Characterization of chickpea differentials for pathogenicity assay of ascochyta blight and identification of chickpea accessions resistant to Didymella rabiei     

W. Chen †  C. J. Coyne  T. L. Peever  F. J. Muehlbauer 《Plant pathology》2004,53(6):759-769

Forty-eight chickpea germplasm lines, including 22 differentials used in previous studies, were characterized for disease phenotypes following inoculation with six isolates of Didymella (anamorph Ascochyta ) rabiei , representing a wide spectrum of pathogenic variation. Representative isolates were also directly compared with six previously identified races on eight chickpea genotypes. Many of the chickpea differentials reacted similarly to inoculation with each isolate of D. rabiei , and several previously identified races caused similar levels of disease on the differentials. This indicates that the number of differentials can be reduced significantly without sacrificing accuracy in describing pathogenic variation of D. rabiei on chickpea. Pathogenic variation among samples of US isolates allowed classification of the isolates into two pathotypes. The distribution of disease phenotypes of the 48 germplasm lines was bimodal after inoculation with pathotype I isolates, whereas the distribution of disease phenotypes was continuous after inoculation with pathotype II isolates. Such distinct distribution patterns suggest that chickpea plants employ different resistance mechanisms to each pathotype and that the two pathotypes may have different genetic mechanisms controlling pathogenicity. The advantages of using the two-pathotype system in assaying pathogenicity of the pathogen and in studying resistance mechanisms of the host are discussed. Three chickpea accessions, PI 559361, PI 559363 and W6 22589, showed a high level of resistance to both pathotypes, and can be employed as resistance sources in chickpea breeding programmes for resistance to ascochyta blight.  相似文献   

Novel sources of witches’ broom resistance (causal agent <Emphasis Type="Italic">Moniliophthora perniciosa</Emphasis>) from natural populations of <Emphasis Type="Italic">Theobroma cacao</Emphasis> from the Brazilian Amazon     

Paulo S. B. de Albuquerque  Stela D. V. M. Silva  Edna D. M. N. Luz  José L. Pires  Afrânio M. C. Vieira  Clarice G. B. Demétrio  Sérgio F. Pascholatti  Antonio Figueira 《Euphytica》2010,172(1):125-138

Witches’ broom is a severe disease of Theobroma cacao L. (cacao), caused by the basidiomycete Moniliophthora perniciosa. The use of resistant cultivars is the ultimate method of control, but there are limited sources of resistance. Further, resistance from the most widely used source (‘Scavina 6’) has been overcome after a few years of deployment. New sources of resistance have been intensively searched for in the Amazon basin. Here, we evaluated for witches’ broom resistance, cacao accessions from various natural cacao populations originally collected in the Brazilian Amazon. Resistance of 43 families was evaluated under nursery and/or field conditions by artificial or natural infection, respectively, based on disease incidence. Screening for resistance by artificial inoculation under nursery conditions appeared to be efficient in identifying these novel resistance sources, confirmed by natural field evaluation over a nine-year period. The increase in natural field infection of ‘Scavina 6’ was clearly demonstrated. Among the evaluated families with the least witches’ broom incidence, there were accessions originally collected from distinct river basins, including the Jamari river (‘CAB 0371’; ‘CAB 0388’; ‘CAB 0392’; and ‘CAB 0410’); Acre (‘CAB 0169’); Javari (‘CAB 0352’); Solimões (‘CAB 0270’); and from the Purus river basin, the two most outstanding resistant accessions, ‘CAB 0208’ and ‘CAB 0214’. The large genetic diversity found in cacao populations occurring at river basins from Acre and Amazonas states, Brazil, increased the chance that the selected resistant accessions would be genetically more dissimilar, and represent distinct sources of resistance to M. perniciosa from ‘Scavina 6’.  相似文献   

Measurement of the field response of <Emphasis Type="Italic">Musa</Emphasis> genotypes to <Emphasis Type="Italic">Radopholus Similis</Emphasis> and <Emphasis Type="Italic">Helicotylenchus Multicinctus</Emphasis> and the implications for nematode resistance breeding     

J. B. Hartman  D. Vuylsteke  P. R. Speijer  F. Ssango  D. L. Coyne  D. De Waele 《Euphytica》2010,172(1):139-148

Crop growth and damage parameters (plant growth and yield, root damage and nematode population densities), believed to be associated with resistance of Musa genotypes to nematodes under field conditions, were evaluated in a field trial of 24 Musa genotypes inoculated at planting with a combination of Radopholus similis and Helicotylenchus multicinctus with the objective to identify parameters with strong association with nematode resistance and high heritability. Correlation and path analysis of the association between plant growth, yield, root damage and nematode population densities showed a strong negative association between percentage dead roots, percentage root necrosis, R. similis and H. multicinctus population densities and yield. The strongest negative association was observed between percentage dead roots and yield. Broad-sense genotype heritability estimates demonstrated that heritability estimates for percentage dead roots, number of large lesions and nematode population density were most affected by inoculation with nematodes. These results indicate therefore that effective selection for nematode resistance under field conditions could be obtained by using an index, that includes percentage dead roots, the number of large lesions, and nematode population density.  相似文献   

The effect of synthetic pesticides and sulfur used in conventional and organically grown strawberry and soybean on Neozygites floridana,a natural enemy of spider mites          下载免费PDF全文

Thiago Castro  Samuel Roggia  Vitalis W Wekesa  Rafael de Andrade Moral  Clarice GB Demétrio  Italo Delalibera Jr  Ingeborg Klingen 《Pest management science》2016,72(9):1752-1757

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Does habitat fragmentation affect landscape-level temperatures? A global analysis     

Mendes  Clarice B.  Prevedello  Jayme A. 《Landscape Ecology》2020,35(8):1743-1756

Landscape Ecology - Habitat fragmentation per se (habitat subdivision independent of habitat loss) is a major driver of biodiversity change, potentially due to its impacts on climate. Habitat...  相似文献   

Gene silencing by RNAi via oral delivery of dsRNA by bacteria in the South American tomato pinworm,Tuta absoluta     

Flavia MM Bento  Rodrigo N Marques  Felippe B Campana  Clarice GB Demtrio  Roseli A Leandro  Jos Roberto P Parra  Antonio Figueira 《Pest management science》2020,76(1):287-295

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A comparison of four methods for measuring respiration in organic material     

Keith Van Cleve  Patrick I. Coyne  Enid Goodwin  Craig Johnson  Marilyn Kelley 《Soil biology & biochemistry》1979,11(3):237-246

Four methods for measurement of respiration (CO₂ evolution) were compared on uniformly prepared, birch forest-floor organic matter; the methods included infrared gas analysis (i.r.g.a.), gas chromatography (g.c.), KOH absorption of CO₂ (b.a.) and the Gilson respirometer. Respiration estimates were made at a single temperature and also at variable temperatures at constant moisture contents. The i.r.g.a. and b.a. methods gave maximum estimates for respiration; the g.c. gave lowest, with the Gilson intermediate. Lower estimates for the g.c. are attributed to the closed system employed, which included no means of increasing gas diffusion (such as a KOH-CO₂ sink or continuous gas flow) out of the sample into the unoccupied space of the respiration chamber.At 25°C, the minimum sensitivity of the g.c. and Gilson were 3.8 and 3.6 μg CO₂, respectively. The minimum sensitivity of the b.a. method (44 μg CO₂) could have been improved with use of a micro-liter burette for titrations. The least minimum sensitivity, 0.31 μg CO₂, was attained with the i.r.g.a.Conditions under which any of the techniques may be used to estimate respiration should be carefully worked out. The relationship between sample size, gas flow rate (open system), chamber atmosphere composition (closed system), and chamber design should be established with sufficient confidence so that stimulation of respiration by excessive gas flow rate, or exhaustion of O₂ or CO₂ inhibition through extended chamber closure does not adversely affect respiration estimates.  相似文献   

Use of Sterol and Bile Acid Biomarkers to Identify Domesticated Animal Sources of Fecal Pollution     

Punam Tyagi  Dwayne R. Edwards  Mark S. Coyne 《Water, air, and soil pollution》2008,187(1-4):263-274

The objective of this study was to demonstrate the use of chemical biomarkers (fecal sterols and bile acids) to identify selected sources of fecal pollution in the environment. Fecal sterols and bile acids were determined for pig, horse, cow, and chicken feces. Ten to twenty-six fresh fecal samples were collected for each animal, and the concentrations of fecal sterols (coprostanol, epicoprostanol, cholesterol, cholestanol, stigmastanol, and stigmasterol) and bile acids (lithocholic acid, deoxycholic acid, cholic acid, chenodeoxycholic acid, ursodeoxycholic acid, hyodeoxycholic acid) were determined using a gas chromatography and mass spectrometer (GC-MS) technique. Correlation study was performed among sterol and bile acid variables for selected animals, and a ratio (cholesterol + epicoprostanol)/(deoxycholic acid + chenodeoxycholic acid + hyodeoxycholic acid) has been proposed as an indicator for assessing fecal input. The levels of (cholesterol + epicoprostanol)/(deoxycholic acid + chenodeoxycholic acid + hyodeoxycholic acid) in horse, cow, chicken and pig were observed 3.258?±?1.191, 1.921?±?1.006, 1.013?±?0.726, and 0.205?±?0.119 respectively and the ratio of horse: cow: chicken: pig was 16: 9: 5: 1. This ratio suggests the potential of sterol and bile acid biomarkers in identifying sources and occurrence of fecal matter. While additional work using polluted water (as opposed to fresh fecal samples) as well as multiple pollution sources are needed to investigate the transport of these biomarkers into water bodies.  相似文献   

The control of floating macrophytes by grass carp in net cages: experiments in two tropical hydroelectric reservoirs          下载免费PDF全文

Fernando D Domingues  Fernando L R M Starling  Clarice C Nova  Bruna R Loureiro  Leonardo C e Souza  Christina W C Branco 《Aquaculture Research》2017,48(7):3356-3368

The efficiency of grass carp (Ctenopharyngodon idella Val.) for biological control of floating aquatic macrophytes in net cages was assessed in two eutrophic tropical hydroelectric reservoirs through experiments using three macrophyte species (Eichhornia crassipes, Pistia stratiotes and Salvinia auriculata). A total of twenty experiments were performed in these reservoirs with a duration period between 21 and 30 days, during distinct seasons of the year. Sets of experiments were conducted using the three macrophyte species simultaneously in both reservoirs, and additional experiments were performed in one reservoir involving the separate use of each species. All macrophytes demonstrated significant growth in the absence of fish with total per day biomass increase rate ranging from 0.06 to 17.00%. The presence of grass carp significantly reduced macrophyte biomass in both reservoirs independent of fish size, stocking rate and available cage space. In all seasons, grass carp grazing pressure was higher for S. auriculata and lower for P. stratiotes. The results show that grass carp in net cages was able to use aquatic macrophytes as the only food source, controlling massive plant growth (especially S. auriculata and E. crassipes). Fish cages, already implemented in several reservoirs in Brazil, are easily manageable units at relatively low cost. Thus, biocontrol of macrophytes using caged grass carp is proposed as an effective low‐budget ecotechnological tool to control consumable plants while avoiding the removal of desirable aquatic vegetation and the resultant impact on local fauna.  相似文献   

Tartaric acid induces toxicity in Madin–Darby canine kidney cells,but not human kidney-2 cells in vitro,and is prevented by organic anion transporter inhibition and human OAT-4 transfection     

Sean R. Coyne  Greg M. Landry PhD  DABT 《Journal of Veterinary Emergency and Critical Care》2023,33(3):298-304

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