Genetic variability within Phaeoisariopsis griseola from Central America and its implications for resistance breeding of common bean   总被引：1，自引：0，他引：1  

G. S. Mahuku  C. Jara  J. B. Cuasquer  G. Castellanos 《Plant pathology》2002,51(5):594-604

The genetic and virulence variability of 112 isolates of Phaeoisariopsis griseola , collected from various locations in Central America, were studied using seven random amplified polymorphic DNA (RAPD) primers and 12 common-bean differential genotypes. Broad molecular diversity ( H  = 0·92) among isolates was found using RAPD markers. Fifty pathotypes were identified on 12 differential bean genotypes, 29 of which were represented by only one isolate. Only 18 pathotypes were found in two or more countries. Pathotype 63-63 was the most virulent and caused leaf spots on all 12 common-bean differential genotypes. Comparison of virulence phenotypes and RAPD profiles to known Andean P. griseola isolates confirmed that all isolates belonged to the Mesoamerican group. Pairwise comparison between individual RAPD loci showed that the majority were in gametic phase linkage disequilibrium, revealing that P. griseola maintains a genetic structure that is consistent with asexual reproduction. The molecular and virulence diversities of P. griseola isolates from Central America imply that using single resistance genes to manage angular leaf spot is inadequate and stacking resistance genes may be necessary to manage the disease effectively.  相似文献   

Liposome encapsulation and EDTA formulation of dsRNA targeting essential genes increase oral RNAi‐caused mortality in the Neotropical stink bug Euschistus heros     

Nathaly L Castellanos  Guy Smagghe  Rohit Sharma  Eugênio E Oliveira  Olivier Christiaens 《Pest management science》2019,75(2):537-548

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Quantitative trait loci underlying the adhesion of Azospirillum brasilense cells to wheat roots     

José Luis Díaz De León  Thelma Castellanos  Jie Ling  Adriana Rojas-Hernández  Marion S. Röder 《Euphytica》2015,204(1):81-90

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Reply     

Thelma Lee Gross  Thierry Olivry†  Desmond Tobin‡ 《Veterinary dermatology》2001,12(6):352-352

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Carbon stocks in coffee agroforests and mixed dry tropical forests in the western highlands of Guatemala     

Mikaela Schmitt-Harsh  Tom P. Evans  Edwin Castellanos  J. C. Randolph 《Agroforestry Systems》2012,86(2):141-157

Tree removal in Latin American coffee agroforestry systems has been widespread due to complex and interacting factors that include fluctuating international markets, government-supported agricultural policies, and climate change. Despite shade tree removal and land conversion risks, there is currently no widespread policy incentive encouraging the maintenance of shade trees for the benefit of carbon sequestration. In facilitation of such incentives, an understanding of the capacity of coffee agroforests to store carbon relative to tropical forests must be developed. Drawing on ecological inventories conducted in 2007 and 2010 in the Lake Atitlán region of Guatemala, this research examines the carbon pools of smallholder coffee agroforests (CAFs) as they compare to a mixed dry forest (MDF) system. Data from 61 plots, covering a total area of 2.24 ha, was used to assess the aboveground, coarse root, and soil carbon reservoirs of the two land-use systems. Results of this research demonstrate the total carbon stocks of CAFs to range from 74.0 to 259.0 Megagrams (Mg)?C ha^?1 with a mean of 127.6?±?6.6 (SE)?Mg?C ha^?1. The average carbon stocks of CAFs was significantly lower than estimated for the MDF (198.7?±?32.1?Mg?C?ha^?1); however, individual tree and soil pools were not significantly different suggesting that agroforest shade trees play an important role in facilitating carbon sequestration and soil conservation. This research demonstrates the need for conservation-based initiatives which recognize the carbon sequestration benefits of coffee agroforests alongside natural forest systems.  相似文献   

Enhancing rotifer Brachionus calyciflorus population growth with commercial probiotics     

Rubn Alonso Contreras‐Tapia  María Elena Castellanos‐Pez  S. Nandini  Marcela Ivonne Benítez‐Díaz‐Mirn  Gabriela Garza‐Mourio 《Aquaculture Research》2020,51(5):2102-2111

The effect of a commercial probiotic (NanoCrusta, Altacrusta, Mexico City, Mexico) on the growth performance of Brachionus calyciflorus Pallas, 1766, was evaluated. In a first approach, probiotics were supplied in four densities (2.0 × 10³, 1.1 × 10⁵, 2.1 × 10⁵ and 2.1 × 10⁶ cells/ml), alone and in combination with Chlorella vulgaris (1 × 10⁶ cells/ml). The test rotifer did not grow on the probiotic alone. However, when probiotics + C. vulgaris were added, the maximum densities (D_max; ind/ml) and population growth rates (r) observed were higher. In the second experiment, probiotics were supplied at five higher densities (2.1 × 10⁶, 4.2 × 10⁶, 8.5 × 10⁶, 1.7 × 10⁷ and 3.4 × 10⁷ cells/ml) with C. vulgaris and a control treatment with only C. vulgaris (probiotic‐free). Treatments supplied with probiotics between 2.1 × 10⁶ and 1.7 × 10⁷ cells/ml showed significantly higher D_max and r than the control treatment. The results showed a positive effect of probiotic bacteria when supplied with C. vulgaris. The best outcome showed a D_max 2.16 times and an r 1.63 times higher than the density of the control treatment. Growth rates were higher in the treatments with probiotics compared to the control. We conclude that application of NanoCrusta is feasible to improve B. calyciflorus production, but the effects need to be tested in larger scales.  相似文献   

Nutritional characteristics of Cassava (Manihot esculenta Crantz) leaf protein concentrates obtained by ultrafiltration and acidic thermocoagulation     

R. Castellanos  S. B. Altamirano  R. H. Moretti 《Plant foods for human nutrition (Dordrecht, Netherlands)》1994,45(4):357-363

Some nutritional characteristics of cassava (Manihot esculenta) leaf protein concentrates obtained by ultrafiltration were compared with that obtained by acidic thermocoagulation. Protein concentrates did not show noticable differences in their proximal composition and amino acids content. However, higher values of total carotene, available lysine, and in vitro digestibility were found, in contrast with less content of total cyanide in protein concentrates obtained by ultrafiltration. Protein efficiency ratio (PER) values of the leaf protein concentrates obtained by ultrafiltration were higher than those obtained by thermocoagulation, 1.81 and 1.60 respectively. These values increased to 2.30 and 1.90 when the concentrates were mixed with sesame flour, in proportion according to the chemical score of their proteins.  相似文献   

Scientific and moral considerations for live market practices     

Gross TL 《Journal of the American Veterinary Medical Association》2003,222(3):285-288

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POSITIVE-CONTRAST RHINOGRAPHY     

Robert L.  Goring  DVM  James W.  Ticer  DVM  PhD†  Thelma L.  Gross  DVM‡  Norman  Ackerman  DVM† 《Veterinary radiology & ultrasound》1984,25(3):98-105

Contrast rhinography is a simple noninvasive procedure that may be a useful diagnostic method for positive-contrast radiographic evaluation of the nasal cavity, nasopharynx, and paranasal sinuses in the dog. A standardized and reliable technique was developed using healthy adult Greyhounds. The radiographic appearance of the regional anatomy after intranasal administration of positive-contrast medium was established. Four contrast media: 60% propyl iodine, 37% organically bound iodine, a 60% barium sulfate suspension, and a 30% barium sulfate suspension were evaluated on the basis of their radiographic contrast and detail, distribution, and degree of evoked tissue reaction as defined by clinical assessment. A 30% barium sulfate suspension was selected using these criteria. Contrast medium enhanced the radiographic appearance of the regional anatomy when compared with noncontrast techniques. A procedure for positive-contrast radiographic evaluation of the nasal cavity, nasopharynx, and paranasal sinuses is described in detail. Recommendations are made regarding methods of contrast medium administration and positioning to ensure uniform distribution within the area of interest.  相似文献   

Effect of cultivar and growing location on the trypsin inhibitors, tannins, and lectins of common beans (Phaseolus vulgaris L.) grown in the semiarid highlands of Mexico     

de Mejía EG  Guzmán-Maldonado SH  Acosta-Gallegos JA  Reynoso-Camacho R  Ramírez-Rodríguez E  Pons-Hernández JL  González-Chavira MM  Castellanos JZ  Kelly JD 《Journal of agricultural and food chemistry》2003,51(20):5962-5966

Trypsin inhibitors (TI), tannins, and lectins appear to have a role in preventing chronic diseases in humans. The genetic variability of these traits in common bean needs to be ascertained in order to increase levels through breeding. The variability of TI, tannin, and lectins was determined in five bean cultivars grown at five locations in Mexico. TI and tannins contents in colored beans that belong to the Jalisco race were higher (11.1-11.9 trypsin units inhibited (TUI)/mg and 29.0-38.1 mg catechin equivalent (CE)/g, respectively) than cultivars of the Durango race (7.9-8.3 TUI/mg and 16.8-19.9 CE/mg, respectively). Bayo Victoria, a Durango race cultivar, had three times more lectins than levels reported for soybean. Cultivar influenced TI and tannins contents (p < 0.001), whereas site affected lectins (p < 0.001). An increase in levels of TI and tannins could be enhanced through breeding.  相似文献