Genetic Diversity in Bean Populations Based on Random Amplified Polymorphic DNA Markers

Diversity and nodulation effectiveness of rhizobia and mycorrhizal presence in climbing dry beans grown in Prespa lakes plain, Greece

The Prespa lakes plain is an isolated area where about 1000 ha are seeded to Phaseolus vulgaris L. and Phaseolus coccineus L. Nodulation, arbuscular mycorrhizal fungal (AMF) presence and the genetic diversity of rhizobia were evaluated by 16S-ITS-23S-RFLP patterns and by sequencing. The bean rhizobial population in the region was diverse, despite its geographic isolation. No biogeographic relationships were detected, apart from a Rhizobium tropici-related strain that originated from an acidic soil. No clear pattern was detected in clustering with bean species and all isolates formed nodules with both bean species. Most strains were related to Rhizobium leguminosarum and a number of isolates were falling outside the already characterized species of genus Rhizobium. Application of heavy fertilization has resulted in high soil N and P levels, which most likely reduced nodulation and AMF spore presence. However, considerable AMF root length colonization was found in most of the fields.

Detection of tropical bovine theileriosis by polymerase chain reaction in cattle

Tropical bovine theileriosis, a tick borne disease, caused by, Theileria annulata with marked clinical signs of pyrexia (102-105 °F), enlargement of lymphnodes etc., causes heavy economic losses in terms of high mortality and morbidity rates. Diagnosis of theileriosis is mainly based on clinical symptoms and microscopic examination of stained blood smears and lymph node biopsy smears but limitations of these methods against Theileria sp. limits the specificity. Hence, to overcome the limitations, the present study reports the detection of T. annulata in blood samples of cattle by polymerase chain reaction. The study was conducted on 155 cattle having typical clinical symptoms and blood smear after staining with Giemsa stain was examined for the presence of T. annulata in RBC. The Primer sequences were used as per d'Oliveira et al. The assay employs primers specific for the gene encoding the 30-kDa major merozoite surface antigen of T. annulata and the amplification of 721 bp was done. Out of the total 155 animals, 34 were positive for T. annulata by blood smear method whereas 134 samples were positive by PCR. So diagnosis of blood samples by PCR is found to be the most sensitive and specific methodology as compared to cytological blood smear examination. The sensitivity was 23.88 % and specificity was 90.47 % of blood smear method considering PCR as gold standard and it was found that PCR is more sensitive than the conventional method of examination.