracted to a certain person (or people), and another to others. I will place this discussion of the mysteries of attraction and desire in historical perspective by tracing Pico’s changing relationship to astrology during the course of his short but passionate life, and in historiographic perspective by revising Frances Yates’s still influential views concerning Pico’s contribution to Renaissance thought and his relationship with Marsilio Ficino.     

流式细胞仪在微型浮游植物生态学中的应用

微型浮游植物是水域生态系统中的初级生产者 ,是海洋生态系统存在的基础。习惯上浮游植物根据其粒径大小有分为小型浮游植物 (ｍｉｃｒｏ - ｐｈｙｔｏｐｌａｎｋｔｏｎ ,>2 0ｕｍ) ,微型浮游植物 (ｎａｎｏ - ｐｈｙｔｏｐｌａｎｋ ｔｏｎ ,<2 0ｕｍ ,>2ｕｍ )和超微型浮游植物( ｐｉｃｏ - ｐｈｙｔｏｐｌａｎｋｔｏｎ ,<2ｕｍ )三类[13 ] 。本文将后两类统称为微型浮游植物。在早期的多数研究中 ,检测技术和方法落后 :譬如测定水域中的生物量和叶绿素ａ含量常用的拖网方法 ,几乎丢失了所有的微型浮游植物 ;即使是实验室内常用 0 .45ｕｍ…     

Determination of diaminopimelic acid in rat feces by high-performance liquid chromatography using the Pico Tag method

The purpose of the study was to develop a method for the determination of diaminopimelic acid (DAPA) concentrations in rat feces by reversed-phase high-performance liquid chromatography (HPLC) using the Pico Tag method. Precolumn derivatization with phenylisothyocyanate (PITC) and UV (254 nm filter) detection were used. Samples were hydrolysed in 6 M HCl at 110 degrees C for 24 h. Hydrolysates were then diluted, dried and derivatized, and samples (10 microliter injected onto a 300x3.9 mm NovaPak C(18) (Waters) HPLC column. Under the conditions used, DAPA eluted as one single peak between those of tyrosine and valine. On-column DAPA concentrations in standards were 41.5-83 pmol, which were in the range of the amounts present in fecal samples of rats fed semisynthetic diets. Amounts of DAPA determined in fecal samples of rats fed broad bean- or chickpea-based diets were, respectively, 2.56 and 2.98 mg g(-1). The advantages of the method and the relevance of the results for nutritional studies in monogastric animals are discussed.     

Hybridization and speciation in the genusDryopteris (Pteridophyta:Dryopteridaceae) on Pico Island in the Azores

The cytology of wild hybrids ofDryopteris from Pico, Azores has been examined. This has confirmed the parentage of the hybrids, and provided evidence to support the view that the tetraploid speciesD. crispifolia has evolved in the Azores from two diploid species,D. aemula andD. azorica, by hybridization and polyploidy.     

Checklist and one new species of Bromeliaceae from Pico do Itambé, Minas Gerais,Brazil

A checklist of the 11 genera and 16 species of Bromeliaceae from the Parque Estadual do Pico do Itambé in Santo Antônio do Itambé and Serra Azul de Minas, Minas Gerais, south‐eastern Brazil, is presented. Bromelioideae is the most diverse subfamily and is concentrated in forested areas. Tillandsioideae and Pitcairnioideae are most abundant in elevated areas of campo rupestre vegetation. Vriesea medusa Versieux, a new night‐blooming species belonging to section Xiphion (E.Morren) E.Morren ex Mez, was found in the area and is described and illustrated. It appears to be an endemic species distinguished from Vriesea nanuzae Leme by a combination of the usually larger dimensions in the rosette, the curved inflorescence which has lateral peduncles bearing up to five sterile bracts, the larger number of flowers, floral bracts and sepals that become dark purplish‐brown towards the apex and the coloration of the leaves. Dyckia glandulosa L.B.Sm. & Reitz and Vriesea densiflora Mez, previously poorly known, were rediscovered and are depicted in their habitat for the first time. Vriesea procera var. tenuis L.B.Sm. is a new record for the state. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 709–715.     

Feeding Ecology of Black-headed Uacaris (Cacajao melanocephalus melanocephalus) in Pico da Neblina National Park,Brazil

From June 1994 to October 1995, I conducted a study of the feeding ecology of one group of black-headed uacaris (Cacajao melanocephalus melanocephalus) in Pico da Neblina National Park, Brazil, near the Venezuelan border (01°10N to 00°26S, 65°03W to 66°52W). Of a total of 429 feeding records, 89% corresponded to fruits from which black-headed uacaris ate ripe and unripe seeds, mesocarps and arils. Seeds were the single most important food item year-around, corresponding to 81% of the feeding records for fruits. Black-headed uacaris used 120 different plant species in 32 families as food. The 3 most important plant species in their diet, Micrandra spruceana, Eperua leucantha, and Hevea braziliensis (all trees), accounted for 38% of the feeding records for fruits. These species produced fruits that were protected by very hard green husks, were barochorous, did not have fleshy mesocarps, and were slow to mature, thus being available as unripe fruits for long periods. The second and third most important species in the diet of black uacaris, Eperua leucantha and Hevea braziliensis, were dominant in the forest: approximately 30% of trees 10 cm dbh sampled in a 2-ha botanical transect at the study site. I discuss the formation of large social groups of black-headed uacaris in Pico da Neblina National Park in light of the peculiar floristic composition of the study site.     

Use of sequence characterised amplified region and RAPD markers in the identification of the white truffle Tuber magnatum Pico

Isolates of white truffles were identified as Tuber magnatum Pico species using a pair of primers selected from a sequence characterised amplified region (SCAR) and a specific random amplified polymorphic DNA (RAPD) marker. The present study reveals that PCR-fragment-pattern polymorphisms, the construction of probes and couples of primers from one or more of these polymorphic fragments may provide a useful and rapid tool for identifying species of ectomycorrhizal fungi in addition to conventional methods (morphological parameters).     

Actinobacteria may influence white truffle (Tuber magnatum Pico) nutrition,ascocarp degradation and interactions with other soil fungi

To test the hypothesis that truffle-associated bacteria may improve truffle nutrition, we isolated bacteria from white truffle ascocarps and tested Actinobacteria for their ability to solubilise phosphate and iron, nutrients that have limited availability in white truffle grounds. Two isolates with sequence similarities to Curtobacterium flaccumfaciens and Rhodococcus sp. were characterized in detail. Both solubilised Ca₃(PO₄)₂ in a way that was dependent on the nitrogen and carbon sources present. Neither strain broke down phytate, but both produced chelating compounds, performed ammonification, and broke down β-glucan. Additionally, C. flaccumfaciens decomposed chitin, pectin, lipids and proteins, while Rhodococcus sp. exhibited urease activity. Three potentially fungicolous fungi were isolated from diseased white truffle ascocarps and bioassayed against the isolated Actinobacteria. The Rhodococcus isolate inhibited Verticillium leptobactrum, neither bacterium affected Clonostachys rosea, while both isolates promoted growth of Trichoderma sp. The results suggest that Actinobacteria might be involved in improving truffle nutrition, ascocarp degradation and establishing relationships with other soil fungi.