No abstract

This work aimed to study the pathogenicity and to investigate the antimicrobial susceptibility and resistance patterns of Helicobacter pullorum (H. pullorum). The minimum inhibitory concentration (MIC) value of ciprofloxacin, ampicillin, gentamycin, erythromycin, colistin sulfate and tetracycline was determined for eight different H. pullorum isolates. H. pullorum resulted into 33.3% mortality of infected chickens with signs of diarrhea, stunted growth and poor conversion rate in survivors. All experimentally infected embryonated chicken eggs showed embryonic mortalities within 48-h post yolk sac inoculation. H. pullorum was re-isolated from cecum, liver, yolk sac and air-sacs of all dead and sacrificed infected chickens. H. pullorum was also re-isolated from dead embryos, embryonic membranes and fluids of infected embryonated chicken eggs. Polymerase Chain Reaction (PCR) assay was used to detect H. pullorum in experimentally infected chickens and embryonated chicken eggs. All tested H. pullorum isolates were resistant to ciprofloxacin, gentamycin and erythromycin, while 7 out of 8 isolates were resistant to tetracycline. All isolates were susceptible to colistin sulfate and ampicillin.

No abstract

Vitamin-C content (VCC) was evaluated in 74 guava landraces using direct titration method with iodine during two seasons. Results showed that the highest value of VCC was 284.0±1.33, while the lowest VCC was 152.83±1.83 with an average of 221.26±3.17 mg/100g fresh weight. Analysis of variance showed the presence of highly significant differences among the tested landraces, as well as the interaction between landraces and seasons. Data of VCC showed normal distribution with high values of both broad sense heritability (0.97) and genetic advance (78.49) indicating high ability for selection. On the other hand, molecular analysis was performed using two molecular markers, i.e. sequence related amplified polymorphism (SRAP) and inter sequence simple repeats (ISSR) to determine unique and specific bands for high or low VCC. SRAP was more informative than ISSR and was able to generate 12 specific bands. Among these bands, 10 bands were specific for bulked DNA of landraces with high VCC, while the other two bands were specific for low VCC. However, ISSR only showed four bands where all of them were specific for low VCC. Results of this study gave good information for genotype selection for high VCC which could be used in guava breeding programs and/or biotechnological approaches. In addition, the specific bands generated by SRAP might assist in rapid screening for genotypes with high VCC, which could be identified in seedling or graft stage, therefore this would save time in a plant with long juvenile period like guava. Furthermore, these bands would be analyzed by sequencing in subsequent studies to locate related genome regions.

No abstract

No abstract

Phenotypic characterization and molecular evaluation were compared in their differentiating influence and quantity of information to assess the genetic diversity in guava. Forty nine genotypes were analyzed phenotypicaly using eleven quantitative traits; out of them ten were selected for the comparison. Analysis of variance showed highly significant differences amongst guava genotypes in all traits except total sugar content. On the other hand, the sequence related amplified polymorphism (SRAP) was used for the molecular analysis. A total of 88 SRAP amplicons were generated by five primer combinations, of which 58 bands (65.9%) were polymorphic. Both cluster analysis of unweighted pair-grouping method with arithmetic averages (UPGMA) and principal coordinate (PCO) analysis based on phenotypic data and SRAP clearly separated the genotypes according to their relationships. However, the clustering arrangement was different depending on the data used for the analysis. In addition, the percentage of polymorphism amongst the tested genotypes varied between the two marker systems. SRAP marker was able to generate some unique specific bands for certain genotypes which could be helpful for further use in guava genetic enhancement.

No abstract