Phylogenetic position of the disjunct species <Emphasis Type="Italic">Musa ornata</Emphasis> (Musaceae): first approach to understand its distribution     

Mireya Burgos-Hernández  Dolores González  Gonzalo Castillo-Campos 《Genetic Resources and Crop Evolution》2017,64(8):1889-1904

Musa L. commonly known as the banana group is one of the most important and oldest food crops of humankind. Among the wild relatives with ornamental interest in the genus, Musa ornata Roxb. shows a disjunct distribution between Asia and North America (Mexico). The wild occurrence of this species in Mexico has led to speculation about the evolutionary relationships with its Asian relatives. This study examined the phylogenetic relationships between intercontinental specimens of this species and, based on registered evidence, explored the more likely hypothesis about the origins of its distribution. The phylogeny of intercontinental specimens, along with other representatives of the same genus, was carried out using three molecular markers (ITS, trnL-F, and atpB-rbcL) and applying three phylogenetic reconstruction methods: maximum parsimony, maximum likelihood, and Bayesian inference. The genetic analysis of the combined dataset grouped together all the Mexican and most Asian specimens, but the monophyly of the species was not supported. The relationships suggest that Mexican populations may have originated from an Asian invasion. However, several studies and historical documents suggest the presence of Musa in America long before the arrival of Europeans. Based on its current distribution, phylogenetic evidence, and fossil record, this species’ disjunct distribution could be explained in terms of an ancestral distribution range that encompassed America and Asia, followed by its subsequent restriction to the Old World and a secondary dispersal by humans. However, further studies are necessary to shed more light on the origins of this disjunct distribution.  相似文献   

Physicochemical, Rheological and Structural Characteristics of Starch in Maize Tortillas     

Juan P. Hernández-Uribe  Gonzalo Ramos-López  Hernani Yee-Madeira  Luis A. Bello-Pérez 《Plant foods for human nutrition (Dordrecht, Netherlands)》2010,65(2):152-157

Fresh and stored maize (white and blue) tortillas were evaluated for physicochemical, rheological and structural characteristics assessed by calorimetry, x-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, dynamic viscoelastic tests, and high-performance size-exclusion chromatography. Two endotherms were found in studies of fresh and stored tortillas. The low temperature endotherm (50–56 °C) was due to reorganized (retrograded) amylopectin, while the high temperature endotherm (105–123 °C) was attributed to retrograded amylose. The enthalpy value for the lower temperature transition was minor than that of the high temperature transition. Fresh tortillas showed an amorphous starch arrangement by x-ray diffraction study. Stored samples showed the presence of peaks at 2θ = 17o and 23o, indicating re-crystallization of starch components. FTIR results confirmed the development of higher levels of starch crystals during storage. Differences in the viscoelastic parameters were also observed between fresh and stored samples. At the longest storage times, white tortillas were more rigid than blue tortillas. Molar mass values for starch increased for both white and blue tortillas as storage time progressed, though relatively higher values were obtained for white tortillas. More starch reorganization occurred in white tortillas, in accordance to calorimetric, x-ray diffraction, FTIR and rheological results. These results corroborate that changes occurring in tortillas during storage are related to reorganization of starch components, and the maize variety more than the color plays an important role.  相似文献   

Evidence that active transmission of porcine cysticercosis occurs in Venezuela     

Cortez Alcobedes  Maria M.  Boggio  Gonzalo  Guerra  Ma. de Lourdes  de Gavidia  Magda Rodríguez  Rojas Reyes  Glenda C.  Ferrer  Elizabeth  Lares  Maria  Alviarez  Yenny  Harrison  Leslie J. S.  Parkhouse  R. Michael E. 《Tropical animal health and production》2010,42(3):531-537

There is a paucity of quantitative data on the status of porcine cysticercosis in Venezuela, information which is essential for understanding the level of disease transmission. This study was, therefore, conducted in a typical small rural community in Yaracuy State, Venezuela, where previous cases of human Taenia solium taeniasis/cysticercosis had been reported and where the free-ranging pig management practices and the lack of rudimentary sanitary facilities indicated an obvious risk for transmission of the disease. Serum samples from 52 village pigs were screened by enzyme-linked immunosorbent assays for anti-cysticercal antibodies (Ab-ELISA), using T. solium cyst fluid as the antigen and the HP10, monoclonal antibody-based, antigen trapping ELISA for parasite antigen (HP10 Ag-ELISA). Significantly, a high proportion of the animals (65.4% for the Ab-ELISA and 42.3% for the HP10 Ag-ELISA) were sero-positive. Five of the pigs, which were selected on that basis of positive tongue palpation, were killed for autopsy, and large numbers of viable cysticerci were found in the carcases. This unequivocal documentation of porcine cysticercosis in Venezuelan pigs presents clear evidence that T. solium is actively transmitted in Venezuela. Further detailed studies and implementation of appropriate control measures are therefore indicated.  相似文献   

Effect of additives on subcritical water hydrolysis of whey protein isolate     

Espinoza AD  Morawicki RO 《Journal of agricultural and food chemistry》2012,60(20):5250-5256

The objective was to examine the effect of the additives acetic acid, lactic acid, sodium bicarbonate, sodium chloride, and sodium hydroxide on the hydrolysis of whey protein isolate with subcritical water. A screening experimental design was used to study the effect of temperature, time, and additives. The most influential additive, sodium bicarbonate, along with temperature and time was used in a second experimental design to predict the treatment conditions to maximize the degree of hydrolysis and production of free amino acids. The maximum degree of hydrolysis achieved was 50% at a concentration of 1.24 M sodium bicarbonate, 291 °C, and 28 min. The highest concentration of total amino acids was 83.0 mg/g of whey protein isolate with 0.83 M sodium bicarbonate at 264 °C for 29 min. Compared to water alone, sodium bicarbonate increased the degree of hydrolysis 4-fold and the production of amino acids by 44% and decreased peptides' molecular weight.  相似文献   

A tissue culture method for the rapid propagation of potatoes     

W. M. Roca  N. O. Espinoza  M. R. Roca  J. E. Bryan 《American Journal of Potato Research》1978,55(12):691-701

A tissue culture method for the rapid propagation of potatoes was studied using 38 varieties. At least 50 plantlets were regeneratedin vitro, in a sequential procedure, from a single isolated shoot tip. Rapid proliferation of shoots was enhanced by shake culture of previously differentiated organogenic cultures. These shoots in turn were used to regenerate complete plantlets by the culture of nodal sectionsin vitro. Culture initiation was more dependent on the variety than culture proliferation. The culture media contained the Murashige-Skoog basal components supplemented with 6-benzylaminopurine, gibberellic acid and naphthalene acetic acid. The system described, whereby high propagation rates can be achieved, was referred to as “multi-meristem” culture in contrast to the 1:1 rate normally obtained by the conventional, “single-meristem” culture. Evaluations of varietal stability, using both biochemical and morphological criteria showed no detectable changes due to thein vitro procedures. It is proposed to utilize the “multi-meristem” propagation technique for the conservation and international distribution of valuable clonal germplasm.  相似文献   

Antioxidant activity of uruguayan propolis. In vitro and cellular assays     

Silva V  Genta G  Möller MN  Masner M  Thomson L  Romero N  Radi R  Fernandes DC  Laurindo FR  Heinzen H  Fierro W  Denicola A 《Journal of agricultural and food chemistry》2011,59(12):6430-6437

The antioxidant capacity of propolis from the southern region of Uruguay was evaluated using in vitro as well as cellular assays. Free radical scavenging capacity was assessed by ORAC, obtaining values significantly higher than those of other natural products (8000 μmol Trolox equiv/g propolis). ORAC values correlated well with total polyphenol content (determined by Folin-Ciocalteu method) and UV absorption. Total polyphenol content (150 mg gallic acid equiv/g propolis) and flavonoids (45 mg quercetin equiv/g propolis) were similar to values reported for southern Brazilian (group 3) and Argentinean propolis. Flavonoid composition determined by RP-HPLC indicates a strong poplar-tree origin. Samples high in polyphenols efficiently inhibit low-density lipoprotein lipoperoxidation and tyrosine nitration. In addition, Uruguayan propolis was found to induce the expression of endothelial nitric oxide synthase and inhibit endothelial NADPH oxidase, suggesting a potential cardiovascular benefit by increasing nitric oxide bioavailability in the endothelium.  相似文献   

Vaccination of one-day-old broiler chicks against infectious coryza     

Conde MD  Huberman YD  Espinoza AM  Delgado RI  Terzolo HR 《Avian diseases》2011,55(1):119-122

In order to evaluate the protection conferred by an experimental inactivated vaccine against infectious coryza, three challenge trials were undertaken using 112 1-day-old broilers. The vaccine "Hepa Inmuno NC" included bacterial antigens of Avibacterium paragallinarum (serogroups A, B, variant B, and C) as well as antigens of Newcastle virus and hepatitis virus. Fifty-six broiler chicks were vaccinated at the first day of life at the hatchery while another 56 chicks were left unvaccinated. Three infection trials were conducted simultaneously using each of the three serogroups A, B, or C of Av. paragallinarum. In each trial, 17 vaccinated and 17 unvaccinated broilers were used. Challenge was performed at day 31 of life by injection, into the left infraorbital sinus, of approximately 1 x 10(5) colony forming units of the corresponding Av. paragallinarum strain. Clinical signs were recorded on day 2 postchallenge. All broilers were euthanatized and both infraorbital sinuses were bacteriologically examined for the presence of Av. paragallinarum on day 5 postchallenge. In comparison with the unvaccinated broilers, the vaccine significantly reduced the number of broilers with clinical signs after challenge with serogroup B, and significantly fewer vaccinated broilers were positive for the presence of Av. paragallinarum after challenge with serogroup C. On the other hand, no significant protection was observed when broilers were challenged with Av. paragallinarum from serogroup A. Despite the high infection rates in vaccinated chicks after an experimental infection with Av. paragallinarum, it was possible to reduce colonization of Av. paragallinarum (serogroup B) and clinical signs (serogroup C) in broiler chicks by vaccination at the first day of life. Further cross-protection trials should be done, including other Av. paragallinarum strains in the vaccine, especially those from serogroup A.  相似文献   

ADVANCES IN DIAGNOSIS OF IRON DEFICIENCY IN AVOCADO     

Alexander Neaman  Gonzalo Espinoza 《Journal of plant nutrition》2013,36(1):38-45

Several methods for determination of extractable iron (Fe; or so-called “active Fe”) have been proposed. In this study, three methods of Fe extraction were tested: 1.5% phenanthroline (pH 3) and 1 M hydrochloric acid (HCl) from fresh leaves, and 1 M HCl from oven-dry leaves. A six-year-old avocado orchard (cultivar ‘Hass’), grown on a calcareous soil in the proximity of Cabildo (Valparaíso region, Chile), was selected for the study. Samples of mature (5–7 moths-old) leaves of different degree of chlorosis were collected. Total Fe concentrations in chlorotic leaves were similar or even greater than in green leaves. Regressions between the extractable Fe concentrations and the leaf SPAD-color were statistically significant for phenanthroline method, while non-significant for HCl methods. Thus, phenanthroline method was superior over others for diagnosis of Fe deficiency in avocado. Phenanthroline-extractable Fe concentration of 6 mg kg^?1 was considered as a critical value for mature avocado leaves.  相似文献   

Errata     

W. M. Roca  N. O. Espinoza  M. R. Roca  J. E. Bryan 《American Journal of Potato Research》1979,56(3):175-175

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A new vision-based approach to differential spraying in precision agriculture   总被引：4，自引：0，他引：4  

Alberto Tellaeche  Xavier P. BurgosArtizzu  Gonzalo Pajares  Angela Ribeiro  Csar Fernndez-Quintanilla 《Computers and Electronics in Agriculture》2008,60(2):144-155

One of the objectives of precision agriculture is to minimize the volume of herbicides by using site-specific weed management systems. To reach this goal, two major factors need to be considered: (1) the similarity of spectral signatures, shapes, and textures between weeds and crops and (2) irregular distribution of weeds within the crop. This paper outlines an automatic computer vision method for detecting Avena sterilis, a noxious weed growing in cereal crops, and differential spraying to control the weed. The proposed method determines the quantity and distribution of weeds in the crop fields and applies a decision-making strategy for selective spraying, which forms the main focus of the paper. The method consists of two stages: image segmentation and decision-making. The image segmentation process extracts cells from the image as the low-level units. The quantity and distribution of weeds in the cell are mapped as area and structural based attributes, respectively. From these attributes, a multicriteria decision-making approach under a fuzzy context allows us to decide whether any given cell needs to be sprayed. The method was compared with other existing strategies.  相似文献