The use of diatom Skeletonema costatum on aquaculture‐produced purple sea urchin (Paracentrotus lividus) larvae and post‐larvae diet     

Joo Araújo  Ana Candeias‐Mendes  Ivo Monteiro  Diogo Teixeira  Florbela Soares  Pedro Pouso‐Ferreira 《Aquaculture Research》2020,51(6):2545-2554

The quality of the microalgae provided on Paracentrotus lividus larvae rearing is a primordial factor having a direct (nutritional properties) and indirect (water quality) impact on growth, competence and survival. Skeletonema costatum is a diatom commonly used in the bivalve cultivation. However, the use of this diatom in P. lividus larval cultivations is poorly known. The Rhodomonas spp. is a microalgae commonly used in sea urchin larvae culture. Three different diets were tested on P. lividus larvae and post‐larvae cultivation (D1—Rhodomonas marina, D2—S. costatum, D3—mixture of both algae). Larvae fed with the D2 diet (55.8%) and D3 (39.9%) had a survival at 15 DAH higher than D1 (5.5%). The low survival in D1 could be due to the higher microbiological load on microalgae (Vibrio alginolyticus and V. pectenicide). Larvae fed with S. costatum (D2) showed a lower development than other diets. The competency index was lower for larvae fed with the D2. These results show that microalgae diversified diets contribute to a better development of P. lividus larvae. During the settlement and post‐settlement phase, there was also a lower growth of the sea urchin fed with the D2 and a higher survival for D3.  相似文献   

Early maritime economy and El Nino events at quebrada tacahuay, peru     

DK Keefer  SD deFrance  ME Moseley  JB Richardson  DR Satterlee  A Day-Lewis 《Science (New York, N.Y.)》1998,281(5384):1833-1835

The archaeological site of Quebrada Tacahuay, Peru, dates to 12,700 to 12,500 calibrated years before the present (10,770 to 10,530 carbon-14 years before the present). It contains some of the oldest evidence of maritime-based economic activity in the New World. Recovered materials include a hearth, lithic cutting tools and flakes, and abundant processed marine fauna, primarily seabirds and fish. Sediments below and above the occupation layer were probably generated by El Nino events, indicating that El Nino was active during the Pleistocene as well as during the early and middle Holocene.  相似文献   

Predatory dinosaur remains from madagascar: implications for the cretaceous biogeography of gondwana   总被引：1，自引：0，他引：1  

SD Sampson  LM Witmer  CA Forster  DW Krause  PM O'Connor  P Dodson  F Ravoavy 《Science (New York, N.Y.)》1998,280(5366):1048-1051

Recent discoveries of fossil vertebrates from the Late Cretaceous of Madagascar include several specimens of a large theropod dinosaur. One specimen includes a nearly complete and exquisitely preserved skull with thickened pneumatic nasals, a median frontal horn, and a dorsal projection on the parietals. The new materials are assigned to the enigmatic theropod group Abelisauridae on the basis of a number of unique features. Fossil remains attributable to abelisaurids are restricted to three Gondwanan landmasses: South America, Madagascar, and the Indian subcontinent. This distribution is consistent with a revised paleogeographic reconstruction that posits prolonged links between these landmasses (via Antarctica), perhaps until late in the Late Cretaceous.  相似文献   

Genetic transformation of Citrus sinensis cv. Hamlin with hrpN gene from Erwinia amylovora and evaluation of the transgenic lines for resistance to citrus canker     

Janaynna Magalhães Barbosa-Mendes  Francisco de Assis Alves Mourão Filho  Armando Bergamin Filho  Ricardo Harakava  Steven V. Beer  Beatriz Madalena Januzzi Mendes 《Scientia Horticulturae》2009

Transgenic Citrus sinensis (L.) Osb. cv. Hamlin plants expressing the hrpN gene were obtained by Agrobacterium tumefaciens (Smith and Towns) Conn-mediated transformation. hrpN encodes a harpin protein, which elicits the hypersensitive response and systemic acquired resistance in plants. The gene construct consisted of gst1, a pathogen-inducible promoter, a signal peptide for protein secretion to the apoplast, the selection genes nptII or aacC1 and the Nos terminator. The function of gst1 in citrus was evaluated in transgenic C. sinensis cv. Valencia harboring the reporter gene uidA (gus) driven by this promoter. Histochemical analysis for gus revealed that gst1 is activated in citrus leaves by both wounding and inoculation with Xanthomonas axonopodis Starr and Garces pv. citri (Hasse) Vauterin et al. Genetic transformation was confirmed by Southern blot hybridization in eight cv. Hamlin acclimatized plants. RT-PCR confirmed hrpN gene expression in seven cv. Hamlin transgenic lines before pathogen inoculation. Some hrpN transgenic lines showed severe leaf curling and abnormal growth. Six hrpN transgenic lines were propagated and evaluated for susceptibility to X. axonopodis pv. citri. RT-PCR confirmed gene expression in all six hrpN transgenic lines after pathogen inoculation. Several of the hrpN transgenic lines showed reduction in susceptibility to citrus canker as compared with non-transgenic plants. One hrpN transgenic line exhibited normal vegetative development and displayed very high resistance to the pathogen, estimated as up to 79% reduction in disease severity. This is the first report of genetic transformation of citrus using a pathogen-inducible promoter and the hrpN gene. Further evaluations of the transgenic plants under field conditions are planned. Nevertheless, the evidence to date suggests that the hrpN gene reduces the susceptibility of citrus plants to the canker disease.  相似文献   

Maize participatory breeding in Portugal: Comparison of farmer's and breeder's on‐farm selection          下载免费PDF全文

Pedro Mendes‐Moreira  Zlatko Satovic  João Mendes‐Moreira  João Pedro Santos  João Pedro Nina Santos  Silas Pêgo  Maria Carlota Vaz Patto 《Plant Breeding》2017,136(6):861-871

“VASO” is a Portuguese participatory maize breeding project (1984), where several maize landraces such as “Pigarro” have been selected both by a farmer's (phenotypic recurrent selection) and a breeder's approach (S2 lines recurrent selection). The objectives of this study were to determine the phenotypic and genotypic responses to participatory selection using these two different approaches, to clarify to which extent both selection methods preserve genetic diversity, and conclude what is the preferred method to apply in sustainable farming systems. The results, obtained via ANOVA, regression analyses and molecular markers, indicate that for both selection methods, genetic diversity was not significantly reduced, even with the most intensive breeder's selection. Although there were some common outputs, such as the determinated versus indeterminated ears, cob and ear weight ratio per ear and rachis 2, specific phenotypic traits evolved in opposite directions between the two selection approaches. Yield increase was only detected during farmer selection, indicating its interest on PPB. Candidate genes were identified for a few of the traits under selection as potential functional markers in participatory plant breeding.  相似文献   

Bat richness and activity in heterogeneous landscapes: guild-specific and scale-dependent?     

Eduardo S. Mendes  Carlos Fonseca  Sara F. Marques  Daniela Maia  Maria João Ramos Pereira 《Landscape Ecology》2017,32(2):295-311

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A loop-mediated isothermal amplification (LAMP) assay based on unique markers derived from genotyping by sequencing data for rapid in planta diagnosis of Panama disease caused by Tropical Race 4 in banana     

N. Ordóñez  M. Salacinas  O. Mendes  M. F. Seidl  H. J. G. Meijer  C. D. Schoen  G. H. J. Kema 《Plant pathology》2019,68(9):1682-1693

The socio-economic impact of Fusarium odoratissimum, which is colloquially called tropical race 4 (TR4), is escalating as this fungal pathogen spreads to new banana-growing areas. Hence, the development of simple, reliable and rapid detection technologies is indispensable for implementing quarantine measures. Here, a versatile loop-mediated isothermal amplification (LAMP) assay has been developed that is applicable under field and laboratory conditions. DNA markers unique to TR4 isolates were obtained by diversity arrays technology sequencing (DArTseq), a genotyping by sequencing technology that was conducted on 27 genotypes, comprising 24 previously reported vegetative compatibility groups (VCGs) and three TR4 isolates. The developed LAMP TR4 assay was successfully tested using 22 TR4 isolates and 45 non-target fungal and bacterial isolates, as well as on infected plants under greenhouse and field conditions. The detection limit was 1 pg µL⁻¹ pure TR4 DNA or 10² copies plasmid-localized TR4 unique sequence (SeqA) per reaction, which was not affected by background DNA in complex samples. The LAMP TR4 assay offers a powerful tool for the routine and unambiguous identification of banana plants infected with TR4, contributing to advanced diagnosis in field situations and monitoring of fusarium wilt.  相似文献