Fourteen strains of nitrogen-fixing bacteria were isolated from different agricultural plant species, including cassava, maize and sugarcane, using nitrogen-deprived selective isolation conditions. Ability to fix nitrogen was verified by the acetylene reduction assay. All potentially nitrogen-fixing strains tested showed positive hybridization signals with a nifH probe derived from Azospirillum...

A RAPD analysis on six species of the rodent genus Oligoryzomys trapped in a wide area (ranging from 01 degrees N to 32 degrees S) of Brazilian territory was performed in order to determine the levels of genetic variability within and between its populations and species. One-hundred and ninety-three animals were collected in 13 different sites (corresponding to 17 samples) located at Pampas, At...

Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) markers were used to evaluate the relative contribution of gene flow as a determinant of the population genetic structure of the wild rodent Calomys musculinus (the reservoir of Argentine hemorrhagic fever [AHF]) in central Argentina. One hundred eighty-seven individuals from 13 populations (9 of them from the endemic zone of...

Genetic variability due to host plants was studied in whitefly, Bemisia tabaci (Genn.), populations that were collected from fields of different crops (cotton, brinjal, potato, tomato and soyabean) and a weed (Sida sp.), and maintained on their respective host plants for 12 generations. Comparative RAPD-PCR analysis of these populations led to identification of 85 different polymorphic bands or...

Helicobacter pylori isolates show greater genetic diversity than other bacterial species studied, but the basis for this phenomenon is unknown. Whether detectable genomic mutation appears within an H. pylori population during persistent colonization was investigated. Paired H. pylori populations obtained across 7- to 10-year intervals from 13 patients were characterized by use of methods includ...

Genetic similarity and polymorphisms among the three Egyptian water buffalo flocks (Beheiry, Minoufy and Saidy) were studied using both random amplified polymorphic DNA (RAPD) and restriction fragment length polymorphism (RFLP) techniques. Ten random primers were used to amplify DNA fragments in these three flocks. RAPD patterns with a level of polymorphism were detected among flocks. The resul...

Thirty-one strains of Acinetobacter species, including type strains of the 18 genomic species and 13 clinical isolates, were compared by amplified ribosomal DNA restriction analysis (ARDRA), random amplified polymorphic DNA analysis (RAPD), and amplified fragment length polymorphism (AFLP) fingerprinting. ARDRA, performed with five different enzymes, showed low discriminatory power for differen...

Little is known about the molecular genetic diversity of most Passiflora species. We used RAPD markers to evaluate the genetic diversity of 24 genotypes of the 'sleep' passion fruit (Passiflora setacea). Twelve primers generated 95 markers, 88% of which were polymorphic. The genetic distance estimated by the complement of the Dice index ranged from 0.29 (among accessions Ps-G1 and Ps-G13) ...

Genetic relationships of 16 cultivars of pigeonpea (Cajanus cajan (L) Millsp.) and its two wild relatives (C. albicans and C. lineatus) from different parts of the India were analysed using 22 random amplified polymorphic DNAs (RAPDs) primers and 10 inter simple sequence repeats (ISSRs) primers. Twenty two RAPD primers yielded 151 polymorphic markers (71.2%) with an average of 6.8 polymorphic b...