Isolation of five new monosomic alien addition lines of Gossypium australe F. Muell in G. hirsutum L. by SSR and GISH analyses     

D. Sarr  J‐M. Lacape  M. Rodier‐Goud  J‐M. Jacquemin  H. Benbouza  A. Toussaint  R. Palm  L. Ahoton  J‐P. Baudoin  G. Mergeai 《Plant Breeding》2011,130(1):60-66

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Bridging dimensions: demultiplexing ultrahigh-density nanowire circuits     

Beckman R  Johnston-Halperin E  Luo Y  Green JE  Heath JR 《Science (New York, N.Y.)》2005,310(5747):465-468

A demultiplexer is an electronic circuit designed to separate two or more combined signals. We report on a demultiplexer architecture for bridging from the submicrometer dimensions of lithographic patterning to the nanometer-scale dimensions that can be achieved through nanofabrication methods for the selective addressing of ultrahigh-density nanowire circuits. Order log2(N) large wires are required to address N nanowires, and the demultiplexer architecture is tolerant of low-precision manufacturing. This concept is experimentally demonstrated on submicrometer wires and on an array of 150 silicon nanowires patterned at nanowire widths of 13 nanometers and a pitch of 34 nanometers.  相似文献   

Multidrug-resistant <Emphasis Type="Italic">Salmonellae</Emphasis> isolated in Japanese quails reared in Abeokuta,Nigeria     

Ezekiel O. Omoshaba  F. O. Olufemi  O. E. Ojo  A. O. Sonibare  M. Agbaje 《Tropical animal health and production》2017,49(7):1455-1460

Salmonellosis is a major bacterial disease causing huge economic losses in the poultry industry worldwide. This study was carried out to determine the period prevalence and antimicrobial susceptibility of Salmonella enterica in Japanese quails in Abeokuta, Nigeria. Four hundred cloacal swabs of quail birds were collected from 4 locations within Abeokuta. Salmonella was isolated from the samples using conventional methods for selective isolation of Salmonella and biochemical identification. Isolates were confirmed by polymerase chain reaction assays for the amplification and detection of Salmonella-associated virulence genes (invA and stn) using specific primers. Antimicrobial susceptibility testing was done using the Kirby-Bauer disk diffusion method. In all, Salmonella was isolated from 14 (3.5%) cloacal swabs. All 14 isolates possessed invA and stn genes. The Salmonella isolates showed resistance to tetracycline (100%), doxycycline (100%), ampicillin (100%), sulphamethoxazole (92.9%), nalidixic acid (85.8%), ceftazidime (78.6%), neomycin (64.3%), streptomycin (50%) and gentamycin (28.6%) but all the isolates were susceptible to ciprofloxacin. The isolates were resistant to at least three antimicrobials indicating multidrug resistance. The results concluded that Japanese quails harbour multidrug-resistant Salmonella which could be transmitted to humans through consumption of contaminated food or by direct and indirect contact with the carrier birds. Antimicrobial resistance could be due to overdependence on antimicrobials. Ciprofloxacin could be considered in the treatment of zoonotic Salmonellosis in humans.  相似文献   

Analysis of the geographic distribution and relationships among Peruvian wild species of <Emphasis Type="Italic">Arracacia</Emphasis>     

R. Blas  M. Hermann  J.-P. Baudoin 《Genetic Resources and Crop Evolution》2008,55(5):643-655

Relationships between Arracacia species were studied according to 28 morphological discriminant characters, in 90 accessions: 83 Arracacia (Arracacia elata, A. incisa and A. xanthorrhiza), and seven accessions of Neonelsonia acuminata, which has been confused with A. elata. The geographic distribution of the Arracacia species was determined from the passport data of the 90 accessions. A. elata was clearly differentiated from N. acuminata according to morphological characteristics. The species A. incisa was more closely related to A. xanthorrhiza. Within A. xanthorrhiza two forms, monocarpic, and polycarpic, were identified. The distribution of wild Arracacia species in Peru is characterized by two main ecological zones: (1) a dry zone, like the western Yunga and western and inter-Andean valleys of the Quechua region (with seasonal rain from November to March), where the species A. incisa and A. xanthorrhiza are present, and (2) a humid zone, like the Eastern Quechua where A. elata is adapted. These informations could be useful to establish strategies for in situ and ex situ conservation and management of germplasm.  相似文献   

Genetic structure of Lima bean (<Emphasis Type="Italic">Phaseolus lunatus</Emphasis> L.) landraces grown in the Mayan area     

Luciana Camacho-Pérez  Jaime Martínez-Castillo  Javier O. Mijangos-Cortés  Miriam M. Ferrer-Ortega  Jean Pierre Baudoin  Rubén H. Andueza-Noh 《Genetic Resources and Crop Evolution》2018,65(1):229-241

Lima bean (Phaseolus lunatus L.) is an important crop in the Mayan culture. The Mayan area, considered as a main center of Mesoamerican diversity, has been divided into two subareas: the Mayan lowlands and the Mayan highlands. The Yucatan Peninsula is part of the Mayan lowlands and holds the highest number of Lima bean landraces of Mexico, but Lima beans are in high risk of genetic erosion due to intensification of the traditional Mayan agriculture. However, information on genetic diversity of Lima beans of the Mayan highlands is lacking. By using 46 landraces collected in the Mayan area (23 from each subarea) and 73 ISSR loci (inter-simple sequence repeats), we analyzed the structure, diversity and genetic relationships of Lima beans of this part of Mesoamerica. High levels of diversity (H _BAY = 0.45) and genetic structure (F _ST = 0.66) were found for the whole Mayan area. Genetic diversity in the Mayan lowlands was apparently higher than the Mayan highlands (H _BAY = 0.44 and 0.36, respectively); but differences were not statistically significant. Genetic structure between the subareas was high (AMOVA = 30% of total variation), most landraces grouping according to their geographic origin. This study shows the importance of the Mayan culture in the diversification and conservation of Lima beans. The results provide important information that should be considered when implementing strategies to collect Lima bean landraces and planning in situ and ex situ programs to conserve these landraces in the Mayan region.  相似文献   

Cytogenetics of the 'glandless-seed and glanded-plant' trait from Gossypium sturtianum Willis introgressed into upland cotton (Gossypium hirsutum L.)   总被引：1，自引：0，他引：1  

I. Vroh  Bi  J. P. Baudoin  G. Mergeai 《Plant Breeding》1998,117(3):235-241

In order to introgress the ‘glandless-seed and glanded-plant’ trait from Gossypium sturtianum Willis (2n= 2x= 26, C₁ genome) into the cultivated upland cotton Gossypium hirsutum L. (2n= Ax= 52 (AD), genome), two trispecific hybrids have been created using either Gossypium thurberi Torado (2n= 2x= 26, D₁ genome) or Gossypium raimondii Ulbrich (2n= 2x= 26, D₅ genome) as bridge species. The cross of both trispecific hybrids by G. hirsutum produced the first backcross progenies (BCl). Cytogenetic analysis showed that the trispecific hybrids had 52 chromosomes, their chromosome configurations at metaphase I (Ml) being 15.071 + 15.3411 + 0.93III + 0.69IV + 0.26VI in G. thurberi×G. sturtianum×G. hirsutum (TSH) and 14.421 + 17.0311 + 0.82III + 0.15IV + 0.07VI in G. hirsutum × G. raimondii ×. G. sturtianum (HRS), respectively. Among six BCl plants analysed, the only plant expressing the ‘glandless-seed and glanded-plant’ trait had 52 chromosomes and a meiotic configuration of 5.261 + 20.61II + 0.69III + 0.77IV at MI. Pollen fertility was 2.90% in TSH, 8.97% in HRS, and ranged from 0% to 40.28% in the BCl progenies. The introgressed BCl plant is perennial in growth habit. It can be used in breeding programmes aiming at the introgression of the ‘glandless-seed and glanded-plant’ trait into a cultivar of upland cotton.  相似文献   

Direct seeding mulch-based cropping increases both the activity and the abundance of denitrifier communities in a tropical soil     

Ezékiel Baudoin  Laurent Philippot  Dominique Chèneby  Lydie Chapuis-Lardy  David Bru  Bodovololona Rabary 《Soil biology & biochemistry》2009,41(8):1703-1709

This study evaluated the impact of direct seeding mulch-based cropping (DMC), as an alternative to conventional tilling (CT), on a functional community involved in N cycling and emission of greenhouse gas nitrous oxide (N₂O). The study was carried out for annual soybean/rice crop rotation in the Highlands of Madagascar. The differences between the two soil management strategies (direct seeding with mulched crop residues versus tillage without incorporation of crop residues) were studied along a fertilization gradient (no fertilizer, organic fertilizer, organic plus mineral fertilizers). The activity and size of the denitrifier community were determined by denitrification enzyme activity assays and by real-time PCR quantification of the denitrification genes. Denitrification activity and total C and N content in the soil were significantly increased by DMC both years, whereas the fertilization regime and sampling year (crop and mulch types, climatic conditions) had very little effect. Similar results were also observed for denitrification gene densities. Denitrification enzyme activity was more closely correlated with C content than with N content in the soil and denitrification gene densities. Principal component analysis confirmed that soil management had the strongest impact on the soil denitrifier community and total C and N content for both years and further indicated that changes in microbial and chemical soil parameters induced by the use of fertilizer were favored in DMC plots. Overall, the alternative DMC system had a significant positive effect on denitrifier densities and potential activities, which was not altered by crop rotation and the level of fertilization. These data also suggest that in these clayey soils, the DMC system simultaneously increased the size of the soil N pool and accelerated the N cycle, by stimulating the denitrifier community. Complementary investigations should further determine in greater detail the influence of DMC on in situ N-fluxes caused by denitrification.  相似文献   

Shifts in size,genetic structure and activity of the soil denitrifier community by nematode grazing     

Djibril Djigal  Ezékiel Baudoin  Laurent Philippot  Alain Brauman  Cécile Villenave 《European Journal of Soil Biology》2010,46(2):112-118

Bacterial-feeding nematodes represent an important driver of the soil microbial activity and diversity. This study aimed at characterizing the impact of nematode grazing on a model functional bacterial guild involved in N-cycling, the denitrifiers. Bacterial-feeding nematodes (Cephalobus pseudoparvus) were inoculated into soil microcosms whose indigenous nematofauna had previously been removed. The size, genetic structure and activity of the soil denitrifier community were characterized 15 and 45 days after nematodes inoculation using quantitative PCR of the nirK, nirS and nosZ denitrification genes, fingerprinting of the nirK and nirS genes and denitrification enzyme activity measurements, respectively. A significant impact of C. pseudoparvus was observed on genetic structure of the nirK community, mainly due to shifts in the relative abundance of the dominant populations, but not on the nirS community. The grazing pressure also tended to decrease the density of all denitrification genes as well as that of 16S rRNA genes. Despite being non-significant, the extent of this decline in gene copy numbers ranged between 60 and 80% of the control microcosm genes densities. Finally, compared to non-inoculated microcosms, denitrification activity significantly decreased by 8% in response to the nematodes inoculation. The herewith data showed that predation by a single species of bacterial-feeding nematode can affect the soil denitrifier community.  相似文献   

Morphological and molecular diversity within Algerian cowpea (<Emphasis Type="Italic">Vigna unguiculata</Emphasis> (L.) Walp.) landraces     

Naima Ghalmi  Marie Malice  Jean-Marie Jacquemin  Sidi-Mohamed Ounane  Leila Mekliche  Jean-Pierre Baudoin 《Genetic Resources and Crop Evolution》2010,57(3):371-386

Twenty landraces of cowpea (Vigna unguiculata (L.) Walp.) scattered throughout Algeria were compared through morphological and genetic characterization. At the morphological level, for qualitative characters there was no intra-landrace variation and for quantitative characters the variations were low except for landrace NAG2 Three different cultigroups were located in Algeria: Biflora that was dominant in the Sahara, Melanophtalmus in the North and Unguiculata including one landrace in Kabylia and two in Sahara. The AMOVA analysis indicated that the genetic variation was lower within than among agro-ecological regions. A Mantel test, revealed a correlation between the qualitative morphological data and the geographical data (R = 0.28; P < 0.01), indicating that the degree of morphological change among landraces was roughly proportional to the geographical distances separating them. Genetic diversity was analyzed by using 11 random amplified polymorphic DNA (RAPD) and 12 inter-simple sequence repeat (ISSR) markers. No intra-landrace variability was found. The eleven RAPD primers yielded 77 bands, of which 45 (58.44%) were polymorphic; the genetic similarity ranged from 66.0 to 96.7%. The twelve ISSR primers provided a total of 104 bands, of which 65 (62.5%) were polymorphic; the genetic similarity ranged from 62.8 to 97.8%. cluster analysis showed a good match between genetic background and geographical distribution, which was confirmed by the results of the Mantel test. In particular, geographical data and genetic data were found to be correlated: (R = 0.33; P < 0.01) for RAPD, (R = 0.37; P < 0.01) for ISSR, and (R = 0.33; P < 0.01) for a combined RAPD-ISSR dataset. Moreover, despite the absence of significant correlation between morphological and RAPD data (R = 0.14; P = 0.14), significant correlations between morphological data and both ISSR (R = 0.27, P < 0.05) and a combined RAPD-ISSR dataset (R = 0.22, P < 0.05) were noted. ISSR markers were better linked to morphological variation than were RAPD markers. However, despite this, genetic distances among these landraces were found to be essentially the same no matter which markers were used.  相似文献   

Development of a real-time PCR method to quantify the PGPR strain Azospirillum lipoferum CRT1 on maize seedlings     

Olivier Couillerot  Marie-Lara Bouffaud  Ezékiel Baudoin  Daniel Muller  Jesus Caballero-Mellado 《Soil biology & biochemistry》2010,42(12):2298-2305

Azospirillum lipoferum CRT1 is a promising phytostimulatory PGPR for maize, whose effect on the plant is cell density-dependent. A nested PCR method is available for detection of the strain but does not allow quantification. The objective was to develop a real-time PCR method for quantification of A. lipoferum CRT1 in the rhizosphere of maize seedlings. Primers were designed based on a strain-specific RFLP marker, and their specificity was verified under qualitative and quantitative PCR conditions based on successful CRT1 amplification and absence of cross-reaction with genomic DNA from various rhizosphere strains. Real-time PCR conditions were then optimized using DNA from inoculated or non-inoculated maize rhizosphere samples. The detection limit was 60 fg DNA (corresponding to 19 cells) with pure cultures and 4 × 10⁴ CFU equivalents g⁻¹ lyophilized sample consisting of mixture of rhizosphere soil and roots. Inoculant quantification was effective down to 10⁴ CFU equivalents g⁻¹. Assessment of CRT1 rhizosphere levels in a field trial was in accordance with estimates from semi-quantitative PCR targeting another locus. This real-time PCR method, which is now available for direct rhizosphere monitoring of A. lipoferum CRT1 in greenhouse and field experiments, could be used as a reference for developing quantification tools for other Azospirillum inoculants.  相似文献