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1.
Twenty-eight Egyptian cotton (Gossypium barbadense L.) genotypes (varieties and hybrids) were used for analysis of genetic diversity using DNA based markers (ISSR, SSR, and EST) and to study varietal development of cotton. The ISSR markers gave the highest percentage of polymorphic bands as well as polymorphic information content compared with the other molecular markers (i.e. EST and SSR markers). Using clustering analysis, no general clustering according to the pedigree history of the genotypes was observed. Using principal coordinate analysis (PCOORDA), cotton genotypes were separated by the first three principal coordinates (PC1, PC2, and PC3) accounting for 11.5, 8.6, and 7.2% of the total genetic variance, respectively. The cotton genotypes were distributed into three parts based on the first PC, each part containing a group of varieties having a common ancestor. ‘Giza 12’ variety was the common ancestor for the varieties included in the first part and ‘Ashmouni’ variety was the common ancestor for the varieties included in the second part, while both ‘Sakha 3’ and ‘Sakha 4’ varieties were common ancestors for the varieties included in the third part. The results of the PCOORDA also showed better resolution of the genetic diversity than cluster analysis especially in the illustration of the varietal development of cotton. That means that principal coordinate analysis can be strongly used either alone or in combination with cluster analysis to discuss both genetic diversity and varietal development in the cotton genotypes.  相似文献   
2.
In the spring of 2012, symptoms of a disease resembling citrus blast and citrus black pit were observed in some orchards in Tunisia. The epidemic spread rapidly in the following years. Twenty‐four commercial citrus orchards from four Tunisian regions showing characteristic symptoms of bacterial diseases were surveyed during a 3‐year study. Eighty‐eight Pseudomonas‐like bacterial isolates were successfully obtained from the northeast and west of Tunisia. No isolates were recovered from the central region. Overall, 46 isolates were identified as Pseudomonas syringae pv. syringae and most of them showed similar phenotypic and genetic profiles. The virulence of three selected isolates differed from one plant cultivar to another as well as from the type of plant organ used for the inoculation. In a bioassay test, all isolates produced syringomycin, which was confirmed by molecular detection based on the syrB and syrD genes. Only EC122 possessed syrD but not syrB. DNA fingerprints, based on repetitive sequence‐based polymerase chain reaction (rep‐PCR) and PCR melting profile (PCR MP), were used to determine the potential genetic diversity among strains. Clustering of PCR MP fingerprinting data matched with rep‐PCR fingerprinting data. The generated distribution tree showed that Tunisian isolates were closely related to the citrus reference strain LMG5496. In contrast, EC112, isolated from citrus, and the almond isolate EC122 were distantly related to the type strain LMG1247T isolated from lilac. Such studies have not been reported until now for P. syringae from citrus.  相似文献   
3.
Phospholipids and wheat gluten blends: interaction and kinetics   总被引:1,自引:0,他引:1  
A model system comprising of lysophosphatidylcholine (LPC) and isolated gluten were used help understand the positive effect of PL on bread-loaf volume. The kinetics of the effect of gluten on the thermal properties of LPC were determined using DSC. Blends of PL and 3, 6, and 10% gluten were heated from 0 to 70 °C at rates between 3 and 19 °C/min and cooled to 0 °C. The onset and peak temperatures and ΔH were recorded. The peak temperature was used to calculate the activation energy (Ea) and Z value. The transition for pure LPC vesicle formation was detectable by DSC in the presence of gluten. Gluten increased the activation energy of LPC during vesicle formation and disruption. The increase in gluten content from 3 to 6% and then to 10% had a slight effect on the activation energy value of LPC during vesicle disruption, whereas during formation a steady increase was noticed with higher gluten additions. Overall, the ΔH of the blends showed a decrease at higher heating rate. The change in the PL activation energy in the presence of gluten is indicative of a form of interaction.  相似文献   
4.
Two commercial broiler pure lines that were previously identified to differ in their susceptibility to Marek's disease (MD) were line-crossed to generate an F1 population. Eight F1 males were randomly mated to four or five F1 females to produce an F2 test population that would be segregating for genes affecting MD. All F2 progeny (four hatches) were pedigreed at hatch and placed in colony houses as nonvaccinated. At 5 days of age, they were challenged intraabdominally with MD virus RB1B. Clinical signs, mortality, and gross and microscopic lesions were recorded during the MD challenge. At 8 wk postchallenge, all remaining birds were euthanatized and necropsied. During the MD challenge of the first two hatches, we observed that several severely stunted broilers originated from certain families and the differences in body weight among birds appeared as early as 3 wk postchallenge. To confirm this observation, body weight at 6 wk postchallenge was determined for all surviving birds in hatches 3 and 4 (n = 242). Genetic variation in body weight among broiler sire families was apparent; the average body weight for males at this time was 2.07 kg, whereas with females, it was 1.87 kg. At least 12.2% of the broilers, including both sexes, weighed less than 1 kg ("severely stunted") at this time. The incidence of these growth-stunted birds within each broiler sire family ranged from 0 to 26% and for dam families, 0 to 60%. Correlation analyses between stunting and other MD-associated traits revealed that the incidence of stunting had a significant and positive association with paralysis (r = 0.50). Therefore, the data suggest that there may be a genetic component affecting body weight loss during MD infection. The genetic component is speculated to affect susceptibility to MD paralysis with an indirect effect on the body weight of birds. The significance of this finding is best exemplified by the identification of a broiler sire family with over 26% of its progeny affected by this MD-associated trait.  相似文献   
5.
1. The study was on a population of the Egyptian local strain Dandarawi. Hatching records were obtained from three lines over two generations (1996 and 1997). Sex ratios were calculated using a total of 5,822 1-d-old chicks. 2. Sex could be identified at hatch by down colour. Female chicks showed a black spot on the head or irregular strips on the back, whereas males had no marks on head and back. At 8 weeks of age, progeny could be easily sexed by feather colour, which was black and white for males and brown for females. The sexual dimorphism in feather colour at that age is due to the presence of the autosomal recessive wild type allele CO*N. Accuracy for autosexing at hatching time was 89-02% for males and 92-42% for females. 3. Sex ratio deviated significantly from the expected value, 1:1, in one line (line E) where the number of female chicks exceeded that of males, over the two generations. Chicks of both sexes exhibited the same survival rate up to 8 weeks of age.  相似文献   
6.
Journal of Soils and Sediments - Tailings are generally characterized by severe physicochemical conditions that limit the establishment of vegetation. The present study aimed to select suitable...  相似文献   
7.
Studies of the amino acids distribution in plants subjected to nutrient regimes are limited. The present study investigated the effect of NO3‐N and FeSO4‐Fe regimes on chlorophyll and total amino acids composition of tomato and wheat plants. Also the distribution of 17 amino acids between the different plant parts was studied. Increasing the NO3‐N level up to 200 mg kg‐1 greatly increased the total amino acids content of tomato plants. The total amino acids content of wheat plants continued to increase with addition of NO3‐N up to 400 mg kg‐1. The response of chlorophyll content to NO3‐N supply was highly dependent on Fe level both in tomato and wheat plants. The interaction between NO3‐N and FeSO4‐Fe had a great effect on the total amino acids content and distribution. Iron increased the translocation of proline from roots to leaves. The overall amino acids contents of leaves was higher than that of stems or roots.  相似文献   
8.
This work is aimed at characterizing compost maturity and, organic matter transformation during this process, by the use of nondestructive spectroscopic and thermal techniques, together with some chemical analysis. Composting was conducted in a laboratory over a period of one year using the organic fraction of domestic wastes, fresh farmyard manure, spent coffee and sawdust as the raw materials. Samples were retired after different periods of composting and were analyzed by differential scanning calorimetry (DSC) and fourier transform infrared (FTIR) spectroscopy as well as by routine chemical parameters including temperature, pH, C/N, ash content and humic-like substances content. Results showed that in case of domestic wastes, spent coffee and farmyard manure, the C/N ratios, ash and humic acid content showed a typical high rate of change during the first 197 days of composting and tended to stabilize thereafter, probably as a result of the maturity of the produced composts. In contrast, sawdust underwent only a very limited transformation even after one year of composting. Thermoanalytical and spectroscopic data confirms these finding and gives useful and complementary information with respect to the structure, the heterogeneity and the relative stability of the compost products. In particular, as the decomposition proceeded, there was an increase in aromatic to aliphatic structure ratio and a decrease in the importance of peptide structures of composts. Besides, both the spectroscopic and the thermal behavior of compost samples, retired beyond 197 days of composting, tended to be regular, less dependent on the raw material and close to that characterizing mature composts, with the exception of sawdust samples. We concluded that the spectroscopic and thermal techniques used are complementary to one another and to chemical tests and could be a powerful and fast approach for the study of compost maturity.  相似文献   
9.
The aqueous alcohol-soluble fraction of wheat gluten is gliadin. This component has been implicated as the causative principle in celiac disease, which is a physiological condition experienced by some infants and adults. The outcome of the ingestion of whole wheat products by susceptible individuals is malabsorption of nutrients resulting from loss of intestinal vili, the nutrient absorption regions of the digestive system. This leads to incessant diarrhea and weight loss in these individuals. Only recently has this health condition been properly recognized and accurately diagnosed in this country. The culprit gliadin is characterized by preponderant glutamine side-chain residues on the protein surface. Gliadin is commercially available as a wheat gluten extract, and in our search for new biobased and environmentally friendly products from renewable agricultural substrates, we have exploited the availability of the glutamine residues of gliadin as synthons to produce novel elastomeric nonfood products dubbed "milkglyde", "saliglyde", and soyglyde from milkweed, salicornia and soybean oils. The reaction is an amidolysis of the oxirane groups of derivatized milkweed, salicornia, and soybean oils under neat reaction conditions with the primary amide functionalties of glutamine to give the corresponding amidohyroxy gliadinyl triglycerides, respectively. The differential scanning calorimetry, thermogravimetric analyses, and rheological data from a study of these products indicate properties similar to those of synthetic rubber.  相似文献   
10.
Fusarium culmorum is a major pathogen able to cause foot and root rot and the incitant of Fusarium head blight in wheat in Tunisia. The aims of the present study were to evaluate by PCR the type of mycotoxins produced, to determine the mating type and to analyse the genetic diversity by microsatellite markers of 82?F. culmorum isolates recovered from two separated Tunisian fields. Specific sequences in the Tri6-Tri5 intergenic region, Tri7 and Tri13 were used to identify 3-AcDON- or 15-AcDON-. All studied F. culmorum isolates, were of the 3-AcDON- type. No 15-AcDON- and NIV types were detected in this research. Both mating types MAT1-1 and MAT1-2 were recovered from the two fields in approximately equal proportions. Five polymorphic microsatellite markers were applied to F. culmorum isolates, to determine the genetic variation in and among populations. Sixty-four haplotypes were identified; the analysis of the population structure did not reveal a strong variation between fields. Total gene diversity (H T ?=?0.505; H S ?=?0.497) and analysis of molecular variance confirmed that most of the genetic variability was within populations (Φ ST ?=?0.033; P?<?0.0039). Gene flow (N m ?=?31.05) indicated little differentiation among populations. Based on these results, the F. culmorum isolates collected from different fields might be part of one large panmictic population and in addition the low linkage disequilibrium values with high genetic variation within populations suggest that the population is recombining sexually.  相似文献   
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