DNA from 14 Pythium species, Verrucalvus flavofaciens and Zoophagus insidians was characterized by CsCl-bisbenzimide density gradients in order to investigate its taxonomic potential. A few incomplete analyses were made for other species. All clearly assignable Pythium species produced three DNA bands in the gradient. Pythium undulatum along with Verrucalvus and Zoophagus produced only two band...

One of the major field constraints to seed production in safflower has proven tobe soil born pathogens, Phytophthora drechsleri and Pythium ultimum. In order toevaluate the efficiency of a field-laboratory selection method to improve resistanceof safflower against soil born pathogens, Ph. drechsleri and P. ultimum, a two-yearinvestigation was conducted. The results showed that selection is an e...

There is increasing evidence that microbial volatiles (VOCs) play an important role in natural suppression of soil-borne diseases, but little is known on the factors that influence production of suppressing VOCs. In the current study we examined whether a stress-induced change in soil microbial community composition would affect the production by soils of VOCs suppressing the plant-pathogenic o...

Leaf composts were studied for their suppressive effects on Pythium ultimum sporangium germination, cottonseed colonization, and the severity of Pythium damping-off of cotton. A focus of the work was to assess the role of fatty-acid-metabolizing microbial communities in disease suppression. Suppressiveness was expressed within the first few hours of seed germination as revealed by reduced P. ul...

Fungal phytopathogens are cause of many plant diseases and much loss of crop yields, especially in tropical and subtropical regions. Chemical fungicides are extensively used in agriculture. However, these products may cause problems such as environmental pollution and affect human health. Microorganisms as biocontrol agents have high potential to control plant pathogens and no effect on the env...

The bacterium Pseudomonas aureofaciens 63-28 is antagonistic to several plant pathogenic fungi, including Pythium spp. The bacterium produced at least four antifungal metabolites active against Pythium ultimum and Phytophthora cryptogea when tested in culture for antifungal activity. Two of these compounds were identified as the novel butyrolactones (Z)-4-hydroxy-4-methyl-2-(1-hexenyl)-2-buteno...

during 2000-2001, soil pythium species were studied in fars province. soil samples werecollected from various parts of the province (abadeh, bajgah, bayza, borazjan, darab, estahban, fasa,khafr, sepidan, shiraz, moharloo, and zarghan). isolates were recovered from soil by baiting. specieswere identified based on morphological characters of sexual and asexual organs, growth rate at differenttemp...