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101.
Wide distribution of Nitzschia navis-varingica, a new domoic acid-producing benthic diatom found in Vietnam 总被引:2,自引:0,他引:2
102.
103.
Mihiretu Cherinet Hundayehu ;Elsa Du Toit ;Sunette Laurie ;Martin Steyn ;Ria Greyling ;Nokuthula Myeza 《农业科学与技术》2014,(10):811-821
The aim of this study was to assess the effect of long-term in vitro sub-culturing on the varietal degeneration of three sweet potato varieties, namely, Monate, Mokone and Ndou which were sub-cultured for 32, 23 and 12 generations, respectively. Each generation was cultured in a media which is made from 4.43 g/L Murashige and Skoog (MS), 30 g/L sucrose and 2 g/L gelrite, respectively, and grown under 16 h light and 8 h dark photoperiod for 30 d. For each generation, 45 plantlets were acclimatized for two months in a glasshouse. Data on in vitro growth performance and 11 morphological characteristics during acclimatization were recorded. Early root and shoot formation was observed after the 27th and 21st sub-cultured generations of Monate and Mokone, respectively. During acclimatization, plantlets from the same variety showed differences in morphological traits such as leaf colour, abaxial leaf pigmentation, vine pigmentation, petiole pigmentation, leaf wrinkling and flowering. However, the rate of these morphological differences is random and irrespective to increase in sub-culturing. Therefore, to understand the genetic base of these morphological variability, two plantlets from each variety were subjected to genetic analysis by using five simple sequence repeat (SSR) primers (IB-242, IB-318, IB-255F, 1B-248 and IB-255). Although SSR loci IB-255F and IB-318 could distinguish between the three varieties, there were no allelic polymorphisms detected in plantlets from the same varieties. Therefore, long-term sub-culturing do not leads to quality degeneration in the three sweet potato varieties. 相似文献
104.
Breeding barriers between the cultivated strawberry, Fragaria × ananassa, and related wild germplasm 总被引:1,自引:0,他引:1
Arias E. Marta Elsa L. Camadro Juan C. Díaz-Ricci Atilio P. Castagnaro 《Euphytica》2004,136(2):139-150
Five-hundred interspecific and intergeneric crosses were performed among accessions of the wild strawberries Fragaria vesca(2x), Duchesnea indica (8x), Potentilla tucumanensis (2x) and 9 genotypes of the cultivated strawberry, Fragaria×ananassa (8x), following an incomplete diallele mating design. Crosses between D. indica and F.×ananassa produced many putative hybrids when D. indica was used as female but a few achenes and plants when used as male; therefore, pollen-pistil compatibility relations were
analyzed by fluorescence microscopy in this direction of the cross. Of the genotypic combinations, 78.6% were incompatible
at the stigma level and 17.2% at the first third of the style. Only 3.6% were pollen-pistil compatible and produced fruits
with achenes (seven did not germinate or originated short-lived plants and nine produced normal plants). F.vesca×F.×ananassa crosses produced 35 hybrid achenes but only 14% germinated, yielding short-lived plants; histological analyses revealed that
inviable seeds had less developed (or collapsed) endosperms and smaller embryos than control plump F. vesca seeds. P.tucumanensis was only used as male, with negative results. These species and genera are partially isolated by a complex system of pre-
and post-zygotic barriers. Knowledge of their nature would allow the breeder to devise strategies to put the genetic variability
available in the group into a useful form.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
105.
Beltran E Fenet H Cooper JF Coste CM 《Journal of agricultural and food chemistry》2000,48(9):4399-4403
A kinetic study of the chemical hydrolysis of isoxaflutole [5-cyclopropyl-4-(2-methanesulfonyl-4-trifluoromethylbenzoyl)is oxazol e (IFT)], a new herbicide recently developed by Rh?ne-Poulenc Agro, in buffered, sterile aqueous solutions was carried out in the dark at 295, 308, and 323 K and at nine pH values between 1.8 and 10.1. Samples were analyzed by HPLC-UV. The decrease in IFT concentration was accompanied by an increase in the concentration of its diketonitrile derivative (DKN). Obeying pseudo-first-order kinetics, isoxaflutole hydrolysis increased with increasing pH and temperature: for 295 K and pH 9.3 the rate of degradation was 100-fold faster than at pH 3.8. Using the Arrhenius equation, the rate constants K(obsd), activation energies E(a), and entropies DeltaS() were calculated, and plotting log(K(obsd)) against pH showed that the effect of pH varied with temperature. According to DeltaS() values the mechanism of the reaction was found to be different with respect to pH range. The benzoic acid derivative, known as a degradation product of DKN in plants, was not detected in the present study. 相似文献
106.
107.
Elsa L. Camadro Luis A. Verde Olga N. Marcellán 《American Journal of Potato Research》1998,75(2):81-85
The basis of low seed set was investigated in a diploid hybrid population with germplasm from the cultivated speciesSolanum tuberosum spp.tuberosum andS. tuberosum ssp.phureja and the wild speciesS. chacoense. Controlled crosses were performed following an incomplete diallel mating design which included the hybrid population and the parental species. Pollen grain germination and pollen tube growth were observed with fluorescence microscopy in 174 intrapopulation and interspecific combinations of genotypes. Fifty percent of the combinations of genotypes within the hybrid population and 46% of those between this population and the parental species were incompatible; overall, 71% of the interspecific combinations of genotypes were compatible when plants of the hybrid population were used as females, vs. 5% when used as males. Although the site of reaction could vary in a given intrapopulation or interspecific cross with the combinations of genotypes, pollen tube inhibition occurred in the first third of the style in 42% of them. Since the gene pool of the hybrid population had been widened with germplasm from other geographic areas and the genotypes ofS. tuberosum ssp.tuberosum, S. chacoense andS. tuberosum ssp.phureja used in this study were not the ones involved in the original crosses, it is concluded that the S-locus is not controlling the incompatibility reaction but rather that a cross-incompatibility system, possibly governed by more than one locus, is acting. 相似文献
108.
Brinch-Pedersen H Hatzack F Stöger E Arcalis E Pontopidan K Holm PB 《Journal of agricultural and food chemistry》2006,54(13):4624-4632
The present paper addresses the question of thermotolerance of in planta synthesized heterologous enzymes using phytase as a model. Two individual transgenic wheat materials expressing an Aspergillus fumigatus phytase with a low denaturation temperature (62.5 degrees C) but a high refolding capacity, and a rationally designed consensus phytase engineered to a high denaturation temperature (89.3 degrees C), were evaluated. High levels of endosperm specific expression were ensured by the wheat high molecular weight glutenin 1DX5 promoter. Immunodetection at the light and electron microscopical level shows unequivocally that the heterologous phytase is deposited in the vacuole, albeit that the transformation constructs were designed for secretion to the apoplast. Evaluation of heat stability properties and kinetic properties unraveled that, under these deposition conditions, heat stability based on high unfolding temperature is superior to high refolding capacity and represents a realistic strategy for improving phosphate and mineral bioavailability in cereal-based feed and food. 相似文献
109.
Kendal Harr John Harvey Robert Bonde David Murphy Mark Lowe Maya Menchaca Elsa Haubold Ruth Francis-Floyd 《Journal of zoo and wildlife medicine》2006,37(2):151-159
Manatees (Trichechus manatus latirostris) are afflicted with inflammatory and infectious disease secondary to human interaction, such as boat strike and entanglement, as well as "cold stress syndrome" and pneumonia. White-blood-cell count and fever, primary indicators of systemic inflammation in most species, are insensitive in diagnosing inflammatory disease in manatees. Acute phase-response proteins, such as haptoglobin and serum amyloid A, have proven to be sensitive measures of inflammation/infection in domestic large animal species. This study assessed diagnosis of generalized inflammatory disease by different methods including total white-blood-cell count, albumin: globulin ratio, gel electrophoresis analysis, C-reactive protein, alpha, acid glycoprotein, haptoglobin, fibrinogen, and serum amyloid A. Samples were collected from 71 apparently healthy and 27 diseased animals during diagnostic medical examination. Serum amyloid A, measured by ELISA, followed by albumin:globulin ratio, measured by plasma gel electrophoresis, were most sensitive in diagnosing inflammatory disease, with diagnostic sensitivity and specificity of approximately 90%. The reference interval for serum amyloid A is <10-50 microg/ml with an equivocal interval of 51-70 microg/ml. The reference interval for albumin:globulin ratio by plasma gel electrophoresis is 0.7-1.1. Albumin: globulin ratio, calculated using biochemical techniques, was not accurate due to overestimation of albumin by bromcresol green dye-binding methodology. Albumin:globulin ratio, measured by serum gel electrophoresis, has a low sensitivity of 15% due to the lack of fibrinogen in the sample. Haptoglobin, measured by hemoglobin titration, had a reference interval of 0.4-2.4 mg/ml, a diagnostic sensitivity of 60%, and a diagnostic specificity of 93%. The haptoglobin assay is significantly affected by hemolysis. Fibrinogen, measured by heat precipitation, has a reference interval of 100-400 mg/dl, a diagnostic sensitivity of 40%, and a diagnostic specificity of 95%. 相似文献
110.
We investigated extraction from soil of glomalin, a glycoprotein produced by arbuscular mycorrhizal fungi, and we examined its measurement. The most commonly used protocols for extracting glomalin require autoclaving of soil in citrate solution, followed by centrifugation to separate the supernatant, and then measurement by either Bradford protein assay or enzyme-linked immunosorbent assay (ELISA). We found that lengthening the time of autoclaving increased easily extractable glomalin extraction. Delay of centrifugation after autoclaving, however, diminished Bradford-reactive substances in the supernatant, suggesting that extracted substances might be reversibly immobilized on soil particles. Surprisingly, increasing the volume of extraction solution did not accelerate extraction of “total glomalin”, but instead, substantially increased the amount extracted. Multiple autoclave cycles nevertheless denature glomalin, which may not be as heat-resistant as thought. Repeated 1-h autoclaving of supernatant diminished both its Bradford-reactive substances (7.3% h?1) and immunoreactive protein (22% during the first hour and 9.5% h?1 of the remainder thereafter), although a large initial volume of extractant could reduce the loss of immunoreactive protein. Proteins and polyphenols that survive the extraction process are measured non-specifically by the Bradford assay. When we added other glycoproteins to dry soils, we recovered a maximum 34% bovine serum albumin and 22% bovine mucin, primarily in the first two, 1-h extraction cycles. These added proteins may adhere to soil organic matter and thereby be protected from denaturation. In addressing the endpoint of glomalin extraction, we found that the Michaelis–Menten equation closely fits cumulative glomalin per extraction cycle such that its asymptote provides an objective estimate of total extractable glomalin for a given set of extraction conditions. Additionally, the equation provides a curvature parameter that reflects the soil-specific efficiency of an extraction protocol. Although the soils that we investigated with 7.6% or more soil organic matter had the most asymptotic total glomalin, they were extracted the least efficiently. 相似文献