Biometrical, biological, biochemical and molecular characteristics of Meloidogyne incognita isolates and related species     

Marcilene Fernandes Almeida dos Santos  Cleber Furlanetto  Maria Rita Alves Almeida  Marina Dechechi Gomes Carneiro  Fabiane Castro Mota  Ana Cristina Meneses Mendes Gomes  Natália Orrú Reis Silveira  Joelma Gardênia Pereira Silva  Philippe Castagnone-Sereno  Myrian Silvana Tigano  Regina Maria Dechechi Gomes Carneiro 《European journal of plant pathology / European Foundation for Plant Pathology》2012,134(4):671-684

Meloidogyne incognita is one of the most polyphagous species of root-knot nematodes occurring in Brazil and worldwide. Eight M. incognita isolates were studied, representing two enzymatic phenotypes (esterase and malate desydrogenase: I1/N1, I2/N1) and four cryptic Meloidogyne sp.1 (S2/N1) isolates, representing one cytological type (3n?=?40–46). Three M. hispanica isolates (Hi3/N1, 2n?=?32–36) and two of an atypical Meloidogyne sp.2 (S2a/N3, 3n?=?40–44) were included in this study for comparison. All isolates were tested with three M. incognita-specific molecular markers. The primer pairs B06F/R, miF/R and incK14F/R amplified three species-specific fragments of 1,200?bp, 955?bp and 399?bp, respectively for M. incognita and Meloidogyne sp.1 isolates. No amplification occurred in the M. hispanica and Meloidogyne sp.2 isolates, except with primers miF/R (1,650?bp). The genetic variability of the Meloidogyne spp. isolates was evaluated, using RAPD and ISSR markers. The phylogenetic analyses revealed two strongly supported monophyletic clades: clade I, consisting of M. hispanica and the atypical Meloidogyne sp.2 isolates, and clade II, clustering together all M. incognita and the Meloidogyne sp.1 isolates. Considering the biometrical, cytological and molecular approaches, it was possible to conclude that the isolates with three enzymatic phenotypes (I1/N1, I2/N1 and S2/N1) presented the characteristics described for M. incognita. Some correlations were detected between the isozymatic phenotypes and the tree topology (S2a/N3, Hi3/N1, I1/N1, S2/N1), but no strict correlation could be observed for the phenotype I2/N1 and one isolate of S2/N1. Morphologically, the Msp.2 isolates differ from M. incognita and M. hispanica by the female stylet features presenting straight cone tip and round pear shaped knobs, posteriorly sloping. The results of this study suggested that the Msp.2 isolates with phenotypes S2aN3 belong to a new or an unidentified species closely related to M. hispanica.  相似文献   

Stem elongation in Pennisetum purpureum results from a fixed pattern of vegetative development potentially enhanced by the initiation of flowering     

Guilherme Portes Silva  Sila Carneiro da Silva  Abraham Escobar‐Guttirrez  Gilles Lemaire  Gaëtan Louarn 《Grass and Forage Science》2019,74(4):708-719

The characterization of stem elongation is of fundamental importance in C4 tropical grasses as it affects forage quality and determines optimal management practices. The objectives of this study were to analyse the determinants of stem elongation and leaf area production in shoots of Pennisetum purpureum cv. Napier (elephant grass) using unstressed isolated plants. Three experiments were conducted in Brazil during the spring, summer and autumn seasons. Regular measurements of leaf and pseudostem length were performed on the main and primary axes. Ten destructive measurements were also performed during each experiment to monitor apical meristem height, internode length and the number of initiated leaves. The onset of stem elongation occurred at the same vegetative stage (i.e., appearance of leaf 13) irrespective of the seasons and experiments. The first internode to elongate belonged to phytomer 8, and a constant lag of five phyllochrons was systematically observed between internode production and its rapid elongation period. Higher stem and internode elongation rates were observed during the reproductive phase (autumn) versus the vegetative phase (summer and spring group). Maximal internode length reached 8–10 cm in summer and spring and 20 cm in autumn, at approximately phytomers 12–13. A similar pattern was reported for all primary axes irrespective of the experiments, the position of the first internode to elongate descending regularly down the main axis. These results provide key elements to predict the onset of stem elongation in the field from simple measurements. They could contribute to improving crop models for perennial tropical C4 grasses.  相似文献   

Strategy to identify resistance to white mould associated with high yield for irrigated common bean in Brazil     

Renan C. Lima  Pablo H. Teixeira  Ari F. F. Souza  Trazilbo J. Paula Júnior  Hudson Teixeira  Miller S. Lehner  José E. S. Carneiro  Tiago S. Marçal  Rogerio F. Vieira 《Plant pathology》2020,69(6):1172-1184

Development of common bean cultivars with partial white mould resistance through breeding techniques has been a challenge in Brazil. As yet, lines/cultivars from breeding programmes have not been investigated for resistance; therefore, this study screened 107 lines/cultivars for their reactions to white mould in 14 preliminary trials conducted under irrigation. Thirteen resistant lines/cultivars (three of Andean origin) and six Mesoamerican cultivars (three intermediately resistant and three susceptible) were selected for further investigation. These lines/cultivars and the resistant control A195 were evaluated in six advanced trials and two straw tests to assess the effectiveness of the screening procedure. In 11 preliminary trials, screenings were performed under moderate/high or higher disease pressure. These pressures occurred in two advanced trials in which, when yields were averaged across moderate/high and high pressures, 10 Mesoamerican lines/cultivars selected for resistance yielded 14%, 23%, and 38% more than intermediately resistant cultivars, A195, and susceptible cultivars, with median disease ratings (1–9 scale) of 4.5, 5.7, 5.7, and 6.7, respectively. In the straw test, three Andean lines/cultivars (A195 included) and two susceptible cultivars in the field were among those with the highest levels of physiological resistance. Thus, field rating under high disease pressure and greenhouse rating did not correlate significantly, suggesting that field trials are critical to evaluating resistance and to identifying high-yielding beans. Therefore, lines/cultivars from breeding programmes assessed in field trials may provide a low cost and fast way to identify high-yielding bean cultivars with partial resistance to white mould in the subtropical southern hemisphere.  相似文献   

Mediterranean versus Atlantic monk parakeets Myiopsitta monachus: towards differentiated management at the European scale     

Jose‐Luis Postigo  Diederik Strubbe  Emiliano Mori  Leonardo Ancillotto  Inês Carneiro  Panagiotis Latsoudis  Mattia Menchetti  Liviu G Pru  Dave Parrott  Luís Reino  Anne Weiserbs  Juan Carlos Senar 《Pest management science》2019,75(4):915-922

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Comparison of serological assays for the diagnosis of canine visceral leishmaniasis in animals presenting different clinical manifestations   总被引：1，自引：0，他引：1  

Ferreira Ede C  de Lana M  Carneiro M  Reis AB  Paes DV  da Silva ES  Schallig H  Gontijo CM 《Veterinary parasitology》2007,146(3-4):235-241

Three serological methods, indirect fluorescent immunoassay (IFI), enzyme-linked immunosorbent assay (ELISA) and direct agglutination test (DAT) that are commonly employed in the diagnosis of canine visceral leishmaniasis (CVL), have been assessed. A total of 234 domestic dogs, drawn from an area in the municipality of Belo Horizonte, Minas Gerais, Brazil, endemic for visceral leishmaniasis, were submitted to clinical and parasitological examinations and serological assay. Sera collected from confirmed non-infected dogs (n=20), and from dogs with other parasitic diseases including Trypanosoma cruzi (n=7), Leishmania braziliensis (n=5), Toxoplasma gondii (n=5) and Ehrlichia canis (n=3), were also included in the study. IFI presented a lower sensitivity (72%) than ELISA (95%), although the specificities of these assays were low (52 and 64%, respectively) and both exhibited cross-reactivity with sera from dogs infected with T. cruzi, L. braziliensis and E. canis. In contrast, DAT exhibited a high sensitivity (93%) and a high specificity (95%) and cross-reacted with only one serum sample derived from an E. canis-infected dog. The reproducibilities of the ELISA and DAT assays were excellent, whilst that of IFI was considered to be acceptable. The results produced by ELISA and DAT were in complete agreement, those between ELISA and IFI were at an acceptable level of agreement, whilst the concurrence between the IFI and DAT results were either acceptable or poor depending on the clinical conditions of the group of dogs examined. Since there is no readily accessible method for the diagnosis of CVL that offers 100% specificity and sensitivity, the choice of technique employed must depend on the aim of the investigation.  相似文献   

Irrigation effects on elephant grass morphology,and its genotype-dependent responses     

Robson Elpídio Pereira Ribeiro  Alexandre Carneiro Leão de Mello  Márcio Vieira da Cunha  Suellen Brandão de Miranda Costa  Janerson José Coelho  Rayanne Thalita de Almeida de Souza  Mércia Virginia Ferreira dos Santos 《Grass and Forage Science》2023,78(1):194-203

This study hypothesised that different elephant grass genotypes respond differently in terms of their morphological development to irrigation. The objective of this study was to evaluate how water availability could affect the morphological development of different genotypes of elephant grass. The treatments consisted of four genotypes of elephant grass [Cenchrus purpureus (Schumach.) Morrone], managed under irrigation or not, during a two-year field trial. The experiment was arranged in a randomised block design in a split-plot, with four replicates per treatment (n = 4). Between the genotypes, two of them were classified as tall-sized (IRI 381 and Elephant B), and two as dwarfs (Taiwan A-146 2.37 and Mott). A three-way interaction between season, irrigation, and genotype affected the variables plant height, stem diameter, number of dead tillers, light interception (LI), and leaf area index (LAI) (p < .05). The morphological development of all genotypes was negatively impacted by the dry season. All genotypes grew taller during the rainy season (p < .05) and had a greater light interception (62%–80%) compared to the dry period (28%–59%). The genotype Mott, showed comparable LI and LAI to the tall-sized genotypes, whilst Taiwan A-146 2.37 was characterized by the lowest values, despite being the genotype with the greatest tiller density (60 tillers m⁻²) (p < .05). The use of irrigation mitigated the negative effects of the dry season on the plants, however, the type and size (tall vs. dwarf) of the elephant grass genotypes defined the extent of the responses to the use of the irrigation during the dry period.  相似文献   

Effects of an Enterococcus faecium‐based probiotic on growth performance and health of Pirarucu,Arapaima gigas     

Natalino da Costa Sousa  Mrcia Valria Silva do Couto  Higo Andrade Abe  Peterson Emmanuel Guimares Paixo  Carlos Alberto Martins Cordeiro  Emilly Monteiro Lopes  Jonathan Stuart Ready  Gabriel Fernandes Alves Jesus  Mauricio Latera Martins  Jos Luiz Pereira Mourio  Paulo Csar Falanghe Carneiro  Alexandre Nizio Maria  Rodrigo Yudi Fujimoto 《Aquaculture Research》2019,50(12):3720-3728

Intensive fish farming has resulted in an increased concern for disease outbreaks. Probiotic use is one of the strategies being developed to improve fish health and productivity. Measures of probiotic colonization, growth performance, haematological characteristics and parasite load were used to evaluate the effect of diets supplemented with Enterococcus faecium on growth and health of Arapaima gigas juveniles. A completely randomized design with four treatments (diet with E. faecium at 1 × 10⁶ CFU/g and 1 × 10⁸ CFU/g, control diet and diet with the culture medium MRS) and three replicates was used. Ninety‐six Arapaima juveniles were distributed in 12 cages fed with the specified diet for 68 days. Colonization of the intestinal tract by lactic acid bacteria reduced the total number of heterotrophic bacteria in fish fed with probiotics compared to controls. Fish fed a supplemented diet containing 1 × 10⁸ CFU/g presented higher values of weight gain, survival and fish growth uniformity, and lower values of feed conversion ratio. The prevalence of Trichodina sp. could have affected the survival of fish in the control group. Reduction in parasite load and an increase in haematocrit, the number of erythrocytes, thrombocytes, neutrophils and monocytes were also observed in fish fed the diet containing 1 × 10⁸ CFU/g. Enterococcus faecium presented a probiotic effect in A. gigas juveniles and can be recommended for use at a concentration of 1 × 10⁸ CFU/g to modify the gut microbiota, improve growth performance and haematology and reduce parasitic load.  相似文献   

Combining ability of common bean parents in different seasons,locations and generations     

Lisandra Magna Moura  Rafael Silva Ramos dos Anjos  Renata Oliveira Batista  Naine Martins do Vale  Cosme Damião Cruz  José Eustáquio de Souza Carneiro  Juarez Campolina Machado  Pedro Crescêncio Souza Carneiro 《Euphytica》2018,214(10):181

The objectives of this study were to obtain information about genetic parameters of a partial diallel in common bean, as well as to evaluate the effects of growing seasons, locations and generations in these estimates in order to define the best strategies for the use of diallel analysis as methodology of selection of parents and populations in common bean breeding. Twelve parents were crossed in a partial diallel scheme (5?×?7), and the F₁ and F₂ generations were evaluated in four experiments (I, II, III, and IV). The effects of seasons were determined in the Experiments I and II, in which the F₁ generation was evaluated in two distinct growing seasons. To quantify the effect of locations, we used Experiments III and IV, in which the F₂ generation was evaluated in the same season, but at different locations, and to quantify the effect of generations, the experiments II (generation F₁) and III (F₂ generation) were evaluated in the same season and location. As for grain yield the genetic control varied according to the environment. An effect of interaction on the genetic parameters of the diallel was observed for generation, whereas for grain yield, effects of season and location were observed. For plant architecture, parental combining ability should therefore be estimated using the F₁ generation, while for grain yield, both the F₁ and F₂ can be used. The recombination between the best hybrids is a promising strategy for extraction of superior black bean lines.  相似文献   

Potential use of NIR spectroscopy to identify Cryptomeria japonica varieties from southern Brazil     

Silvana Nisgoski  Felipe Zatt Schardosin  Francielli Rodrigues Ribeiro Batista  Graciela Inés Bolzon de Muñiz  Mayara Elita Carneiro 《Wood Science and Technology》2016,50(1):71-80

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Low genetic variability in Sclerotinia sclerotiorum populations from common bean fields in Minas Gerais State,Brazil, at regional,local and micro‐scales          下载免费PDF全文

M. S. Lehner  T. J. Paula Júnior  B. T. Hora Júnior  H. Teixeira  R. F. Vieira  J. E. S. Carneiro  E. S. G. Mizubuti 《Plant pathology》2015,64(4):921-931

Sclerotinia sclerotiorum, causal agent of white mould, is the most destructive and widely distributed soilborne pathogen of common bean during the autumn–winter season in Brazil. Nevertheless, little is known about the genetic structure of the pathogen population. Microsatellite (SSR) markers and mycelial compatibility groups (MCGs) were used to characterize 118 isolates collected from 20 bean fields located in the most important growing regions of Minas Gerais State (MG). Additionally, the genetic variability among 10 isolates obtained from a single sclerotium was investigated in 10 different sclerotia. Seventy SSR haplotypes and 14 MCGs were identified among the 118 isolates. The genetic differences within bean growing areas accounted for most of the genetic variation (72%). Despite the relatively high genotypic diversity, the SSR loci were at linkage disequilibrium. Moreover, 70% of the isolates were assigned to only two MCGs, and haplotypes of a given MCG were closely related. The discriminant analysis of principal components revealed five groups. There was strong genetic differentiation between isolates collected in one municipality in southern MG when compared to other regions. Common bean resistance to white mould should be assessed with representative isolates of the five genetic groups and, if possible, of the different MCGs detected in the present study. One to five haplotypes were detected among the 10 isolates obtained from a single sclerotium. Therefore, in order to ensure genetic identity of an isolate, hyphal tip or monoascosporic isolates should be used.  相似文献