Transformation and transduction to tryptophan independence of strains of Bacillus subtilis carrying the "trpE26" chromosomal aberrations (a translocation and an inversion) with a "normal" 168 type strain as donor induce a tandem duplication of the thrA-ilvA region of the chromosome. The clones possessing this unstable duplication segregate besides the Trp- some stable Trp+ cells which retain on...

The occurrence of polyandry in Planococcuscitri, presumed by earlier observations of mating behavior, was confirmed using microsatellite genotyping of pools of over 400 eggs resulting from controlled crosses of one female with two males. The genetic contribution of both mated males was confirmed in 13 out of 43 crosses. In three crosses it was possible to determine that only the first male fert...

Sunn pest is one of the most important cereal pests that affect both grain yield and quality of cerealin Iran. One potential control strategy is to use entomopathogenic fungi such as Beauveriabassiana Vuillemin as mycoinsecticide to control this pest. Naturally infested Sunn pests inKermanshah province were collected and brought to laboratory. 10 isolates were selected forfurther analysis in th...

Somaclonal variation, aneuploidy, and genotypic specificity are major limitations of anther culture and bread wheat x Hordeum bulbosum crosses for producing haploids (n=3x=21, ABD). Sexual combinations of wheat x Zea mays have since emerged as an alternate and significant procedure as wheat genotypic specificity does not exist. This procedure has been refined and simplified over the last decade...

The ubiquitous environmental human pathogen Cryptococcus neoformans is traditionally considered a haploid fungus with a bipolar mating system. In nature, the alpha mating type is overwhelmingly predominant over a. How genetic diversity is generated and maintained by this heterothallic fungus in a largely unisexual alpha population is unclear. Recently it was discovered that C. neoformans can un...

The genus Saccharomyces consists of several species divided into the sensu stricto and the sensu lato groups. The genomes of these species differ in the number and organization of nuclear chromosomes and in the size and organization of mitochondrial DNA (mtDNA). In the present experiments we examined whether these yeasts can exchange DNA and thereby create novel combinations of genetic material...

Diploids of the yeast Hansenula wingei are nonagglutinative and do not form zygotes in mixed cultures with either sexually agglutinative haploid mating type. However, a low frequency of diploid x haploid cell fusions (about 10(-3)) is detectable by prototrophic selection. This frequency of rare diploid x haploid matings is not increased after the diploid culture is induced for sexual agglutinat...

ninety barley doubled haploid lines originated from crossing between six barley cultivars in cereal research department, seed and plant improvement institute, karaj, iran were evaluated for resistance to powdery mildew and some agronomic traits in field in 2007. six parent cultivars and a powdery mildew susceptible check cultivar, afzal were also included. sixty two doubled haploid lines showed...

sunn pest is one of the most important cereal pests that affect both grain yield and quality of cerealin iran. one potential control strategy is to use entomopathogenic fungi such as beauveriabassiana vuillemin as mycoinsecticide to control this pest. naturally infested sunn pests inkermanshah province were collected and brought to laboratory. 10 isolates were selected forfurther analysis in th...