水稻土施硅对土壤-水稻系统中镉的降低效果

水稻中镉的积累造成人类健康的风险,增加水稻硅素能减轻镉中毒症状,降低稻米镉积累,但是硅对重金属的作用机理尚不清楚。主要研究了在中度和高度镉污染的土壤中,通过施用固态和液态的富硅物质对土壤-水稻系统中镉的吸收和转运的影响,探明决定镉和硅在根与芽的质外体和共质体中的作用机理。试验结果表明:(1)在中度和高度污染的土壤中,镉在土壤-作物系统中的转移和积累情况是不同的,可以通过富硅物质中的单硅酸与镉离子的相互作用,增加镉在硅物质表面的吸附来减少镉在土壤中的流动;(2)富硅物质可以降低水稻根和芽中镉的积累,在高度镉污染的情况下,施用硅可以使镉大量积累在水稻根及其共质体中,并降低根及其共质体中镉的转换和积累;(3)新鲜土壤中水萃取态的单硅酸含量与镉在土壤-作物系统中的流动性、转运以及积累等主要参数密切相关。     

Female ornaments in the Pied Flycatcher Ficedula hypoleuca: associations with age, health and reproductive success

Female ornamentation has received little attention in studies of sexual selection. Traditionally, female ornaments have been explained as a genetically correlated response to selection in males. However, recent findings suggest that female ornaments may be adaptive. Southern populations of Pied Flycatchers Ficedula hypoleuca are suited for studies of female ornamentation because, in addition to the white wing patch, some females also express the white forehead patch characteristic of males. We thus addressed the associations of these two ornaments with female age and with some health and breeding parameters in a Spanish population of Pied Flycatchers. Female ornament expression was not associated with haemoparasite prevalences, clutch size or parental provisioning effort. However, females expressing the white forehead patch raised more fledglings, and females with larger wing patches bred earlier, had higher number of hatchlings and showed increased levels of total serum immunoglobulins. Thus, these two unrelated epigamic ornaments may indicate some aspects of female quality. Further experimental studies could test the possibility that these plumage traits might function as signals to the males or might be used during female–female aggressive encounters in competition for nest-sites and mates.     

Systematics and cladistics of a new Naupactini genus (Coleoptera: Curculionidae: Entiminae) from the Andes of Colombia and Ecuador

A new genus of broad‐nosed weevils belonging to the tribe Naupactini (Coleoptera: Curculionidae) is described, based on six species from the Páramo–Puna subregion (Andean region) of South America. Three species are new and three have been transferred from the genus Asymmathetes (Asymmathetes nigrans, Asymmathetes rugicollis, and Asymmathetes vulcanorum). The new genus is recognized by the black, denuded, and shiny tegument, the well‐developed pre‐epistome, the elytral base curved backwards on middle, the reduction of the hindwings, and the widely separated procoxae, closer to the anterior than to the posterior margin of the prosternum. A cladistic analysis of the six species of the new genus plus five out‐groups (Amitrus, Amphideritus, Asymmathetes, Melanocyphus, and Trichocyphus), using 49 morphological characters, resulted in a single cladogram. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 166 , 54–71.     

Application of Photoacoustic Phase Angle Spectroscopy (φAS) to Eumelanins and Pheomelanins

A new technique, based on the measurement of the phase angle of the photoacoustic signal, was used for investigating the absorption spectra of melanins in the dry state. The main advantages of such a method are the insensitivity to scattering of the light and the applicability to nontransparent or highly adsorbing and thermally thick samples. The spectra obtained on different kinds of natural and synthetic melanins show much more details than the corresponding ones obtained spectrophotometrically on aqueous suspensions of the pigment. Some relevant features of the spectra still cannot be interpreted, yet we were able to show the presence in eumelanins of dopachrome at 475 nm and melanochrome at 540 nm, and in pheomelanins of compounds previously isolated from red chicken feathers. Moreover, the well known trend of the optical absorption, i.e., its decrease with increasing wavelength, was unambiguously confirmed.     

Three new species of Rubus from Spain

Three new species of Rubus subgenus Rubus series Pallidi from Spain are described, mapped and illustrated: R. Cyclops, R. castroviejoi and R. urbionicus.     

Seed Morphology, Anatomy and Ultrastructure ofPhyllocladusL. C. & A. Rich. ex Mirb. (Phyllocladaceae (Pilg.) Bessey) in Connection with the Generic System and Phylogeny

To analyse the status and phylogeny of the genusPhyllocladus,seedsof all seven species of the genus were studied. The complexof features of thePhyllocladusreproductive system point to theisolated position of the genus within the conifers. Relationswith Podocarpaceae s. l., Taxaceae s. l. and Cephalotaxaceaeappeared to be remote because a complex of features clearlydistinguishesPhyllocladusfrom the afore-mentioned taxa. We findit advisable to circumscribe the family Phyllocladaceae as Bessey(1907) did, and place it into the order Taxales Knobl. in Warming(1890). From investigations of the seeds it appears the genusPhyllocladusconsistsof seven species, forming five groups. There is a significanttendency for transformation of the female reproductive structureswithin the generic boundaries ofPhyllocladus—seeds, originallysolitary, tending to aggregate in various kinds of compact clusters.Copyright1999 Annals of Botany Company PhyllocladusL. C. & A. Rich, ex Mirb., seed anatomy, seed morphology, systematics, phylogenetic relationships, Phyllocladaceae, Podocarpaceae s. str., Acmopyleaceae, Nageiaceae, Austrotaxaceae, Amentotaxaceae, Torreyaceae, Taxaceae, s. str., Cephalotaxaceae, Taxales.     

Festuca inops and Festuca gracilior (Poaceae): are they two different species?

According to current systematics, Festuca inops and F. gracilior are two distinct species. However, they are hardly distinguishable from each other on the basis of their morphological characters. Festuca inops is considered a diploid species endemic to Italy, while F. gracilior has a discontinuous distribution area, apparently related to chromosomal levels: diploid populations in Italy and south-east France, tetraploid populations in north-east Spain. The diploid populations of both taxa from Italy and south-east France are investigated in the present study. Nearly 1000 exsiccata were examined and morphometric analysis was carried out on macro- and micromorphological features of 119 specimens (including type-specimens) and on 20 natural populations (including loci classici ). All these data showed that the two species should be referred to a single taxon, for which the rank of species seems to be appropriate. This result is supported by karyological, ecological and chorological data and was confirmed by the results of ISSR analysis. According to nomenclatural rules, the legitimate name for the species is Festuca inops De Not.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 239–258.     

Multiple refugia and barriers explain the phylogeography of the Valais shrew,Sorex antinorii (Mammalia: Soricomorpha)

The aim of the present study was to investigate the genetic structure of the Valais shrew (Sorex antinorii) by a combined phylogeographical and landscape genetic approach, and thereby to infer the locations of glacial refugia and establish the influence of geographical barriers. We sequenced part of the mitochondrial cytochrome b (cyt b) gene of 179 individuals of S. antinorii sampled across the entire species' range. Six specimens attributed to S. arunchi were included in the analysis. The phylogeographical pattern was assessed by Bayesian molecular phylogenetic reconstruction, population genetic analyses, and a species distribution modelling (SDM)‐based hindcasting approach. We also used landscape genetics (including isolation‐by‐resistance) to infer the determinants of current intra‐specific genetic structure. The phylogeographical analysis revealed shallow divergence among haplotypes and no clear substructure within S. antinorii. The starlike structure of the median‐joining network is consistent with population expansion from a single refugium, probably located in the Apennines. Long branches observed on the same network also suggest that another refugium may have existed in the north‐eastern part of Italy. This result is consistent with SDM, which also suggests several habitable areas for S. antinorii in the Italian peninsula during the LGM. Therefore S. antinorii appears to have occupied disconnected glacial refugia in the Italian peninsula, supporting previous data for other species showing multiple refugia within southern refugial areas. By coupling genetic analyses and SDM, we were able to infer how past climatic suitability contributed to genetic divergence of populations. The genetic differentiation shown in the present study does not support the specific status of S. arunchi. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 864–880.