Eight endophytic isolates assigned to Pseudomonas, Azospirillum, and Bacillus genera according to pheno-genotypic features were retrieved from barley seeds under selective pressure for nitrogen-fixers. Genetic relationships among related isolates were investigated through RAPD. Six isolates displayed nitrogen-fixing ability, while all could biosynthesize indolacetic acid in vitro and showed no ...

Survival of pathogens in soil and water.................................... 232 Symbiosis and antibiosis ........................... 235 Antagonistic effects of bacteria..................................... 241 Spore-forming bacteria..................................... 243 Non-spore-forming bacteria..................................... 245 Actinomycetes..................................... 249...

the effect of eight cucumis l. (cucurbitaceae) genotypes, including native cucumber genotypes (hormozgan, bushehr and gilan), greenhouse cucumber genotypes (girtap, negeen, sepehr and pouya) and armenian cucumber (cucumis melo var. flexuosus) was studied on the life table and population growth parameters of aphis gossypii glover to evaluate antibiosis resistance. the experiment was conducted at...

Switching by parasites to novel hosts has profound effects on ecological and evolutionary disease dynamics. Switching requires that parasites are able to establish contact with novel hosts and to overcome host defenses. For most host-parasite associations, it is unclear as to what specific mechanisms prevent infection of novel hosts. Here, we show that parasitic fungal species in the genus Esco...

Switchgrass, Panicum virgatum L., is a perennial warm-season grass that has been identified as a model species for the development of bioenergy crops in the United States. The objectives of this research were to evaluate selected switchgrass populations for host suitability and differential resistance to potential aphid pests, determine the categories (antibiosis, antixenosis, and/or tolerance)...

new sources of maize resistance to the maize weevil, sitophilus zeamais infestation are indispensable in successful breeding programs against post harvest grain damage. the study investigated the characters and mechanisms that confer resistance to weevil infestation using twenty elite maize genotypes. detailed morphological and physical studies were conducted on whole-maize grain. the grain hul...